Divergent breast cancer incidence trends by hormone receptor status in the state of Sarawak, Malaysia.

Recent studies from high-risk countries such as the US, Denmark and Ireland have shown rising incidence rates of hormone receptor (HR)-positive and falling rates of HR-negative breast cancers (BC). However, it remains unclear whether a similar pattern occurs in low-risk countries. Detailed clinical and risk factor data were collected from 2,977 female invasive BC patients (≥20 years) in Sarawak General Hospital, Malaysia, representing 93% of the population. The population-at-risk was obtained from the Department of Statistics Malaysia. Secular trends in age-standardized incidence rates were assessed using estimated average annual percent changes. Associations between established BC risk factors and tumor subtypes defined by HR or joint human epidermal growth factor receptor 2 (HR/HER2) status were examined by case-case comparisons using logistic regression. From 2006 to 2015, incidence rates increased for HR-positive cancers by 4.46%/year (95% CI = 2.19-6.78) and decreased for HR-negative cancers by 2.29%/year (95% CI = -4.31 to -0.24). When further stratified by HER2, the most contrasting difference in linear trends was observed between HR+/HER2- and HR-/HER2- subtypes. After controlling for potential confounders, cases with excess body weight (ORoverweight vs. normal = 0.82; 95% CI = 0.69-0.98; ORobese vs. normal = 0.62; 95% CI = 0.48-0.80), later age at first birth (OR≥26 years vs. <23 years = 0.82; 95% CI = 0.66-1.02), nulliparity (ORnulliparous vs. <23 years = 0.74; 95% CI = 0.59-0.94) and never-breastfeeding (ORnever vs. ever = 0.73; 95% CI = 0.55-0.97) were less frequent among HR-negative cases than among HR-positive cases. Diverging incidence trends by HR expression were similar in Sarawak and Western countries, possibly reflecting changes in the prevalence of risk factors with opposing effects by tumor subtypes in low- and high-risk populations.

Bimodal age distribution at diagnosis in breast cancer persists across molecular and genomic classifications.

PURPOSE: Female breast cancer demonstrates bimodal age frequency distribution patterns at diagnosis, interpretable as two main etiologic subtypes or groupings of tumors with shared risk factors. While RNA-based methods including PAM50 have identified well-established clinical subtypes, age distribution patterns at diagnosis as a proxy for etiologic subtype are not established for molecular and genomic tumor classifications. METHODS: We evaluated smoothed age frequency distributions at diagnosis for Carolina Breast Cancer Study cases within immunohistochemistry-based and RNA-based expression categories. Akaike information criterion (AIC) values compared the fit of single density versus two-component mixture models. Two-component mixture models estimated the proportion of early-onset and late-onset categories by immunohistochemistry-based ER (n = 2860), and by RNA-based ESR1 and PAM50 subtype (n = 1965). PAM50 findings were validated using pooled publicly available data (n = 8103). RESULTS: Breast cancers were best characterized by bimodal age distribution at diagnosis with incidence peaks near 45 and 65 years, regardless of molecular characteristics. However, proportional composition of early-onset and late-onset age distributions varied by molecular and genomic characteristics. Higher ER-protein and ESR1-RNA categories showed a greater proportion of late age-at-onset. Similarly, PAM50 subtypes showed a shifting age-at-onset distribution, with most pronounced early-onset and late-onset peaks found in Basal-like and Luminal A, respectively. CONCLUSIONS: Bimodal age distribution at diagnosis was detected in the Carolina Breast Cancer Study, similar to national cancer registry data. Our data support two fundamental age-defined etiologic breast cancer subtypes that persist across molecular and genomic characteristics. Better criteria to distinguish etiologic subtypes could improve understanding of breast cancer etiology and contribute to prevention efforts.

Trends in premature mortality in the USA by sex, race, and ethnicity from 1999 to 2014: an analysis of death certificate data.

