Neoadjuvant chemoradiotherapy best restricted to high-risk rectal cancer patients

Last Updated: 2020-07-31

By David Douglas

NEW YORK (Reuters Health) - Because neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer carries a high risk of adverse effects, careful selection is needed to avoid possibly harmful treatment, according to new research.

The findings "justify the omission of neoadjuvant chemoradiotherapy with its adverse effects in more than 40% of patients with clinical stage-II/III rectal cancer," Dr. Theodor Junginger of the University Medical Center Mainz, in Germany, told Reuters Health by email

Dr. Junginger and colleagues conducted a prospective observational study of 1,093 patients who were followed for a median of 61 months. Among their aims was "the preoperative identification of patients with a low risk of local recurrence (LR) who can be cured at high rates by total mesorectal excision (TME) surgery alone and patients with a high risk of LR who require nCRT before surgical resection."

Patient risk profile as determined by MRI was used "to find the optimal range between undertreatment and overtreatment," the write in the Journal of the American College of Surgeons.

Altogether 878 (80.3%) of the patients were treated according to the study protocol in which nCRT before TME was indicated in high-risk patients with involved or threatened mesorectal fascia (of 1 mm or less) or cT4 or cT3 carcinomas of the lower rectal third. All other patients received primary surgery.

Overall, 526 patients (59.9%) underwent primary surgery, and 352 patients (40.1%) underwent nCRT followed by surgery. The median interval between the end of nCRT and surgery was 52 days.

At three years the locoregional recurrence rate was 3.1% in all patients treated according to protocol. In high-risk patients it was 3.9%, without significant differences between patients undergoing primary surgery (3.6%) and patients undergoing nCRT followed by surgery (4.2%).

In addition, of patients with clinical stages II and III who underwent primary surgery, 27.3% were diagnosed with pathological stage I. These tumors, say the researchers, "were overstaged by MRI and would have received nCRT had they been treated according to the existing guidelines. The chosen selection criteria excluded these patients from nCRT and reduced the risk of overtreatment."

The researchers conclude that given highly accurate MRI diagnostics, TME surgery and a standardized examination of the resected specimen, "nCRT - with its adverse acute and late effects, costs, and treatment time - can be avoided in more than 40% of patients with stages II and III rectal cancer, with only a minimal risk of undertreatment while avoiding overtreatment."

SOURCE: https://bit.ly/3hPtTiK Journal of the American College of Surgeons, online 19 July, 2020.