Colorectal cancer is the second leading cause of cancer-related death in North America, and one-third of these cases are rectal cancer. The treatment of rectal cancer most commonly involves radiotherapy to the rectum, followed by surgery. After the rectum is surgically removed, the large intestine (colon) from above is connected to the lower portion of the remaining rectum, or the anus, to maintain normal transit of stool from below. While this operation avoids a permanent bag at the skin level, many patients experience bothersome bowel symptoms as a consequence of losing their rectum (e.g., going often, not emptying their bowels fully, accidental leakage of liquid and gas). Additionally, some individuals may notice changes in their urination and sex life as a consequence of pelvic surgery and radiotherapy. Poor bowel function has a negative impact on ones quality of life, and can lead to frustration, as there is no single intervention that has proven to be effective, and each patient has to undergo trial and error to find a solution. As people struggle with bowel dysfunction after surgery, they describe feeling hopeless and isolated. The prevalence and risks for developing psychiatric distress after rectal cancer surgery remains unknown.
We will use a large hospital-admissions database (HES) and primary-care database (CPRD) to study psychiatric morbidity in rectal cancer patients and its relation to various factors including patient and disease characteristics, as well as post-operative disturbance in bowel, sexual, and urinary function.
The most common operation performed for rectal cancer is a restorative proctectomy. While this operation avoids a permanent ostomy, many patients (~70%) are left with significant bowel dysfunction (e.g., frequency, urgency, and incontinence) that impairs their quality of life. Furthermore, patients may experience urinary and sexual dysfunction, both of which can be consequences of pelvic surgery and radiotherapy. The purpose of this study is to assess the psychiatric morbidity of patients who have undergone restorative proctectomy for rectal cancer, as well as to identify risk factors for developing psychiatric morbidity, namely the presence of bowel dysfunction and sexual/urinary symptoms after restorative proctectomy, using population-level data.
This will be a large cohort study making use of two linked databases. Cohort inclusion criteria will be based on relevant rectal surgery procedures codes in the HES database. Variables of interest, including bowel dysfunction and sexual/urinary dysfunction will be defined using symptom read-codes recorded in CPRD. Outcomes including psychiatric morbidity and mortality will be defined using diagnosis codes, prescription product codes, and health service in HES and CPRD. The cohort will be described using demographic, patient, and disease characteristics. A Cox proportional hazards model will be used to estimate the risk of psychiatric morbidity and mortality adjusting for potential confounders. The principal exposures of interest will include pre-existing psychiatric morbidity, postoperative complications and presence of bowel and/or sexual, urinary dysfunction. Sensitivity analyses will be performed to test the robustness of our results, focusing primarily on outcome classification.
The following outcomes will be measured in this cohort: (1) psychiatric morbidity; (2) mortality attributed to psychiatric cause. Each of these outcomes will be operationally defined using read-codes and ICD10 codes for relevant diagnoses and prescriptions recorded in CPRD GOLD and HES.
Samy Suissa - Chief Investigator - Sir Mortimer B Davis Jewish General Hospital
Samy Suissa - Corresponding Applicant - Sir Mortimer B Davis Jewish General Hospital
Jeongyoon Moon - Collaborator - McGill University
Marylise Boutros - Collaborator - McGill University
Paul Brassard - Collaborator - McGill University
Sophie Dell'Aniello - Collaborator - McGill University
HES Admitted Patient Care