Smokeless Tobacco Consumption and Breast Cancer in Women: Findings of a Case-Control Study

Background: Breast cancer is the most commonly occurring cancer in women and the second most common cancer overall. Among the various risk factors of breast cancer, smokeless tobacco is the neglected potential one. Hence the study was conducted to assess the association between smokeless tobacco consumption & breast cancer risk among the women. Objective: The objective of the study was to assess the association between smokeless tobacco consumption and breast cancer in women and to compare the pattern of smokeless tobacco consumption, relevant other factors of breast cancer and the socio-demographic characteristics between the cases and controls. Methods: This case control study was conducted in 302 women of two tertiary hospitals of Dhaka city from January to December’2020. The study enrolled 151 breast cancer patients as cases and another 151 non cancer age-matched women as controls. Convenient technique was used for data collection. A pre-tested semi-structured questionnaire and a checklist were used for face to face interview and to review the medical record respectively. The data were analyzed by SPSS software. Quality control checks of the data were done at all stages of the study. All ethical issues were maintained strictly and informed written consent was taken from each case and control. Results: The mean (±SD) age of cases and controls was 44.4(±10.56) &44.82(±10.2) years respectively (p=0.769). Maximum cases (90.1%) were married in comparison to controls (76.2%) and the association was significant (p=0.003). Majority of the cases (63.58%) had monthly income of 21000-50000tk compared to controls (51.66%) and this difference was significant (p=0.01).Among the cases, 36.4% were exposed to smokeless tobacco in comparison to 33.8% controls. Though this association was not significant (p=0.630) but maximum cases (70.9%) were found to be exposed for 16-30 years in comparison to controls (43.9%) and it was statistically significant (OR: 7.58, 95%CI: 0.865-66.404). Among the cases, who were exposed to zarda were 3.25 times more likely to have it >10 times in comparison to 2.6% controls (OR: 3.25, 95% CI: 1.05-9.99, p=0.040). Conclusion: Increased frequency and duration of smokeless tobacco intake is found significantly associated with breast cancer so specific preventive intervention is required for prevention of smokeless tobacco consumption among women to alleviate breast cancer. Bangladesh Medical Res Counc Bull 2023; 49(2): 83-90