February 12, 2019

The power of one, benefiting the many

Close up of a person using a laptop.

When the first volunteer signed up for the Ontario Health Study (OHS), carefully filling out a detailed online health questionnaire, they no doubt hoped their efforts would do some good. They could never have predicted that, 10 years on, their de-identified health data is now pooled with those of nine million other altruists, from across four continents, in addition to being part of a Canadian national database.

The pooling of these already-large data sets is a gift to cancer researchers. It offers an opportunity to tease out new associations and patterns, to assess risks from uncommon exposures, by scanning the breadth of data and samples from participants with varied genetic make-ups, differing lifestyle habits and disparate environmental exposures. This information could be used to flag for early or increased screening those individuals at highest risk of developing cancer, or to promote changes in lifestyle and the avoidance of certain environmental exposures to reduce the risk of cancer forming.

The Ontario Health Study is the largest contributor of data and biosamples to the Canadian Partnership for Tomorrow Project (CPTP), a pan-Canadian federation of six regional cohorts. The CPTP is a ready-made platform for researchers to access more than 1,600 data points on everything from family history of cancers, to diet, sleep and activity patterns, and samples of blood, urine and saliva. Data collected from two OHS health questionnaires are already being used by scientists working on eight CPTP projects.

It’s big data at its best, explains John McLaughlin, Chief Science Officer at Public Health Ontario, and Executive Director, CPTP. Cancer collaborators can accomplish more, faster, and at lower costs than they could ever undertake looking only at their own national data set.

“And it allows Canada to work with the best centres in the world,” says McLaughlin, who also served as the first OHS Principal Investigator.

Funded in part by the Ontario Institute for Cancer Research (OICR), OHS is thriving as OICR’s largest program focused on cancer prevention. The 225,000 OHS participants are now part of a global cancer data consortium, one that has enormous potential to investigate the origins and causes of rare and less-studied cancers. The National Cancer Institute Cohort Consortium is an ambitious collaboration that brings together the datasets and biosamples of 58 large health studies from 20 countries.

McLaughlin projects back to that early OHS participant dutifully tapping out their health history, and marvels.

“For them, it doesn’t seem like cutting edge – ‘you’re asking me for the obvious’. But when it scales up, to a collaboration involving millions of participants, it really is at the cutting edge of science.”