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1.
Int J Cancer ; 148(9): 2158-2170, 2021 05 01.
Article in English | MEDLINE | ID: mdl-33180326

ABSTRACT

The presence of preexisting morbidities poses a challenge to cancer patient care. There is little information on the profile and prevalence of multi-morbidities in breast cancer patients across middle income countries (MIC) to lower income countries (LIC) in sub-Saharan Africa (SSA). The African Breast Cancer-Disparities in Outcomes (ABC-DO) breast cancer cohort spans upper MICs South Africa and Namibia, lower MICs Zambia and Nigeria and LIC Uganda. At cancer diagnosis, seven morbidities were assessed: obesity, hypertension, diabetes, asthma/chronic obstructive pulmonary disease, heart disease, tuberculosis and HIV. Logistic regression models were used to assess determinants of morbidities and the influence of morbidities on advanced stage (stage III/IV) breast cancer diagnosis. Among 2189 women, morbidity prevalence was the highest for obesity (35%, country-specific range 15-57%), hypertension (32%, 15-51%) and HIV (16%, 2-26%) then for diabetes (7%, 4%-10%), asthma (4%, 2%-10%), tuberculosis (4%, 0%-8%) and heart disease (3%, 1%-7%). Obesity and hypertension were more common in upper MICs and in higher socioeconomic groups. Overall, 27% of women had at least two preexisting morbidities. Older women were more likely to have obesity (odds ratio: 1.09 per 10 years, 95% CI 1.01-1.18), hypertension (1.98, 1.81-2.17), diabetes (1.51, 1.32-1.74) and heart disease (1.69, 1.37-2.09) and were less likely to be HIV positive (0.64, 0.58-0.71). Multi-morbidity was not associated with stage at diagnosis, with the exception of earlier stage in obese and hypertensive women. Breast cancer patients in higher income countries and higher social groups in SSA face the additional burden of preexisting non-communicable diseases, particularly obesity and hypertension, exacerbated by HIV in Southern/Eastern Africa.


Subject(s)
Breast Neoplasms/epidemiology , Africa South of the Sahara , Breast Neoplasms/mortality , Female , Healthcare Disparities , Humans , Outcome Assessment, Health Care , Survival Analysis
2.
Int J Cancer ; 147(2): 361-374, 2020 07 15.
Article in English | MEDLINE | ID: mdl-31600408

ABSTRACT

Multimorbidity in women with breast cancer may delay presentation, affect treatment decisions and outcomes. We described the multimorbidity profile of women with breast cancer, its determinants, associations with stage at diagnosis and treatments received. We collected self-reported data on five chronic conditions (hypertension, diabetes, cerebrovascular diseases, asthma/chronic obstructive pulmonary disease, tuberculosis), determined obesity using body mass index (BMI) and tested HIV status, in women newly diagnosed with breast cancer between January 2016 and April 2018 in five public hospitals in South Africa. We identified determinants of ≥2 of the seven above-mentioned conditions (defined as multimorbidity), multimorbidity itself with stage at diagnosis (advanced [III-IV] vs. early [0-II]) and multimorbidity with treatment modalities received. Among 2,281 women, 1,001 (44%) presented with multimorbidity. Obesity (52.8%), hypertension (41.3%), HIV (22.0%) and diabetes (13.7%) were the chronic conditions that occurred most frequently. Multimorbidity was more common with older age (OR = 1.02; 95% CI 1.01-1.03) and higher household socioeconomic status (HSES) (OR = 1.06; 95% CI 1.00-1.13). Multimorbidity was not associated with advanced-stage breast cancer at diagnosis, but for self-reported hypertension there was less likelihood of being diagnosed with advanced-stage disease in the adjusted model (OR 0.80; 95% CI 0.64-0.98). Multimorbidity was associated with first treatment received in those with early-stage disease, p = 0.003. The prevalence of multimorbidity is high among patients with breast cancer. Our findings suggest that multimorbidity had a significant impact on treatment received in those with early-stage disease. There is need to understand the impact of multimorbidity on breast cancer outcomes.


Subject(s)
Breast Neoplasms/epidemiology , Diabetes Mellitus/epidemiology , HIV Infections/epidemiology , Hypertension/epidemiology , Obesity/epidemiology , Adult , Age Factors , Aged , Breast Neoplasms/pathology , Clinical Decision-Making , Comorbidity , Female , Humans , Middle Aged , Neoplasm Staging , Prevalence , Risk Assessment , Self Report , Socioeconomic Factors , South Africa/epidemiology
3.
Environ Geochem Health ; 42(4): 1047-1056, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31054071

ABSTRACT

Primary prevention is a key strategy to reducing the global burden of cancer, a disease responsible for ~ 9.6 million deaths per year and predicted to top 13 million by 2030. The role of environmental geochemistry in the aetiology of many cancers-as well as other non-communicable diseases-should not be understated, particularly in low- and middle-income countries where 70% of global cancer deaths occur and reliance on local geochemistry for drinking water and subsistence crops is still widespread. This article is an expansion of a series of presentations and discussions held at the 34th International Conference of the Society for Environmental Geochemistry and Health in Livingstone, Zambia, on the value of effective collaborations between environmental geochemists and cancer epidemiologists. Key technical aspects of each field are presented, in addition to a case study of the extraordinarily high incidence rates of oesophageal cancer in the East African Rift Valley, which may have a geochemical contribution. The potential merit of veterinary studies for investigating common geochemical risk factors between human and animal disease is also highlighted.


