Significance of nodal yield after rectal resection in the TNT era: does count matter?

Neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer facilitates tumour downstaging and complete pathological response (pCR), but is known to decrease nodal yield. Total neoadjuvant therapy (TNT) differs from nCRT with the addition of systemic chemotherapy prior to rather than subsequent to surgery. The relative effect of TNT on nodal yield comparative to nCRT remains unknown. Institutional colorectal oncology databases in two nationally designated rectal cancer centres were interrogated from January 2012 to December 2024. Inclusion criteria comprised patients with histologically confirmed rectal cancer who had undergone neoadjuvant therapy and subsequent TME. A total of two hundred and one patients (n = 201) met the eligibility criteria and were included in the final statistical analysis. This comprised eighty-four patients in the TNT group (n = 84) and one hundred and seventeen patients in the nCRT group (n = 117). Of these 80% were clinically node positive (cN+) prior to commencing treatment (TNT 83% cN+, nCRT 77% cN+). Median nodal yield was significantly reduced in the TNT comparative to nCRT cohort (12 vs. 14, p = 0.004). In this study, TNT regimens appear to further decrease nodal yield comparative to standard neoadjuvant chemoradiotherapy in rectal cancer. Nodal yield as a key prognostic indicator of technical adequacy of resection in the era of TNT may need to be interpreted in the context of the neoadjuvant regimen in question.