title: Predictive and prognostic value of KRAS mutations in metastatic colorectal cancer patients treated with cetuximab: a meta-analysis of 22 studies.
abstract: The published data on the predictive and prognostic value of KRAS mutations in metastatic colorectal cancer (mCRC) treated with cetuximab seemed inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Systematic computerised searches of the PubMed, EMBase, BIOSIS, and SCOPUS were performed. A total of 22 studies were identified. Random-effects model or fix-effects model was used according to between-study heterogeneity. A total of 2188 mCRC patients were included in the final meta-analysis. The rate of KRAS mutations was 38% (829/2188). The overall response rate (ORR) of mutant KRAS patients was 14% (119/829), whereas the ORR of wild-type KRAS patients was 39% (529/1359). The overall pooled relative ratio (RR) for ORR was 0.24 (95% confidence intervals (CI): 0.16-0.38; P<0.01) when mutant KRAS patients were compared with wild-type KRAS patients. Median PFS was significantly shorter in mutant KRAS patients compared with that in wild-type KRAS patients (3.0 versus 5.8 months; HR=1.94; 95% CI: 1.62-2.33; P<0.01). Similarly, median OS was significantly shorter in mutant KRAS patients compared with that in wild-type KRAS patients (6.9 versus 13.5 months; HR=2.17; 95% CI: 1.72-2.74; P<0.01). The meta-analysis strongly suggests that KRAS mutations represent adverse predictive and prognostic biomarkers for tumour response and survival in mCRC patients treated with cetuximab. Patients with tumours that harbour mutant-type KRAS are more likely to have a worse response, PFS, and OS when treated with cetuximab.
authors.affiliation: Department of Medical Oncology, Cancer Hospital, Fudan University, Shanghai, China.
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Qiu
authors.forename: Chen
authors.initials: C
authors.lastname: Mao
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Zhu
authors.forename: Ru-Yan
authors.initials: RY
authors.lastname: Liao
authors.forename: Kai
authors.initials: K
authors.lastname: Xue
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000235:genetics*; D018572:Disease-Free Survival; D006801:Humans; D009154:Mutation / Q000235:genetics*; D009362:Neoplasm Metastasis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D017594:Publication Bias; D016896:Treatment Outcome; D018631:ras Proteins / Q000235:genetics*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D000068818:Cetuximab