Subject(s)
Environmental Exposure , Esophageal Neoplasms/etiology , Neoplasms/epidemiology , Neoplasms/etiology , Africa, Eastern/epidemiology , Animals , Carcinogens/toxicity , Environmental Exposure/adverse effects , Environmental Monitoring , Environmental Science , Esophageal Neoplasms/epidemiology , Global Health , Humans , Livestock
4.
Int J Cancer ; 144(3): 459-469, 2019 02 01.
Article in English | MEDLINE | ID: mdl-30117158

ABSTRACT

Squamous cell esophageal cancer is common throughout East Africa, but its etiology is poorly understood. We investigated the contribution of alcohol consumption to esophageal cancer in Kenya, based on a hospital-based case-control study conducted from 08/2013 to 03/2018 in Eldoret, western Kenya. Cases had an endoscopy-confirmed esophageal tumor whose histology did not rule out squamous cell carcinoma. Age and gender frequency-matched controls were recruited from hospital visitors/patients without digestive diseases. Logistic regression was used to calculate odds ratios (ORs) and their 95% confidence intervals (CI) adjusting for tobacco (type, intensity) and 6 other potential confounders. A total of 422 cases (65% male, mean at diagnosis 60 (SD 14) years) and 414 controls were included. ORs for ever-drinking were stronger in ever-tobacco users (9.0, 95% CI: 3.4, 23.8, with few tobacco users who were never drinkers) than in never-tobacco users (2.6, 95% CI: 1.6, 4.1). Risk increased linearly with number of drinks: OR for >6 compared to >0 to ≤2 drinks/day were 5.2 (2.4, 11.4) in ever-tobacco users and 2.1 (0.7, 4.4) in never-tobacco users. Although most ethanol came from low ethanol alcohols (busaa or beer), for the same ethanol intake, if a greater proportion came from the moonshine chang'aa, it was associated with a specific additional risk. The population attributable fraction for >2 drinks per day was 48% overall and highest in male tobacco users. Alcohol consumption, particularly of busaa and chang'aa, contributes to half of the esophageal cancer burden in western Kenya.


Subject(s)
Alcohol Drinking/epidemiology , Alcoholic Beverages/classification , Esophageal Neoplasms/epidemiology , Esophageal Squamous Cell Carcinoma/epidemiology , Aged , Case-Control Studies , Female , Humans , Kenya/epidemiology , Male , Middle Aged , Risk
5.
Int J Cancer ; 145(1): 99-109, 2019 07 01.
Article in English | MEDLINE | ID: mdl-30582155

ABSTRACT

There are no studies of oral health in relation to esophageal cancer in Africa, or of Eastern Africa's endemic dental fluorosis, an irreversible enamel hypo-mineralization due to early-life excessive fluoride intake. During 2014-18, we conducted a case-control study of squamous cell esophageal cancer in Eldoret, western Kenya. Odds ratios (AORs (95% confidence intervals)) were adjusted for design factors, tobacco, alcohol, ethnicity, education, oral hygiene and missing/decayed teeth. Esophageal cancer cases (N = 430) had poorer oral health and hygiene than controls (N = 440). Compared to no dental fluorosis, moderate/severe fluorosis, which affected 44% of cases, had a crude OR of 20.8 (11.6, 37.4) and on full adjustment was associated with 9.4-fold (4.6, 19.1) increased risk, whilst mild fluorosis (43% of cases) had an AOR of 2.3 (1.3, 4.0). The prevalence of oral leukoplakia and tooth loss/decay increased with fluorosis severity, and increased cancer risks associated with moderate/severe fluorosis were particularly strong in individuals with more tooth loss/decay. Using a mswaki stick (AOR = 1.7 (1.0, 2.9)) rather than a commercial tooth brush and infrequent tooth brushing also independently increased risk. Geographic variations showed that areas of high esophageal cancer incidence and those of high groundwater fluoride levels have remarkably similar locations across Eastern Africa. In conclusion, poor oral health in combination with, or as a result of, high-altitude susceptibility to hydro-geologically influenced dental fluorosis may underlie the striking co-location of Africa's esophageal cancer corridor with the Rift Valley. The findings call for heightened research into primary prevention opportunities of this highly fatal but common cancer.


Subject(s)
Esophageal Neoplasms/epidemiology , Esophageal Squamous Cell Carcinoma/epidemiology , Fluorosis, Dental/epidemiology , Africa/epidemiology , Case-Control Studies , Female , Humans , Male , Middle Aged , Oral Health/statistics & numerical data , Prevalence
6.
Int J Cancer ; 143(11): 2732-2740, 2018 12 01.
Article in English | MEDLINE | ID: mdl-29992553

