High-Dose Chemoradiotherapy and Watchful Waiting May Be Alternative to Surgery in Some Patients With Distal Rectal Cancer


Key Points

  • Clinical complete response to chemoradiotherapy and watchful waiting was achieved in 40 of 51 eligible patients with distal rectal cancer.
  • The 1-year rate of local recurrence was 15.5%.

In a Danish prospective observational study reported in The Lancet Oncology, Appelt et al found that high-dose chemoradiotherapy and watchful waiting may be an alternative to abdominoperineal resection in some patients with distal rectal cancer.

Study Details

In the study, 55 patients with primary resectable T2 or T3, N0–N1 adenocarcinoma in the lower 6 cm of the rectum from three sites in Denmark received chemoradiotherapy consisting of 60 Gy in 30 fractions to tumor, 50 Gy in 30 fractions to elective lymph node volumes, 5 Gy of endorectal brachytherapy boost, and oral tegafur-uracil 300 mg/m² every weekday for 6 weeks. Endoscopies and biopsies of the tumor were performed at baseline; treatment weeks 2, 4, and 6; and 6 weeks after the end of treatment.


Among 51 eligible patients, 40 had complete clinical tumor regression, negative tumor site biopsies, and no nodal or distant metastases on imaging 6 weeks after treatment and were assigned to watchful waiting. These patients were followed closely with endoscopies and selected-site biopsies, with surgical resection performed for local recurrence. Median follow-up for local recurrence in the observation group was 23.9 months. The local recurrence rate at 1 year was 15.5%.

The most common grade 3 adverse event during treatment was diarrhea (8%). No fecal incontinence was reported by 18 of 25 patients (72%) at 1 year and 11 of 16 patients (69%) at 2 years. The most common late toxicity was rectal mucosa bleeding, which was observed in 2 of 30 patients (7%) at 1 year and 1 of 17 patients (6%) at 2 years. No unexpected serious adverse events or treatment-related deaths were observed.

The investigators concluded: “High-dose chemoradiotherapy and watchful waiting might be a safe alternative to abdominoperineal resection for patients with distal rectal cancer.”

Ane L. Appelt, PhD, of Vejle Hospital, is the corresponding author of The Lancet Oncology article.

The study was funded by the Lundbeck Foundation Center for Interventional Research in Radiation Oncology and the Danish Council for Strategic Research.

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