The intersection of race/ethnicity and socioeconomic status: inequalities in breast and cervical cancer mortality in 20,665,005 adult women from the 100 Million Brazilian Cohort.

OBJECTIVES: There is limited evidence regarding the impact of race/racism and its intersection with socioeconomic status (SES) on breast and cervical cancer, the two most common female cancers globally. We investigated racial inequalities in breast and cervical cancer mortality and whether SES (education and household conditions) interacted with race/ethnicity. DESIGN: The 100 Million Brazilian Cohort data were linked to the Brazilian Mortality Database, 2004-2015 (n = 20,665,005 adult women). We analysed the association between self-reported race/ethnicity (White/'Parda'(Brown)/Black/Asian/Indigenous) and cancer mortality using Poisson regression, adjusting for age, calendar year, education, household conditions and area of residence. Additive and multiplicative interactions were assessed. RESULTS: Cervical cancer mortality rates were higher among Indigenous (adjusted Mortality rate ratio = 1.80, 95%CI 1.39-2.33), Asian (1.63, 1.20-2.22), 'Parda'(Brown) (1.27, 1.21-1.33) and Black (1.18, 1.09-1.28) women vs White women. Breast cancer mortality rates were higher among Black (1.10, 1.04-1.17) vs White women. Racial inequalities in cervical cancer mortality were larger among women of poor household conditions, and low education (P for multiplicative interaction <0.001, and 0.02, respectively). Compared to White women living in completely adequate (3-4) household conditions, the risk of cervical cancer mortality in Black women with 3-4, 1-2, and none adequate conditions was 1.10 (1.01-1.21), 1.48 (1.28-1.71), and 2.03 (1.56-2.63), respectively (Relative excess risk due to interaction-RERI = 0.78, 0.18-1.38). Among 'Parda'(Brown) women the risk was 1.18 (1.11-1.25), 1.68 (1.56-1.81), and 1.84 (1.63-2.08), respectively (RERI = 0.52, 0.16-0.87). Compared to high-educated White women, the risk in high-, middle- and low-educated Black women was 1.14 (0.83-1.55), 1.93 (1.57-2.38) and 2.75 (2.33-3.25), respectively (RERI = 0.36, -0.05-0.77). Among 'Parda'(Brown) women the risk was 1.09 (0.91-1.31), 1.99 (1.70-2.33) and 3.03 (2.61-3.52), respectively (RERI = 0.68, 0.48-0.88). No interactions were found for breast cancer. CONCLUSION: Low SES magnified racial inequalities in cervical cancer mortality. The intersection between race/ethnicity, SES and gender needs to be addressed to reduce racial health inequalities.

Reproductive history and breast cancer survival: Findings from the African breast cancer-Disparities in outcomes cohort and implications of Africa's fertility transition on breast cancer prognosis.

Reproductive characteristics are known risk factors for breast cancer but, other than recent birth, their role as prognostic factors is less clear, and has not been studied in Sub-Saharan Africa (SSA). In this setting, we examined whether reproductive factors independently influence breast cancer survival in a subset of the African Breast Cancer-Disparities in Outcomes cohort study. In 1485 women with incident breast cancer recruited between 2014 and 2017, we examined birth cohort changes in reproductive factors, and used Cox models to examine whether reproductive characteristics were associated with all-cause mortality after adjusting for confounders (age, stage, treatment, HIV, and social factors). Four years after diagnosis, 822 (56%) women had died. Median parity was 4 (IQR = 2, 6) and 209 (28%) of premenopausal women had had a recent birth (<3 years prior to cancer diagnosis). Each pregnancy was associated with a 5% increase (95% CI: 2%, 8%) in mortality rates, which held among postmenopausal women (5%, [1%-9%]). Pre-menopausal women with a recent birth had 52% (20%, 92%) higher mortality rates. Fertility trends by birth cohort showed declining parity, increasing age at first birth and declining age at last birth, however the impact of these population-level changes on future average survival was predicted to be very small (<3% absolute gain).

Breast Cancer Polygenic Risk Score and Contralateral Breast Cancer Risk.

