Second- and third-line treatments remain a challenge in advanced colorectal cancer. Studies of bimonthly regimens of high-dose leucovorin (LV) and 5-fluorouracil (5-FU) by continuous infusion combined with oxaliplatin (L-OHP) have shown encouraging response rates in patients not responding to a bimonthly LV/5-FU regimen. Hyperthermic enhancement of L-OHP efficiency by increased DNA adduct formation has been demonstrated in vitro. This study was designed to address feasibility, toxicity and efficacy issues of whole-body hyperthermia (WBH) as an adjunct to L-OHP/LV/5-FU in pretreated patients after progression to first- and second-line treatments with LV/5-FU by continuous infusion and irinotecan.
PATIENTS AND METHODS:
Forty-four patients with advanced colorectal cancer, who had progressed during or within 3 months after completion of chemotherapy with LV/5-FU 24-h infusion (LV/5-FU(24h)) (eight patients) or irinotecan combined with or after LV/5-FU(24h )(36 patients), were treated with L-OHP 85 mg/m(2), 2-h intravenous (i.v.) infusion, followed by LV 200 mg/m(2), 1-h i.v. infusion, and 5-FU 3 g/m(2), 48-h continuous infusion. Every second cycle of the biweekly regimen was combined with WBH, thus allowing a comparison of toxicity with and without WBH in the same patient. Whole-body hyperthermia was administered by a humidified radiant heat device. The target temperature of 41.8 degrees C was maintained for 60 min. L-OHP (2-h infusion) was started at a core body temperature of 39 degrees C.
All patients could be evaluated for toxicity, and 41 patients were evaluable for response. A total of 273 L-OHP-containing regimens were administered, 130 with and 143 without WBH. Hyperthermic treatment combined with L-OHP/LV/5-FU showed no unexpected toxicities. WHO grade 3 toxicities were rare and evenly balanced between cycles given with or without WBH. One early death occurred due to sepsis and tumor lysis. The overall response rate was 20%, with two complete and six partial responses. Twenty-three patients (56%) had stable disease and nine patients (22%) progressive disease. With a median observation time of 70 weeks, the median time to progression was 21 weeks [95% confidence interval (CI) 17-25 weeks] and the median survival was 50 weeks (95% CI 39-61 weeks) from the start of therapy.
This trial suggests some advantage of combining L-OHP/LV/5-FU with WBH. Results compare favorably with the activity of similar regimens without WBH in less extensively pretreated patients. These data support further evaluation and warrant phase III studies.