Associated risk factors in Breast cancer: A comparative Sri Lankan perspective

Abstract

Breast cancer (BC) is the commonest carcinoma among women in Sri Lanka. Various modifiable and non-modifiable risk factors are reported as causatives of BC, even though studies on the incidence and relevance of these risk factors to the Sri Lankan context are not comprehensively documented. Thus, objectives of the present study were to assess the odds related to the incidence of known and unknown risk factors in BC development in Sri Lanka. The risk factors including age at diagnosis of BC, age at menarche, age at menopause, parity, duration of breastfeeding, history of abortions, usage of hormonal contraceptives, smoking, involvement of exercises, frequency of consumption of selected foods etc. were collected from an interviewer-administered questionnaire from 355 participants (255 BC patients and 150 healthy women). Ethical approval for the study was obtained. The majority (63%) of the BC patients were postmenopausal and the commonest age group at diagnosis of the carcinoma was 51-60 years. A woman was observed to have 3.6 (Odds Ratio= 3.58, Confidence Interval 1.37-9.34) and 2.1 (Odds Ratio 2.13, Confidence Interval 1.0-4.95) times risk in developing BC when_having first-order relatives and second-order relatives with breast cancer respectively. A woman had three times the odds (Odds Ratio= 3.02, Confidence Interval 1.59-5.75) of developing BC with the use of hormonal contraceptives for more than two consecutive years and three times the risk of _having BC (Odds Ratio= 3.12, Confidence Interval 1.63-5.98) if she has had one or more spontaneous or induced abortions. Factors including consumption of selected food, use of bottled water and usage of microwave ovens with inappropriate containers (plastic containers) among BC patients were not significantly different compared to healthy. The risk factors including a woman in the age close to or soon after menopause, having a family history of BC, having used hormonal contraceptives and having experienced one or more abortions showed a higher risk compared to other factors studied.

KEYWORDS: Breast cancer, risk factors, family history, abortions, menopausal status