Cancer of the upper rectum

Area of Science:

• Oncology
• Surgical Gastroenterology
• Radiology

Background:

• Rectal cancer incidence is rising, with a significant proportion in the upper rectum.
• Optimal surgical management, particularly total mesorectal excision (TME), is debated for upper rectal cancers.
• The adequacy of partial mesorectal excision (PME) and the necessity of neoadjuvant therapy remain controversial.

Purpose of the Study:

• To evaluate the adequacy of mesorectal excision and its impact on oncological outcomes in rectal cancer patients.
• To specifically investigate the efficacy of PME versus TME for upper rectal cancers.
• To assess the influence of distal resection margins and tissue shrinkage on surgical radicality.

Main Methods:

• Postoperative pelvic MRI to assess the extent and completeness of mesorectal excision.
• Kaplan-Meier analysis to determine local recurrence rates in patients treated with PME.
• MRI of fresh and fixed surgical specimens to measure tissue shrinkage and distal margin reduction.

Main Results:

• 40% of patients had residual mesorectal tissue post-surgery, particularly after PME.
• PME was associated with a significantly higher 3-year local recurrence rate (14%) compared to TME (3%).
• Surgical specimen length and distal margins reduce by 30% after fixation, necessitating larger margins for PME.

Conclusions:

• Suboptimal mesorectal excision is common, especially with PME, leading to increased local recurrence.
• TME is superior to PME for upper rectal cancer, offering better local control.
• Accurate assessment of distal radicality requires accounting for significant tissue shrinkage post-fixation.