Analysis of polymorphisms in genes associated with the FA/BRCA pathway in three patients with multiple primary malignant neoplasms

Cases of more than three primary cancers are very rare. This study analyzed the genetic susceptibility of gene polymorphisms in three patients with multiple primary malignant neoplasms and examined the possible pathogenesis. The clinical data and whole genome sequence of three patients (1 with 5 primary cancers, 1 with 4 primary cancers, and 1 with 3 primary cancers) were aligned with a series of databases. We found the three patients contained a total of seven types of malignant tumours (endometrial cancer, ovarian cancer, breast cancer, colon cancer, ureter cancer, bladder cancer and kidney cancer). It was found that the varied genes in Patient 1 (5 primary cancers) were BRIP1, FANCG, NBN, AXIN2, SRD5A2, and CEBPA. Patient 2 (4 primary cancers) had variations in the following genes: BMPR1A, FANCD2, MLH3, BRCA2, and FANCM. Patient 3 (3 primary cancers) had variations in the following genes: MEN1, ATM, MSH3, BRCA1, FANCL, CEBPA, and FANCA. String software was used to analyze the KEGG pathway of the variations in these three samples, which revealed that the genes are involved in the Fanconi anaemia pathway. Defects in DNA damage repair may be one of the causes of multiple primary cancers.