Preoperative FU-based chemoradiation with or without weekly oxaliplatin in locally advanced rectal cancer: Preliminary safety findings of the STAR (Studio Terapia Adiuvante Retto)-01 randomized trial

4040 Introduction: Oxaliplatin (OXA) significantly enhances the efficacy of 5-Fluorouracil (FU)-based chemotherapy (CT) in metastatic and radically resected, early stage colon cancer. Weekly OXA, at systemically active doses, can be added to preoperative FU-based pelvic chemoradiation (CRT) (Aschele, Ann Oncol 2005). Methods: An open-label, multicenter, randomized, phase III trial was launched to compare the efficacy (disease-free and overall survival) and activity (pathological response rate) of infused FU (225 mg/msq/day) concomitant to external-beam pelvic radiation (50.4 Gy in 28 daily fractions) (Arm A) to that of the same regimen plus weekly OXA (60 mg/msq weekly x 6) (Arm B). TME surgery is scheduled 6–8 weeks after completing CRT. FU-based adjuvant CT (4 cycles) is planned in both arms. Eligible patients (pts) have resectable tumors located within 12 cm from the anal verge and radiological evidence of perirectal fat or regional nodes involvement. Results: 410 pts (median age 63 years; males/females: 66/34 %; cT3/cT4: 66/18 %; cN+: 56 %; median distance from the anal verge: 6 cm) were randomized between 11/2003 and 10/2006 at 40 Italian centers. Toxicity data from the first 250 randomized pts are reported in the table . CRT was completed by 89 % and 74 % of pts in arm A and B, respectively. The median cumulative dose of delivered radiotherapy was 50.4 Gy in both arms. 120 of 123 pts in arm A and 109 of 112 pts in arm B were operated with a median interval from the end of treatment to surgery of 7.3 and 7.4 weeks, respectively. Conclusions: This analysis provides the first comparative toxicity data showing that OXA, at systemically active doses, can be safely added to standard FU-based CRT with an increased frequency and severity of acute toxicity but without major unexpected adverse events and without affecting the ability to deliver full RT doses and to perform surgery. [Table: see text] No significant financial relationships to disclose.