Value of mismatch repair, @entity984 , and XXXX mutations in predicting recurrence and benefits from chemotherapy in @entity14 .

@entity1 @entity4181 @entity137 @entity984 @entity5 @entity14 @entity817 @entity1487
PURPOSE: It is uncertain whether modest benefits from adjuvant chemotherapy in @entity14 justify the @entity137 , cost, and inconvenience. We investigated the usefulness of defective mismatch repair (dMMR), @entity817 , and @entity984 mutations in predicting @entity5 recurrence and sensitivity to chemotherapy. @entity1 AND METHODS: Immunohistochemistry for dMMR and pyrosequencing for @entity984 / @entity817 were performed for 1,913 @entity1 randomly assigned between @entity1487 and @entity4181 chemotherapy and no chemotherapy in the Quick and Simple and Reliable (QUASAR) trial. RESULTS: Twenty-six percent of 695 right-sided colon, 3% of 685 left-sided colon, and 1% of 407 @entity5 were dMMR. Similarly, 17% of right colon, 2% of left colon, and 2% of @entity5 were @entity817 mutant. @entity984 mutant @entity5 were more evenly distributed: 40% right colon, 28% left colon, and 36% @entity5 . Recurrence rate for dMMR @entity5 was half that for MMR-proficient @entity5 (11% [25 of 218] v 26% [438 of 1,695] recurred; risk ratio [RR], 0.53; 95% CI, 0.40 to 0.70; P < .001). Risk of recurrence was also significantly higher for @entity984 mutant than @entity984 wild-type @entity5 (28% [150 of 542] v 21% [219 of 1,041]; RR, 1.40; 95% CI, 1.12 to 1.74; P = .002) but did not differ significantly between @entity817 mutant and wild-type @entity5 (P = .36). No marker predicted benefit from chemotherapy with efficacy not differing significantly by MMR, @entity984 , or @entity817 status. The prognostic value of MMR and @entity984 was similar in the presence and absence of chemotherapy. CONCLUSION: MMR assays identify @entity1 with a low risk of recurrence. @entity984 mutational analysis provides useful additional risk stratification to guide use of chemotherapy.
