Predictors of Bowel Function in Long-term Rectal Cancer Survivors with Anastomosis

Abstract

Background: Bowel function in long-term rectal cancer survivors with anastomosis has not been characterized adequately. We hypothesized that bowel function is associated with patient, disease, and treatment characteristics.

Methods: The cohort study included Kaiser Permanente members who were long-term (≥5 years) rectal cancer survivors with anastomosis. Bowel function was scored using the self-administered, 14-item Memorial Sloan-Kettering Cancer Center Bowel Function Index. Patient, cancer, and treatment variables were collected from the electronic medical chart. We used multiple regression to assess the relationship of patient- and treatment-related variables with the bowel function score.

Results: The study included 381 anastomosis patients surveyed an average 12 years after their rectal cancer surgeries. The total bowel function score averaged 53 (standard deviation, 9; range, 31-70, higher scores represent better function). Independent factors associated with worse total bowel function score included receipt of radiation therapy (yes vs. no: 5.3-unit decrement, p < 0.0001), tumor distance from the anal verge (≤6 cm vs. >6 cm: 3.2-unit decrement, p < 0.01), and history of a temporary ostomy (yes vs. no: 4.0-unit decrement, p < 0.01). One factor measured at time of survey was also associated with worse total bowel function score: ever smoking (2.3-unit decrement, p < 0.05). The regression model explained 20% of the variation in the total bowel function score.

Conclusions: Low tumor location, radiation therapy, temporary ostomy during initial treatment, and history of smoking were linked with decreased long-term bowel function following an anastomosis. These results should improve decision-making about surgical options.

Figure 1. Distribution of Bowel Function Scores Across 14 Items

*Cutpoints for scores are provided in the footnotes to Table 1.