FOLFOX4 versus sequential dose-dense FOLFOX7 followed by FOLFIRI in patients with resectable metastatic colorectal cancer (MIROX): a pragmatic approach to chemotherapy timing with perioperative or postoperative chemotherapy from an open-label, randomized phase III trial.

BACKGROUND: Perioperative FOLFOX4 (oxaliplatin plus 5-fluorouracil/leucovorin) chemotherapy is the current standard in patients with resectable metastases from colorectal cancer (CRC). We aimed to determine whether a sequential chemotherapy with dose-dense oxaliplatin (FOLFOX7) and irinotecan (FOLFIRI; irinotecan plus 5-fluorouracil/leucovorin) is superior to FOLFOX4. The chemotherapy timing was not imposed, and was perioperative or postoperative. PATIENTS AND METHODS: In this open-label, phase III trial, patients with resectable or resected metastases were randomly assigned either to 12 cycles of FOLFOX4 (oxaliplatin 85 mg/m(2)) or 6 cycles of FOLFOX7 (oxaliplatin 130 mg/m(2)) followed by 6 cycles of FOLFIRI (irinotecan 180 mg/m(2)). Randomization was done centrally, with stratification by chemotherapy timing, type of local treatment (surgery versus radiofrequency ablation with/without surgery), and Fong's prognostic score. The primary end point was 2-year disease-free survival (DFS). RESULTS: A total of 284 patients were randomized, 142 in each treatment group. Chemotherapy was perioperative in 168 (59.2%) patients and postoperative in 116 (40.8%) patients. Perioperative chemotherapy was preferentially proposed for synchronous metastases, whereas postoperative chemotherapy was more frequently used for metachronous metastases. Two-year DFS was 48.5% in the FOLFOX4 group and 50.0% in the FOLFOX7-FOLFIRI group. In the multivariable analysis, more than one metastasis [hazard ratio (HR) = 2.15] and synchronous metastases (HR = 1.63) were independent prognostic factors for shorter DFS. Five-year overall survival (OS) rate was 69.5% with FOLFOX4 versus 66.6% with FOLFOX7-FOLFIRI. CONCLUSIONS: FOLFOX7-FOLFIRI is not superior to FOLFOX4 in patients with resectable metastatic CRC. Five-year OS rates observed in both groups are the highest ever reported in this setting, possibly reflecting the pragmatic approach to chemotherapy timing. CLINICAL TRIALS NUMBER: NCT00268398.

Taking into account successive treatment lines in the analysis of a colorectal cancer randomised trial.

The FFCD 2000-05 randomised trial included 410 patients with advanced colorectal cancer and compared a sequential arm S treated with 5-fluorouracil and leucovorin (LV5FU2) followed by FOLFOX (LV5FU2+oxaliplatin) and then FOLFIRI (LV5FU2+irinotecan) and a combination arm C that begins directly with FOLFOX followed by FOLFIRI. The first aim of this study was to analyse the prognostic effects on overall survival of disease progression, and of toxicities under first-line therapy. We also studied the benefit of introducing irinotecan in each arm. Finally, we compared the effect of treatment on repeated progression and toxicities. For this purpose, we used Cox regression models with time-dependent variables and shared gamma frailty regression models. We found that early on during follow-up, the prognostic effect on survival of progression under first-line therapy was greater in C (hazard ratio [HR]=18.0 [7.9-41.2]) than in S (HR=7.7 [3.9-17.4]). This difference was significant, but it decreased over time. The prognostic effect of severe toxicities was greater in S (HR=2.0 [1.4-2.9]) than in C (HR=1.3 [0.9-1.9]). Introducing irinotecan was significantly more beneficial in S (HR=0.2 [0.1-0.4]) than in C (HR=0.3 [0.2-1.5]). The risk of repeated progression was not significantly different between the two groups (HR=0.9 [0.8-1.1]) whereas the risk of toxicities was greater in C (HR=1.7 [1.4-2.1]). Overall, this study suggests that starting with less toxic first-line treatment is a valid option since it does not exert a deleterious effect on the risk of overall progression or death.