Abstract:

Objective To detect the status of PIK3CA in triple-negative breast cancer （TNBC）， and to analyze the relationships between PIK3CA mutation and clinical features and its impact on prognosis. Methods From January 1， 2016 to December 31， 2018， 50 patients with primary TNBC admitted to Xinxiang Central Hospital of Henan Province were collected. The PIK3CA mutation status was detected， and the relationships between PIK3CA mutation and clinical characteristics of patients with TNBC and its impact on prognosis were analyzed. Results PIK3CA gene mutation was detected in 9 of 50 TNBC patients， with a mutation frequency of 18.0%. H1047R mutation was found in 4 cases， E545K mutation in 3 cases and E542K mutation in 2 cases. PIK3CA gene mutation was not associated with age （χ²=3.55， P=0.060）， tumor location （χ²=1.01， P=0.315）， tumor size （χ²<0.01， P>0.999）， lymph node status （χ²=0.76， P=0.385）， clinical stage （χ²=0.65， P=0.420）， Ki-67 value （χ²<0.01， P>0.999）， P53 status （χ²=0.02， P=0.894） and human epidermal growth factor receptor-2 （HER-2） status （χ²=1.65， P=0.200）. Prognostic analysis showed that 3-year disease-free survival rates of wild-type PIK3CA patients was significantly higher than that of mutant PIK3CA patients （80.5% vs. 11.1%， χ²=28.23， P<0.001）. Conclusion The frequency of PIK3CA gene mutation is higher in TNBC patients. There is no correlation between PIK3CA mutation and clinicopathologic features in TNBC patients. PIK3CA gene mutation may be significantly associated with poor prognosis of TNBC patients.

Key words: Triple negative breast cancer, PIK3CA gene mutation, Prognosis