ABSTRACT

There is a growing population of older women living with HIV/AIDS (WLWHA). Breast cancer is a common cancer in women worldwide, but the global number of breast cancers in WLWHA is not known. We estimated, for each UN sub-region, the number and age distribution of WLWHA who were diagnosed with breast cancer in 2012, by combining IARC-GLOBOCAN estimates of age-country specific breast cancer incidence with corresponding UNAIDS HIV prevalence. Primary analyses assumed no HIV-breast cancer association, and a breast cancer risk reduction scenario was also considered. Among 16.0 million WLWHA aged 15+ years, an estimated 6,325 WLWHA were diagnosed with breast cancer in 2012, 74% of whom were in sub-Saharan Africa, equally distributed between Eastern, Southern and Western Africa. In most areas, 70% of HIV-positive breast cancers were diagnosed under age 50. Among all breast cancers (regardless of HIV status), HIV-positive women constituted less than 1% of the clinical burden, except in Eastern, Western and Middle Africa where they comprised 4-6% of under age 50 year old breast cancer patients, and in Southern Africa where this patient subgroup constituted 26 and 8% of breast cancers diagnosed under and over age 50 respectively. If a deficit of breast cancer occurs in WLWHA, the global estimate would reduce to 3,600. In conclusion, worldwide, the number of HIV-positive women diagnosed with breast cancer was already substantial in 2012 and with an expected increase within the next decade, early detection and treatment research targeted to this population are needed.


Subject(s)
Breast Neoplasms/epidemiology , HIV Infections/epidemiology , Adolescent , Adult , Africa South of the Sahara/epidemiology , Age Distribution , Aged , Breast Neoplasms/virology , Female , HIV/pathogenicity , Humans , Incidence , Prevalence , Young Adult
7.
Breast Cancer Res Treat ; 160(3): 531-537, 2016 12.
Article in English | MEDLINE | ID: mdl-27757717

ABSTRACT

PURPOSE: Bimodal age distributions at diagnosis have been widely observed among US and European female breast cancer populations. To determine whether bimodal breast cancer distributions are also present in a sub-Saharan African population, we investigated female breast cancer in South Africa. METHODS: Using the South African National Cancer Registry data, we examined age-at-diagnosis frequency distributions (density plots) for breast cancer overall and by their receptor (oestrogen, progesterone and HER2) determinants among black and white women diagnosed during 2009-2011 in the public healthcare sector. For comparison, we also analysed corresponding 2010-2011 US SEER data. We investigated density plots using flexible mixture models, allowing early/late-onset membership to depend on receptor status. RESULTS: We included 8857 women from South Africa, 7176 (81 %) with known oestrogen receptor status, and 95064 US women. Bimodality was present in all races, with an early-onset mode between ages 40-50 years and a late-onset mode among ages 60-70 years. The early-onset mode was younger in South African black women (age 38), compared to other groups (45-54 years). CONCLUSIONS: Consistent patterns of bimodality and of its receptor determinants were present across breast cancer patient populations in South Africa and the US. Although the clinical spectrum of breast cancer is well acknowledged as heterogeneous, universal early- and late-onset age distributions at diagnosis suggest that breast cancer etiology consists of a mixture two main types.


Subject(s)
Black People , Breast Neoplasms/epidemiology , White People , Adult , Age Distribution , Aged , Aged, 80 and over , Biomarkers, Tumor , Breast Neoplasms/diagnosis , Female , Humans , Middle Aged , Population Surveillance , Registries , SEER Program , South Africa/epidemiology , South Africa/ethnology , United States/epidemiology
8.
Breast Cancer Res ; 15(5): R84, 2013.
Article in English | MEDLINE | ID: mdl-24041225

ABSTRACT

INTRODUCTION: Estimates of the proportion of estrogen receptor negative (ERN) and triple-negative (TRN) breast cancer from sub-Saharan Africa are variable and include high values. Large studies of receptor status conducted on non-archival tissue are lacking from this region. METHODS: We identified 1218 consecutive women (91% black) diagnosed with invasive breast cancer from 2006­2012 at a public hospital in Soweto, South Africa. Immunohistochemistry based ER, progesterone receptor (PR) and human epidermal factor 2 (HER2) receptors were assessed at diagnosis on pre-treatment biopsy specimens. Mutually adjusted associations of receptor status with stage, age, and race were examined using risk ratios (RRs). ER status was compared with age-stratified US Surveillance Epidemiology and End Results program (SEER) data. RESULTS: 35% (95% confidence interval (CI): 32-38) of tumors were ERN, 47% (45-52) PRN, 26% (23-29) HER2P and 21% (18-23) TRN. Later stage tumors were more likely to be ERN and PRN (RRs 1.9 (1.1-2.9) and 2.0 (1.3-3.1) for stage III vs. I) but were not strongly associated with HER2 status. Age was not strongly associated with ER or PR status, but older women were less likely to have HER2P tumors (RR, 0.95 (0.92-0.99) per 5 years). During the study, stage III + IV tumors decreased from 66% to 46%. In black women the percentage of ERN (37% (34-40)) and PRN tumors (48% (45-52)) was higher than in non-black patients (22% (14-31) and 34% (25-44), respectively, P = 0.004 and P = 0.02), which remained after age and stage adjustment. Age-specific ERN proportions in black South African women were similar to those of US black women, especially for women diagnosed over age 50. CONCLUSION: Although a greater proportion of black than non-black South African women had ER-negative or TRN breast cancer, in all racial groups in this study breast cancer was predominantly ER-positive and was being diagnosed at earlier stages over time. These observations provide initial indications that late-stage aggressive breast cancers may not be an inherent feature of the breast cancer burden across Africa.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Receptor, ErbB-2/metabolism , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Adult , Age Factors , Aged , Aged, 80 and over , Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , Breast Neoplasms, Male/diagnosis , Breast Neoplasms, Male/epidemiology , Breast Neoplasms, Male/metabolism , Breast Neoplasms, Male/pathology , Female , Humans , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , Population Groups , SEER Program , South Africa/epidemiology , Time Factors , Triple Negative Breast Neoplasms/diagnosis , Triple Negative Breast Neoplasms/epidemiology , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology , Young Adult
9.
PLOS Glob Public Health ; 3(10): e0002432, 2023.
Article in English | MEDLINE | ID: mdl-37874786

