Subanalysis of CALGB/SWOG 80405 by Surgical Intervention

Conference Correspondent - ESMO 2014 - Gastrointestinal and Head & Neck Cancer

The phase 3 CALGB/SWOG 80405 clinical trial analyzed the clinical benefit of the addition of cetuximab or bevacizumab to first-line chemotherapy with FOLFOX or FOLFIRI in KRAS wild-type (codons 12 and 13) in 1137 patients with metastatic colorectal cancer. In the current subset analysis, the characteristics and the long-term outcomes of patients enrolled in the CALGB/SWOG 80405 trial who subsequently underwent surgery after first-line chemotherapy plus cetuximab or bevacizumab was determined (Venook A, et al. CALGB/SWOG 80405. ESMO 2014: Abstract LBA10).

The results of the analysis showed that 180 (16%) patients received surgery at some point after chemotherapy. The median age of this subgroup was 55 years, and the majority (58%) of patients had received cetuximab added to the FOLFOX regimen (80%). Of the 180 patients, 132 were determined to have no evidence of disease (NED) immediately after surgery. The median overall survival (OS) from randomization was 64.7 months (95% confidence interval [CI], 59.8-78.9). There was no significant difference in OS based on the regimen of first-line chemotherapy plus cetuximab or bevacizumab that they received (64.1 vs 67.4 months; hazard ratio, 1.2; P = .56). The overall response rate in the 111 evaluable resected patients with NED was 78%. The disease-free survival from surgical resection among patients with NED was 15.9 months (95% CI, 10.4-21.2); the time from randomization to postsurgical recurrence was 25.7 months (95% CI, 20.5-33.5).

The findings of this subgroup analysis showed that approximately 10% of patients enrolled in the CALGB/SWOG 80405 trial reached NED after first-line chemotherapy plus bevacizumab or cetuximab followed by surgery, and survived for more than 5 years. Based on this preliminary analysis, patients receiving cetuximab-containing regimens are more likely to reach NED than patients receiving bevacizumab-containing regimens.