Colon and Rectal Surgery Research

Research Supports Short Course Radiation as a New Standard of Care for Rectal Cancer

General Surgery Residents in lab coats studying research information.

Rectal cancer is a type of cancer in which abnormal cells form in the tissues of the rectum, a region representing the last 6-8 inches of the colon. These cancerous cells form in the innermost layer of the rectum and have the potential to spread to other tissues, lymph nodes or organs nearby. The spread of cancerous cells determines the stage of cancer, defining it as localized, regional or distant. Treatments for rectal cancer are advancing through the research conducted by physicians at institutions globally, and Washington University School of Medicine in St. Louis is a primary innovator for more effective treatment regimens.

Background and Research Model

Researchers from Washington University have published a project supporting the effectiveness of short-course radiation therapy to treat localized rectal cancer. “Total Neoadjuvant Therapy With Short-Course Radiation: US Experience of a Neoadjuvant Rectal Cancer Therapy” was written with the collaboration of a dozen researchers with William Chapman, Jr., a general surgery chief resident, as first author. The multidisciplinary research was conducted by members of the Departments of Surgery, Radiation Oncology and Medical Oncology as a retrospective study performed at a National Cancer Institute-designated cancer center.

This project builds on previous research performed at WashU, in which results of a clinical trail of RAPIDO (Rectal Cancer And Pre-operative Induction Therapy Followed by Dedicated Operation) demonstrated the efficacy of this as a new standard for treating rectal cancer. Surgeons from the Section of Colon and Rectal Surgery, alongside radiologists from the Mallinckrodt Institute of Radiology and oncologists from the Department of Medicine participated in this study, described several benefits to this treatment regimen of short course radiation. This mode of therapy is also cost effective, as studied in previous publications.

Dr. Chapman describes the project in an interview with the journal Diseases of the Colon and Rectum. The study aimed to compare clinical performance and oncologic outcomes of two rectal cancer neoadjuvant treatment standards: short-course total neoadjuvant therapy versus standard chemoradiation. “We compared clinical performance in ontological outcomes,” Chapman describes, “in colorectal patients undergoing two competing neoadjuvant treatment regimen, standard chemoradiation versus a new type of total neoadjuvant that incorporates short-course radiation (short-course TNT).”

The researchers were interested in outlining the potential advantages of short-course TNT over other traditional chemoradiation treatment. Chemoradiation treatment (CRT) combines chemotherapy with radiation therapy. CRT has been an established treatment for a diverse range of local tumors. Advantages with this treatment regimen have been demonstrated through clinical examples focusing on anal, cervical, non-small-cell lung cancer (NSCLC), and bladder cancer. Further benefits, however, have been seen within short-course TNT over these traditional treatments. Previous studies have outlined potential advantages of short-course TNT, including shorter treatment periods, better response rates, and a potential disease-free survival advantage compared with the standard CRT.

Research Outcomes

In the new study, researchers considered tumor downstaging – measured by complete response and “low” neoadjuvant rectal score rates – and progression-free survival. Secondary analyses included treatment characteristics, treatment completion, sphincter preservation and recurrence rates.

The short-course total neoadjuvant therapy regimen correlated with improved downstaging and similar progression-free survival of patients with rectal cancer when compared to other forms of chemoradiation. These positive results were achieved with shortened radiation courses, improved treatment completion and less time spent with other procedures, such as diverting ostomies. Short-course total neoadjuvant therapy, the researchers conclude, is an optimal regimen for locally advanced rectal cancer, although its efficacy with regional or distant cancer requires further study.

Rectal Cancer Treatment at Washington University

According to the American Cancer Society, colorectal cancer is the third most common cancer diagnosed in the United States and the third leading cause of cancer-related death. Despite these statistics, death rates from colorectal cancer have been on the decline as patients attend screening, promoting early detection and removal.

Research continues to advance the treatment regimens for those experiencing colorectal cancer. Improving the current standard of care decreases treatment time, increases the positive outcomes for patients, and improves prognosis after treatment. The results of this research publication have the potential to improve patient outcomes and reduce colorectal cancer death rates even further through the use of short-course TNT as a new standard of care. Surgeons in the Section of Colon and Rectal Surgery at Washington University provide the most relevant and innovative care in all aspects of colon and rectal surgery, striving to advance treatment options to achieve optimal patient outcomes.

To make an appointment with a Washington University colorectal surgeon, please call 314-454-7177 or visit the Colon and Rectal Surgery website.

To learn more about the Colorectal Cancer Screening Program at Siteman Cancer Center, please call 314-747-3046 or visit the Siteman Cancer Center website.

Publication citation:

Chapman, William C. Jr., et al. (2022). Total Neoadjuvant Therapy With Short-Course Radiation: US Experience of a Neoadjuvant Rectal Cancer Therapy. Diseases of the Colon & Rectum,  Volume 65, Issue 2 (198-206).


Chapman, William C. Jr. M.D., M.P.H.S.

Kim, Hyun M.D.

Bauer, Philip M.D.

Makhdoom, Bilal A. B.A.

Trikalinos, Nikolaos A. M.D., M.S.

Pedersen, Katrina S. M.D.

Glasgow, Sean C. M.D.

Mutch, Matthew G. M.D.

Silviera, Matthew L. M.D.

Roy, Amit M.D.

Parikh, Parag J. M.D.

Hunt, Steven R. M.D.