RESUMEN
BACKGROUND: Colorectal cancer remains the second leading cause of cancer death in North America. Fluorouracil and oxaliplatin based adjuvant chemotherapy for resected colon cancer (CC) reduces cancer recurrence, but also causes significant toxicity requiring dose reductions. The effect of dose intensity on survival outcomes is not fully understood and strengthening the evidence supports informed decision making between patients and oncologists. METHODS: Patients treated with adjuvant chemotherapy, between 2006 and 2011, for resected colon cancer at four Canadian academic cancer centers were retrospectively analyzed. All patients must have received oxaliplatin with either capecitabine (CAPOX) or 5-FU (FOLFOX). Dose intensity (DI) was calculated as total delivered dose of an individual chemotherapy agent divided by the cumulative intended dose of that agent. The influence of DI on overall survival was examined. RESULTS: Five hundred thirty-one patients with high-risk stage II or stage III resected CC were eligible and included in the analysis. FOLFOX was the most common regimen (69.6%) with 29.7% of patients receiving CAPOX and 0.7% receiving both therapies. Median follow-up was 36.7 months. The median DI for 5-FU and capecitabine was 100% and 100% with 13.6% and 9.8% of patients receiving ≤ 80% DI, respectively. The median DI of oxaliplatin was 70% with 56.8% of patients receiving ≤ 80% DI. A DI of > 80% for each chemotherapy component was associated with a significant improvement in overall survival compared to those with a DI of ≤ 80% (5-FU HR = 0.23, 95% CI = 0.08-0.65, p = 0.006; capecitabine HR = 0.56, 95% CI = 0.33-0.94, p = 0.026; oxaliplatin HR = 0.52, 95% CI = 0.33-0.82, p = 0.005). Patients with T2 and/or N2 disease with an oxaliplatin DI > 80% had a trend towards improved survival (HR = 0.62, 95% CI = 0.38-1.02, p = 0.06). CONCLUSIONS: In resected CC an adjuvant chemotherapy DI of > 80%, of each chemotherapy agent, is associated with improved overall survival.
Asunto(s)
Neoplasias del Colon , Neoplasias Testiculares , Masculino , Humanos , Capecitabina , Oxaliplatino , Leucovorina , Estudios Retrospectivos , Compuestos Organoplatinos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Estadificación de Neoplasias , Recurrencia Local de Neoplasia/patología , Canadá , Quimioterapia Adyuvante/efectos adversos , Neoplasias del Colon/patología , Fluorouracilo , Neoplasias Testiculares/tratamiento farmacológicoRESUMEN
There is evidence that achieving a dose intensity > 80% in adjuvant colon cancer treatment improves survival. In total, 192 consecutive patients with resected stage III and high-risk stage II colon cancer that received adjuvant chemotherapy were retrospectively analyzed. Patients who received at least 6 weeks of adjuvant therapy were included. The primary objective was to assess the influence of dose index (DI) and relative dose intensity (RDI) on DFS and OS at 3 and 5 years in patients receiving fluorouracil-based doublet therapy with oxaliplatin (FOLFOX) (5-FU and oxaliplatin assessed separately), or capecitabine monotherapy. In the capecitabine group, DFS rates for 3 and 5 years were 66.7% and 57.6%, respectively, while OS rates were 80.3% and 66.7%, respectively. Those who received FOLFOX had DFS rates of 76.9% and 71.2% at 3 and 5 years, respectively. OS rates were 86.4% and 76.7% at 3 and 5 years, respectively. Median RDI was 73.8% for capecitabine and 76.3% and 85.6% for the oxaliplatin and 5-FU components respectively. Based on a multivariate analysis in patients receiving FOLFOX, those with an oxaliplatin DI > 80% had improvements in DFS and OS compared to those with an oxaliplatin DI of ≤80%. Otherwise, there was no significant difference in DFS or OS when comparing patients who achieved an RDI or a DI of above versus below 80% in the patients receiving adjuvant chemotherapy for resected colon cancer.