BACKGROUND: Reduction of premature mortality is a UN Sustainable Development Goal. Unlike other high-income countries, age-adjusted mortality in the USA plateaued in 2010 and increased slightly in 2015, possibly because of rising premature mortality. We aimed to analyse trends in mortality in the USA between 1999 and 2014 in people aged 25-64 years by age group, sex, and race and ethnicity, and to identify specific causes of death underlying the temporal trends. METHODS: For this analysis, we used cause-of-death and demographic data from death certificates from the US National Center for Health Statistics, and population estimates from the US Census Bureau. We estimated annual percentage changes in mortality using age-period-cohort models. Age-standardised excess deaths were estimated for 2000 to 2014 as observed deaths minus expected deaths (estimated from 1999 mortality rates). FINDINGS: Between 1999 and 2014, premature mortality increased in white individuals and in American Indians and Alaska Natives. Increases were highest in women and those aged 25-30 years. Among 30-year-olds, annual mortality increases were 2·3% (95% CI 2·1-2·4) for white women, 0·6% (0·5-0·7) for white men, and 4·3% (3·5-5·0) and 1·9% (1·3-2·5), respectively, for American Indian and Alaska Native women and men. These increases were mainly attributable to accidental deaths (primarily drug poisonings), chronic liver disease and cirrhosis, and suicide. Among individuals aged 25-49 years, an estimated 111 000 excess premature deaths occurred in white individuals and 6600 in American Indians and Alaska Natives during 2000-14. By contrast, premature mortality decreased substantially across all age groups in Hispanic individuals (up to 3·2% per year), black individuals (up to 3·9% per year), and Asians and Pacific Islanders (up to 2·6% per year), mainly because of declines in HIV, cancer, and heart disease deaths, resulting in an estimated 112 000 fewer deaths in Hispanic individuals, 311 000 fewer deaths in black individuals, and 34 000 fewer deaths in Asians and Pacific Islanders aged 25-64 years. During 2011-14, American Indians and Alaska Natives had the highest premature mortality, followed by black individuals. INTERPRETATION: Important public health successes, including HIV treatment and smoking cessation, have contributed to declining premature mortality in Hispanic individuals, black individuals, and Asians and Pacific Islanders. However, this progress has largely been negated in young and middle-aged (25-49 years) white individuals, and American Indians and Alaska Natives, primarily because of potentially avoidable causes such as drug poisonings, suicide, and chronic liver disease and cirrhosis. The magnitude of annual mortality increases in the USA is extremely unusual in high-income countries, and a rapid public health response is needed to avert further premature deaths. FUNDING: US National Cancer Institute Intramural Research Program.

Metformin use and survival after non-small cell lung cancer: A cohort study in the US Military health system.

Research suggests that metformin may be associated with improved survival in cancer patients with type II diabetes. This study assessed whether metformin use after non-small cell lung cancer (NSCLC) diagnosis is associated with overall survival among type II diabetic patients with NSCLC in the U.S. military health system (MHS). The study included 636 diabetic patients with histologically confirmed NSCLC diagnosed between 2002 and 2007, identified from the linked database from the Department of Defense's Central Cancer Registry (CCR) and the Military Health System Data Repository (MDR). Time-dependent multivariate Cox proportional hazards models were used to assess the association between metformin use and overall survival during follow-up. Among the 636 patients, 411 died during the follow-up. The median follow-up time was 14.6 months. Increased post-diagnosis cumulative use (per 1 year of use) conferred a significant reduction in mortality (adjusted hazard ratio (HR) = 0.76; 95% CI = 0.65-0.88). Further analysis by duration of use revealed that compared to non-users, the lowest risk reduction occurred among patients with the longest duration of use (i.e. use for more than 2 years) (HR = 0.19; 95% CI = 0.09-0.40). Finally, the reduced mortality was particularly observed only among patients who also used metformin before lung cancer diagnosis and among patients at early stage of diagnosis. Prolonged duration of metformin use in the study population was associated with improved survival, especially among early stage patients. Future research with a larger number of patients is warranted.

The impact of breast cancer-specific birth cohort effects among younger and older Chinese populations.

