Mutation of k-ras mutation and evaluation of anti-EGFR monoclonal antibody combined with chemotherapy in Chinese colorectal cancer patients / 肿瘤研究与临床

ABSTRACT

Objective To observe the k-ras mutation rate of colorectal cancer in China, and assess the effect and toxicity in advanced colorectal cancer (CRC) patients (pts) receiving chemotherapy combined with monoclonal antibody against Epidermal Growth Factor Receptor (EGFR). Methods The k-ras mutation of 139 samples collected from our hospital were tested by pyrophosphoric acid sequencing. Twenty-three advanced colorectal cancer patients were treated with chemotherapy combined with anti-EGFR monoclonal antibody, including 3 initial treated and 20 retreated. In the total 23 patients, 18 were treated with cetuximab and chemotherapy, and S were treated with nimotuzumab and chemotherapy. Cetuximab was taken with 400 mg/m2 first time, and then 250 mg/m2 every week. Nimotuzumab was taken with 400 mg first time, and then 200 mg every week. Eight patients of the total 23 received anti-EGFR monoclonal antibody combined with irinotecan, 12 with FOLFIRI, 3 with FOLFOX4. Results k-ras mutation type (mt) was detected in 39.6 % (55/139) of pts, k-ras wild type (wt) was 60.4 % (94/139). In 22 effect evaluable patients, 5 received PR and 9 SD, and RR and DCR were 22.7 % and 63.6 %, respectively. TTP was 124 days. Thirteen of the 22 patients tested k-ras mutation, of the 11 k-ras mt pts, 4 received PR, 4 SD and 3 PD. Two patients of k-ras mt received PD after 2 cycles treatment. Acneform eruptions were observed in 15 patients of 18 pts who received cetuximab and paronychia in 3 pts. Eruption or paronychia was not observed in all patients who received nimotuzumab. Grade 3 hypersensitivity were occured in 2 patients with cetuximab, and one of them alternated nimotuzumab in next cycle didn't get hypersensitivity any more. Conclusion The mutation rate of k-ras in Chinese colorectal cancer patients was similar with westerners. The effect of cetuximab combined with chemotherapy on advanced colorectal cancer was reliable. Nimotuzumab combined with chemotherapy worth to be studied further because of the promising effect and mild toxicity.