Experience Update of Neoadjuvant Chemoradiation Therapy for Locally Advanced Rectal Cancer Using UFT and Leucovorin

Abstract

Materials/Methods: Data was prospectively collected for EB pts from 2010-2012. Historical controls receiving NA 3D or IM at the same institution from 2008-2012 were identified and data gathered retrospectively from pt charts. Pts undergoing NA EB received 4 consecutive daily 6.5-Gy fx w/o chemotherapy, while those undergoing 3D or IM received 28 daily (M-F) 1.8-Gy fx w/5-FU. Response was assessed by a blinded radiologist using RECIST applied to pre/post-RT MRI. Slides from 5 randomly selected pts from each group were re-reviewed by a blinded pathologist to document differences in treatment effect. Results: Three-dimensional, IM, and EB groups consisted of 14, 11, and 7 pts with median follow-up of 15, 12 and 7 mos, respectively. Mean age (58 12 vs. 52 8 vs. 60 17 yrs; pZ 0.32), T stage (86 vs. 73 vs. 71% T3; p Z 0.66), and N stage (57 vs. 55 vs. 43% N1; p Z 0.82) were not different between groups. All pts underwent definitive surgical resection. Time from RT start to surgery was less for EB (52 vs. 103 and 100 days for 3D and IM; p < 0.0001), as was time from RT end to surgery (49 vs. 64 and 60 days; p Z 0.042). There was a trend towards higher rate of pCR in EB (43 vs. 7 and 13%; p Z 0.06). Rates of margin (p Z 0.52) and lymph node (p Z 0.57) positivity at resection were similar for all groups. Acute toxicity was less for EB (57%) vs. 3D (100%) and IM (82%) (p Z 0.025). Overall (100% all groups) and progression free (100 vs. 93 and 91%) survival were similar at 6 mos. On MRI, EB achieved a similar reduction in tumor volume (89 vs. 87 and 93%; p Z 0.78) and rates of CR (14 vs. 0 and 14%; p Z 0.46) and PR (57 vs. 90 and 86%; p Z 0.12). EB led to similar post-operative complication and sphincter preservation rates. Histopathologic comparison showed similar treatment effects among all groups; however, EB had more superficial changes and fewer serosal adhesions. Conclusions: Preliminary trial data show that pts treated with EB experience less toxicity and shorter time to surgery without compromising margin or lymph node status at resection. Follow-up was not sufficient for survival analysis, but EB appears non-inferior to 3D and IM at 6 mos. EB alone achieves similar radiologic and favorable pathologic tumor response rates when compared to 5-6 weeks of conventional chemoradiation. Author Disclosure: J. Smith: None. A. Wild: None. A. Singhi: None. S. Raman: None. R. Kumar: None. I. Kamel: None. J. Efron: None. N. Azad: None. S. Gearhart: None. J. Herman: None.