Cetuximab led to a significant increase in RR and OS in patients with KRAS/BRAF wild-type rectal cancer, but the primary end point of improved CR was not met.

In this updated analysis of the EXPERT-C trial we show that, in magnetic resonance imaging-defined, high-risk, locally advanced rectal cancer, adding cetuximab to a treatment strategy with neoadjuvant CAPOX followed by chemoradiotherapy, surgery, and adjuvant CAPOX is not associated with a statistically significant improvement in progression-free survival (PFS) and overall survival (OS) in both KRAS/BRAF wild-type and unselected patients. In a retrospective biomarker analysis, TP53 was not prognostic but emerged as an independent predictive biomarker for cetuximab benefit. After a median follow-up of 65.0 months, TP53 wild-type patients (n = 69) who received cetuximab had a statistically significant better PFS (89.3% vs 65.0% at 5 years; hazard ratio [HR] = 0.23; 95% confidence interval [CI] = 0.07 to 0.78; two-sided P = .02 by Cox regression) and OS (92.7% vs 67.5% at 5 years; HR = 0.16; 95% CI = 0.04 to 0.70; two-sided P = .02 by Cox regression) than TP53 wild-type patients who were treated in the control arm. An interaction between TP53 status and cetuximab effect was found (P < .05) and remained statistically significant after adjusting for statistically significant prognostic factors and KRAS.

Background:Bevacizumab is commonly used in combination with chemotherapy in the treatment of metastatic colorectal cancer, but to date, despite extensive research, no predictive or prognostic biomarkers for bevacizumab have been identified. The development of bevacizumab-induced arterial hypertension has recently been suggested as a potential predictive biomarker.Methods:Blood pressure was recorded during the BOXER study, a phase II study of capecitabine, oxaliplatin (CAPOX) plus bevacizumab as peri-operative treatment in 45 patients with poor-risk colorectal liver-only metastases unsuitable for upfront resection. In this analysis, the development of bevacizumab-induced hypertension was correlated with clinical outcomes.Results:Fifteen percent of patients developed ⩾grade 1 hypertension while receiving neoadjuvant chemotherapy, and 4% developed grade 3 hypertension. There was no correlation between the development of hypertension and radiological response rate (P=0.642), progression-free survival (P=0.644) or overall survival (P=0.480) in those who developed hypertension compared with those who did not.Conclusion:Bevacizumab-induced hypertension did not predict radiological response or survival in our study. The results highlight a number of important issues regarding the use of hypertension as a biomarker.