SummaryBackgroundMenarche and menopause mark the onset and cessation, respectively, of ovarian activity associated with reproduction, and affect breast cancer risk. Our aim was to assess the strengths of their effects and determine whether they depend on characteristics of the tumours or the affected women.MethodsIndividual data from 117 epidemiological studies, including 118 964 women with invasive breast cancer and 306 091 without the disease, none of whom had used menopausal hormone therapy, were included in the analyses. We calculated adjusted relative risks (RRs) associated with menarche and menopause for breast cancer overall, and by tumour histology and by oestrogen receptor expression.FindingsBreast cancer risk increased by a factor of 1·050 (95% CI 1·044–1·057; p<0·0001) for every year younger at menarche, and independently by a smaller amount (1·029, 1·025–1·032; p<0·0001), for every year older at menopause. Premenopausal women had a greater risk of breast cancer than postmenopausal women of an identical age (RR at age 45–54 years 1·43, 1·33–1·52, p<0·001). All three of these associations were attenuated by increasing adiposity among postmenopausal women, but did not vary materially by women's year of birth, ethnic origin, childbearing history, smoking, alcohol consumption, or hormonal contraceptive use. All three associations were stronger for lobular than for ductal tumours (p<0·006 for each comparison). The effect of menopause in women of an identical age and trends by age at menopause were stronger for oestrogen receptor-positive disease than for oestrogen receptor-negative disease (p<0·01 for both comparisons).InterpretationThe effects of menarche and menopause on breast cancer risk might not be acting merely by lengthening women's total number of reproductive years. Endogenous ovarian hormones are more relevant for oestrogen receptor-positive disease than for oestrogen receptor-negative disease and for lobular than for ductal tumours.FundingCancer Research UK.

Objective Predictors of intrinsic breast cancer subtypes, including the triple-negative (TN) subtype, are largely unknown. We evaluated whether anthropometrics, demographics, and reproductive history were associated with distinct breast cancer subtypes. Methods Invasive breast tumors from a population-based case–control study of 476 (116 black and 360 white) Atlanta women aged 20–54, diagnosed between 1990 and 1992, were centrally reviewed and immunohistochemically analyzed for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2); then grouped [TN (ER−PR−HER2−); ER−PR−HER2+; ER/PR+HER2+; ER/PR+HER2− (case-only reference group)]. Data were from interviews and anthropometric measurements; adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression, including both case-only and case-control comparisons. Results From the case-only analyses and compared with the ER/PR+HER2− subtype, women with TN tumors were more likely to be obese than normal/underweight [OR = 1.89 (95% CI = 1.22, 2.92)]. Regardless of HER2 status, ER−PR− tumors were associated with black race, young age at first birth, having a recent birth, and being overweight. Conclusions Distinct breast cancer subtypes have unique sociodemographic, anthropometric and reproductive characteristics and possibly different pathways for development.

Cancer death rates vary considerably by level of education. Identifying groups at high risk of death from cancer by level of education as well as by race may be useful in targeting interventions and tracking cancer disparities.

Avoidance of tobacco smoking and alcohol drinking is the most desirable way not only to prevent primary oral cancers, but also to reduce risk of second cancers of the aerodigestive system.

Prostate cancer occurs more frequently in Blacks than Whites in the United States. A population-based case-control study which investigated the association between tobacco use and prostate cancer risk was carried out among 981 pathologically confirmed cases (479 Blacks, 502 Whites) of prostate cancer, diagnosed between 1 August 1986 and 30 April 1989, and 1,315 controls (594 Blacks, 721 Whites). Study subjects, aged 40 to 79 years, resided in Atlanta (GA), Detroit (MI), and 10 counties in New Jersey, geographic areas covered by three, population-based, cancer registries. No excesses in risk for prostate cancer were seen for former cigarette smokers, in Blacks (odds ratio [OR] = 1.1, 95 percent confidence interval [CI] = 0.7-1.5) and in Whites (OR = 1.2, CI = 0.9-1.6), or for current cigarette smokers, in Blacks (OR = 1.0, CI = 0.7-1.4) and in Whites (OR = 1.2, CI = 0.8-1.7). Increases in risk were noted for smokers of 40 or more cigarettes per day, among former (OR = 1.4, CI = 1.0-1.5) and current (OR = 1.5, CI = 1.0-2.4) smokers. Duration of cigarette use and cumulative amount of cigarette use (pack-years) were not associated with prostate cancer risk for Blacks or Whites. By age, only the youngest subjects, aged 40 to 59 years, showed excess risk associated with current (OR = 1.5, CI = 1.0-2.3) and former (OR = 1.7, CI = 1.1-2.6) use of cigarettes, but there were no consistent patterns in this group according to amount or duration of smoking.(ABSTRACT TRUNCATED AT 250 WORDS)