ABSTRACT

The South African Breast Cancer and HIV Outcomes prospective cohort (SABCHO) study was established to investigate survival determinants among HIV-positive and HIV-negative SA women with breast cancer. This paper describes common and unique characteristics of the cancer centres and their participants, examining disparities in pathways to diagnosis, treatment resources and approaches adopted to mitigate resource constraints. The Johannesburg (Jhb), Soweto (Sow), and Durban (Dbn) sites treat mainly urban, relatively better educated and more socioeconomically advantaged patients whereas the Pietermaritzburg (Pmb) and Empangeni (Emp) sites treat predominantly rural, less educated and more impoverished communities The Sow, Jhb, and Emp sites had relatively younger patients (mean ages 54 ±14.5, 55±13.7 and 54±14.3 respectively), whereas patients at the Dbn and Pmb sites, with greater representation of Asian Indian women, were relatively older (mean age 57 ±13.9 and 58 ±14.6 respectively). HIV prevalence among the cohort was high, ranging from 15%-42%, (Cohort obesity (BMI ≥ 30 kg/m2) at 60%, self-reported hypertension (41%) and diabetes (13%). Direct referral of patients from primary care clinics to cancer centre occurred only at the Sow site which uniquely ran an open clinic and where early stage (I and II) proportions were highest at 48.5%. The other sites relied on indirect patient referral from regional hospitals where significant delays in diagnostics occurred and early-stage proportions were a low (15%- 37.3%). The Emp site referred patients for all treatments to the Dbn site located 200km away; the Sow site provided surgery and endocrine treatment services but referred patients to the Jhb site 30 Km away for chemo- and radiation therapy. The Jhb, Dbn and Pmb sites all provided complete oncology treatment services. All treatment centres followed international guidelines for their treatment approaches. Findings may inform policy interventions to address national and regional disparities in breast cancer care.

10.
PLoS One ; 18(2): e0281916, 2023.
Article in English | MEDLINE | ID: mdl-36795733

ABSTRACT

OBJECTIVE: In low- and middle-income countries (LMICs), advanced-stage diagnosis of breast cancer (BC) is common, and this contributes to poor survival. Understanding the determinants of the stage at diagnosis will aid in designing interventions to downstage disease and improve survival from BC in LMICs. METHODS: Within the South African Breast Cancers and HIV Outcomes (SABCHO) cohort, we examined factors affecting the stage at diagnosis of histologically confirmed invasive breast cancer at five tertiary hospitals in South Africa (SA). The stage was assessed clinically. To examine the associations of the modifiable health system, socio-economic/household and non-modifiable individual factors, hierarchical multivariable logistic regression with odds of late-stage at diagnosis (stage III-IV), was used. RESULTS: The majority (59%) of the included 3497 women were diagnosed with late-stage BC disease. The effect of health system-level factors on late-stage BC diagnosis was consistent and significant even when adjusted for both socio-economic- and individual-level factors. Women diagnosed in a tertiary hospital that predominantly serves a rural population were 3 times (OR = 2.89 (95% CI: 1.40-5.97) as likely to be associated with late-stage BC diagnosis when compared to those diagnosed at a hospital that predominantly serves an urban population. Taking more than 3 months from identifying the BC problem to the first health system entry (OR = 1.66 (95% CI: 1.38-2.00)), and having luminal B (OR = 1.49 (95% CI: 1.19-1.87)) or HER2-enriched (OR = 1.64 (95% CI: 1.16-2.32)) molecular subtype as compared to luminal A, were associated with a late-stage diagnosis. Whilst having a higher socio-economic level (a wealth index of 5) reduced the probability of late-stage BC at diagnosis, (OR = 0.64 (95% CI: 0.47-0.85)). CONCLUSION: Advanced-stage diagnosis of BC among women in SA who access health services through the public health system was associated with both modifiable health system-level factors and non-modifiable individual-level factors. These may be considered as elements in interventions to reduce the time to diagnosis of breast cancer in women.


