Approaches and genetic determinants in predicting response to neoadjuvant chemotherapy in locally advanced gastric cancer
The combination of docetaxel, cisplatin, and S-1 (DCS) chemotherapy is expected to be a promising regimen for advanced gastric cancer. This study was performed to evaluate the efficacy and safety of neoadjuvant DCS chemotherapy for locally advanced resectable gastric cancer. Patients with locally advanced gastric cancer received 2 courses of preoperative chemotherapy with S-1 (40 mg/m2 b.i.d.) on days 1–14 and docetaxel (60 mg/m2) plus cisplatin (60 mg/m2) on day 8 every 3 weeks, followed by standard curative surgery within 4–8 weeks. The primary endpoint was R0 resectability. Expression of damage DNA binding protein complex subunit 2 (DDB2)/excision repair cross-complementing 1 (ERCC1) in the pretreated tumor tissues was examined by immunohistochemistry. A total of 43 patients received neoadjuvant chemotherapy. The response rate was 74.4 %, and disease control ratio was 100 %. Grade 4 neutropenia developed in 53.5 % of patients and febrile neutropenia in 16.3 %. Non-hematological grade 3/4 adverse events were anorexia (23.3 %), nausea (14.0 %), and diarrhea (23.3 %), but these were generally transient and manageable. The proportion of R0 resections in the 43 eligible patients was 90.7 %, and a pathological response was found in 65.9 % of patients. There were no treatment-related deaths and no major surgical complications. The accuracy of the combination of DDB2 and ERCC1 expression for predicting chemoresistance was 82.5 %. Preoperative treatment with DCS combination for locally advanced gastric cancer demonstrated a sufficient R0 resection rate and a good pathological response with manageable toxicities. The DDB2/ERCC1-high phenotype, as determined by immunohistochemistry, may be useful predictor of resistance to DCS chemotherapy.