ABSTRACT
<p><b>OBJECTIVE</b>To detect RAS mutations in the circulating cell-free DNA (cfDNA) in the plasma and explore the their correlation with the clinicopathological features in patients with colorectal cancer.</p><p><b>METHODS</b>Real-time PCR was used to detect RAS mutations in plasma cfDNA and matched tumor tissue DNA samples from 71 colorectal cancer patients. The correlation of RAS mutations with the clinicopathological features of the patients were analyzed.</p><p><b>RESULTS</b>Of the 71 patients with colorectal cancer, 23 (32.39%) showed RAS mutations in the cfDNA and 36 (50.7%) showed RAS mutations in tumor tissue DNA, with a concordance rate of 76.06% in the results between the two samples (Kappa=0.523). RAS mutations in the cfDNA were not related to the patients' age (P=0.072), gender (P=0.320), tumor stage (IVa and IVb, P=0.450), primary tumor position (P=0.324), lung metastasis (P=0.237), CEA level (P=0.284) or CA199 level (P=0.427). The positivity rate of RAS mutations in plasma cfDNA was significantly higher in patients with liver metastasis than those without liver metastasis (P=0.045).</p><p><b>CONCLUSION</b>Plasma cfDNA can be a reliable source of diagnostic DNA to replace the tumor tissue DNA for diagnosis of RAS mutations. RAS mutations in plasma cfDNA occur more frequently in colorectal cancer patients with liver metastasis.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To compare the efficacy, time to disease progression (TTP), overall survival (OS) and toxicity of FOLFOX6 and TLF regimens for advanced gastric cancer.</p><p><b>METHODS</b>The clinical data of 81 chemotherapy-naive patients with advanced gastric cancer were analyzed. Of the 81 patients, 41 were treated with FOLFOX6 regimen and 40 with TLF regimen. The patients in FOLFOX6 group received intravenous infusion of L-OHP(100 mg/m2) at day 1, bolus injection of 5-FU (400 mg/m2) at day 1, and continuous intravenous infusion of 5-FU (1200 mg/m2/d) for 22 h at days 1-2, each treatment cycle lasting 14 days. The patients in TCF group received TAX (90 mg/m2) at day 1, bolus injection of 5-FU (400 mg/m2) at days 1-2, and continuous intravenous infusion of 5-FU (400 mg/m2/d) for 22 h at days 1-2, and each treatment cycle also lasted 14 days.</p><p><b>RESULTS</b>The objective response rates were 48.8% in FOLFOX6 group and 50.0% in TLF group (P=0.962). The median TTP in the two groups was 6.30 months and 6.50 months (P=0.958), with median survival time of 9.80 months and 10.70 months (P=0.578), respectively. The most frequent adverse events were nausea, vomiting and hematologic toxicities. The incidences of grade III-IV leucopenia and neutropenia were lower in FOLFOX6 group than in TLF group, but the difference was not statistically significant (12.2% vs 30.0%, P=0.112; 14.6% vs 32.5%, P=0.126). Three patients in FOLFOX6 group developed intestinal obstruction during the chemotherapy.</p><p><b>CONCLUSION</b>Both FOLFOX6 and TLF regimens are effective in treating advanced gastric cancer and the toxicities can be tolerated.</p>