IntroductionOver recent decades, the burden of breast cancer has been increasing at an alarming rate in Asia. Prognostic research findings from Western countries may not readily be adapted to Asia, as the outcome of breast cancer depends on a multitude of factors ranging from genetic, clinical and histological predictors, to lifestyle and social predictors. The primary aim of this study is to determine the impact of lifestyle (eg, nutrition, physical activity), mental and sociocultural condition, on the overall survival and quality of life (QoL) among multiethnic Malaysian women following diagnosis of breast cancer. This study aims to advance the evidence on prognostic factors of breast cancer within the Asian setting. The findings may guide management of patients with breast cancer not only during active treatment but also during the survivorship period.MethodsThis hospital-based prospective cohort study will comprise patients with breast cancer (18 years and above), managed in the University Malaya Medical Centre (UMMC). We aim to recruit 1000 cancer survivors over a 6-year period. Data collection will occur at baseline (within 3 months of diagnosis), 6 months, and 1, 3 and 5 years following diagnosis. The primary outcomes are disease-free survival and overall survival, and secondary outcome is QoL. Factors measured are demographic and socioeconomic factors, lifestyle factors (eg, dietary intake, physical activity), anthropometry measurements (eg, height, weight, waist, hip circumference, body fat analysis), psychosocial aspects, and complementary and alternative medicine (CAM) usage.Ethics and disseminationThis protocol was approved by the UMMC Ethical Committee in January 2012. All participants are required to provide written informed consent. The findings from our cohort study will be disseminated via scientific publication as well as presentation to stakeholders including the patients, clinicians, the public and policymakers, via appropriate avenues.