Neoadjuvant Chemotherapy with Capecitabine, Oxaliplatin and Bevacizumab Followed by Concomitant Chemoradiation and Surgical Resection in Locally Advanced Rectal Cancer with High Risk of Recurrence - A Phase II Study

Abstract

Aim: To evaluate feasibility and safety of neoadjuvant chemotherapy with capecitabine, oxaliplatin and bevacizumab followed by concomitant standard chemoradiation and surgical resection in patients with high-risk locally advanced rectal cancer.

Patients and methods: Magnetic resonance imaging (MRI)-defined high-risk cT3/4 rectal cancer patients were treated with 3 cycles of neoadjuvant chemotherapy with capecitabine (1,000 mg/m² twice daily days 1-14, 22-35, 43-56), oxaliplatin (130 mg/sqm on days 1, 22, 43) and bevacizumab (7.5 mg/kg on days 1, 22, 43) followed by capecitabine (825 mg/m² twice daily on radiotherapy days week 1-4) concomitantly with radiotherapy (1.8 Gy daily up to 45 Gy in 5 weeks) and surgical resection by total mesorectal excision. Feasibility, safety, response rate and postoperative morbidity were evaluated.

Results: Twenty-five patients were recruited. Median age was 62 years (range=24-78 years) and all patients had Eastern Cooperation Oncology Group (ECOG) performance status 0. From all patients, 79.2% finished neoadjuvant chemotherapy. Twenty patients underwent surgery. Pathologic complete remission rate, R0 resection and T-downstaging were achieved in 25%, 95% and 54.2% of the "intention to treat" (ITT) patients. The most common grade 3 adverse events (AEs) during neoadjuvant chemotherapy were diarrhea (16.6%) and mucositis (12.5%). In one patient, a grade 4 acute renal failure occurred (4.2%). During chemoradiation, skin reactions (5.3%) were the most common grade 3 AEs. Two major perioperative complications required re-intervention.

Conclusion: Neoadjuvant chemotherapy with bevacizumab, capecitabine and oxaliplatin followed by concomitant standard chemoradiation is feasible in patients with high-risk locally advanced rectal cancer (LARC) and resulted in complete pathologic remission (pCR) rate of 25% and neoadjuvant chemotherapy completion rate of 80%.

Keywords: Neoadjuvant chemotherapy; capecitabine; oxaliplatin and bevacizumab; rectal cancer.