54P - Efficacy of total neoadjuvant therapy (TNT) in rectal cancer: A meta-analysis of randomized controlled trials

Background

Surgery is performed after neoadjuvant chemoradiotherapy (CRT) as standard in locally advanced rectal cancer. However, in recent years, it has been observed that oncological outcomes can be improved with a treatment approach called total neoadjuvant therapy (TNT), applied with different strategies. This meta-analysis investigated the efficacy of randomized controlled trials (RCTs) comparing standard CRT with TNT.

Methods

PubMed and Cochrane Library databases were searched for this meta-analysis, and studies published until 01 January 2022 were included in the analysis. Standard arm; Patients who underwent surgery after neoadjuvant CRT, and the TNT arm was defined as patients who received chemotherapy for at least 3 months before or after CRT or short-term RT, and then surgery. This Meta-analysis was performed using Review Manager, version 5.4 (RevMan), a proprietary software provided by the Cochrane Collaboration.

Results

Six RCTs were included in this meta-analysis, and a total of 2307 patients were analyzed (three phase 3, three phase 2). There were 1195 patients in the TNT arm and 1112 patients in the CRT arm, with a median age of 62 years in both arms. In the joint analysis of the six studies, the pathological complete response rate was 25% in the TNT arm and 13% in the CRT arm (OR:2.13, 95% CI 1.71-2.65, p<0.001)(I² =47% ). There are 3 studies reporting 3-year disease-free survival results, and in the joint analysis of these studies, 3-year disease-free survival rate was 74.2% in the TNT arm, while it was 69% in the CRT arm (HR :1.31, 95% CI 1.07-1.60, p=0.01)( I²= 0%). Because overall survival data were not shared in most studies, overall survival analysis could not be performed.

Conclusions

In locally advanced rectal cancer, the rate of pathological complete response with TNT increases 2 times compared to standard CRT. In addition, 3-year disease-free survival results were found to be better with TNT. Longer follow-up results need to be awaited to see if the better pathological complete response and 3-year disease-free survival achieved with TNT are reflected in overall survival outcomes.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The author.

Funding

Has not received any funding.

Disclosure

The author has declared no conflicts of interest.