Previous research has shown that polygenic risk scores (PRSs) can be used to stratify women according to their risk of developing primary invasive breast cancer. This study aimed to evaluate the association between a recently validated PRS of 313 germline variants (PRS313) and contralateral breast cancer (CBC) risk. We included 56,068 women of European ancestry diagnosed with first invasive breast cancer from 1990 onward with follow-up from the Breast Cancer Association Consortium. Metachronous CBC risk (N = 1,027) according to the distribution of PRS313 was quantified using Cox regression analyses. We assessed PRS313 interaction with age at first diagnosis, family history, morphology, ER status, PR status, and HER2 status, and (neo)adjuvant therapy. In studies of Asian women, with limited follow-up, CBC risk associated with PRS313 was assessed using logistic regression for 340 women with CBC compared with 12,133 women with unilateral breast cancer. Higher PRS313 was associated with increased CBC risk: hazard ratio per standard deviation (SD) = 1.25 (95%CI = 1.18-1.33) for Europeans, and an OR per SD = 1.15 (95%CI = 1.02-1.29) for Asians. The absolute lifetime risks of CBC, accounting for death as competing risk, were 12.4% for European women at the 10th percentile and 20.5% at the 90th percentile of PRS313. We found no evidence of confounding by or interaction with individual characteristics, characteristics of the primary tumor, or treatment. The C-index for the PRS313 alone was 0.563 (95%CI = 0.547-0.586). In conclusion, PRS313 is an independent factor associated with CBC risk and can be incorporated into CBC risk prediction models to help improve stratification and optimize surveillance and treatment strategies.

Incidence and prevalence of drugs used for chronic diseases in survivors of adult-onset gynaecological cancer - A nationwide cohort study.

OBJECTIVES: To evaluate both incidence and prevalence of drugs used for chronic diseases in survivors of adult-onset gynaecological cancer. DESIGN: A prospective study. SETTING: Population-based registries. POPULATION: 1.76 million women, including 17 500 women with gynaecological cancers. METHODS: Data from the Cancer Registry of Norway was linked to the Norwegian Prescription Database and other national databases. MAIN OUTCOME MEASURES: Prevalence ratios (PRs) and hazard ratios (HRs), with 95% confidence intervals (CIs), of dispensed drugs in gynaecological cancer patients (up to 15 years after diagnosis) were estimated by log-binomial and Cox regression, respectively, with cancer-free women as reference. RESULTS: For gynaecological cancer patients, the incidence of drugs used for pain control was higher than in cancer-free women, especially the first 5 years after diagnosis, and the prevalence was high at least 10 years after. The prevalence of sex hormones was high in women with gynaecological cancer at least 10 years after diagnosis (cervical and ovarian cancer PR = 23, 95% CI 18-30 and PR = 29, 95% CI 15-38, respectively), but low in cancer-free women (0.3%). Patients with uterine corpus cancer had a higher prevalence of antidiabetics before and at least 10 years after diagnosis, most pronounced in women diagnosed before age 50 (PR = 10, 95% CI 5.0-21). The prevalence of antidepressants was moderately elevated in women with gynaecological cancers. CONCLUSIONS: Gynaecological cancer survivors, particularly cervical and ovarian cancer survivors, had an increased long-term use of drugs for pain control and sex hormones. Survivors of uterine corpus cancer used antidiabetics more often, both before and after diagnosis.

Treatment guideline concordance, initiation, and abandonment in patients with non-metastatic breast cancer from the African Breast Cancer-Disparities in Outcomes (ABC-DO) cohort in sub-Saharan Africa: a prospective cohort study.

