Prevalence and characterization of ATM germline mutations in Chinese BRCA1/2-negative breast cancer patients.

PURPOSE: The ataxia telangiectasia-mutated (ATM) gene is a moderate susceptibility gene for breast cancer. However, little is known about the breast cancer phenotypes associated with ATM mutation. We therefore investigated the spectrum and clinical characteristics of ATM germline mutations in Chinese breast cancer patients.

METHODS

A multi-gene panel was performed to screen for ATM germline mutations in 7657 BRCA1/2-negative breast cancer patients. All deleterious mutations were validated by independent polymerase chain reaction (PCR)-Sanger sequencing.

RESULTS

A total of 31 pathogenic mutations in the ATM gene across 30 carriers were identified, and the ATM mutation rate was 0.4% (30/7,657) in this cohort. The majority of the mutations (90.3%, 28/31) were nonsense or frameshift mutations. Of the total ATM mutations, 61.3% (19/31) were novel mutations and 13 recurrent mutations were found. ATM mutations carriers were significantly more likely to have a family history of breast and/or ovarian cancer (26.7% in carriers vs. 8.6% in non-carriers, p < 0.001), as well as a family history of any cancer (60.0% in carriers vs. 31.5% in non-carriers, p = 0.001). In addition, ATM mutations carriers were significantly more likely to have oestrogen receptor (ER)-positive (p = 0.011), progesterone receptor (PR)-positive (p = 0.040), and lymph node-positive breast cancer (p = 0.034).

CONCLUSIONS

The prevalence of the ATM mutation is approximately 0.4% in Chinese BRCA1/2-negative breast cancer. ATM mutation carriers are significantly more likely to have a family history of cancer and to develop ER- and/or PR-positive breast cancer or lymph node-positive breast cancer.