A multicenter evaluation of intensified, ambulatory, chronomodulated chemotherapy with oxaliplatin, 5-fluorouracil, and leucovorin as initial treatment of patients with metastatic colorectal carcinoma. International Organization for Cancer Chronotherapy.

BACKGROUND

The combination of 5-fluorouracil (5-FU), leucovorin (LV), and oxaliplatin (I-OHP) was shown to be both more active against metastatic colorectal carcinoma and better tolerated if the drug delivery rate was chronomodulated according to circadian rhythms rather than constant. This allowed the authors to intensify the three-drug chronotherapy regimen and to assess its activity as the initial treatment of metastatic colorectal carcinoma patients in ten centers from four countries.

METHODS

Patients with previously untreated and inoperable measurable metastases from colorectal carcinoma received a daily administration of chronomodulated 5-FU (700 mg/m2/day, peak delivery rate at 04:00 hours), LV (300 mg/m2/day, peak delivery rate at 04:00 hours), and 1-OHP (25 mg/m2/day, peak delivery rate at 16:00 hours) for 4 days every 14 days. Intrapatient escalation of 5-FU dose was performed if toxicity was less than World Health Organization (WHO) Grade 2.

RESULTS

Of 90 enrolled patients, 35 had a WHO performance status of 1 or 2; 49 had metastases in > or = 2 organs. The liver was involved in 79 patients, 30 of whom had clinical hepatomegaly. The main dose-limiting toxicities were WHO modified Grade 3 or 4 diarrhea (41% of patients, 8.2% of courses), stomatitis (30% of patients, 5.1% of courses), and Grade 2 cumulative peripheral sensory neuropathy (19% of patients after 12 courses). Two patients died with severe gastrointestinal toxicity. Using the intent-to-treat method, the overall objective response rate was 66% (95% confidence limits, 56-76%). Surgical removal of previously inoperable metastases was successful in 31 patients (34%). Histologic necrosis of metastases was >90% in 7 patients and complete in 1 patient. The median progression free survival and survival durations were 8.4 months (range, 5.9-10.9 months) and 18.5 months (range, 13.2-23.8 months), respectively, with 38% of the patients alive at 2 years of follow-up.

CONCLUSIONS

The objective response rate appeared to be approximately 3-fold as high as that achieved with current 5-FU-based regimens and translated into an approximately 50% increase in median survival. The hypothesis that this intensified, ambulatory, chronotherapy regimen can increase survival currently is being investigated in a multicenter randomized study conducted by the European Organization for Research and Treatment of Cancer Chronotherapy Study Group.