PREOPERATIVE SHORT-COURSE RADIOTHERAPY COMBINED WITH CHEMOTHERAPY, LOCAL HYPERTHERMIA AND DELAYED SURGERY IN TREATMENT OF RECTAL CANCER: PHASE II TRIAL

Abstract

Objective : to evaluate efficacy and safety of the short-course radiotherapy combined with capecitabine chemotherapy, intracavitary hyperthermia and delayed surgical treatment as neoadjuvant therapy of rectal cancer Materials and methods . Patients with T2–3N0–2M0 newly diagnosed rectal cancer were included. All patients received short-course radiotherapy with total dose of 25 Gy in several fractions of 5 Gy each, along with capecitabine and metronidazole therapy and local hyperthermia. Capecitabine (1000 mg/m2 ) was administrated twice daily on days 1–14. Local hyperthermia (41–45 °С, 60 min) was applied on days 3–5. Metronidazole (10 g/m2 per rectum) was given on days 3 and 5. Patients underwent surgical treatment not earlier than 4 weeks after neoadjuvant therapy completion. The primary endpoint of the study was assessment of pathologic complete response rate. Secondary endpoints included evaluation of neoadjuvant treatment toxicity, tumor regression, surgical treatment results and oncological results. Results . 81 patients were enrolled. 10 of them (12.3 %) were found to have grade III toxicity, 1 (1.2 %) – grade IV toxicity. Sphincter preservation surgery was carried out in 78 (96.3 %) patients. Postoperative mortality was 0 %. Postoperative complications were registered in 11 (13.8 %) cases. Pathologic complete responses (pCR) were observed in 16 (19.8 %) patients. Median follow-up time was 40.9 months. Distant metastases developed in 10 (12.3 %) patients. Three-year overall survival rate was 97 %, three-year relapse-free survival rate was 85 %. Conclusion. Short-course radiotherapy combined with chemotherapy, radiomodificators and delayed surgical treatment is a safe method for rectal cancer treatment; its results are comparable with the results of prolonged chemoradiotherapy course in terms of tumor regression frequency.