We have the ComPARe study findings. Now how can we use them?
The ComPARe study gives us vital information about how many cancer cases we can prevent. But understanding prevention is only one piece of the cancer control puzzle. To determine where and how to focus our cancer control and research efforts, we need to consider other key characteristics. These include:
- preventability – how preventable the cancer is
- detectability – whether there are opportunities to detect the cancer early through screening or other means
- incidence – the number of cancer cases expected in 2019
- survival – the percentage of people expected to survive at least 5 years past their diagnosis
- mortality – the number of cancer deaths expected in 2019
Figure 4.5 from Canadian Cancer Statistics 2019 shows findings from the ComPARe study across 23 cancer types. For each cancer type, the 5 characteristics were colour-coded as green, yellow or red (good, OK or bad, respectively). This approach of mapping characteristics can help highlight gaps and opportunities in cancer control and identify priority areas for research.
Consider lung cancer, for example. The incidence, survival and mortality are all red, which tells us that it’s a high-burden cancer. It’s the most commonly diagnosed cancer in Canada and the leading cause of cancer death, and it has one of the lowest 5-year survival rates of all cancers. Since it is also one of the most preventable cancers in Canada, its preventability is green. And since people without symptoms are sometimes screened for lung cancer, its detectability is yellow.
Together these findings suggest that lung cancer must continue to be a high priority. We’ve made progress in tobacco control, but there is an enormous opportunity to do more in lung cancer prevention. Opportunities in early detection may also increase. Some provinces and territories have started looking at how to implement organized lung cancer screening programs instead of the opportunistic screening that currently occurs.
Colorectal cancer is also among the most commonly diagnosed cancers and leading causes of cancer death in Canada. The ComPARe study found that about 46% of colorectal cancers can be prevented. Colorectal cancer screening can identify treatable precancerous polyps and earlier-stage colorectal cancer, and there are organized colorectal cancer screening programs in most provinces and territories. But participation rates are far below recommended levels. Improving participation in colorectal cancer screening can have a meaningful impact on this high-burden cancer.
Pancreatic cancer is another cancer that must be a high priority for further research. Its incidence is yellow, but it is expected to be the third leading cause of cancer death in Canada in 2019. It also has the lowest survival of all 23 cancers studied. Unlike lung and colorectal cancers, pancreatic cancer is limited in its opportunities for prevention and early detection. Research is urgently needed to better understand how to detect it earlier and treat it more effectively.
The biggest opportunities in cancer control are different across cancer types. For example, we need increased prevention for lung cancer, higher screening participation for colorectal cancer and enhanced research for pancreatic cancer. As we work to develop comprehensive cancer control strategies, the ComPARe study findings can help.
Darren Brenner, PhD
Co-principal investigator, Canadian Population Attributable Risk of Cancer (ComPARe) study
Assistant Professor, Departments of Oncology and Community Health Sciences, University of Calgary
Leah Smith, PhD
Chair, Canadian Cancer Statistics Advisory Committee
Senior Manager, Surveillance, Canadian Cancer Society
ComPARe study Knowledge Translation team