Subject(s)
Breast Neoplasms , HIV Infections , Healthcare Disparities , Female , Humans , Black People , Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , HIV Infections/diagnosis , HIV Infections/epidemiology , HIV Infections/pathology , Neoplasm Staging , South Africa/epidemiology
11.
Cancer Causes Control ; 22(12): 1709-20, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21987079

ABSTRACT

PURPOSE: To investigate the hypothesis that non-steroidal anti-inflammatory drugs (NSAIDs) lower lung cancer risk. METHODS: We analysed pooled individual-level data from seven case-control and one cohort study in the International Lung Cancer Consortium (ILCCO). Relative risks for lung cancer associated with self-reported history of aspirin and other NSAID use were estimated within individual studies using logistic regression or proportional hazards models, adjusted for packyears of smoking, age, calendar period, ethnicity and education and were combined using random effects meta-analysis. RESULTS: A total of 4,309 lung cancer cases (mean age at diagnosis 65 years, 45% adenocarcinoma and 22% squamous-cell carcinoma) and 58,301 non-cases/controls were included. Amongst controls, 34% had used NSAIDs in the past (81% of them used aspirin). After adjustment for negative confounding by smoking, ever-NSAID use (affirmative answer to the study-specific question on NSAID use) was associated with a 26% reduction (95% confidence interval 8 to 41%) in lung cancer risk in men, but not in women (3% increase (-11% to 30%)). In men, the association was stronger in current and former smokers, and for squamous-cell carcinoma than for adenocarcinomas, but there was no trend with duration of use. No differences were found in the effects on lung cancer risk of aspirin and non-aspirin NSAIDs. CONCLUSIONS: Evidence from ILCCO suggests that NSAID use in men confers a modest protection for lung cancer, especially amongst ever-smokers. Additional investigation is needed regarding the possible effects of age, duration, dose and type of NSAID and whether effect modification by smoking status or sex exists.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Aspirin/pharmacology , Lung Neoplasms/epidemiology , Aged , Female , Humans , Male , Middle Aged , Risk Factors , Surveys and Questionnaires
12.
Int J Cancer ; 127(2): 452-61, 2010 Jul 15.
Article in English | MEDLINE | ID: mdl-19924817

ABSTRACT

Percent mammographic density (PMD) is a strong marker of breast cancer risk. It may be a correlate of the rate of breast tissue aging, as proposed by Pike to explain breast cancer age-incidence. We examined longitudinal changes in PMD in 645 breast screening attendees in London, UK, in which each had between 2 and 5 screens spanning 3-12 years at ages 50-65 years and compare these to Pike's model. Within-woman PMD declined during these ages, with a slowing rate of decline. Annual rates of decline were 1.4% (95% confidence interval: 1.2-1.6), 0.7% (0.6-0.9) and 0.1% (-0.2 to 0.4) at ages 50, 57 and 64. Dense area declined similarly, but the absolute magnitude of the rate of increase of nondense area was almost double that of dense area. PMD dropped by 2.4% (1.4-3.4) on menopausal transition and increased by 2.4% (1.4-3.5) with the use of hormone therapy. Higher body mass index, greater parity and being Afro-Caribbean or South Asian ethnicities were associated with lower PMD, but did not affect rate of change of PMD at these ages. Within-woman rank correlation of PMD was 0.80 for readings taken 9 years apart. Effects of menopause and parity and the lack of effect of menarche on age-specific PMD at these ages are consistent with the predicted determinants in Pike's model. A high degree of tracking of PMD indicates that at ages 50-65 years high-risk women could be identified by a single early screen at age older than 50.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/prevention & control , Mammography/statistics & numerical data , Models, Statistical , Aged , Breast Neoplasms/pathology , Female , Follow-Up Studies , Humans , Longitudinal Studies , Middle Aged , Prognosis , Retrospective Studies , Risk Factors , United Kingdom/epidemiology
13.
Int J Cancer ; 127(10): 2248-56, 2010 Nov 15.
Article in English | MEDLINE | ID: mdl-20162609

ABSTRACT

Since 1987, the Gambia National Cancer Registry has provided nationwide cancer registration for the Gambia. We used data from 1998 to 2006 to assess age-standardized incidence rates (ASRs) of 2 common cancers in women, breast and cervix. With an ASR of 15.42 (95% CI [14.18-16.66]) for cervix and 5.86 (95% CI [5.12-6.59]) for breast per 10(5) person-years, these cancers ranked first and third, respectively, among Gambian women (the second most common being liver, ASR 14.90). Incidence of both cancers, breast and cervix, increased rapidly at young ages to reach a peak at ages 40-44 years. Significant differences were observed in relation to ethnicity. Using the Mandinka (42% of the population) as a reference, breast cancer incidence rates were 2.16-fold higher (95% CI [1.33-3.52]) in Jola (10% of the population), specially at early-onset ages (before 40 years). For cervix cancer, highest rates were observed in Fula (18% of the population; risk ratio (RR): 1.84 (95% CI [1.44-2.36])). In contrast, a significantly lower risk was observed in the Serrahuleh (9% of the population; RR: 0.54 (95% CI [0.31-0.96]). This study revealed a preponderance of early-onset breast cancer among Gambian women similar to that seen in African women in more developed countries but also demonstrates large ethnic variations. It points to the need for further studies on cancer determinants to improve prevention, early detection and therapeutic management of these diseases in a low-resource setting in West Africa.