Historically low breast cancer incidence rates among Asian women have risen worldwide; purportedly due to the adoption of a "Western" life style among younger generations (i.e., the more recent birth cohorts). However, no study has simultaneously compared birth cohort effects between both younger and older women in different Asian and Western populations. Using cancer registry data from rural and urban China, Singapore and the United States (1990-2008), we estimated age-standardized incidence rates (ASR), annual percentage change (EAPC) in the ASR, net drifts, birth cohort specific incidence rates and cohort rate ratios (CRR). Younger (30-49 years, 1943-1977 birth cohorts) and older women (50-79 years; 1913-1957 birth cohorts) were assessed separately. CRRs among Chinese populations were estimated using birth cohort specific rates with US non-Hispanic white women (NHW) serving as the reference population with an assigned CRR of 1.0. We observed higher EAPCs and net drifts among those Chinese populations with lower ASRs. Similarly, we observed the most rapidly increasing cohort-specific incidence rates among those Chinese populations with the lowest baseline CRRs. Both trends were more significant among older than younger women. Average CRRs were 0.06-0.44 among older and 0.18-0.81 among younger women. Rapidly rising cohort specific rates have narrowed the historic disparity between Chinese and US NHW breast cancer populations particularly in regions with the lowest baseline rates and among older women. Future analytic studies are needed to investigate risk factors accounting for the rapid increase of breast cancer among older and younger women separately in Asian populations.

Investigation of breast cancer sub-populations in black and white women in South Africa.

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.

Epidemiology of Anorectal Melanoma in the United States: 1992 to 2011.

BACKGROUND: Anorectal melanoma is a rare type of malignant melanoma and thus the epidemiology of patients with this tumor has been poorly defined. OBJECTIVE: To describe the epidemiology of anorectal melanoma in the United States. METHODS AND MATERIALS: We obtained case and population data from the Surveillance, Epidemiology, and End Results 13 Registries Database (SEER 13) between 1992 and 2011 using rectal diagnostic codes C20.9 to 21.8 and ICD-O-3 melanoma codes 8720 to 8721 and 8742 to 8746. RESULTS: There were 260 primary anorectal melanomas in SEER 13 from 1992 to 2011, occurring mostly in the rectum. The incidence of anorectal melanoma was higher among women than men with the highest rates occurring among white Hispanics ages 65 to 74 years. During this time period, the age-adjusted incidence rates rose significantly (p < .05) for both women and men with estimated annual percentage changes of 3.02% and 5.08%, respectively. Overall and melanoma-specific survival was poor irrespective of gender or ethnicity. CONCLUSION: Anorectal melanoma in the United States is increasing in both men and women, with the highest rates in elderly Hispanic white women. Hispanic whites were more likely to develop anorectal melanoma than non-Hispanic whites, suggesting that this population may be targeted for screening interventions. These results warrant further investigation to better understand the gender, racial, ethnic, and geographic variations for anorectal melanomas.

Racial disparities in prostate cancer incidence rates by census division in the United States, 1999-2008.

BACKGROUND: Black men have a higher incidence of prostate cancer than white men in the U.S., but little is known whether incidence or racial differences vary geographically. Understanding these differences may assist future studies on causes of prostate cancer. To address such, we leverage the unique resource of the National Program of Cancer Registries (NPCR) combined with Surveillance, Epidemiology and End Results (SEER). METHODS: Prostate cancer counts and population denominators by race (black, white), age, calendar year, and U.S. census division, for the period 1999-2008, were extracted from NPCR and SEER. We calculated age-standardized incidence rates (ASR) and estimated annual percent changes (EAPC) by race and census division. We assessed black-to-white incidence rate ratios (BWIRR) by census division and by calendar period. RESULTS: This analysis included 1,713,471 prostate cancer cases and 1,217 million person-years. Black ASRs ranged from 176 per 100,000 person-years in Mountain division to 259 in Middle Atlantic. BWIRRs ranged from 1.20 in Western divisions to 1.72 in Southeastern divisions. EAPCs indicated that prostate cancer incidence is not decreasing in East South Central, unlike all other divisions. White EAPCs displayed similar variations by census division, resulting in modest temporal changes in BWIRRs. CONCLUSIONS: Within the U.S., there exists significant geographic variability in prostate cancer incidence rates. Although there are large geographic differences in BWIRRs, temporal trends are fairly stable. This may indicate that primary factors affecting prostate cancer incidence rates vary geographically but affect both black and white men to a similar degree.

