Long-term prescribed drug use in stage I–III rectal cancer patients in Sweden, with a focus on bowel-regulating drugs after surgical and oncological treatment

TL;DR

This study found that rectal cancer survivors in Sweden use more bowel-regulating drugs long-term compared to the general population, indicating ongoing gastrointestinal issues after treatment.

Contribution

The study provides new insights into long-term drug use patterns in rectal cancer survivors, focusing on bowel-related medications.

Findings

Rectal cancer patients had higher dispensing rates of drugs for constipation, diarrhea, and gastrointestinal disorders up to 10 years after surgery.

Hartmann’s procedure was linked to higher digestive drug use, but this was mainly due to increased diabetic drug use.

Advanced cancer stage was associated with higher digestive drug dispensing, but not with chemotherapy or radiotherapy.

Abstract

To describe long-term prescribed drug use after rectal cancer treatment.

We identified 12,871 rectal cancer patients without distant metastasis between 2005 and 2016 and 64,341 matched population comparators using CRCBaSe (a Swedish nationwide register linkage of colorectal cancer patients). Mean defined daily doses (DDDs) of drug dispensing during relapse-free follow-up were calculated by Anatomical Therapeutic Chemical drug categories. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) from negative binomial regression were used to compare drug dispensing between patients and comparators.

The overall pattern of drug dispensing was similar among cancer survivors and comparators, although patients had higher mean DDDs of drugs regulating the digestive system. Excess dispensing of drugs for constipation (IRR, 3.35; 95% CI, 3.12–3.61), diarrhea (IRR, 6.43; 95% CI, 5.72–7.22), functional gastrointestinal disorders (IRR, 3.78; 95% CI, 3.15–4.54), and vitamin and mineral supplements (IRR, 1.37; 95% CI, 1.24–1.50) was observed up to 10 years after surgery. Treatment with Hartmann’s procedure was associated with higher dispensing rates of digestive drugs compared to surgery with anterior resection and abdominoperineal resection but the association was attributed to higher use of diabetic drugs. Additionally, excess digestive drug dispensing was associated with more advanced cancer stage but not with (chemo)radiotherapy treatment.

Excess drug use after rectal cancer is primarily driven by bowel-regulating drugs and is not modified by surgical or oncological treatment.

The excess use of bowel-regulating drugs after rectal cancer indicated long-standing postsurgical gastrointestinal morbidity and need of prophylaxis. Reassuringly, no excess use of other drug classes was noted long term.

The online version contains supplementary material available at 10.1007/s11764-024-01548-9.

Figures