Feasibility of Oxaliplatin and Infusional Fluorouracil/Leucovorin (FOLFOX4) for Japanese Patients with Unresectable Metastatic Colorectal Cancer

Background: A combination of oxaliplatin and infusional fluorouracil/leucovorin (FOLFOX4) is one of the standard regimens for palliative and adjuvant chemotherapy for colorectal cancer. However, the feasibility of FOLFOX4 for Japanese patients has not been determined. We conducted this prospective study to evaluate the feasibility of FOLFOX4. Methods: Previously treated or untreated patients with unresectable metastatic colorectal cancer were enrolled. The primary endpoint was the rate of completion which was defined as completion of the first 4 cycles with relative dose-intensity of oxaliplatin of 80 % or higher. Results: Of the 32 enrolled patients, 31 received FOLFOX4. Twenty-four patients (75%) had received prior chemotherapy. The rate of completion of the first four cycles was 87% (27/31; 95 % CI, 70.2–96.4%). With the median number of cycles of nine (range, 1–26), grade 3 or 4 hematological toxicity and non-hematological toxicity were seen in 12 (39%) and 5 (16%) patients, respectively. Grade 1 or 2 sensory neuropathy was seen in 28 patients (90%), but no grade 3 or 4 neuropathy was seen. Grade 1 or 2 allergic reaction was seen in five patients (16%). One patient developed fatal interstitial pneumonitis and died of respiratory failure. Objective response rate was 28.6 % (6/21; 95 % CI, 11.3– 52.2%) in the patients with measurable lesions. Median progression-free survival was 6.5 months (95 % CI, 4.6–8.5 months) in all patients. Conclusions: The completion rate of the first four cycles was as high as expected with manageable toxicity, although fatal pneumonitis developed in one case. FOLFOX4 is feasible for Japanese patients. Key words: FOLFOX – oxaliplatin – feasibility study – colorectal cancer – interstitial pneumoniti