The rising trend of breast cancer both in developed and developing countries is a real threat challengingall efforts to screening, prevention and treatment aspects to reduce its impact. In spite of modern preventivestrategies, the upward trend of breast cancer has become a matter of great concern in both developed anddeveloping countries. Chittaranjan National Cancer Institute is a premier regional cancer institute in easternregion of India catering to a large number of cancer patients every year. A pilot case control study of fifty breastcancer patients and 100 matched controls was conducted during 2013 to evaluate the effects of habitual factorslike working in night shift, not having adequate sleep, and not sleeping in total darkness on breast cancer ofwomen. The study revealed that not sleeping in total darkness was associated with higher odds of outcome ofbreast cancer of women. This positive correlation can play a vital role in formulation of preventive strategiesthrough life style modification.