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The Ontario Health Study (OHS): a resource for cancer etiology and early marker studies

Mar 26, 2021 // Study Updates

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In this prospective cohort study of 225,620 participants, 10,436 incident cancers were ascertained over an average 8-yr follow-up, including 1,645 breast, 907 lung, 840 colorectal, 509 bladder, 227 pancreatic, and 181 ovarian cancer cases. The proportion of cancers diagnosed at stage III/IV was highest for pancreatic (69%) and oral (69%), followed by lung (66%), gastrointestinal (66%), renal (62%), ovarian (58%), and bladder (48%). 41,194 participants provided blood samples. Phenotypic and genotypic data, and large sample sizes, will enable studies of risk factors for cancer and biomarkers for early detection.