Abstract

Aim: Total Neoadjuvant Therapy (TNT) based on long course chemoradiation followed by consolidation chemotherapy has been recently advocated as a strategy to enhanced non operative management (NOM) in selected patients with locally advanced rectal cancer (LARC) (1). However, there is no clear evidence if short course radiotherapy (SCRT) may also be useful to improve NOM in a TNT context. The aim of the present study is to evaluate the initial results of a TNT strategy on based SCRT followed by consolidation chemotherapy as a way to improve NOM in a public hospital from Latin America. Method: Retrospective study that included LARC patients treated with TNT from October 01, 2019 to November 30, 2021 at Complejo Asistencial Doctor Sotero del Rio, Santiago, Chile. TNT consisted in SCRT (25Gy in 5 doses) followed by consolidation chemotherapy based on FOLFOX or CAPEOX. For all patients, tumor response was assesed using the Memorial Sloan Kettering Regression Schema (2). NOM was considered for selected patients with a cCR. For patients with a incomplete response (IR), total mesorectal excision (TME) was recommended. The combined rate of cCR/pCR was reported. Results: A total of 15 patients were included. The median age was 58 years (34 to 78), 11 (73%) were male. Median distance of the tumor to the anal verge was 6 cm (1 to 10 cm). 11 patients (74%) were considered node-positive by a baseline MRI. 11 patients (74%) received consolidation FOLFOX with a median number of 9 cycles (5 to 9). The remaining patients received 6 cycles of CAPEOX. A total of 6 patients (40%) had a cCR, all of them recruited into a NOM protocol. Additionally, 2 patients (13%) who underwent TME had a pCR. No differences were observed in the cCR/pCR group compared to the TME group. Conclusion: In our study, the implementation of a TNT protocol based on SCRT and consolidation chemotherapy was associated with higher rates of cCR/pCR (53%). Prospective studies are needed to adopt this approach as a NOM strategy.