A retrospective outcome study in the elder patient with locally advanced rectal cancer treated with hypofractionated or conventional preoperative radiotherapy

Abstract

Background: Neoadjuvant chemoradiotherapy is considered the standard approach for T3-4 M0 rectal cancer; however, the optimal dose remains undefined for the elderly. We performed a retrospective analysis to compare conventional (C) and hypofractionated (HF) schedules in elderly patients. We compared survival rates, local control and morbidity.

Methods: From 2000 to 2008, 177 patients older than 65 years with T3-4 M0 rectal cancer received preoperative radiotherapy according to either a conventional protocol (45 to 50.4 Gy in 1.8-2 Gy daily fractions) or a hypofractionated (39 Gy in 3 Gy daily fractions) protocol. Fifty-five patients in the conventional group and none of the patients in the hypofractionated group received concomitant chemotherapy. Both groups were equivalent in terms of their characteristics. The median follow-up was 36 months.

Results: The occurrence of early grade 3-4 radiation toxicity was equivalent between the 2 groups (7%). Surgery was performed in 98% of the patients in the HF group versus 92% in the conventional (p=0.08). The delay between radiotherapy and surgery was 22 days in the HF group versus 45 days in the conventional group (p=0.0021). The downstaging rates were 39% in HF group and 45% in the C group (p=0.53). For lower rectum tumors, the conservative surgery rates were 43% in the HF group and 35% in the C group, (p=0.52). The postoperative death rates at 30 days were equal between the two groups (3%). The 5-year local control rates was 87.3% in group C and 91.7% in group HF (p=0.5). Based on a Kaplan-Meier analysis, the 1-, 3- and 5-year overall survival rates were 88%, 67% and 45%, respectively, in the C group and 84%, 60% and 39%, respectively, in the HF group (p=0.28). In a multivariate analysis, the prognostic factors for overall survival were a Charlson index < 2 (p=0.0034 HR=0.3), pT stage ≤2 (p=0.0042 HR=0.16), pN0 stage (p=0.0072 HR=0.388), and downstaging (p=0.0498 HR=0.651). Radiation schedule and concomitant chemotherapy had no impact.

Conclusion: In this series, the local control rates and the overall survival results are equivalent for patients treated with HP and C radiation schedules. As hypofractionated radiotherapy is more convenient for elderly patients and has equivalent morbidity, additional prospective studies with this population could be of great interest.