New, more up-to-date and comprehensive statistics have been released on incidence of cancer in Algoma.
The new numbers were unveiled earlier this month at Sault College by Dr. Jennifer Loo, associate medical officer of health at Algoma Public Health (APH).
For some cancers, most notably prostate and breast, the updated counts differ sharply from incidence rates previously cited by APH.
But the new metrics are based on a much larger data set and health officials are downplaying comparisons to other local cancer statistics released by APH as recently as 16 months ago.
Here are the latest Algoma cancer incidence stats, as made public by Dr. Loo at the Jan. 15 Science Café, a monthly community forum organized by Dryer Fire to discuss scientific issues in an informal and accessible environment:
Incidence of cancer in Algoma
- 567.3 new cases of cancer per 100,000 people per year
Most common types of cancer in Algoma (highest incidence)
- #1 - lung cancer, with 90.8 new cases per 100,000 people per year
- #2 - prostate cancer, with 72.0 new cases per 100,000 people per year
- #3 - colon cancer, with 71.2 new cases per 100,00 people per year
- #4 - breast cancer, with 67.7 new cases per 100,000 people per year
- #5 - oral cancer, with 16.2 new cases per 100,000 people per year
- #6 - malignant melanoma skin cancer, with 15.3 new cases per 100,000 people per year
Our total number of 567.3 new cancer cases per 100,000 population per year is higher than the comparable Ontario-wide number af 519.5, but not nearly as high as the 752.8 cases reported in the Algoma Community Health Profile, released in September, 2018.
Comparing the new numbers to APH's 2018 rankings, it would appear lung cancer has jumped from the #3 spot in 2018 (with 93.6 new cases per 100,000 people) to become Algoma's most common cancer type.
Prostate cancer, #1 in the 2018 statistics with a worrisome 212.8 cases, seems to have dropped to #2, and breast cancer (female) has apparently dropped to #4 from 193.1 cases per 100,000 16 months ago.
Further muddying the local statistical waters is Dr. Kim Barker's Algoma Cancer Report, published in 2015 and covering the decade from 2000 to 2009.
That report ranked Algoma's top three cancers as:
- #1 - prostate cancer, with 118.0 cases per 100,000 people per year
- #2 - breast cancer, with 100.2 cases per 100,000 people per year
- #3 - lung cancer, with 64.7 cases per 100,000 people per year
But not so fast.
Jordan Robson, APH's epidemiologist and vice-president of the Association of Public Health Epidemiologists in Ontario, says the figures released this year are derived from a decidedly different data set than the 2018 numbers.
"This [new] data represents an updated and more comprehensive picture of the burden of cancer across Algoma that is informed by 30 years of data, compared to the single-year estimate that was available at the time and published in our Community Health Profile in 2018," Robson tells SooToday.
The statistics unveiled by Dr. Loo this month draw on local cancer cases from 1986 to 2016, while the 2018 Community Health Profile was based on just one year of data, from 2013.
"Between 1986 and 2016, the incidence for all cancers was 567.3 cases per 100,000 population in Algoma," Robson says.
"Algoma’s rate over this period is statistically higher than the Ontario rate of 519.5 cases per 100,000. Between 1986 and 2016, there were over 22,000 cases of cancer diagnosed in the Algoma population."
"Over the period of 1986 to 2016, Algoma residents were more likely to be diagnosed with lung, colorectal, and oral cancer than an Ontario resident. Algoma residents experienced similar amounts of breast, cervical and prostate cancer compared to Ontario while experiencing statistically lower amounts of malignant melanoma."
"The single-year cancer incidence in Algoma has been stable between 1986 and 2016. Individual years for single cancer types are not presented due to the small number of cases and general overlapping of confidence intervals across the whole time period which hinders meaningful insight," Robson told us.
"It's hard for us in Algoma to be able to get really specific data for just our district or just the city of the Sault, because our population is small and it takes a lot of years of cumulative information for us to be able to draw conclusions from data," Dr. Loo told this month's Science Café.
Asked about drawing Sault Ste. Marie's cancer statistics from the Algoma numbers, Dr. Loo responded: "The problem is Sault Ste. Marie's population is currently around 70,000. In order to report a stat like that, it has to be pretty stable as a number. The unit that we report them in, is so many cases per 100,000 people. For common cancers, we might be able to give you a number for Sault Ste. Marie, but you'd have to do it over a number of years.""Your numbers are small that, even for common cancers, your estimates are going to have a huge range of variability."
"When it comes to cancer, we're not all that different from the rest of Ontario. When we look at Ontario statistics and we look at Algoma statistics, there's very little reason for us to think that Sault Ste. Marie is going to vary dramatically from those numbers," Dr. Loo said.