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.

Summary In a case-control study of 84 multiple myeloma patients and 168 age-and sex-matched controls with tumours at other sites, reported prior allergies were associated with an elevated risk of myeloma (RR = 3.1, P<0.001). In addition, more myeloma patients than controls reported prior myxoedema (RR= 5.0 Incidence rates for multiple myeloma in British Columbia are 3.4 and 2.2 per 100,000 in males and females respectively (B.C. Ministry of Health, 1976). A recent study has indicated that the incidence has been increasing over the last 30 years (Velez et al., 1983). The highest reported incidence in the world is in U.S. black males (Waterhouse et al., 1976). Several occupational risks have been demonstrated, with Milham showing elevated mortality for myeloma among farmers, woodworkers, smeltermen and forgemen (Milham, 1976). Several studies have shown nuclear workers to be at high risk for myeloma (Dolphin, 1976;Lewis, 1963;Cuzick, 1981).Schafer and Miller in a study of 153 patients showed elevated risks of prior biliary disease and peptic ulcer in patients with IgA myeloma when compared to patients with all other myeloma types (Schafer & Miller 1979), and Allen found an elevated frequency among myeloma patients of individuals with group A blood (Allen, 1970). Familial occurrence of myeloma has been reported in spouses (Kyle et al., 1976) and in blood relatives (Maldonado & Kyle 1974 C) The

SummaryThe incidence and spectrum of non-Hodgkin lymphoma (NHL) differ between the Chinese and Caucasian populations. Using population-based registries, we studied the pattern of NHL in Chinese migrants to British Columbia (BC). The records of all NHL cases of Chinese descent diagnosed between 1980 and 1997 were retrieved. Age-standardized incidences were calculated by 5-year intervals in terms of age and calendar years and the relative rates were compared between the migrant, Hong Kong and BC populations. The histological distribution of NHL was compared with 4500 consecutive NHL cases diagnosed in the two populations. A total of 211 cases of migrant NHL were identified, with an age-standardized incidence rate of 7AE11 per 100 000 per year, compared with the Hong Kong and BC rates of 7AE91 [standardized incidence ratio (SIR) ¼ 0AE86, P ¼ 0AE01] and 11AE88 (SIR ¼ 0AE56, P < 0AE01). The standardized rates of follicular lymphoma remained low, but the incidence of gastric and nasal natural killer/ T lymphomas in migrants were lower than expected. Genetic factors appeared to be stronger than environmental factors in governing the overall incidence of NHL in Chinese. However, certain subtypes of lymphoma may show decreased rates in migrants because of environmental factors.

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