KRAS and neoplasm: Two useful meta-analyses of these ten trials have been done, drawing attention to a lack of consistency in outcomes, especially among patients with KRAS wild-type tumours.16, 30 Unexplained antagonistic interactions with other cancer drugs have been proposed: combinations with bevacizumab, capecitabine, or oxaliplatin have produced poor results, whereas single-agent therapy or combinations with irinotecan or fluorouracil have had more success.