The predictors of response to neoadjuvant chemotherapy in patients with locally advanced gastric cancer

BACKGROUND: Chemotherapy-sensitivity test is crucial to screen out patients who are insensitive to the treatment and to avoid unnecessary preoperative chemotherapy. OBJECTIVE: To investigate the predictors for the response to mFOLFOX7 neoadjuvant chemotherapy (NACT) in advanced gastric cancer. METHODS: The expression of C-met, EGFR, HER2, Ki-67, MMP7, P53 and TOPOII in tumor tissue from 53 locally advanced gastric cancer patients (AGC) was detected by immunohistochemistry. The relationship between tumor marker expression and the efficacy of NACT was determined by chi-square test and multivariate logistic regression analysis. The relationship between the combined expression of HER2 and P53 and the efficacy of NACT was further analyzed by chi-square test. RESULTS: The overall response rate was 52.8% (28/53). There were no significant differences of tumor markers' expression before and after chemotherapy (P > 0.05). The response rate in HER2-positive patients (83.33%) was significantly higher than that in HER2-negative patients (43.90%, P = 0.016), whereas the response rate in P53-positive patients (35.71%) was significantly lower than that in P53-negative patients (72.0%, P = 0.008). Moreover, the response rate was the highest in the patients who were positive for HER2 but negative for P53. CONCLUSION: HER2 and P53 were identified as independent predictors for the response to mFOLFOX7 NACT in AGC.