Pedigree analysis exploring the inconsistency between diverse phenotypes and testing criteria for germline TP53 mutations in Chinese women with breast cancer

In the present study, we addressed the inconsistency between the testing criteria and diverse phenotypes for germline TP53 mutation in patients with breast cancer in the Chinese population.

We proposed a new added item (synchronous or metachronous bilateral breast cancer) as one of the testing criteria (aimed at high-penetrance breast cancer susceptibility genes) and applied it for determining TP53 germline mutation status in 420 female patients with breast cancer using multigene panel-based next-generation sequencing, Sanger sequencing, and mass spectrometry.

We found that 1.4% of patients carried a pathogenic or likely pathogenic germline TP53 mutation. Compared with BRCA mutation carriers (8.0%) and non-carriers (7.1%), TP53 mutation carriers (33.3%) developed breast cancer earlier. The majority of TP53 mutation carriers (66.7%) developed breast cancer after age 30 and had bilateral breast cancer (33.3%). Pedigree investigation of four TP53 carriers and a patient with a TP53 variant of unknown significance revealed that neither of their parents harbored the same mutations as the probands, indicating that the mutations might occur de novo.

Our study revealed distinguishing features of TP53 carriers among Chinese women with breast cancer, which is inconsistent with the currently used testing criteria; therefore, the newly proposed testing criteria may be more appropriate.