Cases included in a population-based case-control study of breast cancer in men were recruited from 10 geographic areas of the United States from 1983 to 1986. Controls, matched to cases on age and geographic area, were selected by random digit dialing for men under age 65 years and from Health Care Financing Administration files for older men. Results are based on responses from 227 cases and 300 controls to questions asked in a standardized personal interview. An increased risk of breast cancer was most strongly associated with undescended testes and was also related to orchiectomy, orchitis, testicular injury, late puberty, and infertility; and a decreasing trend in risk was observed with an increasing number of children. Relative risk estimates were also elevated in relation to a history of high blood cholesterol, rapid weight gain, benign breast conditions, and possibly obesity. These findings suggest that breast cancer in men develops in response to androgen deficiency associated with testicular dysfunction and under conditions associated with excess estrogen. Risk was also found to be elevated in men with a history of amphetamine use, diabetes, and cigar smoking and reduced in men with prior head trauma.

Data from a population-based case-control study of breast cancer in men were used to examine the hypothesis that occupational exposure to electromagnetic fields increases the risk of breast cancer. Incident cases (n = 227) diagnosed between 1983 and 1987 were obtained from 10 population-based cancer registries of the Surveillance, Epidemiology, and End Results program of the National Cancer Institute. Controls (n = 300) were selected by random digit dialing and from Medicare eligibility lists. Exposure status, defined as ever having been employed in a job which has been classified as involving potential exposure to electromagnetic fields, was assigned without knowledge of case/control status. An elevated risk was found for any job with exposure (odds ratio (OR) = 1.8, 95 percent confidence interval (CI) 1.0-3.7), and risk was highest among electricians, telephone linemen, and electric power workers (OR = 6.0, 95 percent CI 1.7-21) and radio and communications workers (OR = 2.9, 95 percent CI 0.8-10). Risk did not vary with duration of exposed employment. The risk was highest among subjects who were first employed in jobs with exposure before the age of 30 years and who were initially exposed at least 30 years prior to diagnosis. These results lend support to the theory that electromagnetic fields may be related to breast cancer in men. The hypothesis warrants evaluation in women.

Black women with breast cancer are less likely than white women to be diagnosed while their disease is still at a localized stage. Racial differences in the prevalence of obesity in the United States have also been documented. This study was undertaken to determine the extent to which the observed racial difference in stage at diagnosis of breast cancer could be explained by racial differences in obesity, specifically severe obesity. This was a population-based, retrospective study of 145 black women and 177 white women in Connecticut who were diagnosed with breast cancer between January 1987 and March 1989. Severe obesity was associated with both race and stage at diagnosis: Black women were significantly more likely than white women to be severely obese (26% vs. 7%, respectively), and severe obesity was significantly associated with diagnosis at TNM stage II or greater (multivariate-adjusted odds ratio = 3.10, 95% confidence interval (CI) 1.28-7.52). Adjustment for severe obesity in a logistic regression model reduced the risk of later stage at diagnosis in blacks relative to whites by 33%, from an odds ratio of 1.98 (95% CI 1.22-3.19) to one of 1.66 (95% CI 1.01-2.73). The higher prevalence of severe obesity among black women may play an important role in explaining their relative disadvantage in stage at diagnosis of breast cancer.

Background. A race difference in the stage at diagnosis of breast cancer is well established: African American women are less likely than white women to be diagnosed at a localized stage. The purpose of this study was to determine the extent to which the observed race (black/white) difference in stage at diagnosis of breast cancer could be accounted for by race differences in the mammography screening history. Methods. This was a population‐based, retrospective study of 145 African American and 177 white women with newly diagnosed breast cancer in Connecticut, between January, 1987 and March, 1989. Cases were ascertained through active surveillance of 22 Connecticut hospitals. Results. Black women were diagnosed more commonly with later stage cancer (TNM stage ⩾II) (age‐adjusted odds ratio [OR] = 2.01, 95% confidence interval [CI] 1.24‐3.24) than were white women. Blacks were also more likely than whites to report that they had not received a mammogram in the 3 years before development of symptoms or diagnosis (OR = 2.05, 95% CI 1.26‐3.35); this association was not altered substantially with adjustment for socioeconomic status. In race‐specific analyses, mammography was protective against later stage diagnosis in white women, but not in black women. With adjustment for mammography screening, the OR for the race‐stage association was reduced only minimally, and race remained a significant predictor of stage at diagnosis. Conclusions. In these population‐based data, history of mammography screening was not an important explanatory variable in the race‐stage association. Specifically, history of mammographic screening accounted for less than 10% of the observed black/white difference in stage at diagnosis of breast cancer.

Prostate cancer is the most frequently diagnosed cancer in males in the United States, accounting for an estimated 186,320 new cases in 2008. There are striking racial or ethnic differences in prostate cancer incidence and mortality rates in the United States, with Black males 1.6 times more likely to be diagnosed and 2.4 times more likely to die with prostate cancer than Whites. Stage at diagnosis is a key prognostic factor for prostate cancer survival, with African-Americans generally diagnosed at a more advanced stage. To identify factors that explain the race-stage disparity in prostate cancer, we conducted a population-based casecase study of 251 African-American (46%) and White (54%) prostate cancer cases diagnosed in Connecticut between January 1987 and October 1990. Multivariate logistic regression was used to identify potential explanatory factors, including clinical, sociodemographic, medical care, insurance, digital rectal examination screening history, and lifestyle factors. Cox proportional hazards models assessed the impact of study variables on race differences in long-term survival. Modifiable factors such as screening practice and sociodemographic factors accounted for >60% of the race difference in prostate cancer stage at diagnosis. Histologic grade (Gleason score) accounted for comparatively less. Survival analyses confirmed the importance of tumor characteristics, education, and insurance in explaining observed race differences in survival. Although cases were identified before the widespread use of prostate-specific antigen (PSA) screening, the results should also be relevant to countries that have large underserved populations and/or disparities in access to medical care and cancer screening. (Cancer Epidemiol Biomarkers Prev 2008;17(10):2825 -34)