Preoperative Short-Course Concurrent Chemoradiation Therapy Followed by Delayed Surgery for Locally Advanced Rectal Cancer: A Phase 2 Multicenter Study (KROG 10-01)
Mené sur 73 patients atteints d'un cancer rectal de stade cT3-4, cet essai prospectif multicentrique de phase 2 évalue, du point de vue de la régression du stade de la maladie et du grade tumoral, l'efficacité et la toxicité d'une chimioradiothérapie concomitante de courte durée par 5-fluorouracile-leucovorine et suivie d'une intervention chirurgicale
A prospective phase 2 multicenter trial was performed to investigate the efficacy and safety of preoperative short-course concurrent chemoradiation therapy (CRT) followed by delayed surgery for patients with locally advanced rectal cancer. Seventy-three patients with cT3-4 rectal cancer were enrolled. Radiation therapy of 25 Gy in 5 fractions was delivered over 5 consecutive days using helical tomotherapy. Concurrent chemotherapy was administered on the same 5 days with intravenous bolus injection of 5-fluorouracil (400 mg/m2/day) and leucovorin (20 mg/m2/day). After 4 to 8 weeks, total mesorectal excision was performed. The primary endpoint was the pathologic downstaging (ypStage 0-I) rate, and secondary endpoints included tumor regression grade, tumor volume reduction rate, and toxicity. Seventy-one patients completed the planned preoperative CRT and surgery. Downstaging occurred in 20 (28.2%) patients, including 1 (1.4%) with a pathologic complete response. Favorable tumor regression (grade 4-3) was observed in 4 (5.6%) patients, and the mean tumor volume reduction rate was 62.5 ± 21.3%. Severe (grade ≥3) treatment toxicities were reported in 27 (38%) patients from CRT until 3 months after surgery. Preoperative short-course concurrent CRT followed by delayed surgery for patients with locally advanced rectal cancer demonstrated poor pathologic responses compared with conventional long-course CRT, and it yielded considerable toxicities despite the use of an advanced radiation therapy technique.
International Journal of Radiation Oncology, Biology, Physics