Abstract

Introduction: Breast cancer is one of the most important problems in general health of women in the world. Advances in the treatment have led to longevity of patients, resulting in the risk of other diseases, including second cancers. The aim of this study was to determine the types and risks of second primary cancers after breast cancer. Methods: A protocol was developed and a sensitive search in databases including PubMed, PubMed central, and Google scholar and also in the list of referenced articles was conducted without time limitation. All letters, comments, editorial studies and studies about breast cancer metastases and inhumane studies were excluded. The quality of papers was verified with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results: 15 papers were selected and reviewed, including colorectal, bone marrow malignancies, esophageal cancer, soft tissue sarcoma, lung cancer, thyroid malignancies and ovarian cancer as second cancers in breast cancer patient. These articles declared their review and findings regarding these cancers as second cancer after breast cancer. All of these second cancers were associated with chemotherapy and/or auxiliary radiotherapy, especially intensive doses of radiation. Conclusion: The studies have been shown the treatment approach of BC may be the main cause of second cancer development after BC which consisted of bone marrow neoplasm, sarcoma, thyroid, esophageal, lung and uterine cancer. Intensive radiotherapy and chemotherapy had the potential risk of second cancer development, as well as they had syngism effect with each other.