ASCO 2014 Report: In metastatic colorectal cancer treatment, overall survival is similar for continuous delivery and intermittent delivery

by Bruce Sylvester – Intermittent strategies for delivering systemic treatment in metastatic colorectal cancer show no clinically significant superiority in overall survival rates when compared to continuous delivery, whether or not maintenance therapy is included.   Notably, quality-of-life is similar or better with use of an intermittent strategy.

The findings appeared in a poster presentation at ASCO 2014

As background, the authors noted that, “There is varied impact on efficacy demonstrated in individual RCTs [randomized clinical trials] of CS [continous] vs IS [intermittent] strategies of delivering systemic Tx [treatment] for mCRC [metastatic colorectal cancer].”

Trials comparing continuous versus delivery were identified by a systematic search and review. The investigators identified trials that were clinically homogeneous, and they pooled the data for analysis.

They extracted overall survival hazard ratios from the most recently reported trial results. They applied a random effects model for all pooling.

They found 11 trials that were eligible for the meta-analysis (n= 4,809).

For 8 trials with available overall survival hazard ratio, systemic treatment received after induction was 0 for 5 trials (n=3,036), fluoropyrimidine  for 1 trial (n=620), and biologic therapy for 2 trials (n=852).

The investigators reported no statistically significant advantage in overall survival for either intermittent vs. continuous treatment.

One sensitivity analysis of the 3 trials (CAIRO3, OPTIMOX2, COIN, n=2,389) with combination systemic treatment induction and no maintenance systemic treatment until disease progression showed a statistically, but non-clinically significant benefit in overall survival for continuous treatment (HR=1.10, 95% CI 1.00-1.20, p=0.05).

Quality-of-Life (analysis of data from 3 trials) was either the same for both treatment strategies (2 trials with no maintenance systemic treatment, n=911) or improved in the intermittent strategy arm (1 trial with no maintenance systemic treatment, n=1,630).

Citation: 2014 ASCO Annual Meeting; General Poster Session, Gastrointestinal (Colorectal) Cancer; Abstract Number 3567