BACKGROUND: In the setting of metastatic colorectal cancer (CRC), anti-EGFR antibodies are not currently recommended for individuals with KRAS mutant tumours. This is based on subgroup analyses of individual clinical trials rather than a formal synthesis of evidence for KRAS status as a predictive biomarker, while newer trials report no benefit for anti-EGFR antibodies irrespective of KRAS status. This study systematically reviewed the evidence for KRAS mutation status as a treatment effect modifier of response to anti-EGFR antibodies and the influence of partner chemotherapy. METHODS: Medline (1966-2010), EMBASE and American and European oncology meeting abstracts were searched for randomised controlled trials reporting the influence of KRAS status on effectiveness of anti-EGFR antibodies in metastatic CRC. The treatment efficacy was summarised by KRAS status using hazard ratios (HR) for progression-free survival (PFS) and risk differences (RD) for objective response. For each study, a measure of effect modification was calculated, and aggregated using random effects meta-analysis to assess the interaction between KRAS and treatment effect. FINDINGS: Eleven studies (8924 patients) were selected from 198 reports. Two studies assessed anti-EGFR antibodies as monotherapy and nine their use with chemotherapy. KRAS status was reported in 7555 cases. In subgroup analysis, the progression HR for KRAS wild patients assigned to anti-EGFR antibodies was 0.80 (4436 patients 95%CI: 0.64, 0.99) and for mutant cases 1.11 (3119 patients, 95%CI: 0.97, 1.27). A significant treatment effect interaction between KRAS status and addition of anti-EGFR antibodies to standard treatment was found for PFS (ratio of HRs 0.71, 95%CI: 0.57, 0.90 p=0.005) and response rate difference (difference in RDs 15%, 95%CI: 8, 22%, p<0.001). There was no evidence that the extent of effect modification differed between chemotherapeutic partners for both PFS (p=0.3) and response rate (p=0.6). INTERPRETATION: KRAS mutation status is a treatment effect modifier for anti-EGFR antibodies in metastatic CRC. Further evidence is needed to determine whether this is true for all chemotherapy partners and all clinical circumstances.
BACKGROUND: In the setting of metastatic colorectal cancer (CRC), anti-EGFR antibodies are not currently recommended for individuals with KRAS mutant tumours. This is based on subgroup analyses of individual clinical trials rather than a formal synthesis of evidence for KRAS status as a predictive biomarker, while newer trials report no benefit for anti-EGFR antibodies irrespective of KRAS status. This study systematically reviewed the evidence for KRAS mutation status as a treatment effect modifier of response to anti-EGFR antibodies and the influence of partner chemotherapy. METHODS: Medline (1966-2010), EMBASE and American and European oncology meeting abstracts were searched for randomised controlled trials reporting the influence of KRAS status on effectiveness of anti-EGFR antibodies in metastatic CRC. The treatment efficacy was summarised by KRAS status using hazard ratios (HR) for progression-free survival (PFS) and risk differences (RD) for objective response. For each study, a measure of effect modification was calculated, and aggregated using random effects meta-analysis to assess the interaction between KRAS and treatment effect. FINDINGS: Eleven studies (8924 patients) were selected from 198 reports. Two studies assessed anti-EGFR antibodies as monotherapy and nine their use with chemotherapy. KRAS status was reported in 7555 cases. In subgroup analysis, the progression HR for KRAS wild patients assigned to anti-EGFR antibodies was 0.80 (4436 patients 95%CI: 0.64, 0.99) and for mutant cases 1.11 (3119 patients, 95%CI: 0.97, 1.27). A significant treatment effect interaction between KRAS status and addition of anti-EGFR antibodies to standard treatment was found for PFS (ratio of HRs 0.71, 95%CI: 0.57, 0.90 p=0.005) and response rate difference (difference in RDs 15%, 95%CI: 8, 22%, p<0.001). There was no evidence that the extent of effect modification differed between chemotherapeutic partners for both PFS (p=0.3) and response rate (p=0.6). INTERPRETATION:KRAS mutation status is a treatment effect modifier for anti-EGFR antibodies in metastatic CRC. Further evidence is needed to determine whether this is true for all chemotherapy partners and all clinical circumstances.
Authors: Antonia R Sepulveda; Stanley R Hamilton; Carmen J Allegra; Wayne Grody; Allison M Cushman-Vokoun; William K Funkhouser; Scott E Kopetz; Christopher Lieu; Noralane M Lindor; Bruce D Minsky; Federico A Monzon; Daniel J Sargent; Veena M Singh; Joseph Willis; Jennifer Clark; Carol Colasacco; R Bryan Rumble; Robyn Temple-Smolkin; Christina B Ventura; Jan A Nowak Journal: J Mol Diagn Date: 2017-02-06 Impact factor: 5.568
Authors: Linda M Pak; Nancy E Kemeny; Marinela Capanu; Joanne F Chou; Taryn Boucher; Andrea Cercek; Vinod P Balachandran; T Peter Kingham; Peter J Allen; Ronald P DeMatteo; William R Jarnagin; Michael I D'Angelica Journal: J Surg Oncol Date: 2017-11-22 Impact factor: 3.454
Authors: Antonia R Sepulveda; Stanley R Hamilton; Carmen J Allegra; Wayne Grody; Allison M Cushman-Vokoun; William K Funkhouser; Scott E Kopetz; Christopher Lieu; Noralane M Lindor; Bruce D Minsky; Federico A Monzon; Daniel J Sargent; Veena M Singh; Joseph Willis; Jennifer Clark; Carol Colasacco; R Bryan Rumble; Robyn Temple-Smolkin; Christina B Ventura; Jan A Nowak Journal: Am J Clin Pathol Date: 2017-02-03 Impact factor: 2.493
Authors: Ana M Aparicio; Li Shen; Elsa Li Ning Tapia; Jing-Fang Lu; Hsiang-Chun Chen; Jiexin Zhang; Guanglin Wu; Xuemei Wang; Patricia Troncoso; Paul Corn; Timothy C Thompson; Bradley Broom; Keith Baggerly; Sankar N Maity; Christopher J Logothetis Journal: Clin Cancer Res Date: 2015-11-06 Impact factor: 12.531