Objectives: 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.
Materials and methods: 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.
Results: 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).
Conclusions: 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.