Greater absolute risk for all subtypes of breast cancer in the US than Malaysia.

Hormone receptor (HR) negative breast cancers are relatively more common in low-risk than high-risk countries and/or populations. However, the absolute variations between these different populations are not well established given the limited number of cancer registries with incidence rate data by breast cancer subtype. We, therefore, used two unique population-based resources with molecular data to compare incidence rates for the 'intrinsic' breast cancer subtypes between a low-risk Asian population in Malaysia and high-risk non-Hispanic white population in the National Cancer Institute's surveillance, epidemiology, and end results 18 registries database (SEER 18). The intrinsic breast cancer subtypes were recapitulated with the joint expression of the HRs (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor-2 (HER2). Invasive breast cancer incidence rates overall were fivefold greater in SEER 18 than in Malaysia. The majority of breast cancers were HR-positive in SEER 18 and HR-negative in Malaysia. Notwithstanding the greater relative distribution for HR-negative cancers in Malaysia, there was a greater absolute risk for all subtypes in SEER 18; incidence rates were nearly 7-fold higher for HR-positive and 2-fold higher for HR-negative cancers in SEER 18. Despite the well-established relative breast cancer differences between low-risk and high-risk countries and/or populations, there was a greater absolute risk for HR-positive and HR-negative subtypes in the US than Malaysia. Additional analytical studies are sorely needed to determine the factors responsible for the elevated risk of all subtypes of breast cancer in high-risk countries like the United States.

Breast reconstruction after mastectomy among Department of Defense beneficiaries by race.

BACKGROUND: Postmastectomy breast reconstruction increased approximately 20% between 1998 and 2008 in the United States and has been found to improve body image, self-esteem, and quality of life. These procedures, however, tend to be less common among minority women, which may be due to variations in health care access. The Department of Defense provides equal health care access, thereby affording an exceptional environment in which to assess whether racial variations persist when access to care is equal. METHODS: Linked Department of Defense cancer registry and medical claims data were used. The receipt of reconstruction was compared between white women (n = 2974) and black women (n = 708) who underwent mastectomies to treat incident histologically confirmed breast cancer diagnosed from 1998 through 2007. RESULTS: During the study period, postmastectomy reconstruction increased among both black (27.3% to 40.0%) and white (21.8% to 40.6%) female patients with breast cancer. Receipt of reconstruction did not vary significantly by race (odds ratio, 0.93; 95% confidence interval, 0.76-1.15). Reconstruction decreased significantly with increasing age, tumor stage, and receipt of radiotherapy and was significantly more common in more recent years and among active service women, TRICARE Prime (health maintenance organization) beneficiaries, and women whose sponsor was an officer. CONCLUSIONS: The receipt of breast reconstruction did not vary by race within this equal-access health system, indicating that the racial disparities reported in previous studies may have been due in part to variations in access to health care. Additional research to determine why a large percentage of patients with breast cancer do not undergo reconstruction might be beneficial, particularly because these procedures have been associated with noncosmetic benefits.

Heterogeneity of breast cancer subtypes and survival among Hispanic women with invasive breast cancer in California.

There are limited data regarding breast cancer subtypes among Hispanic women. The current study assessed the distribution and prognosis of molecular subtypes defined by joint expression of the hormone receptors (HR; estrogen and progesterone) and human epidermal growth factor receptor 2 (HER2). Using California Cancer Registry data, we identified Hispanic women diagnosed with invasive breast cancer from 2005 to 2010. Breast cancer subtypes were defined as HR+/HER2-, HR+/HER2+, HR-/HER2+, and HR-/HER2- (triple negative). We estimated breast cancer subtype frequencies and used polytomous logistic regression, Kaplan-Meier survival plots and Cox regression to examine differences in relation to demographic and clinical characteristics. Among 16,380 Hispanic women with breast cancer, HR+/HER- subtype was the most common (63 %), followed by triple negative (16 %), HR+/HER2+ (14 %), and HR-/HER2+ (8 %). Women in lower SES neighborhoods had greater risk of triple negative and HR-/HER2+ subtypes relative to HR+/HER2- (p < 0.05). Hispanic women with triple negative and HR-/HER2+ tumors experienced poorer survival than those with HR+/HER- tumors. Breast cancer-specific mortality increased with decreasing SES, relative to the highest SES quintile, from HR = 1.38 for quintile 4 to HR = 1.76 for quintile 1 (lowest SES level). Our findings indicate that Hispanic women residing in low SES neighborhoods had significantly increased risk of developing and dying from HR- than HR+ breast cancers. Similar patterns of subtype frequency and prognosis among California Hispanic women and studies of other racial/ethnic groups underscore the need to better understand the impact of SES on risk factor exposures that increase the risk of breast cancer subtypes with poor prognosis.