Subject(s)
Breast Neoplasms/epidemiology , Uterine Cervical Neoplasms/epidemiology , Adult , Age Factors , Aged , Breast Neoplasms/ethnology , Female , Gambia/epidemiology , Humans , Incidence , Middle Aged , Registries , Uterine Cervical Neoplasms/ethnology , Young Adult
14.
Int J Cancer ; 127(10): 2402-11, 2010 Nov 15.
Article in English | MEDLINE | ID: mdl-20162568

ABSTRACT

The carcinogenicity of cigar and pipe smoking is established but the effect of detailed smoking characteristics is less well defined. We examined the effects on cancer incidence of exclusive cigar and pipe smoking, and in combination with cigarettes, among 102,395 men from Denmark, Germany, Spain, Sweden and the United Kingdom in the EPIC cohort. Hazard ratios (HR) and their 95% confidence intervals (CI) for cancer during a median 9-year follow-up from ages 35 to 70 years were estimated using proportional hazards models. Compared to never smokers, HR of cancers of lung, upper aerodigestive tract and bladder combined was 2.2 (95% CI: 1.3, 3.8) for exclusive cigar smokers (16 cases), 3.0 (2.1, 4.5) for exclusive pipe smokers (33 cases) and 5.3 (4.4, 6.4) for exclusive cigarette smokers (1,069 cases). For each smoking type, effects were stronger in current smokers than in ex-smokers and in inhalers than in non-inhalers. Ever smokers of both cigarettes and cigars [HR 5.7 (4.4, 7.3), 120 cases] and cigarettes and pipes [5.1 (4.1, 6.4), 247 cases] had as high a raised risk as had exclusive cigarette smokers. In these smokers, the magnitude of the raised risk was smaller if they had switched to cigars or pipes only (i.e., quit cigarettes) and had not compensated with greater smoking intensity. Cigar and pipe smoking is not a safe alternative to cigarette smoking. The lower cancer risk of cigar and pipe smokers as compared to cigarette smokers is explained by lesser degree of inhalation and lower smoking intensity.


Subject(s)
Neoplasms/epidemiology , Smoking/epidemiology , Adult , Aged , Cohort Studies , Europe/epidemiology , Humans , Incidence , Male , Middle Aged , Neoplasms/etiology , Proportional Hazards Models , Prospective Studies , Smoking/adverse effects
15.
BMC Cancer ; 10: 35, 2010 Feb 09.
Article in English | MEDLINE | ID: mdl-20144221

ABSTRACT

BACKGROUND: Socioeconomic status (SES) is known to be positively associated with breast cancer risk but its relationship with mammographic density, a marker of susceptibility to breast cancer, is unclear. This study aims to investigate whether mammographic density varies by SES and to identify the underlying anthropometric, lifestyle and reproductive factors leading to such variation. METHODS: In a cross-sectional study of mammographic density in 487 pre-menopausal women, SES was assessed from questionnaire data using highest achieved level of formal education, quintiles of Census-derived Townsend scores and urban/rural classification of place of residence. Mammographic density was measured on digitised films using a computer-assisted method. Linear regression models were fitted to assess the association between SES variables and mammographic density, adjusting for correlated variables. RESULTS: In unadjusted models, percent density was positively associated with SES, with an absolute difference in percent density of 6.3% (95% CI 1.6%, 10.5%) between highest and lowest educational categories, and of 6.6% (95% CI -0.7%, 12.9%) between highest and lowest Townsend quintiles. These associations were mainly driven by strong negative associations between these SES variables and lucent area and were attenuated upon adjustment for body mass index (BMI). There was little evidence that reproductive factors explained this association. SES was not associated with the amount of dense tissue in the breast before or after BMI adjustment. The effect of education on percent density persisted after adjustment for Townsend score. Mammographic measures did not vary according to urban/rural place of residence. CONCLUSIONS: The observed SES gradients in percent density paralleled known SES gradients in breast cancer risk. Although consistent with the hypothesis that percent density may be a mediator of the SES differentials in breast cancer risk, the SES gradients in percent density were mainly driven by the negative association between SES and BMI. Nevertheless, as density affects the sensitivity of screen-film mammography, the higher percent density found among high SES women would imply that these women have a higher risk of developing cancer but a lower likelihood of having it detected earlier.


Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , Breast Neoplasms/pathology , Breast/pathology , Mammography/methods , Adult , Body Mass Index , Cross-Sectional Studies , Female , Humans , Middle Aged , Models, Statistical , Premenopause , Regression Analysis , Sensitivity and Specificity , Social Class
16.
Med Phys ; 37(9): 4530-9, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20964170

ABSTRACT

PURPOSE: To compare and evaluate intensity-based registration methods for computation of serial x-ray mammogram correspondence. METHODS: X-ray mammograms were simulated from MRIs of 20 women using finite element methods for modeling breast compressions and employing a MRI/x-ray appearance change model. The parameter configurations of three registration methods, affine, fluid, and free-form deformation (FFD), were optimized for registering x-ray mammograms on these simulated images. Five mammography film readers independently identified landmarks (tumor, nipple, and usually two other normal features) on pairs of diagnostic and corresponding prediagnostic digitized images from 52 breast cancer cases. Landmarks were independently reidentified by each reader. Target registration errors were calculated to compare the three registration methods using the reader landmarks as a gold standard. Data were analyzed using multilevel methods. RESULTS: Between-reader variability varied with landmark (p < 0.01) and screen (p = 0.03), with between-reader mean distance (mm) in point location on the diagnostic/prediagnostic images of 2.50 (95% CI 1.95, 3.15)/2.84 (2.24, 3.55) for nipples and 4.26 (3.43, 5.24)/4.76 (3.85, 5.84) for tumors. Registration accuracy was sensitive to the type of landmark and the amount of breast density. For dense breasts (> or = 40%), the affine and fluid methods outperformed FFD. For breasts with lower density, the affine registration surpassed both fluid and FFD. Mean accuracy (mm) of the affine registration varied between 3.16 (95% CI 2.56, 3.90) for nipple points in breasts with density 20%-39% and 5.73 (4.80, 6.84) for tumor points in breasts with density < 20%. CONCLUSIONS: Affine registration accuracy was comparable to that between independent film readers. More advanced two-dimensional nonrigid registration algorithms were incapable of increasing the accuracy of image alignment when compared to affine registration.


