Comparative analysis of the Memorial Sloan Kettering Bowel Function Instrument and the Low Anterior Resection Syndrome Questionnaire for assessment of bowel dysfunction in rectal cancer patients after low anterior resection.

Aim: Neoadjuvant therapy and total mesorectal excision (TME) for rectal cancer are associated with bowel dysfunction symptoms known as low anterior resection syndrome (LARS). Our study compared the only two validated instruments-the LARS Questionnaire (LARS-Q) and the Memorial Sloan Kettering Bowel Function Instrument (MSK-BFI)-in rectal cancer patients undergoing sphincter-preserving TME.

Methods: One hundred and ninety patients undergoing sphincter-preserving TME for Stage I-III rectal cancer completed the MSK-BFI and LARS-Q simultaneously at a median time of 12 (range 1-43) months after restoration of bowel continuity. Associations between the MSK-BFI total/subscale scores and the LARS-Q score were investigated using Spearman rank correlation (r ). Discriminant validity for the two questionnaires was assessed, and the questionnaires were compared with the European Quality of Life Instrument.

Results: Major LARS was identified in 62% of patients. The median MSK-BFI scores for no LARS, minor LARS and major LARS were 76.5, 70 and 57, respectively. We found a strong association between MSK-BFI and LARS-Q (r -0.79). The urgency/soilage subscale (r -0.7) and the frequency subscale (r -0.68) of MSK-BFI strongly correlated with LARS-Q. Low correlation was observed between the MSK-BFI diet subscale and LARS-Q (r -0.39). On multivariate analysis, both questionnaires showed worse bowel function in patients with distal tumours. A low to moderate correlation with the European Quality of Life Instrument was observed for both questionnaires.

Conclusions: The MSK-BFI and LARS-Q showed good correlation and similar discriminant validity. As the LARS-Q is easier to complete, it may be considered the preferred tool to screen for bowel dysfunction.