(HealthDay News) — For patients with metastatic colorectal cancer, continuing full cytotoxic chemotherapy until progression offers no benefit over observation, according to research published online Dec. 19 in JAMA Oncology.
Mohamad Bassam Sonbol, M.D., from the Mayo Clinic in Phoenix, and colleagues examined the comparative effectiveness of different treatment strategies for metastatic colorectal cancer. Trials of interest included patients treated with an initial period of cytotoxic chemotherapy (with or without a biologic) who were then switched to observation; switched to maintenance with bevacizumab, fluoropyrimidine, or both; or continued the induction regimen until progression. Data were included from 12 trials at low risk for bias (5,540 patients).
The researchers found that continuing full cytotoxic chemotherapy until progression had no benefit versus observation in terms of progression-free survival (PFS; hazard ratio, 0.71; 95 percent confidence interval, 0.46 to 1.09) and overall survival (OS; hazard ratio, 0.95; 95 percent confidence interval, 0.85 to 1.07). Maintenance therapy showed a benefit versus observation in terms of PFS (hazard ratio, 0.58; 95 percent confidence interval, 0.43 to 0.77), but not OS (hazard ratio, 0.91; 95 percent confidence interval, 0.83 to 1.01); significant improvement in PFS was seen with all maintenance strategies.
“Based on these findings, switching to a lighter, maintenance regimen of chemotherapy or even taking a break in treatment for some patients is appropriate, with reintroduction of full chemotherapy when the disease progresses,” Sonbol said in a statement.
Several authors disclosed financial ties to the pharmaceutical industry.