Universal Lynch Syndrome Screening in Newly Diagnosed Colorectal Cancer: Impact of an Alberta-wide Screening Program

Lynch Syndrome (LS) is the most common cause of inherited colorectal cancer (CRC) and is thought to be present in 2-5% of new CRC diagnoses. LS is caused by a germline mutation in one of the DNA Mismatch Repair (MMR) genes and can be diagnosed through germline genetic testing. Universal tumor screening in all new CRCs using Immunohistochemistry (IHC) to assess for loss of MMR-protein expression allows for identification of individuals at increased risk for underlying LS who would benefit from genetic testing. This thesis reports the results of one study performed with the aim of evaluating the early-phase impact of Alberta’s province-wide universal LS screening program for all new CRCs on rates of germline genetic testing for LS as well as key clinical outcomes and wait-times in Alberta’s LS screening and diagnostic pathway. Our retrospective review of quality assurance data showed an increase in the number of CRCs screened per month, increased proportion of women and people living outside urban centers being screened for LS, as well as an increased odds of being referred to medical genetics after program implementation. An absolute reduction in mean time from cancer diagnosis to all key clinical touchpoints was seen (not statistically significant). After implementation there was no significant difference in screen positive patients being seen by medical genetics or undergoing genetic testing which is suggestive of additional barriers not addressed by universal tumor screening alone. Together, these findings demonstrate a likely net positive impact from universal screening worthy of continued provincial funding but with a need for prospective data collection and monitoring to identify and address barriers encountered by patients who would benefit from medical genetics consultation, germline genetic testing, and enrollment in high-risk cancer screening.

Name thesis:degree_name

Master of Science (MSc)

Discipline thesis:degree_discipline

Medicine – Community Health Sciences

Grantor dc:publisher.institution

Graduate Studies

Year dc:date.issued

2025

Author dc:creator

• Iannuzzi, Jordan

Advisor dc:contributor.advisor

• Heitman, Steven

Committee members dc:contributor.committeemember

• Brenner, Darren
• Perrier, Renee

• Lynch Syndrome
• Population Screening

Statement dc:rights

• University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

en

DOI

https://dx.doi.org/10.11575/PRISM/49405

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:1880/121816