BACKGROUND: Comprehensive breast cancer management is essential to achieve high breast cancer survival; however, detailed reports of the treatment regimens received by patients are scarce in sub-Saharan Africa where survival is low. We aimed to examine treatment initiation, guideline concordance, and abandonment in patients with non-metastatic breast cancer in sub-Saharan Africa from the African Breast Cancer-Disparities in Outcomes (ABC-DO) prospective cohort. METHODS: The ABC-DO prospective cohort study recruited women (aged ≥18 years) with newly diagnosed invasive breast cancer in eight hospitals across five sub-Saharan African countries (Namibia, Nigeria, Uganda, South Africa, and Zambia). We analysed treatments received by women who were classified as non-metastatic (M0) at the initial presentation. Data on surgery, radiotherapy, and systemic therapies were obtained from medical records and a self-reported follow-up questionnaire at 6 months after the diagnosis, follow-up calls every 3 months, and a baseline questionnaire. Initiation, completion, and abandonment of treatment modalities and combined therapy regimens were examined overall, by country-specific groups, and by clinical factors relevant for guideline-based treatment. FINDINGS: Of 2313 women recruited into the ABC-DO study between Sept 10, 2014, and Dec 31, 2017, 2226 had histologically or clinically confirmed breast cancer. Of these 2226 women, 510 were excluded from the present analysis because 378 had metastatic disease, 37 were prevalent cases (defined as those previously diagnosed with breast cancer >2 years before baseline), 82 had unknown TNM stage, and 13 were White or Asian women in South Africa (number was too small for analysis). After a median follow-up of 5·2 years (IQR 4·6-5·9), 1163 (68%) of 1716 women underwent breast cancer surgery. Surgery and systemic therapy (ie, multimodality treatment) with radiotherapy was initiated in 370 (36%) of 1028 women with localised tumours versus 156 (23%) of 688 women with locally advanced tumours, whereas multimodality treatment without radiotherapy was initiated in 386 (38%) versus 167 (24%) women, respectively. Of 1530 patients requiring chemotherapy (which excludes 105 who died within 6 months after baseline), 1013 (66%) initiated treatment of neoadjuvant chemotherapy or surgery within 3 months after baseline, which was adequately completed by 359 (35%) of 1013 women, marginally completed by 284 (28%), abandoned by 200 (20%), and unknown in 151 (15%). 19 (2%) women died within 6 months after chemotherapy initiation. Of 1375 women in whom endocrine therapy was indicated, this treatment was initiated in 920, and lasted at least 3 years in 367 (40%) women. Treatment disparities between country-specific groups were substantial for all therapy regimens. INTERPRETATION: A high proportion of patients with non-metastatic breast cancer did not initiate, did not fully complete, or abandoned treatment with surgery, systemic therapy, radiotherapy, or an appropriate combination of these, highlighting the need for improved treatment access and completion in sub-Saharan Africa to potentially prevent premature breast cancer deaths. FUNDING: National Institutes of Health (National Cancer Institute), Susan G Komen, and the International Agency for Research on Cancer.

The association of age at menarche and adult height with mammographic density in the International Consortium of Mammographic Density.

BACKGROUND: Early age at menarche and tall stature are associated with increased breast cancer risk. We examined whether these associations were also positively associated with mammographic density, a strong marker of breast cancer risk. METHODS: Participants were 10,681 breast-cancer-free women from 22 countries in the International Consortium of Mammographic Density, each with centrally assessed mammographic density and a common set of epidemiologic data. Study periods for the 27 studies ranged from 1987 to 2014. Multi-level linear regression models estimated changes in square-root per cent density (√PD) and dense area (√DA) associated with age at menarche and adult height in pooled analyses and population-specific meta-analyses. Models were adjusted for age at mammogram, body mass index, menopausal status, hormone therapy use, mammography view and type, mammographic density assessor, parity and height/age at menarche. RESULTS: In pooled analyses, later age at menarche was associated with higher per cent density (ß√PD = 0.023 SE = 0.008, P = 0.003) and larger dense area (ß√DA = 0.032 SE = 0.010, P = 0.002). Taller women had larger dense area (ß√DA = 0.069 SE = 0.028, P = 0.012) and higher per cent density (ß√PD = 0.044, SE = 0.023, P = 0.054), although the observed effect on per cent density depended upon the adjustment used for body size. Similar overall effect estimates were observed in meta-analyses across population groups. CONCLUSIONS: In one of the largest international studies to date, later age at menarche was positively associated with mammographic density. This is in contrast to its association with breast cancer risk, providing little evidence of mediation. Increased height was also positively associated with mammographic density, particularly dense area. These results suggest a complex relationship between growth and development, mammographic density and breast cancer risk. Future studies should evaluate the potential mediation of the breast cancer effects of taller stature through absolute breast density.

Self-reported arm and shoulder problems in breast cancer survivors in Sub-Saharan Africa: the African Breast Cancer-Disparities in Outcomes cohort study.

