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. The objectives of this study are to determine the frequency of bowel, urinary, and sexual symptoms after surgery for rectal cancer, and to understand factors associated with their development. We will use a large hospital-admissions database (HES) to identify patients relevant to our study, and a large primary-care database (CPRD) to identify bowel, urinary, and sexual symptoms. We will use advanced statistical methods to understand factors most associated with each set of symptoms.
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 primary objective of this study is to estimate the incidence of bowel dysfunction after rectal cancer surgery, and to identify factors associated with its development. Secondary objectives are to estimate the incidence of postoperative sexual and urinary symptoms, as well as to evaluate the association between bowel dysfunction and new-onset postoperative sexual and urinary symptoms. 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, and outcomes will be defined using symptom read-codes and medication prescription product-codes recorded in CPRD. The cohort will be described using demographic, patient, and disease characteristics. The principal exposures of interest will include patient treatment (the use of preoperative radiotherapy, the use of postoperative chemotherapy), operative (operative approach, tumour height, use of a diverting ostomy), and postoperative (anastomotic leak, duration of diversion) characteristics. A Cox proportional hazards model will be used to adjust for potential confounders such as psychiatric morbidity at baseline
The following outcomes will be measured in this cohort: (1) bowel dysfunction; (2) sexual symptoms; and (3) urinary symptoms. Each of these outcomes will be operationally defined using read-codes for relevant symptoms recorded in CPRD GOLD (see section N below).
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
Natasha Caminsky - Collaborator - Sir Mortimer B Davis Jewish General Hospital
Paul Brassard - Collaborator - McGill University
Richard Garfinkle - Collaborator - McGill University
Sophie Dell'Aniello - Collaborator - McGill University
Zharmaine Ante - Collaborator - Sir Mortimer B Davis Jewish General Hospital
HES Admitted Patient Care