When to use adjuvant radiation in colon cancer

  • Wegner RE & al.
  • Ann Surg Oncol
  • 12 Nov 2019

  • curated by Jim Kling
  • Univadis Clinical Summaries
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Takeaway

  • Adjuvant radiotherapy was associated with improved survival in resected colon cancer patients with both T4 disease and positive resection margins.

Why this matters

  • There are no current guidelines covering when adjuvant radiotherapy should be applied in colon cancer.
  • The authors recommend that those considering adjuvant radiation in patients at high risk for local failure should conduct preoperative imaging to assist with targeting and employ clip or fiducial placement at surgery to limit field size and reduce toxicity.

Study design

  • Retrospective analysis of records from the National Cancer Database (n=23,325).
  • Funding: None.

Key results

  • 7% of patients underwent adjuvant radiotherapy.
  • Median radiation dose, 50.4 Gy in 28 fractions.
  • Median follow-up, 36 months.
  • A propensity score-matched analysis showed a median survival of 80 months with radiation and 74 months without radiation (P=.25).
  • Subgroup analyses showed a longer survival associated with surgery in patients with both pT4 and positive margins (66 vs 47 months; P=.02), but not among patients with pT4 or positive margins alone.
  • Radiation was associated with longer survival in patients who underwent R2 resection (57 vs 32 months; P=.04), but not those undergoing R1 resection.

Limitations

  • Retrospective analysis.