Comparison of Capecitabine (Xeloda) vs. Combination of Capecitabine and Oxaliplatin (XELOX) as Neoadjuvant CRT for Locally Advanced Rectal Cancer.

We decided to compare pathologic complete response (pCR) and disease-free survival (DFS) in rectal adenocarcinoma patients who received neoadjuvant chemoradiotherapy (CRT) with capecitabine plus oxaliplatin (XELOX) or capecitabine (Xeloda). In this study, patients with non-metastatic locally advanced rectal cancer (tumor stages of T2, T3, or T4) with or without lymph node involvement were retrospectively included. Patients received concomitant radiation (50.4-54 Gy external beam radiation in 28 to 30 fractions) and neoadjuvant therapy as either Xeloda (capecitabine, 2500 mg/m2 concomitantly with radiation therapy) (42patients) or XELOX [(oxaliplatin (50 mg/m2 intravenously once a week for five weeks) and capecitabine)] (72 patients). Surgery was done eight weeks after CRT. The endpoints were pCR (defined as no evidence of viable tumoral cells) and DFS (the interval from the initial treatment to the first tumor recurrence). Rectal sphincter preservation via low-anterior resection (LAR) was achieved in 73.8% of Xeloda group which was similar to XELOX group (70.8%), P = 0.61. pCR was documented in 11 (26.9%) of Xeloda group and 26 patients (36.1%) of XELOX group (P = 0.27). Tumor recurrence was recorded in 97 patients (85.1%). Mean (±SD) DFS was 52.13 (±31.92) months (median = 48 months). Mean (95% CI) DFS was 129.42 (110.19 to 148.64) in Xeloda group vs. 122.77 (110.72 to 134.83) in XELOX group (P = 0.74). Addition of oxaliplatin to capecitabine as neoadjuvant CRT for locally advanced rectal cancer did not result in improved pCR or better DFS.