Neoadjuvant (re)chemoradiation for locally recurrent rectal cancer: Impact of anatomical site of pelvic recurrence on long-term results.

ABSTRACT

BACKGROUND: Selection criteria to propose neoadjuvant (re)chemoradiation (CHRT) in locally recurrent rectal cancer (LRRC) are required, since re-irradiation is sometimes associated to severe adverse effects. Aim of the present study was to compare chances of R0 surgery and disease-free survival (DFS) in LRRC patients (pts) treated by neoadjuvant (re)CHRT followed by surgery vs. upfront surgery, stratifying pts by each localization of LRRC. METHODS: LRRC pts treated at the National Cancer Institute of Milan (Italy) were retrospectively divided into two groups neoadjuvant (re)CHRT vs. upfront surgery. According to our Milan classification, LRRC were categorized as S1, if located centrally (S1a-b) or anteriorly (S1c) within the pelvis; S2, in case of sacral involvement; S3, in case of lateral pelvic wall infiltration. RESULTS: 152 pts were candidate for multimodal treatment 49 (32.2%) by neoadjuvant (re)CHRT and surgery, including 33 re-irradiations, vs. 103 (67.8%) by upfront surgery. No difference was observed in R0 resection rates (respectively 47.6% vs. 51.0%). However, neoadjuvant (re)CHRT followed by surgery improved the DFS (p = 0.028), also in R1 procedures (p = 0.013), compared with upfront surgery. At multivariate analysis, the R+ surgery (p < 0.0001) strongly predicted unfavorable DFS, while neoadjuvant (re)CHRT followed by surgery was independently associated to better DFS (p = 0.0197). Stratifying by LRRC localization, the combined approach significantly improved DFS in the S1c (p = 0.029) and S2 (p = 0.004) subgroups compared to upfront surgery, but not in S1a-b and S3 pts. CONCLUSION: Anterior (S1c) and sacral-invasive (S2) pelvic recurrences significantly benefit in terms of DFS by combination of neoadjuvant (re)CHRT and radical surgery, also after R1 resection.