Colorectal Cancer in Ontario
Colorectal cancer is among the most commonly diagnosed cancers in Ontario, with 8,797 new cases of colorectal cancer diagnosed in 2016. It is also the second most common cancer among First Nations peoples, with almost 1,000 new cases diagnosed from 1991 to 2010.
Modifiable risk factors for colorectal cancer include:
- excess alcohol consumption
- overweight or obesity
- physical inactivity
- inadequate fruit and vegetable consumption
- tobacco smoking
Overall, Ontario’s cancer system as a whole is performing well with respect to colorectal cancer care compared with other jurisdictions nationally and internationally. Ontario has the best survival rates for colorectal cancer among all Canadian provinces. The 5-year relative survival ratio increased from 63% to 69% between 2002 and 2016. Relative survival is a ratio that compares the survival of people with cancer to the expected survival of people of the same age and sex in the general population.
The following highlights bright spots and opportunities, based on available indicators, to help focus efforts in improving the quality of care for people with colorectal cancer.
Diagnosis and Treatment
- More than 4 million people ages 50 to 74 are eligible for colorectal (bowel) cancer screening in Ontario. Of those, approximately 38% were overdue for screening (i.e., they needed to get screened) in 2017. Colorectal cancer screening participation rates are higher in Ontario than in both Manitoba and Australia. However, there may be differences in data definitions, methodologies and reporting periods. For detailed comparisons, see Colorectal Cancer Screening Participation.
- In June 2019, Cancer Care Ontario transitioned from the fecal occult blood test (FOBT) to the fecal immunochemical test (FIT) as the recommended screening test for people at average risk for developing colorectal cancer. FIT is easier to use, and better at detecting colorectal cancer and some pre-cancerous polyps (growths in the colon or rectum that can turn into cancer over time). It also increases colorectal cancer screening participation. In 2017, the percentage of Ontarians who had an abnormal fecal occult blood test with no follow-up within 6 months improved, decreasing from 23% in 2014 to 20% in 2017.
- The rate of admission to hospital with a perforation within 7 days of outpatient colonoscopy improved overall, with rates decreasing from 0.41 per 1,000 colonoscopies in 2014 to 0.36 per 1,000 colonoscopies in 2017. Compared with England, Ontario performed favourably. However, be aware of differences in reporting periods when interpreting the data. For detailed comparisons, see Colorectal Cancer Screening Quality.
- Stage at diagnosis is one of the most important prognostic factors for cancer. In 2017, approximately 50% of colorectal cancers were diagnosed stage 1 or 2. The proportion of cases diagnosed in stage 2 is higher in Ontario than in both Norway and Scotland. For detailed comparisons, see Reporting of Cancer Stage at Diagnosis.
- Typical treatment options for rectal cancer include chemoradiation, surgery and chemotherapy. Treatment depends on the type of cancer, stage and patient choice.
- The goal of rectal cancer surgery is the complete removal of cancer from the rectum. A “positive margin” means that some cancer cells remain after surgery. In Ontario, 7% of rectal cancer resection reports showed positive margins, which is comparable to resection rates in Scotland. For detailed comparisons, see Margins in Rectal Cancer Surgery.
- Treatment options for colon cancer include surgery and chemotherapy. Treatment depends on the type of cancer, stage and patient choice.
- Checking lymph nodes for cancer cells allows for accurate staging of the cancer. A consensus exists among experts that 12 or more nodes must be examined to adequately stage colorectal cancer. In Ontario, 12 or more lymph nodes were examined in 94% of colon surgery cases in 2017. Ontario performs very well compared with other provinces in Canada, and with Scotland. For detailed comparisons, see Lymph Node Sampling in Colon Cancer Surgery.
- Twenty-two percent of patients visited the emergency department or were readmitted to hospital within 30 days after colorectal cancer surgery. Reviewing unplanned hospital visits after cancer surgery helps us monitor complications and adverse events associated with cancer surgery.
- Recovering from cancer is different for each individual. People need access to the necessary healthcare services to help improve their quality of life after cancer treatment has ended.
- Ongoing symptoms are common after cancer treatment. These may be related to the cancer or side effects of the treatment. Tracking symptoms over time helps clinicians identify changes that may be meaningful to patients and start conversations about symptom management. Electronic symptom screening can result in a greater focus on issues that are most important to the patient. In symptom screens completed by colorectal cancer patients in 2018:
- 47% had at least 1 moderate or severe symptom
- 17% included a moderate to severe level of lack of appetite
- 10% included extreme tiredness
- nearly 20% reported moderate to severe anxiety
- Patients need appropriate follow-up care to detect cancer recurrence or new cancers. The percentage of colorectal cancer survivors who had at least 1 colonoscopy within 18 months of initial surgery ranged from 73.2% to 75.6% between 2013 and 2015.
For a visual summary of data on cancer burden and system performance for colorectal cancer across the cancer continuum, see Colorectal Cancer Overview.