Evaluation of BRCA2 in the genetic susceptibility of familial esophageal cancer

Abstract

Previous studies of esophageal squamous cell carcinoma (ESCC) have shown a high frequency of allelic loss on chromosome 13q, infrequent somatic mutations in BRCA2, and a suggested association between a positive family history (FH+) of upper gastrointestinal cancer and germline BRCA2 mutations. In all, 70 ESCC patients (44 FH+ and 26 FH-) were examined by direct full sequencing of germline DNA for BRCA2 mutations. In addition, 28 family members of three of these patients and 232 unrelated healthy blood bank donor controls were examined for the mutations identified in the 70 ESCC patients. Five BRCA2 germline mutations, including three not previously reported (N1600del, A2054P, and V2109I), were identified in six of 44 FH+ patients, but none of 26 FH- patients (14 vs 0%, P=0.078), consistent with our previous findings (3/34 or 9% FH+ vs 0/22 or 0% FH-, P=0.27). The cumulative frequency of BRCA2 germline mutations in ESCC patients in this and our previous study combined is 12%, with all mutations found in FH+ as opposed to FH- cases (9/78 or 12% FH+ vs 0/48 or 0% FH-, P=0.013). We conclude that germline mutations in BRCA2 in ESCC patients from this high-risk area of China are more frequent in FH+ than FH- cases, suggesting that BRCA2 may play a role in genetic susceptibility to familial ESCC.