Cancer science
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Multicenter Study
Prognostic and predictive value of extended RAS mutation and mismatch repair status in stage III colorectal cancer.
The prognostic and predictive value of KRAS gene mutations in stage III colorectal cancer is controversial because many recent clinical trials have not involved a surgery-alone arm. Additionally, data on the significance of extended RAS (KRAS/NRAS) mutations in stage III cancer are not available. Hence, we undertook a combined analysis of two phase III randomized trials, in which the usefulness of adjuvant chemotherapy with tegafur-uracil (UFT) was evaluated, as compared with surgery alone. ⋯ The MMR status was neither prognostic nor predictive for adjuvant chemotherapy. An interaction analysis showed that there was better RFS among patients treated with UFT with RAS mutations, but not for those without RAS mutations. Extended RAS (KRAS/NRAS) mutations are proposed as predictive indicators with respect to the efficacy of adjuvant UFT chemotherapy in patients with resected stage III colorectal cancer.