Oxaliplatin-based neoadjuvant chemoradiation for locally advanced rectal cancer

Abstract

e15102 Background: Preoperative chemoradiation improves local recurrence in patients with locally advanced rectal cancer1. The survival benefit of 5-FU based chemotherapy with radiation has been questioned2. Oxaliplatin based protocols have shown promise but the optimal regime remains to be defined3,4. We report our experience with addition of Oxaliplatin to neoadjuvant chemoradiation for rectal cancer. Methods: For this retrospective study, thirty-six consecutive patients referred for neoadjuvant chemoradiation for rectal cancer between May 2007 and March 2008 were identified. All patients had histologically proven adenocarcinoma, and were clinical stage T3/T4 or N+, except for one who was T2N0. Outcomes of interest were R0 resection rate and pathological complete response rate(pCR). Neoadjuvant treatment consisted of upto 4 cycles of CapOx(oxaliplatin 130 mg/m2, IV, D1, capecitabine (2,000 mg/m2/day, D1–14, q3 weeks), followed by capecitabine(1650mg/m2/day) with concurrent pelvic radiation(50.4Gy/28 fractions). Restaging to assess resectability was done at 4–6 weeks and definitive TME surgery was undertaken 6–8 weeks after end of chemoradiation Results: Thirty patients(oxaliplatin group) received at least 1 cycle of CapOx(range 1–8). Radical radiotherapy to 50.4Gy/28# was completed in 29/36 patients(81%). Surgical resection was undertaken in 24/36 patients(67%). Resection rate, R0 resection rate, pCR and local recurrence rate were 63%(19/30), 95%(18/19), 32%(6/19), and 5%(1/19) in the oxaliplatin group. In patients with low rectal cancer (0–5cm from anal verge), 16/26(62%) underwent resection. Sphincter sparing surgery was carried out in 7 patients, all of whom had received oxaliplatin, giving a sphincter sparing surgery rate of 64%(7/11) in the oxaliplatin group. Conclusions: Addition of oxaliplatin to neoadjuvant chemoradiation results in a significant number of patients achieving R0 resection, pCR and sphincter sparing surgery, compared to historical controls. No significant financial relationships to disclose.