IS THERE A ROLE FOR TOTAL NEOADJUVANT TREATMENT IN EARLY-STAGE RECTAL CANCER

Introduction: Total neoadjuvant treatment (TNT) is an increasingly used strategy for locally advanced rectal cancer that provides a higher complete response rate and improved treatment compliance. Total mesorectal excision is commonly recommended as the initial treatment option for early-stage rectal cancer (ESRC). Impaired functions and permanent colostomy remain undesirable outcomes, particularly in low-located ESRC. Therefore, the selective use of TNT in ESRC may be a potential treatment option. However, these outcomes are yet to be extensively investigated. This study aimed to present a preliminary series of TNT in ESRC. We hypothesized that TNT may result in organ preservation in ESRC.
Methods: Patients who were recommended TNT between 2015 and 2023 were retrospectively reviewed. Patients who underwent TNT based on their choice for ESRC after either initial diagnosis or transanal excision were analyzed. Demographics, tumor characteristics, treatment methods, and follow-up data were reported. Data are presented as median (IQR) and percentage (%).
Results: This study enrolled 15 patients diagnosed with T2N0 low rectal adenocarcinoma, comprising 10 males and 5 females. The median age was 60 (55.5-68.5), and the median tumor size measured 3.1 cm (2.5-3.9). The median distance from the top of the internal anal sphincter (IAS) was 0.2 cm (0-1.4), with IAS involvement observed in six patients. Nine patients underwent TNT after initial diagnosis. Of these, 7 patients achieved a clinical complete response (cCR) following TNT. One patient underwent endoscopic submucosal dissection (ESD) due to a near-complete response, revealing tubulovillous adenoma upon histopathological examination. Another patient underwent low anterior resection and achieved pathologic complete response (pCR). The overall complete response (CR) rate was 100%. Three patients underwent TNT after transanal excision. The median follow-up period for all patients in the study was 21 months (6.7-27.8). During this period, no disease recurrence or mortality was observed in either group. However, one patient who treated with TNT after the initial diagnosis was scheduled for surgery due to a rectovaginal fistula. The remaining two patients who were recommended TNT after the initial diagnosis and one patient who was recommended TNT after local excision are currently continuing their TNT regimen.
Conclusion: Selective utilization of TNT in stage I rectal cancer holds the potential to promote organ preservation, particularly for tumors located in the lower rectum. Intersphincteric resection may emerge as a potential advantage over abdominoperineal resection for patients who achieve tumor downsizing following TNT.