Subject(s)
Breast Neoplasms/diagnostic imaging , Image Processing, Computer-Assisted/methods , Mammography/methods , Radiology/methods , Adult , Algorithms , Automation , Female , Humans , Magnetic Resonance Imaging , Middle Aged , Models, Theoretical , Observer Variation
17.
Breast Cancer Res ; 11(3): R33, 2009.
Article in English | MEDLINE | ID: mdl-19490643

ABSTRACT

INTRODUCTION: Mammographic breast density is one of the strongest known markers of susceptibility to breast cancer. To date research into density has relied on a single measure (for example, percent density (PD)) summarising the average level of density for the whole breast, with no consideration of how the radiodense tissue may be distributed. This study aims to investigate the spatial distribution of density within the breast using 493 mammographic images from a sample of 165 premenopausal women (~3 medio-lateral oblique views per woman). METHODS: Each breast image was divided into 48 regions and the PD for the whole breast (overall PD) and for each one of its regions (regional PD) was estimated. The spatial autocorrelation (Moran's I value) of regional PD for each image was calculated to investigate spatial clustering of density, whether the degree of clustering varied between a woman's two breasts and whether it was affected by age and other known density correlates. RESULTS: The median Moran's I value for 165 women was 0.31 (interquartile range: 0.26, 0.37), indicating a clustered pattern. High-density areas tended to cluster in the central regions of the breast, regardless of the level of overall PD, but with considerable between-woman variability in regional PD. The degree of clustering was similar between a woman's two breasts (mean within-woman difference in Moran's I values between left and right breasts = 0.00 (95% confidence interval (CI) = -0.01, 0.01); P = 0.76) and did not change with aging (mean within-woman difference in I values between screens taken on average 8 years apart = 0.01 (95% CI = -0.01, 0.02); P = 0.30). Neither parity nor age at first birth affected the level of spatial autocorrelation of density, but increasing body mass index (BMI) was associated with a decrease in the degree of spatial clustering. CONCLUSIONS: This study is the first to demonstrate that the distribution of radiodense tissue within the breast is spatially autocorrelated, generally with the high-density areas clustering in the central regions of the breast. The degree of clustering was similar within a woman's two breasts and between women, and was little affected by age or reproductive factors although it declined with increasing BMI.


Subject(s)
Breast Neoplasms/pathology , Mammography/methods , Adult , Body Mass Index , Breast/pathology , Cluster Analysis , Disease Susceptibility , Early Detection of Cancer , Female , Humans , Middle Aged , Risk Factors , Time Factors
18.
Breast Cancer Res ; 11(3): R38, 2009.
Article in English | MEDLINE | ID: mdl-19545414

ABSTRACT

INTRODUCTION: Sex steroids, insulin-like growth factors (IGFs) and prolactin are breast cancer risk factors but whether their effects are mediated through mammographic density, one of the strongest risk factors for breast cancer, is unknown. If such a hormonal basis of mammographic density exists, hormones may underlie ethnic differences in both mammographic density and breast cancer incidence rates. METHODS: In a cross-sectional study of 270 postmenopausal Caucasian and Afro-Caribbean women attending a population-based breast screening service in London, UK, we investigated whether plasma biomarkers (oestradiol, oestrone, sex hormone binding globulin (SHBG), testosterone, prolactin, leptin, IGF-I, IGF-II and IGF binding protein 3 (IGFBP3)) were related to and explained ethnic differences in mammographic percent density, dense area and nondense area, measured in Cumulus using the threshold method. RESULTS: Mean levels of oestrogens, leptin and IGF-I:IGFBP3 were higher whereas SHBG and IGF-II:IGFBP3 were lower in Afro-Caribbean women compared with Caucasian women after adjustment for higher mean body mass index (BMI) in the former group (by 3.2 kg/m(2) (95% confidence interval (CI): 1.8, 4.5)). Age-adjusted percent density was lower in Afro-Caribbean compared with Caucasian women by 5.4% (absolute difference), but was attenuated to 2.5% (95% CI: -0.2, 5.1) upon BMI adjustment. Despite ethnic differences in biomarkers and in percent density, strong ethnic-age-adjusted inverse associations of oestradiol, leptin and testosterone with percent density were completely attenuated upon adjustment for BMI. There were no associations of IGF-I, IGF-II or IGFBP3 with percent density or dense area. We found weak evidence that a twofold increase in prolactin and oestrone levels were associated, respectively, with an increase (by 1.7% (95% CI: -0.3, 3.7)) and a decrease (by 2.0% (95% CI: 0, 4.1)) in density after adjustment for BMI. CONCLUSIONS: These findings suggest that sex hormone and IGF levels are not associated with BMI-adjusted percent mammographic density in cross-sectional analyses of postmenopausal women and thus do not explain ethnic differences in density. Mammographic density may still, however, be influenced by much higher premenopausal hormone levels.