Divergent estrogen receptor-positive and -negative breast cancer trends and etiologic heterogeneity in Denmark.

Long-term breast cancer trends in incidence in the United States (US) show rising estrogen receptor (ER)-positive rates and falling ER-negative rates. We hypothesized that these divergent trends reflect etiologic heterogeneity and that comparable trends should be observed in other countries with similar risk factor profiles. Therefore, we analyzed invasive female breast cancers in Denmark, a country with similar risk factors as the US. We summarized the overall trend in age-standardized rates with the estimated annual percentage change (EAPC) statistic (1993-2010) and used age-period-cohort models to estimate age-specific EAPCs, cohort rate ratios and projections for future time periods (2011-2018). In Denmark, the overall rate of ER-positive cancers rose between 1993 and 2010 by 3.0% per year (95% CI: 2.8-3.3% per year), whereas the overall rate of ER-negative cancers fell by 2.1% per year (95% CI: -2.5 to -1.6% per year). The ER-positive rate increased fastest among postmenopausal women and the ER-negative rate decreased fastest among premenopausal women, reflecting that cohorts born after 1944 were at relatively higher risk of ER-positive tumors and lower risk of ER-negative tumors. If current trends continue, ER-positive cancers will increase at least 13% by 2018 in Denmark, ER-negative cancers will fall 15% by 2018, and breast cancer overall will increase at least 7% by 2018. Divergent ER-specific trends are consistent with distinct etiologic pathways. If trends in known risk factors are responsible, the Danish and US experience may foreshadow a common pattern worldwide.

Surveillance mammography among female Department of Defense beneficiaries: a study by race and ethnicity.

BACKGROUND: Annual surveillance mammography is recommended after a diagnosis of breast cancer. Previous studies have suggested that surveillance mammography varies by demographics and initial tumor characteristics, which are related to an individual's access to health care. The Military Health System of the Department of Defense provides beneficiaries with equal access health care and thus offers an excellent opportunity to assess whether racial differences in surveillance mammography persist when access to care is equal. METHODS: Among female beneficiaries with a history of breast cancer, logistic regression was used to assess racial/ethnic variations in the use of surveillance mammography during 3 periods of 12 months each, beginning 1 year after diagnosis adjusting for demographic, tumor, and health characteristics. RESULTS: The rate of overall surveillance mammography decreased from 70% during the first year to 59% during the third year (P < .01). Although there was an overall tendency for surveillance mammography to be higher among minority women compared with non-Hispanic white women, after adjusting for covariates, the difference was found to be significant only during the first year among black women (odds ratio [OR], 1.46; 95% confidence interval [95% CI], 1.10-1.95) and the second year among Asian/Pacific Islander (OR, 2.29; 95%CI, 1.52-3.44) and Hispanic (OR, 1.92; 95%CI, 1.17-3.18) women. When stratified by age at diagnosis and type of breast cancer surgery performed, significant racial differences tended to be observed among younger women (aged < 50 years) and only among women who had undergone mastectomies. CONCLUSIONS: Minority women were equally or more likely than non-Hispanic white women to receive surveillance mammography within the Military Health System. The racial disparities in surveillance mammography reported in other studies were not observed in a system with equal access to health care.

Agreement for tumor grade of ovarian carcinoma: analysis of archival tissues from the surveillance, epidemiology, and end results residual tissue repository.

