EPD105 - Short Versus Long Course Radiation for Locally Advanced Rectal Cancer: Comparative Trends in the Era of Total Neoadjuvant Therapy.

Sunday, May 10, 2026

1:02 PM - 1:07 PM ET

ePoster of Distinction Presenter(s)

Bryan Szeglin, MD (he/him/his)

Resident Physician
The Johns Hopkins Hospital
The Johns Hopkins Hospital
Baltimore, MD, United States

All disclosed relationships have been reviewed and managed prior to the start of this activity. Any relevant relationships will be listed below. This individual has no financial relationships to disclose

Author(s)

Megan Breckheimer, MD

Postdoctoral Research Fellow
Johns Hopkins University
Baltimore , MD, United States

Disclosure information not submitted.
Michael S. Consul, n/a (he/him/his)

Medical Student
Johns Hopkins University School of Medicine
Johns Hopkins University School of Medicine
Baltimore, Maryland, United States

Disclosure information not submitted.
JW

James J. Whitbread, MD

Resident Physician
Johns Hopkins University, Department of Surgery
Baltimore, Maryland, United States

Disclosure information not submitted.
MS

Miloslawa Stem, MS

Research Associate
Johns Hopkins School of Medicine
Balitmore, Maryland, United States

Disclosure information not submitted.
AG

Alodia Gabre-Kidan, MD, MPH

Assistant Professor of Surgery
Johns Hopkins School of Medicine
Baltimore, Maryland, United States

Disclosure information not submitted.
Andrea C. Bafford, MD

Associate Professor of Clinical Surgery
Johns Hopkins University School of Medicine
Baltimore, MD, United States

Disclosure information not submitted.

Senior Author(s)

JM

John Migaly, MD

Associate Professor
Johns Hopkins University
Baltimore, Maryland, United States

Disclosure information not submitted.

Purpose/Background: Radiation as a part of total neoadjuvant therapy (TNT) has historically been delivered over 4 weeks, but short course radiation delivered over 5 days has become increasingly common with several large studies showing similar outcomes between short (SCRT) and long course radiation (LCRT). However, the relatively small proportion of SCRT over the past decade has limited comparisons of outcomes in SCRT and LCRT in national databases. Because SCRT now accounts for over 10% of radiation regimens, this study aimed to compare survival and pathological staging after TNT with SCRT and LCRT using a large national database.

Methods/Interventions: Patients with locally advanced (overall stage II and III) rectal adenocarcinoma who received TNT were identified in the National Cancer Database (NCDB, 2018-2022). TNT was defined as receiving all of the following: 1) either neoadjuvant SCRT or LCRT; 2) neoadjuvant chemotherapy; and 3) radical surgical resection (excluding local excision or polypectomy). SCRT was defined as 4-5 radiation fractions with a total dose of 20-30 Gy and LCRT was defined as 20-35 radiation fractions with a total dose of 36-60 Gy. Patients who did not meet either SCRT or LCRT criteria or patients who received immunotherapy were excluded. To control for potential confounders, SCRT patients were propensity score matched to LCRT patients in a 1:1 ratio. Patients were compared with respect to overall survival (OS) (primary outcome) and pathologic staging (secondary outcome).

Results/Outcomes: Of the 13,853 patients included, 1,601 (11.6%) patients received SCRT, and 12,252 (88.4%) patients received LCRT. From 2018-2022, the percentage of patients receiving SCRT increased from 3.8% to 22.8% (p < 0.0001). In the unmatched cohort, SCRT patients tended to receive care at an academic/research program (50.7% vs. 30.8%; p < 0.0001), live >/=25 miles from the hospital of care (33.5% vs. 23.2%; p < 0.0001), and have undergone partial proctectomy (73.2% vs. 67.2%) compared to total proctectomy (abdominoperineal resection [APR]; 14.7% vs. 21.0%; p < 0.0001). SCRT and LCRT groups had similar OS, pre-operative stage, and T stage; however, higher rates of N2 disease were observed in the SCRT group (33.4% vs. 30.4%; p = 0.021). After propensity score matching, 1,067 patients remained in each group. There was no difference in OS (Figure 1) or pathologic stage. Downstaging, tumor grade, surgical margin, 30- and 90-day mortality were also similar between groups.

Conclusion/Discussion: In this large contemporary national cohort of rectal cancer patients receiving TNT, SCRT demonstrated equivalent oncologic outcomes including downstaging and survival compared to LCRT, and in the unmatched cohort SCRT patients tended to have lower rates of APR. These findings support the use of SCRT as an effective alternative to LCRT in the context of TNT. Given that information regarding recurrence is unavailable in the NCDB, future work is needed to further examine recurrence patterns in the context of SCRT and LCRT at scale.

Figure 1

Overall survival of propensity score matched patients truncated at 4 years of follow-up. Log rank p = 0.5521.