From the Guidelines
The correct answer regarding preoperative radiotherapy for rectal adenocarcinoma is E: Reduce risk of local recurrence and improve outcomes in rectal cancer. Preoperative radiotherapy, also known as neoadjuvant radiotherapy, has become a standard approach in the management of locally advanced rectal cancer, as supported by the most recent guideline from 2024 1. It significantly reduces the risk of local recurrence by shrinking the tumor before surgery, which allows for more complete resection and potentially sphincter-preserving procedures. Some key points to consider:
- Preoperative radiotherapy can down-stage tumors, although the exact percentage of cases where this occurs is not consistently reported across studies, with some studies suggesting it happens in approximately 60-70% of cases, not just 50% 1.
- Although it can increase some postoperative complications like delayed wound healing, its benefits generally outweigh these risks, as seen in studies comparing preoperative and postoperative radiation therapy 1.
- Importantly, preoperative radiotherapy has not consistently demonstrated an overall survival advantage compared to surgery alone, despite improving local disease control, as noted in several studies including those from 2018 1.
- It is generally considered more effective than postoperative radiation because it acts on better-oxygenated tissues before surgical disruption of blood supply, resulting in enhanced radiosensitivity and fewer treatment-related complications, a principle supported by the 2024 guideline 1.
- The choice between short-course radiotherapy and long-course chemoradiation should be based on individual patient factors and tumor characteristics, with evidence suggesting both can be effective in reducing local recurrence rates, as discussed in the 2017 ESMO guidelines 1.
From the Research
Preoperative Radiotherapy for Rectal Adenocarcinoma
- Preoperative radiotherapy can reduce the risk of local recurrence and improve overall survival rate in patients with locally advanced rectal adenocarcinoma 2.
- Short-term preoperative radiotherapy does not increase the rate of postoperative complications and is a safe therapeutic adjunct for the treatment of locally advanced rectal cancer 2.
- Preoperative radiotherapy can down-stage tumors, with some studies showing that it can achieve clinical and pathologic complete response in a significant proportion of patients 3.
- The addition of concomitant chemotherapy to preoperative radiotherapy may enhance downstaging and improve the likelihood of sphincter preservation 4.
- Preoperative external beam radiation and attention to mesorectal dissection can achieve low local recurrence and excellent long-term survival rate in patients with adenocarcinoma of the rectum, with low morbidity and mortality 5.
Comparison of Options
- Option A (Improves survival): Supported by 2, which demonstrated that preoperative radiotherapy improves overall survival rate.
- Option B (Increases postoperative morbidity): Not supported by 2, which found that short-term preoperative radiotherapy does not increase the rate of postoperative complications.
- Option C (Down-stages tumour in up to 50% of cases): Supported by 3, which showed that preoperative radiotherapy can achieve clinical and pathologic complete response in a significant proportion of patients.
- Option D (is less effective than postoperative radiation): Not directly addressed by the provided studies, but 4 suggests that preoperative radiotherapy can be effective in reducing local recurrence and improving survival.
- Option E (Reduce risk of local recurrence and improve outcomes in rectal cancer): Supported by 2, 4, and 5, which demonstrate that preoperative radiotherapy can reduce the risk of local recurrence and improve overall survival rate.