Pilot Study of Intense Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: Retrospective Review of a Phase II Study

Abstract

Aims and Background Locally advanced rectal adenocarcinoma is typically treated with neoadjuvant chemoradiotherapy and surgery. We assessed the effect of an additional cycle of capecitabine/oxaliplatin chemotherapy before surgery in 57 patients with T3/4, N+/- or T1/2, N+ rectal cancer. Materials and Study Design Radiotherapy (total dose, 50.4 Gy) was combined with three cycles of chemotherapy (two cycles concomitant with radiotherapy), and each cycle consisted of oxaliplatin (130 mg/m2 on day 1) and capecitabine (825 mg/m2, twice per day from day 1 to day 14) for 21 days. In addition to assessing the safety of this treatment, the primary endpoint was pathological complete response (pCR). The secondary endpoint was the change in primary tumor and node stage from pre-treatment to post-surgery. Results Eleven patients (19%) experienced complete tumor regression and 23 patients (40%) experienced tumor regression grade 3. Tumor down-staging occurred in 31 patients (54.4%) and down-staging of nodes occurred in 25 patients (43.9%). There was a significant difference in tumor stage between pre-treatment and post-surgery (P <0.001). Patients with less advanced N stages had significantly better recurrence-free survival but similar metastasis-free survival and overall survival. Tumor regression grade was not associated with overall survival, recurrence-free survival or metastasis-free survival. The most common adverse events were pulmonary infection (n = 6, 10.5%) and intestinal obstruction (n = 6, 10.5%). Conclusions An additional cycle of chemotherapy given after chemoradiotherapy and before surgery provided good efficacy and had a satisfactory safety profile in patients with locally advanced rectal cancer.