The impact of type 2 diabetes on long-term gastrointestinal sequelae after colorectal cancer surgery: national population-based study

Background Long-term gastrointestinal sequelae are common after colorectal cancer surgery, but the impact of type 2 diabetes (T2D) is unknown. Methods In a cross-sectional design, questionnaires regarding bowel function and quality of life (QoL) were sent to all Danish colorectal cancer survivors, who had undergone surgery between 2001 and 2014 and had more than 2 years follow-up without relapse. The prevalence of long-term gastrointestinal sequelae among colorectal cancer survivors with and without T2D were compared while stratifying for type of surgical resection and adjusting for age, sex, and time since surgery. Results A total of 8747 out of 14 488 colorectal cancer survivors answered the questionnaire (response rate 60 per cent), consisting of 3116 right-sided colonic, 2861 sigmoid, and 2770 rectal resections. Of these, 690 (7.9 per cent) had a diagnosis of T2D before surgery. Survivors with T2D following rectal resection had a 15 per cent (95 per cent c.i. 7.8 to 22) higher absolute risk of major low anterior resection syndrome, whereas survivors with T2D following right-sided and sigmoid resection had an 8 per cent higher risk of constipation (P < 0.001) but otherwise nearly the same long-term risk of bowel symptoms as those without T2D. For all types of colorectal cancer resections, T2D was associated with a 6-10 per cent higher risk of severe pain (P < 0.035) and a 4-8 per cent higher risk of impaired QoL. Conclusion T2D at time of surgery was associated with a higher risk of long-term bowel dysfunction after rectal resection, but not after colon resection excluding a higher risk of constipation. T2D was associated with a slightly higher frequency of severe pain and inferior QoL after both rectal and colonic cancer resection. Among colorectal cancer survivors, type 2 diabetes at time of surgery is associated with a higher risk of long-term bowel dysfunction after rectal resection, but unexpectedly not after colon resection except from a higher risk of constipation. Special attention during follow-up visits should be given to rectal cancer survivors with diabetes to identify and treat long-term side effects of cancer surgery, whereas right-sided colectomy and sigmoid resection survivors with diabetes do not need special attention during follow-up.

Automated summary

Colorectal cancer survivors with type 2 diabetes may have a higher risk of long-term gastrointestinal sequelae, particularly following rectal resection. The study also found that type 2 diabetes is associated with increased risk of severe pain and impaired quality of life among colorectal cancer survivors.