Neoadjuvant Therapy for Localized Rectal Adenocarcinoma

This study is a prospective, single-arm, single-center study of investigator's choice of total neoadjuvant therapy (TNT) or neoadjuvant chemoradiation in locally advanced rectal cancer. The standard of care for rectal adenocarcinomas that are triiodothyronine-thyroxine (T3-T4) or node positive has generally been comprised of neoadjuvant chemoradiation, followed by surgical resection and then adjuvant chemotherapy. More recently, TNT, comprised of neoadjuvant chemotherapy and chemoradiation followed by surgical resection, has been increasingly used as a standard therapy approach. While the use of TNT is increasingly common, prospective study of outcomes following TNT has been limited. Moreover, there are not any biomarkers known at this time that impact clinical decision-making or personalization of therapy in the treatment of rectal cancer. In this study, we will collect pre-treatment rectal adenocarcinoma specimens and determine clinical outcome, including pathologic complete response rate, post-treatment pathologic downstaging rate, recurrence-free survival (RFS), overall survival (OS) and neoadjuvant rectal score, among patients who are treated with standard neoadjuvant chemoradiation or TNT, with an aim to investigate how baseline biomarkers and changes in biomarkers with standard therapies may be associated with, and modulate, clinical outcomes.