Genetic analysis of multiple primary cancers: A case report

Introduction. The occurrence of more than one primary cancer in the same patient is not very common. Multiple cancer prevalence is about 7.9% and the percentage is lower as the number of multiple primary cancers is higher. The incidence of four or more primary cancers in one patient is very rare and its prevalence is around 0.07%. Case Report. We report a rare case of a female with four histopathologically confirmed primary malignant neoplasms. The first tumor was endometrial carcinoma diagnosed at the age of 52. Three additional metachronous tumors were diagnosed as follows: left breast cancer, melanoma, and contralateral breast cancer. Extensive genetic testing was performed and 19 genes were sequenced using the next generation sequencing (BRCA1, BRCA2, ATM, BRIP1, CDH1, CHEK2, MSH2, MLH1, MSH6, PMS2, EPCAM, NBN, NF1, PALB2, PTEN, RAD51C, RAD51D, STK11 and TP53). Even with the existing indicators of genetic etiology, this case showed no pathogenic mutations in any of these genes. This indicates the existence of other underlying mechanisms such as hormonal factors, previous treatment of the primary and subsequent tumors, environmental factors, gene-gene and gene-environment interactions, as well as immunosuppression that could increase the risk for the second and subsequent malignancies. Conclusion. Detailed information on the biology of multiple primary tumors is important for both clinicians and cancer patients during medical management following primary treatment. In addition, genetic information is very important because it has future implications for both patients and their family members.