[BRCA1/2 gene mutation and clinicopathologic features of triple negative breast cancer].

OBJECTIVE

To investigate the incidence of BRCA1/2 gene mutation among triple negative breast cancer (TNBC) patients.

METHODS

Polymerase chain reaction and DNA sequencing were used to detect mutations of BRCA1 (exons 2, 11 and 20) and BRCA2 (exon 11) genes using paraffin-embedded tissue samples of 33 TNBC patients (21 Uyghur patients and 12 Han patients ) in Xinjiang Uygur Autonomous Region.

RESULTS

Among 33 cases of TNBC, 5 cases (5/33, 15.2%) were found to have BRCA1 gene mutation. The exon 11 of BRCA1 gene mutation proportion was seen in 4/5 and exon 20 of BRCA1 gene mutation proportion was seen in 1/5. No germline mutation was found in exon 2 of BRCA1 gene and exon 11 of BRCA2 gene. The onset age of patients with BRCA1 mutations were younger than 50 years. Four BRCA1 mutation patients were premenopausal. The proportions of BRCA1 gene mutation of Uygur TNBC patients and Han TNBC patients were 2/12 and 3/21, respectively, without significant difference (P=0.854). BRCA mutations were mainly found in stageⅠtoⅡ (4/5) and only 1 case (1/5) was found with stage Ⅲ disease. No significant difference was found in fertility status, menstrual status and age at menarche between mutated and non-mutated patients (P>0.05) .

CONCLUSIONS

Germline mutation of BRCA1 may be more often associated with TNBC than BRCA2 for its higher mutation rate. Compared with non-mutated TNBC cases, several clinicopathologic features could be identified among mutated cases.