BACKGROUND: Arm and shoulder problems (ASP), including lymphedema, were common among women with breast cancer in high-income countries before sentinel lymph node biopsy became the standard of care. Although ASP impair quality of life, as they affect daily life activities, their frequency and determinants in Sub-Saharan Africa remain unclear. METHODS: All women newly diagnosed with breast cancer at the Namibian, Ugandan, Nigerian, and Zambian sites of the African Breast Cancer-Disparities in Outcomes (ABC-DO) cohort study were included. At each 3-month follow-up interview, women answered the EORTC-QLQ-Br23 questionnaire, including three ASP items: shoulder/arm pain, arm stiffness, and arm/hand swelling. We estimated the cumulative incidence of first self-reported ASP, overall and stratified by study and treatment status, with deaths treated as competing events. To identify determinants of ASP, we estimated cause-specific hazard ratios using Cox models stratified by study site. RESULTS: Among 1476 women, up to 4 years after diagnosis, 43% (95% CI 40-46), 36% (33-38) and 23% (20-25), respectively, self-reported having experienced arm/shoulder pain, stiffness and arm/hand swelling at least once. Although risks of self-reported ASP differed between sites, a more advanced breast cancer stage at diagnosis, having a lower socioeconomic position and receiving treatment increased the risk of reporting an ASP. CONCLUSION: ASP are very common in breast cancer survivors in Sub-Saharan Africa. They are influenced by different factors than those observed in high-income countries. There is a need to raise awareness and improve management of ASP within the African setting.

Dissecting the journey to breast cancer diagnosis in sub-Saharan Africa: Findings from the multicountry ABC-DO cohort study.

Most breast cancer patients in sub-Saharan Africa are diagnosed at advanced stages after prolonged symptomatic periods. In the multicountry African Breast Cancer-Disparities in Outcomes cohort, we dissected the diagnostic journey to inform downstaging interventions. At hospital presentation for breast cancer, women recalled their diagnostic journey, including dates of first noticing symptoms and health-care provider (HCP) visits. Negative binomial regression models were used to identify correlates of the length of the diagnostic journey. Among 1429 women, the median (inter-quartile range) length (months) of the diagnostic journey ranged from 11.3 (5.7-21.2) in Ugandan, 8.2 (3.4-16.4) in Zambian, 6.5 (2.4-15.7) in Namibian-black to 5.6 (2.3-13.1) in Nigerian and 2.4 (0.6-5.5) in Namibian-non-black women. Time from first HCP contact to diagnosis represented, on average, 58% to 79% of the diagnostic journey in each setting except Nigeria where most women presented directly to the diagnostic hospital with advanced disease. The median number of HCPs visited was 1 to 4 per woman, but time intervals between visits were long. Women who attributed their initial symptoms to cancer had a 4.1 months (absolute) reduced diagnostic journey than those who did not, while less-educated (none/primary) women had a 3.6 months longer journey than more educated women. In most settings the long journey to breast cancer diagnosis was not primarily due to late first presentation but to prolonged delays after first presentation to diagnosis. Promotion of breast cancer awareness and implementation of accelerated referral pathways for women with suspicious symptoms are vital to downstaging the disease in the region.

Geospatial barriers to healthcare access for breast cancer diagnosis in sub-Saharan African settings: The African Breast Cancer-Disparities in Outcomes Cohort Study.

We examined the geospatial dimension of delays to diagnosis of breast cancer in a prospective study of 1541 women newly diagnosed in the African Breast Cancer-Disparities in Outcomes (ABC-DO) Study. Women were recruited at cancer treatment facilities in Namibia, Nigeria, Uganda and Zambia. The baseline interview included information used to generate the geospatial features: urban/rural residence, travel mode to treatment facility and straight-line distances from home to first-care provider and to diagnostic/treatment facility, categorized into country/ethnicity (population)-specific quartiles. These factors were investigated in relation to delay in diagnosis (≥3 months since first symptom) and late stage at diagnosis (TNM: III, IV) using logistic regression, adjusted for population group and sociodemographic characteristics. The median (interquartile range) distances to first provider and diagnostic and treatment facilities were 5 (1-37), 17 (3-105) and 62 (5-289) km, respectively. The majority had a delay in diagnosis (74%) and diagnosis at late stage (64%). Distance to first provider was not associated with delay in diagnosis or late stage at diagnosis. Rural residence was associated with delay, but the association did not persist after adjustment for sociodemographic characteristics. Distance to the diagnostic/treatment facility was associated with delay (highest vs lowest quartile: odds ratio (OR) = 1.56, 95% confidence interval (CI) = 1.08-2.27) and late stage (overall: OR = 1.47, CI = 1.05-2.06; without Nigerian hospitals where mostly local residents were treated: OR = 1.73, CI = 1.18-2.54). These findings underscore the need for measures addressing the geospatial barriers to early diagnosis in sub-Saharan African settings, including providing transport or travel allowance and decentralizing diagnostic services.

Preexisting morbidity profile of women newly diagnosed with breast cancer in sub-Saharan Africa: African Breast Cancer-Disparities in Outcomes study.

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.