The relationship between the risk of biliary tract cancers and menstrual and reproductive factors has been studied in a case-control study conducted in Milan, northern Italy, between January 1984 and February 1993 on 31 incident, histologically confirmed cases and 377 controls in hospital for acute, non-neoplastic, non-gynaecological, non-hormone-related conditions. Odds ratios (ORs) together with their corresponding 95% confidence intervals (CIs) and the significance of the linear trends in risk were estimated by unconditional multiple logistic regression, after adjustment for age and cholelithiasis. Menopause was associated with a decreased risk of biliary tract cancers (OR 0.2), while late menopause and the use of hormone replacement therapy tended to increase the risk (ORs 1.8 and 2.2 respectively). Age at menarche and regular menstrual cycles were not associated. A trend in risk was found with parity, while total abortions and age at first and last birth were not related. Thus, the protective effect of early menopause and the apparent association of multiple full-term pregnancies suggest a role of female hormones in the aetiology of biliary tract cancers.
aMario Negri Institute for Pharmacological Research and bInstitute of Medical Statistics, University of Milan, Milano, Italy Correspondence to Prof Carlo La Vecchia, Istituto di Ricerche Farmacologiche 'Mario Negri', via Eritrea 62, 20157 Milan, Italy Tel: +3902 3901 4527; e-mail: [email protected]
Meat intake has been positively associated with risk of digestive tract cancers in several epidemiological studies, while data on the relation of meat intake with cancer risk at most other sites are inconsistent. The overall data set, derived from an integrated series of case-control studies conducted in northern Italy between 1983 and 1996, included the following incident, histologically confirmed neoplasms: oral cavity, pharynx and esophagus (n = 497), stomach (n = 745), colon (n = 828), rectum (n = 498), liver (n = 428), gallbladder (n = 60), pancreas (n = 362), larynx (n = 242), breast (n = 3,412), endometrium (n = 750), ovary (n = 971), prostate (n = 127), bladder (n = 431), kidney (n = 190), thyroid (n = 208), Hodgkin's disease (n = 80), non-Hodgkin's lymphomas (n = 200) and multiple myelomas (n = 120). Controls were 7,990 patients admitted to hospital for acute, non-neoplastic conditions unrelated to long-term modifications in diet. The multivariate odds ratios (ORs) for the highest tertile of red meat intake (≥7 times/week) compared with the lowest (≤3 times/week) were 1.6 for stomach, 1.9 for colon, 1.7 for rectal, 1.6 for pancreatic, 1.6 for bladder, 1.2 for breast, 1.5 for endometrial and 1.3 for ovarian cancer. ORs showed no significant heterogeneity across strata of age at diagnosis and sex. No convincing relation with red meat intake emerged for cancers of the oral cavity, pharynx and esophagus, liver, gallbladder, larynx, kidney, thyroid, prostate, Hodgkin's disease, non-Hodgkin's lymphomas and multiple myeloma. For none of the neoplasms considered was there a significant inverse relationship with red meat intake. Thus, reducing red meat intake might lower the risk for several common neoplasms. Int. J. Cancer 86:425–428, 2000. © 2000 Wiley-Liss, Inc.