Department of Epidemiology “Works-in-Progress” Seminar

Speakers:

Improving the Effectiveness of Colonoscopy Surveillance for Prevention of Colorectal Cancer

Markus Knudson, PhD
Postdoctoral Research Fellow
Department of Epidemiology
Harvard T.H. Chan School of Public Health

Abstract
We first investigated adherence to colonoscopy surveillance recommendations using the Mass General Brigham (MGB) Colonoscopy Cohort. We then developed a post polypectomy colorectal cancer (PPCRC) risk score for prediction of PPCRC using the three population-based cohorts – the Nurses’ Health Study (NHS) I, II and Health Professionals Follow-up Study (HPFS), and validated the PPCRC risk score in the MGB Colonoscopy Cohort. Lastly, we investigated if individuals screened negative for CRC should have an extended surveillance interval beyond 10 years using the NHS I/II and HPFS cohorts (work in progress). Our findings highlight the need for improving the use of colonoscopy surveillance in the clinic and indicate the potential of tailored surveillance for better prevention of colorectal cancer.

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Associations Between Germline Polygenic Risk Scores and Immune Cell Infiltration in Breast Cancer

Yuxi Liu, PhD
Postdoctoral Research Fellow
Department of Epidemiology
Harvard T.H. Chan School of Public Health
Dana-Farber Cancer Institute

Tumor immune microenvironment (TIME) plays key roles in tumor progression and response to immunotherapy. Studies have shown that germline variants contribute to differences in TIME in cancer patients. Here, we hypothesize that common variants underlying breast cancer risk or cancer-related traits, represented by polygenic risk scores (PRS), may act together to influence immune features in TIME. We assessed the associations between sixteen germline PRS and immune cell abundances estimated from gene expression profiles in breast tumors and adjacent normal breast tissue from 825 breast cancer patients in the Nurses’ Health Study and Nurses’ Health Study II cohorts. Preliminary results will be discussed. Understanding this germline-TIME link may inform us of novel therapeutic targets in breast cancer and improve personalized cancer immunotherapy.