Neoadjuvant therapy abolishes the functional benefits of a larger rectal remnant, as measured by magnetic resonance imaging after restorative rectal cancer surgery.

BACKGROUND

The combination of advances in surgical technique and neoadjuvant therapy for rectal cancer has resulted in more patients undergoing sphincter-preserving surgery. Unfortunately, numerous patients subsequently experience bowel dysfunction, and may suffer from lifelong severe disability with major impact on their quality of life. The aim of the present study was to investigate whether the risk of severe LARS in patients was associated with the length of remnant rectum.

METHODS

A total of 125 patients who underwent sphincter-preserving surgery for rectal cancer were included. Postoperative bowel function was assessed using the low anterior resection syndrome (LARS) score a minimum of one year following surgery. The length of remnant rectum was measured on postoperative MRI of the pelvis and was correlated with the risk of having major LARS.

RESULTS

Overall, major LARS was observed in 38 per cent of patients. In the patients who underwent surgery alone, major LARS was reported by 27 per cent, and a larger remnant rectum was associated with a better functional outcome. In contrast, 80 per cent of patients who underwent combined preoperative chemoradiotherapy and surgery reported having major LARS. No association between the length of remnant rectum and the risk of major LARS was observed in patients treated with combined neoadjuvant therapy and surgery.

CONCLUSION

Both the length of remnant rectum and preoperative chemoradiotherapy had a major impact on the severity of bowel dysfunction after restorative rectal cancer surgery. No functional benefit from an irradiated rectal remnant was observed.