BACKGROUND: Emerging data suggest that ovarian cancers differ by tumor grade. However, the reliability of microscopic grade from paraffin tissue in the general medical community and as reflected in population-based cancer registries is unknown. METHODS: We examined grade agreement between two gynecologic pathologists and the Surveillance Epidemiology and End Results Residual Tissue Repository (SEER). Grade agreement was assessed with percent observer agreement and kappa coefficients for 664 invasive ovarian carcinomas, using previously defined three-tier and two-tier grading systems. A random subset of ovarian carcinomas was selected to compare intra- and inter-pathologist agreement. RESULTS: Five hundred and eighty-six of SEER's 664 tumors were confirmed invasive. Percent agreement was 49 % with fair kappa coefficient = 0.25 (95 % CI: 0.20-0.30) for the 664 tumors. Agreement improved slightly when restricted to the 586 confirmed invasive cancers; it was better for high grade than low grade tumors, for two-tier than three-tier grading systems, and within (66 %) than between study pathologists (43 %). Grade was not a robust independent predictor of ovarian cancer-specific survival. CONCLUSIONS: Grade agreement was fair between SEER and study pathologists irrespective of grading system. Recorded grade in SEER should be used with caution and is probably not a reliable metric for ovarian cancer epidemiology.

Patterns of Cancer Incidence, Mortality, and Prevalence Across Five Continents: Defining Priorities to Reduce Cancer Disparities in Different Geographic Regions of the World.

Efforts to reduce global cancer disparities begin with an understanding of geographic patterns in cancer incidence, mortality, and prevalence. Using the GLOBOCAN (2002) and Cancer Incidence in Five Continents databases, we describe overall cancer incidence, mortality, and prevalence, age-adjusted temporal trends, and age-specific incidence patterns in selected geographic regions of the world. For the eight most common malignancies-cancers of lung, breast, colon and rectum, stomach, prostate, liver, cervix, and esophagus-the most important risk factors, cancer prevention and control measures are briefly reviewed.In 2002, an estimated 11 million new cancer cases and 7 million cancer deaths were reported worldwide; nearly 25 million persons were living with cancer. Among the eight most common cancers, global disparities in cancer incidence, mortality, and prevalence are evident, likely due to complex interactions of nonmodifiable (ie, genetic susceptibility and aging) and modifiable risk factors (ie, tobacco, infectious agents, diet, and physical activity). Indeed, when risk factors among populations are intertwined with differences in individual behaviors, cultural beliefs and practices, socioeconomic conditions, and health care systems, global cancer disparities are inevitable. For the eight most common cancers, priorities for reducing cancer disparities are discussed.

Human Papillomavirus and Rising Oropharyngeal Cancer Incidence in the United States.

PURPOSE: Recent increases in incidence and survival of oropharyngeal cancers in the United States have been attributed to human papillomavirus (HPV) infection, but empirical evidence is lacking. PATIENTS AND METHODS: HPV status was determined for all 271 oropharyngeal cancers (1984-2004) collected by the three population-based cancer registries in the Surveillance, Epidemiology, and End Results (SEER) Residual Tissue Repositories Program by using polymerase chain reaction and genotyping (Inno-LiPA), HPV16 viral load, and HPV16 mRNA expression. Trends in HPV prevalence across four calendar periods were estimated by using logistic regression. Observed HPV prevalence was reweighted to all oropharyngeal cancers within the cancer registries to account for nonrandom selection and to calculate incidence trends. Survival of HPV-positive and HPV-negative patients was compared by using Kaplan-Meier and multivariable Cox regression analyses. RESULTS: HPV prevalence in oropharyngeal cancers significantly increased over calendar time regardless of HPV detection assay (P trend < .05). For example, HPV prevalence by Inno-LiPA increased from 16.3% during 1984 to 1989 to 71.7% during 2000 to 2004. Median survival was significantly longer for HPV-positive than for HPV-negative patients (131 v 20 months; log-rank P < .001; adjusted hazard ratio, 0.31; 95% CI, 0.21 to 0.46). Survival significantly increased across calendar periods for HPV-positive (P = .003) but not for HPV-negative patients (P = .18). Population-level incidence of HPV-positive oropharyngeal cancers increased by 225% (95% CI, 208% to 242%) from 1988 to 2004 (from 0.8 per 100,000 to 2.6 per 100,000), and incidence for HPV-negative cancers declined by 50% (95% CI, 47% to 53%; from 2.0 per 100,000 to 1.0 per 100,000). If recent incidence trends continue, the annual number of HPV-positive oropharyngeal cancers is expected to surpass the annual number of cervical cancers by the year 2020. CONCLUSION: Increases in the population-level incidence and survival of oropharyngeal cancers in the United States since 1984 are caused by HPV infection.

