biostudies-literatureUnknown10(2)Habbous S<h4>Background</h4>In Ontario, patients with breast cancer typically receive their diagnoses through the Ontario Breast Screening Program (OBSP) after an abnormal screen, through screening initiated by a primary care provider or other referring physician, or through follow-up of symptoms by patients' primary care providers. We sought to explore the association of the route to diagnosis (screening within or outside the OBSP or via symptomatic presentation) with use of OBSP-affiliated breast assessment sites (O-BAS), wait times until diagnosis or treatment, health care use and overall survival for patients with breast cancer.<h4>Methods</h4>In this retrospective cohort study, we used the Ontario Cancer Registry to identify adults (aged 18-105 yr) who received a diagnosis of breast cancer froCMAJ openE313-E330https://www.ebi.ac.uk/biostudies/studies/S-EPMC9259434biostudies-literatureDifferences in breast cancer diagnosis by patient presentation in Ontario: a retrospective cohort study.PMC9259434Groome PHomenauth EHabbous SBarisic AKandasamy SEisen AMajpruz VForster KYurcan MChiarelli AMHolloway CMBfalseDifferences in breast cancer diagnosis by patient presentation in Ontario: a retrospective cohort study.<h4>Background</h4>In Ontario, patients with breast cancer typically receive their diagnoses through the Ontario Breast Screening Program (OBSP) after an abnormal screen, through screening initiated by a primary care provider or other referring physician, or through follow-up of symptoms by patients' primary care providers. We sought to explore the association of the route to diagnosis (screening within or outside the OBSP or via symptomatic presentation) with use of OBSP-affiliated breast assessment sites (O-BAS), wait times until diagnosis or treatment, health care use and overall survival for patients with breast cancer.<h4>Methods</h4>In this retrospective cohort study, we used the Ontario Cancer Registry to identify adults (aged 18-105 yr) who received a diagnosis of breast cancer fro2022-01-01T00:00:00Z2022 Apr-Jun2026-05-09T16:02:28.161Z2022-07-23T11:49:42.306ZS-EPMC92594343538303510.9778/cmajo.20210254