From the Guidelines
The correct answer regarding preoperative radiotherapy for rectal adenocarcinoma is E: it reduces the risk of local recurrence and improves outcomes in rectal cancer. Preoperative (neoadjuvant) radiotherapy has become a standard approach for locally advanced rectal cancer, typically administered with concurrent chemotherapy. This approach effectively shrinks tumors before surgery, making them more amenable to complete resection. Studies have consistently demonstrated that preoperative radiotherapy significantly reduces local recurrence rates by approximately 50-60% compared to surgery alone, as shown in the study by 1. While preoperative radiotherapy does down-stage tumors, this occurs in approximately 60-70% of cases, not just 50%. Although it may slightly increase short-term postoperative complications, the long-term oncological benefits generally outweigh these risks. Importantly, preoperative radiotherapy is actually more effective than postoperative radiation because it acts on better-oxygenated tissues before surgical disruption of blood supply, as noted in the study by 1. Some key points to consider include:
- The use of preoperative radiotherapy in rectal cancer, as discussed in the study by 1
- The comparison of preoperative versus postoperative radiotherapy, as shown in the study by 1
- The role of short-course radiotherapy in rectal cancer, as discussed in the study by 1
- The management of locally advanced rectal cancer, as outlined in the study by 1
- The importance of considering tumor stage and other factors when evaluating the effectiveness of preoperative radiotherapy, as noted in the study by 1 While preoperative radiotherapy clearly improves local control and disease-free survival, its impact on overall survival is more modest and depends on tumor stage and other factors. Overall, the evidence supports the use of preoperative radiotherapy as a standard approach for locally advanced rectal cancer, with the goal of reducing local recurrence and improving outcomes.
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.