Neoadjuvant radiotherapy in rectal cancer - less is more?

Area of Science:

• Oncology
• Surgical Oncology
• Radiation Oncology

Background:

• Significant international variation exists in neoadjuvant radiation use before total mesorectal excision for rectal cancer.
• The MERCURY group recommends a selective approach to neoadjuvant chemoradiotherapy (CRT).

Purpose of the Study:

• To evaluate the local relapse rates (LRRs) of a selective neoadjuvant chemoradiotherapy (CRT) strategy in rectal cancer patients.
• To determine if CRT is only necessary for margin-threatening tumors.

Main Methods:

• Retrospective, single-centre study of 272 rectal adenocarcinoma patients (2007-2012).
• Patients categorized into high-, intermediate-, and low-risk groups based on National Institute for Health and Care Excellence guidance.
• Data analyzed from electronic hospital systems, including demographics, treatment, and follow-up.

Main Results:

• Neoadjuvant CRT was administered to 79% of high-risk, 6% of intermediate-risk, and 5% of low-risk patients.
• Overall 5-year local relapse rate (LRR) was 5.2% and distant recurrence rate (DRR) was 17.8%.
• 5-year LRR was 2.0% for surgery-only and 7.4% for neoadjuvant CRT groups; DRR was 8.5% and 18.9%, respectively.

Conclusions:

• Selective neoadjuvant chemoradiotherapy (CRT) for margin-threatening rectal tumors yields exceptionally low local relapse rates.
• This strategy minimizes multimodal treatment morbidity and facilitates earlier systemic therapy to reduce distant recurrence.