The Potential for Overtreatment With Total Neoadjuvant Therapy (TNT): Consider One Local Therapy Instead

Clin Colorectal Cancer. 2022 Mar;21(1):19-35. doi: 10.1016/j.clcc.2021.11.001. Epub 2021 Nov 18.

Abstract

With increased therapeutic options in rectal cancer, a central question has become how to tailor therapy to patient preferences to avoid both over and under treatment. Total Neoadjuvant Therapy (TNT), defined as delivering all planned chemotherapy and radiation therapy (RT) before surgery, was developed with the primary goal of improving overall survival through early elimination of micrometastatic disease. In this narrative review assessing patients with operable adenocarcinoma of the rectum, we sought to evaluate TNT versus alternative options with regard to both quality of life (QoL) and oncologic outcomes. Survey data of patient preferences reveal that an increased focus on QoL when discussing options is essential. While evidence favors TNT improving distant metastases-free survival, this has not yet translated to a clear OS benefit. The improved pathologic complete response rate with TNT compared to short course RT or chemoradiation alone suggests proceeding to surgery might result in overtreatment, lending support to a watch-and-wait option for patients with a goal for nonoperative management if a clinical complete response is achieved. Similarly, for select low-risk patients, surgery may be the only local therapy required allowing for safe omission of RT. In the treatment of rectal cancer, the future appears to be moving toward one local therapy. As an alternative to TNT, there is growing support for the concept we define herein as total definitive therapy instead: chemoradiation followed by consolidation chemotherapy, saving surgery only for incomplete responders rather than as part of the initial treatment plan. Also, selective use of RT should be considered for low-risk patients. By thoroughly assessing how these treatment de-escalation options compare to more traditional treatment algorithms, this narrative review provides guidance on how to honor patient preferences for QoL by avoiding treatments that might offer negligible benefits in oncologic outcomes.

Keywords: Long course; Nonoperative management; Oncologic outcomes; Quality of life; Rectal cancer; Short course; Total definitive therapy; Watch and wait.

Publication types

  • Review

MeSH terms

  • Chemoradiotherapy
  • Humans
  • Neoadjuvant Therapy*
  • Neoplasm Recurrence, Local / drug therapy
  • Overtreatment
  • Quality of Life
  • Rectal Neoplasms* / pathology