Safety and Efficacy of a Modified FLOX Adjuvant Regimen for Patients With Stage III Colorectal Cancer Treated in the Community

Abstract

Background: The efficacy and safety of the combination of a fluoropyrimidine with oxaliplatin for patients with stage III colorectal cancer (CRC) have been evaluated in selected patients who took part in clinical trials. We evaluated the outcomes of FLOX (bolus fluorouracil [5-FU] combined with oxaliplatin) in patients with resected stage III CRC treated in the community in a large cancer center.

Patients and methods: We performed a retrospective unicenter cohort study of all consecutive stage III CRC patients who received adjuvant chemotherapy with an mFLOX (modified FLOX) regimen. The schedule consisted of 5-FU bolus 500 mg/m² and bolus of leucovorin 20 mg/m² per week for 6 consecutive weeks and oxaliplatin 85 mg/m² in a 2-hour infusion at weeks 1, 3, and 5, every 8 weeks. Logistic regression multivariate analyses were used to evaluate prognostic factors for relapse at 2 years, and to investigate potential predictors of Grade ≥3 toxicity.

Results: A total of 267 consecutive patients were eligible and included. The median age was 59 years and pathological stage was mostly IIIB (68.2%). With a median follow-up of 24 months, n = 67 patients (25.1%) relapsed, representing a 74.9% rate of disease-free survival at 2 years. In multivariable analyses, urgent surgery (odds ratio [OR], 1.89; 95% confidence interval [CI], 1.02-3.48; P = .042), angiolymphatic invasion (OR, 1.92; 95% CI, 1.05-3.52; P = .034), and any interruption or dose reduction of chemotherapy (OR, 2.37; 95% CI, 1.31-4.27; P = .004) were predictors of recurrence or death at 2 years. Nine patients (3.4%) died from any cause within 60 days of starting mFLOX. Grade ≥3 toxicity occurred in 98 (36.7%) patients, with diarrhea (n = 43; 16.1%) and neutropenia (n = 38; 15.3%) being the most frequent ones. Peripheral neurotoxicity Grade ≥3 occurred in 5 patients (1.8%). Age 70 years or older (OR, 5.85; 95% CI, 2.5-13.66; P ≤ .001) was independently associated with a higher risk of a Grade ≥3 adverse events.

Conclusion: Results suggest that the effectiveness of combining oxaliplatin with bolus 5-FU in patients in the community is reasonably similar to that obtained in clinical trials. However, community patients presented a higher risk of death, especially for those who were older than 70 years. Adjuvant oxaliplatin should be used carefully and probably restricted to fit patients younger than 70 years in this setting.

Keywords: Adjuvant chemotherapy; Elderly patients; Oxaliplatin; Toxicities.