[Clinical significance of expression of PI3Kp110α in breast cancer].

Objective: To study the clinical significance of PI3Kp110α expression in breast cancer. Methods: The expressions of PI3Kp110α, HER2, PTEN, p-Akt and Ki-67 in invasive ductal carcinoma (IDC), adjacent ductal carcinoma in situ (DCIS) and normal breast tissue were detected by immunohistochemistry in 102 cases of breast cancer. The expression of PI3Kp110α in IDC was compared with those in DCIS and normal breast tissues. Correlations between expression of PI3Kp110α and expression of HER2, PTEN, p-Akt and Ki-67 index in IDC were analyzed. Correlation between expression of PI3Kp110α and stage of IDC was studied as well. Results: In the normal breast tissues, there were 97 cases (95.1%) with low level and 5 cases (4.9%) with high level expression of PI3Kp110α. In the DCIS tissues, there were 67 cases (65.7%) with low level and 35 cases (34.3%) with high level expression of PI3Kp110α. In the IDC tissues, there were 14 cases (13.7%) with low level and 88 cases (86.3%) with high level expression of PI3Kp110α. The difference between expression of PI3Kp110α in normal breast tissue, DCIS and IDC was significant (P<0.001). In the IDC tissues, expression of PI3Kp110α was negatively correlated with expression of HER2 (rs=-0.213, P=0.032) and PTEN (rs=-0.197, P=0.047), while was not significantly correlated with expression of p-Akt (P=0.119) and Ki-67 index (P=0.636). In contrast, expressions of HER-2 and p-Akt were positively correlated with Ki-67 index (P=0.001, P=0.035), while expression of HER2 was not correlated with p-Akt (P=0.177). Expression of PI3Kp110α was negatively correlated with T stage and TNM stage (P=0.003, P=0.016), while not correlated with N stage and M stage(both P>0.05). Expression of HER-2 was positively correlated with T stage (P=0.037), while not correlated with N stage, M stage and TNM stage (P>0.05 for all). Neither Ki-67 index nor expression of PTEN and p-Akt (P=0.194) were correlated with T stage, N stage, M stage and TNM stage. Conclusions: Expression of PI3Kp110α plays an important role in oncogenesis and development of breast cancer. Based on the fact that expression of PI3Kp110α is negatively correlated with expression of HER2 and PTEN and with T stage and TNM stage, we may conclude that increased expression of PI3Kp110α is another independent pathway in breast cancer development, and breast cancer patients with high expression of PI3Kp110α may have a better prognosis.