EP218 - Increasing Neoadjuvant Radiation for Rectosigmoid Cancer: An Unintended Consequence of Modern Rectal Cancer Care?

ePoster Presenter(s)

• 

  Evan M. Abbey, MD

  Resident
  Indiana University
  Indiana University School of Medicine
  Indianapolis, IN, United States

  Disclosure information not submitted.

Author(s)

• EH

  Emma Holler, PhD

  Assistant Professor
  Indiana University School of Medicine
  Indianapolis, Indiana, United States

  Disclosure information not submitted.
• 

  Scott Dolejs, MD, MSc

  Colon and Rectal Surgeon
  Indiana Colon and Rectal Specialists
  Indianapolis, IN, United States

  Disclosure information not submitted.
• TS

  Trista Stankowski, MD (she/her/hers)

  Assistant Professor of Surgery
  Indiana University Department of Surgery
  Indiana University Hospital
  Indianapolis, IN, United States

  All of the relevant financial relationships listed below have been mitigated.
  This individual has no financial relationships with ineligible companies.
• MG

  Michael Guzman, MD

  Indianapolis, IN

  Disclosure information not submitted.
• 

  Joshua Waters, MD

  Associate Professor of Clinical Surgery
  Indiana University
  Indianapolis, IN, United States

  Disclosure information not submitted.
• BH

  Bryan Holcomb, MD

  Assistant Professor of Surgery
  Indiana University Department of Surgery
  Indianapolis, Indiana, United States

  Disclosure information not submitted.
• BR

  Bruce Robb, MD

  Associate Professor of Clinical Surgery
  Indiana University School of Medicine
  Indianapolis, Indiana, United States

  Disclosure information not submitted.
• 

  Samantha Hendren, MD, MPH, FACS, FASCRS

  Professor of Surgery
  Indiana University
  Indiana University
  Indianapolis, IN, United States

  Disclosure information not submitted.

Senior Author(s)

• 

  Sanjay Mohanty, MD MS (he/him/his)

  Assistant Professor
  Indiana University School of Medicine
  Indiana University School of Medicine
  Indianapolis, IN, United States

  All of the relevant financial relationships listed below have been mitigated.
  This individual has no financial relationships with ineligible companies.

Purpose/Background: Outcomes for rectal cancer have improved significantly over time, due in part to the addition of neoadjuvant radiation therapy (NART). However, the utility of NART for cancers of the rectosigmoid junction – approximately 10% of colorectal cancers – is unknown. We hypothesized that an unintended consequence of multimodality rectal cancer care might be overuse of neoadjuvant radiation (NART) in rectosigmoid junction cancer (RSJC). Our objectives were to 1) assess the utilization of NART in the treatment of RSJC over time, and 2) identify patient, tumor, and hospital factors associated with NART.

Methods/Interventions: This was a retrospective cohort study of patients captured in the National Cancer Database (NCDB) from 2004 to 2022. Included patients were adults with clinical Stage II or III RSJC who underwent surgery. Baseline characteristics were compared using chi-square analysis. The use of NART in these patients was examined over time, comparing Stages II, IIIa, and IIIb/c. Multivariable logistic regression was used to identify patient and hospital factors associated with increased odds of receiving NART.

Results/Outcomes: Of 49,506 patients with RSJC, 8,591 (17.4%) received NART and 40,915 did not. The percentage of cases receiving NART increased significantly from 2004 to 2022 in Stages IIIa [8.5% to 17.3%, (OR 1.05, 95% CI 1.02-1.07)] and IIIb/c [17.7% to 33.3%, (OR 1.07, 95% CI 1.06-1.08)]. Conversely, use of NART in Stage II cases declined from 2004 to 2022 (9.4% to 5.7%).
Multivariable logistic regression was used to test for patient, tumor, and facility factors associated with use of NART. Patient factors associated with lower use of NART included female sex (aOR 0.82, 95% CI 0.78–0.87), and higher Charlson-Deyo score (aOR 0.68, 95% CI 0.55–0.83, score of 3 compared to 0). Factors associated with greater adjusted odds of NART included clinical stage III (aOR 1.98, 95% CI 1.74–2.24 for IIIa v. II, and aOR 3.72, 95% CI 3.52–3.93 for IIIb v. II). In addition, uninsured (OR 1.19, 95% CI 1.04–1.37) and Medicaid patients (OR 1.16, 95% CI 1.04–1.28) were more likely to receive NART than those with private insurance.
In terms of facility factors, patients treated at high-volume hospitals (>26 cases/year) were less likely to receive NART (OR 0.78, 95% CI 0.68–0.89 vs. < 8/year). NART recipients also had higher odds of receiving care at multiple facilities (OR 1.27, 95% CI 1.18–1.37) and traveling farther, with those traveling 100–250 miles more likely to receive NART than those traveling < 25 miles (OR 1.46, 95% CI 1.25–1.70).

Conclusion/Discussion: In this national study of patents with rectosigmoid junction cancer, we find that 17.4% of patients received neoadjuvant radiation, and that use of NART has increased over time. NART use was associated with higher clinical stage, male sex, lower comorbidity score, and uninsured/Medicaid insurance type, as well as low-volume hospital care and fragmented care. These findings suggest that NART is selectively applied in the care of RSJC and that multidisciplinary review and decision-making may be particularly useful in RSJC cases to ensure appropriate selection for NART.

Utilization of NART in RSJC
Trend over time in utilization of NART for RSJC by stage.