Role of reproductive factors in breast cancer in a low-risk area: a case–control study

Abstract

S_ary A case-control study of 689 breast cancer patients seen at Tata Memorial Hospital during the period 1980-84 was carried out. During the same period 711 females who attended the hospital without a history of benign breast lesions or gynaecological complaints were selected as controls. Patients were interviewed by trained investigators to collect data on reproductive factors, menstrual history, tobacco smoking and chewing habit, dietary practices (vegetarian and non-vegetarian diet) and alcohol consumption. Cases and controls were stratified into four age groups (<35 years, [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] (Bombay, Maharashtra, others). Odds ratios were calculated by univariate methods as well as by stratified analysis. The Mantel and Haenzel (1959) summary chi-squared test was used for testing statistical significance and a test-based estimation procedure was used for calculation of confidence intervals for odds ratios (Kleinbaum et al., 1982). ResultsGeneral features of breast cancer cases and controls are shown in Table I. The average age of cancer patients was 46.2 years, whereas it was 42.8 years for controls. The religious distribution between cases and controls did not differ and hence is not adjusted for in the analysis. Reproductive factors in cases and controls are presented in Table II. Factors such as age at menarche, age at marriage, age at first pregnancy and number of pregnancies appeared to be similar between the cancer cases and controls.The relative risks (RRs) for factors studied are presented in Table III. Cases and controls were stratified by four age groups and three places of residence. In our study, unmarried women had a 2.3 times higher risk of developing breast cancer than married women. The nulliparous women had 2.2 times the risk of parous women (P<0.OO1). Breast feeding,

Lifelong vegetarianism and risk of breast cancer: A population‐based case‐control study among South Asian migrant women living in England

“…This finding is consistent with results from a hospital-based case-control study carried out in Bombay (India). 25 It is also consistent with findings from large follow-up studies of Western vegetarians and religious groups who tend to abstain from meat. 26 -30 In these studies, however, most subjects cease meat consumption in adult life and therefore it was not possible to exclude the possibility that meat intake might play a role in the causation of breast cancer if pre-adult life is a more critical period.…”

A Multicenter Matched Case Control Study of Breast Cancer Risk Factors among Women in Karachi, Pakistan

“…In similar studies, the risk of BC was higher for unmarried women compared with married women (Gajalakshmi and Shanta, 1991;Rao et al, 1994;Pakseresht et al, 2009). Being single in Pakistani society is :http://dx.doi.org/10.7314/APJCP.2013.14.1.183 A Multicenter Matched Case Control Study of Breast Cancer Risk Factors among Women in Karachi, Pakistan reported to be psychosocially stressful.…”

Cancer patterns in eastern India: The first report of the Kolkata cancer registry

“…Case-control studies in Mumbai and Chennai have identified the usual risk factors of nulliparity, early menarche, late age at marriage and late age at first pregnancy as important risk factors. 29,30 Incidence is much higher in urban than in rural women. 6 -8,10,23 This urban/rural difference could be due to differences in lifestyle factors.…”