Subject(s)
Breast Neoplasms/ethnology , Breast Neoplasms/metabolism , Mammography/methods , Steroids/metabolism , Aged , Black People , Body Mass Index , Breast Neoplasms/diagnostic imaging , Caribbean Region , Cross-Sectional Studies , Estrogens/metabolism , Female , Hormones/metabolism , Humans , Middle Aged , Postmenopause , Somatomedins/metabolism , United Kingdom , White People
19.
Radiology ; 251(2): 347-58, 2009 May.
Article in English | MEDLINE | ID: mdl-19401569

ABSTRACT

PURPOSE: To (a) compare the performance of full-field digital mammography (FFDM), using hard-copy image reading, with that of screen-film mammography (SFM) within a UK screening program (screening once every 3 years) for women aged 50 years or older and (b) conduct a meta-analysis of published findings along with the UK data. MATERIALS AND METHODS: The study complied with the UK National Health Service Central Office for Research Ethics Committee guidelines; informed patient consent was not required, since analysis was carried out retrospectively after data anonymization. Between January 2006 and June 2007, a London population-based screening center performed 8478 FFDM and 31 720 SFM screening examinations, with modality determined by the type of machine available at the screening site. Logistic regression was used to assess whether breast cancer detection rates and recall rates differed between screening modalities. For the meta-analysis, random-effects models were used to combine study-specific estimates, if appropriate. RESULTS: A total of 263 breast cancers were detected. After adjustment for age, ethnicity, area of residence, and type of referral, there was no evidence of differences between FFDM and SFM in terms of detection rates (0.68 [95% confidence interval {CI}: 0.47, 0.89] vs 0.72 [95% CI: 0.58, 0.85], respectively, per 100 screening mammograms; P = .74), recall rates (3.2% [95% CI: 2.8, 3.6] vs 3.4% [95% CI: 3.1, 3.6]; P = .44), positive predictive value (PPV) of an abnormal mammogram, or characteristics of detected tumors. Meta-analysis of data from eight studies showed a slightly higher detection rate for FFDM, particularly at 60 years of age or younger (pooled FFDM-SFM difference: 0.11 [95% CI: 0.04, 0.18] per 100 screening mammograms), but no clear modality differences in recall rates or PPVs. CONCLUSION: Within a routine screening program, FFDM with hard-copy image reading performed as well as SFM in terms of process indicators; the meta-analysis was consistent with FFDM yielding detection rates at least as high as those for SFM.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/epidemiology , Mammography/statistics & numerical data , Mass Screening/statistics & numerical data , Radiographic Image Enhancement , X-Ray Film/statistics & numerical data , Female , Humans , Reproducibility of Results , Sensitivity and Specificity , United Kingdom/epidemiology
20.
Cancer Epidemiol Biomarkers Prev ; 28(12): 2005-2013, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31558508

ABSTRACT

BACKGROUND: Hot beverage consumption is a probable risk factor for esophageal squamous cell carcinoma (ESCC). No standardized exposure assessment protocol exists. METHODS: To compare how alternative metrics discriminate distinct drinking habits, we measured sip temperatures and sizes in an international group of hot beverage drinkers in France (n = 20) and hot porridge consumers (n = 52) in a high ESCC incidence region of China. Building on the knowledge that sip size and temperature affect intraesophageal liquid temperature (IELT), IELTs were predicted by modeling existing data, and compared with first sip temperature and, across all sips, mean temperature and sip-weighted mean temperature. RESULTS: Two contrasting exposure characteristics were observed. Compared with the international group, Chinese porridge consumers took larger first sips [mean difference +17 g; 95% confidence interval (CI), 13.3-20.7] of hotter (+9.5°C; 95% CI, 6.2-12.7) liquid, and their mean sip size did not vary greatly across sips, but the former groups increased in size as temperature decreased. This resulted in higher predicted IELTs (mean 61°C vs. 42.4°C) and sip-weighted temperatures (76.9°C vs. 56°C) in Chinese porridge consumers, and compared with first sip and mean temperature, these two metrics separated the groups to a greater extent. CONCLUSIONS: Distinguishing thermal exposure characteristics between these groups was greatly enhanced by measuring sip sizes. Temperature at first sip alone is suboptimal for assessing human exposure to hot foods and beverages, and future studies should include sip size measurements in exposure assessment protocols. IMPACT: This study provides a logistically feasible framework for assessing human exposure to hot beverages.


Subject(s)
Beverages/adverse effects , Drinking Behavior , Esophageal Neoplasms/etiology , Esophageal Squamous Cell Carcinoma/etiology , Hot Temperature/adverse effects , Adult , Aged , China/epidemiology , Esophageal Neoplasms/epidemiology , Esophageal Squamous Cell Carcinoma/epidemiology , Female , Follow-Up Studies , Humans , Incidence , Male , Middle Aged , Prognosis , Young Adult
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