FTP3.7 Influence of neoadjuvant treatment strategy on operability in locally advanced rectal cancer

Abstract

Abstract Background Neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer facilitates tumour downstaging and complete pathological response (pCR). Neoadjuvant systemic chemotherapy (total neoadjuvant chemotherapy, TNT) further improves pCR rates. While some patients forgo surgery, total mesorectal excision (TME) remains the standard of care. While TNT appears to be non-inferior to nCRT with respect to short-term oncological outcomes, little data exists on perioperative outcomes. Factors such as conversion, sphincter preservation and anastomosis rates do not impact oncological outcomes but affect quality of life (QOL). Methods An institutional colorectal oncology database was interrogated from inception (2009) to November 2022. Inclusion criteria comprised patients with histologically confirmed rectal cancer who had undergone neoadjuvant therapy and TME. Exclusion criteria comprised patients with a non-colorectal primary, those operated on emergently or who had local excision only. Primary outcomes were rates of conversion to open, sphincter preserving surgery and anastomosis formation. Results In total 156 patients were eligible for inclusion (standard nCRT, n= 111, TNT, n=45). Sphincter preservation and anastomosis formation were more frequent in the nCRT cohort, while conversion rates were higher in the TNT cohort. Although these differences were not statistically different, the conversion value approached significance (sphincter preservation, 70% vs 62%, p=0.3484; anastomosis, 72% vs 64%, p=0.4632, conversion, 34% vs 17%, p=0.0501). Conclusions In this series TNT appears to be associated with higher conversion rates and lower rates of anastomosis formation. While larger studies will be required to confirm these findings, QOL factors should be considered alongside oncological benefits when selecting treatment strategies.