P-323 Cisplatin plus capeitabine (CisCape) and radiotherapy (RT) for the neoadjuvant treatment of rectal cancer: final update of previously reported data

Abstract

Introduction: We previously reported results on 17 rectal cancer patients (pts) treated with neoadjuvant CisCape-RT (ESMO World GI 2011). We here present the final report of 52 patients treated with the CisCape-RT regimen. Methods: Fifty-two non-metastatic pts (male:female, 35:17 pts, median age 63 years, range 41-77), clinically staged with endoscopic ultrasound and chest/abdomen/pelvis CT scan as cT2cN1 (5 pts), cT3cN0 (18), cT3cN1 (21), cT3cN2 (4) or cT4cN1 (4), with histologically confirmed moderately (43 pts) or poorly (9) differentiated rectal adenocarcinoma (median distance from the anal verge 5 cm, range 2-13) were treated with standard pelvic radiotherapy (45 Gy/25 fractions) and concurrent capecitabine (825 mg/m2 twice daily days 1 through 14 and 22 through 35) plus cisplatin (40 mg/m2 once every three weeks). Results: radical surgery was performed in 92% of pts, median time elapsed from CRT commencement to surgery was 108 days (76-178), 3 pts underwent palliative surgery because of progression. Complete pathologic response (pCR) was documented in 9 pts (17%). Based on pre-treatment assessment, T and N down-staging were observed in 41% and 38% of pts, respectively. Primary tumour was down-sized in 14 pts (82%) with the median longest diameter reducing from 5.0 cm (range 1.6-16.0) before CRT to 2.0 cm (0-10.0) after CRT, two-tailed p = 0.001 (according to Wilcoxon test for paired samples). Grade 3-4 toxicities occurred in 35% of pts. Median progression-free and overall survival were not yet reached after a median follow-up of 30 months. Conclusion: Despite a good pCR rate, the high occurrence of grade 3-4 toxicities with CisCape-RT makes this regimen not suitable for larger phase III trials.