Significance of MDR-related proteins in the postoperative individualized chemotherapy of gastric cancer.

Abstract

Post-operative adjuvant chemotherapy was beneficial for some patients; however, it may increase the treatment burden and reduce the immunity of other patients. Screening appropriate patients based on molecular markers for individualized adjuvant chemotherapy was necessary. Between June 2002 and June 2004, 119 patients who underwent radical gastrectomy were retrospectively analyzed. Some patients had adjuvant chemotherapy based on platinum and 5-FU for four to six cycles. Topoisomerase II (ToPo II) negative, multidrug resistance protein (MRP) positive, and glutathione S-transferase π (GST-π) positive were regarded as three risk factors that may be associated with chemotherapy resistance and poor prognosis. Patients were divided into two groups: high-risk group (≥ 2 risk factors) and the low-risk group (<2 risk factors), and the tumor recurrence and patient survival time of the two groups were analyzed. The average recurrence time of the low-risk group was significantly longer than that of the high-risk group (21.29 ± 11.10 versus 15.16 ± 8.05 months, P < 0.01).The 3-year and 5-year survival rate of the high-risk group was 57.4% and 42.6%; however, it had no significant difference compared to 66.2% and 58.5% of the low-risk group (P > 0.05). In the high-risk group, the 3-year survival rate of patients with/without chemotherapy were 62.1% and 52.0%, 5-year survival rates were 44.8% and 40.0%, respectively, but the difference was not statistically significant (P > 0.05). In the low-risk group, the 3-year survival rate of patients with/without chemotherapy were 81.2% and 51.5%, and the 5-year survival rates were 71.9% and 45.5%, respectively, and the differences were statistically significant (P < 0.05). Multidrug resistance (MDR)-related proteins ToPo II, MRP, and GST-ð had great significance for the individualized post-operative chemotherapy and prognosis of gastric cancer.