Racial variation in breast cancer treatment among Department of Defense beneficiaries.

BACKGROUND: Although the overall age-adjusted incidence rates for female breast cancer are higher among whites than blacks, mortality rates are higher among blacks. Many attribute this discrepancy to disparities in health care access and to blacks presenting with later stage disease. Within the Department of Defense (DoD) Military Health System, all beneficiaries have equal access to health care. The aim of this study was to determine whether female breast cancer treatment varied between white and black patients in the DoD system. METHODS: The study data were drawn from the DoD cancer registry and medical claims databases. Study subjects included 2308 white and 391 black women diagnosed with breast cancer between 1998 and 2000. Multivariate logistic regression analyses that controlled for demographic factors, tumor characteristics, and comorbidities were used to assess racial differences in the receipt of surgery, chemotherapy, and hormonal therapy. RESULTS: There was no significant difference in surgery type, particularly when mastectomy was compared with breast-conserving surgery plus radiation (blacks vs whites: odds ratio [OR], 1.1; 95% confidence interval [CI], 0.8-1.5). Among those with local stage tumors, blacks were as likely as whites to receive chemotherapy (OR, 1.2; 95% CI, 0.9-1.7) and hormonal therapy (OR, 1.0; 95% CI, 0.6-1.4). Among those with regional stage tumors, blacks were significantly less likely than whites to receive chemotherapy (OR, 0.4; 95% CI, 0.2-0.7) and hormonal therapy (OR, 0.5; 95% CI, 0.3-0.8). CONCLUSIONS: Even within an equal access health care system, stage-related racial variations in breast cancer treatment are evident. Studies that identify driving factors behind these within-stage racial disparities are warranted.

Variation in the risk of radiation-related contralateral breast cancer by histology and estrogen receptor expression in SEER.

Radiation exposure, particularly at a young age, is an established cause of breast cancer. It is not known whether radiation-related breast cancer risk varies by molecular subtype. We characterized the relative risk (RR) of contralateral breast cancer (CBC) related to radiotherapy by histology and estrogen receptor (ER) status of the CBC in five-year survivors in the Surveillance, Epidemiology, and End Results database using Poisson regression models adjusted for attained age and calendar year, age at and year of treatment, ER status of the first breast cancer, and disease stage. 205,316 female breast cancer survivors were followed for an average of 10 years from 1973 until 2007, during which time 6924 women developed a subsequent primary invasive breast cancer in the contralateral breast. The overall RR (and 95% confidence interval (CI)) of radiotherapy-related CBC was 1.11 (1.05-1.16). There was no heterogeneity in risk according to histology of the CBC (P > 0.50) for all ages or young age at exposure, but case numbers were small for subtypes other than ductal and lobular carcinomas. Information on ER status was available from 1990 onwards for 3546 CBC cases, of which 2597 (73%) were ER+ and 949 (27%) were ER-. The RRs were 1.10 (1.02-1.19) for ER+ CBC and 1.19 (1.04-1.35) for ER- CBC (P (difference) = 0.33). Among women treated age <35 years, radiation-related risk of CBC was non-significantly elevated for ER- (RR = 1.38, 95% CI: 0.96-1.97) but not for ER+ tumors (RR = 0.80, 95% CI: 0.47-1.35) (P (difference) = 0.09). We did not find clear evidence that radiation-related risk varies by histology or ER status, but our findings, which were the first to examine this question, were suggestive of possible differences by ER status that may merit further investigation.