Treating Colon Cancer According to Guidelines
Overall, just over half (56%) of Stage III colon cancer patients age 65 and older were treated with guideline-recommended chemotherapy from 2010 to 2015. Rates were significantly lower in patients age 80 and older. Nonetheless, there continues to be variation among regions and age groups.
Measure: Percentage of Stage III colon cancer patients age 65 or over treated with guideline-recommended chemotherapy
As of this Report:
What is cancer surgery?
- Cancer surgery is the removal of cancerous tumours. It is often the first step in treating cancer.
- Removal of cancer tumours also provides an opportunity for a complete pathology assessment, including determining the exact type and stage of the cancer.
- For the purposes of this indicator, surgery is defined as the first surgical procedure after a cancer diagnosis.
What is adjuvant chemotherapy?
- Chemotherapy often slows or stops cancer cells from growing, multiplying or spreading to other parts of the body . Drugs can be administered by pills (oral), injections or intravenously (IV).
- Adjuvant chemotherapy refers to chemotherapy given to patients after surgery in which all of the tumour has been removed. This has been shown to increase the chances of killing any remaining non-visible cancer cells, to prevent recurrence (return) of cancer, to prolong life and to improve the chances of a cure in this group of patients.
What are the colon cancer guidelines?
- Stage III colon cancers are typically first treated by surgical removal of the tumour (resection).
- Adding adjuvant chemotherapy decreases the risk of the cancer returning (recurrence), especially when it has already spread to lymph nodes (Stage III colon cancer).
- Cancer Care Ontario has developed evidence-based treatment guidelines for the administration of post-operative adjuvant chemotherapy for patients with Stage III colon cancer.
- Patients are treated according to guidelines if they receive fluorouracil/leucovorin/oxaliplatin-based post-operative intravenous chemotherapy, or an oral drug (capecitabine, also known as Xeloda®) within 120 days of surgery .
- This indicator measures, by region and age, how well these guidelines were followed.
- A valid stage report is needed because treatment guidelines vary by stage.
- Concordance is measured in patients age 65 and older because complete information on the use of oral chemotherapy is available.
Integrated means that all of the different people involved in my care understand what has been done and what needs to be done and add to the treatment plan not delay or decrease its effectiveness. It’s important because as a cancer patient we need to know that nothing is being missed and we are receiving the best treatment possible because everyone understands what is being done and what the timeline is.
– Laurie P., Patient/Family Advisor
What do the results show?
Moderate variation in the use of guideline-recommended chemotherapy for Stage III colon cancer is present across regions (Figure 1).
- Overall, 56% of Stage III colon cancer patients age 65 or older received any guideline-recommended chemotherapy in 2015. That is similar to previous years.
- Regions vary from just over 50% of their patients being treated according to guidelines to 66%. This suggests an opportunity for improvement.
- Although other provinces report greater percentages of patients receiving chemotherapy following cancer surgery, their data are not directly comparable because they include all patients, including those younger than age 65.
- The jurisdiction with the largest percentage of patients treated according to guidelines for all ages is Saskatchewan, where 65% of Stage III colon cancer patients received guideline-recommended chemotherapy in 2012 .
The use of guideline-recommended chemotherapy for Stage III colon cancer and the use of specific chemotherapy drugs varies significantly by age (Figures 2 and 3).
- For the age groups of 65 to 70 and 71 to 80, the use of guideline-recommended chemotherapy was 81% and 65%, respectively. After age 80, the rate fell to 24% (Figure 2).
- The decrease in use of any guideline-recommended chemotherapy with increasing patient age has previously been reported .
- This may be because trials of adjuvant chemotherapy often do not include older patients, so relying on evidence to make assumptions about the benefits of adjuvant chemotherapy in much older patients may be problematic .
- Older patients may experience greater difficulty tolerating chemotherapy and more adverse events. This also may be a factor in the decreasing prescription of guideline-recommended chemotherapy in those age 80 and older .
- According to the 2015 Cancer System Performance Report by the Canadian Partnership Against Cancer, the decrease in adjuvant chemotherapy among older patients may be due to these patients being more likely to have other health conditions or to be taking medications that may interact negatively with chemotherapy .
- Older patients also have lower referral rates to a medical oncologist from their surgeons, which may be a reason fewer older patients receive guideline-recommended chemotherapy .
- Oral chemotherapy is used more frequently (39%) for those age 71 to 80, while intravenous chemotherapy is more common (67%) for those age 65 to 70. This may be because intravenous chemotherapy (oxaliplatin) has been shown to be less effective in populations over the age of 70 .
Why is this important for patient care?
- Understanding variations in treatment practices and why they occur can contribute to efforts to improve quality of care and associated outcomes.
- Evidence-based treatment guidelines are intended to help clinicians and patients choose the treatments that have the most favourable outcomes.
- Stage III colon cancer patients who receive guideline-recommended chemotherapy are more likely to have better outcomes than those who do not .
- We are best able to determine concordance with guidelines for patients age 65 and older and for those who have a valid stage report because of the lack of data about the use of oral chemotherapy for those younger than 65 and because treatment guidelines vary by stage.
Find out more
For more information on the Systemic Treatment Program, visit Cancer Care Ontario’s website.