Prognostic value of treatment-related factors in metastatic colorectal cancer using a stop-and-go strategy.

Abstract

The purpose of this study is to identify treatment-related factors prognostic of survival in a cohort of patients with metastatic colorectal cancer (mCRC) receiving a palliative, stop-and-go chemotherapy regimen. Consecutive patients receiving first-line treatment with biweekly FLIRI plus bevacizumab were included. The outcome was overall survival. Cox regression analysis was used to identify predictors of outcome. We analysed reduction in chemotherapy dosage (no vs. ≤25 or >25 % reduction), bevacizumab administrated to <50, or ≥50 % to chemotherapy treatments, best response during the first 24 weeks of treatment, and local treatment of metastases. We included 257 patients. Median survival was 23.6 months. Chemotherapy reduction did not influence outcome. Bevacizumab administrations (≥50 %) were associated with improved outcome: hazard ratios (HR) 0.56 (95 % confidence interval (CI) 0.34-0.90, p = 0.018). Partial response (PR) vs. no change (NC) was borderline significant: HR 0.66 (95 % CI 0.43-0.99, p = 0.048), whereas progressive disease (PD) vs. NC increased mortality HR 2.48 (95 % CI 1.19-5.19, p = 0.016). Local treatment of metastases improved outcome: HR 0.30 (95 % CI 0.15-0.61, p = 0.001). In a cohort of mCRC patients, receiving a palliative, stop-and-go regimen, administration of bevacizumab to ≥50 % of chemotherapy treatments and local treatment of metastases were associated with better survival. PR improved outcome compared to NC, whereas PD was prognostic of increased mortality.