A prospective, multicenter, cohort study to evaluate the long-term quality of life and psychological factors among patients with breast cancer, 5-year follow-up: a study protocol

Abstract Background: Breast cancer is the most commonly occurring cancer among women worldwide. Quality of life and psychological status of patients with breast cancer could be affected after diagnosis, especially during treatment. The main objective of this study is investigation of long-term influence of breast cancer on quality of life’s dimensions and mental health status. Methods: This is a multicenter, ongoing longitudinal prospective cohort study which administered in national institute for medical research development in May 2018 in Iran. 1250 patients with breast cancer who were completed their treatments, will be recruited from 5 referral medical centers located in Tehran, to be followed for 5 years. Questionnaires for evaluating the primary and secondary outcomes will be complete by trained investigators during face-to-face interviews with each participant in three phases: immediately after treatment, 1 year and 5 years later. Data will be collected on socio-demographic, quality of life, body image, hope, psychological problems such as anxiety, depression and mood, also sexual function and physical activity. Data will be analyzed in each phase and at the end of the project by SPSS version 22. Discussion: It is the first nationwide, prospective, cohort study with large sample size, long-term follow-up and broad research aims which will evaluate quality of life-related factors in Iranian breast cancer population to justify the existing gap in literature. Trial registration number: National Institute for Medical Research Development (NIMAD) (IR.NIMAD.REC.1397.322) July 1th, 2018.