292 – Competing Risks
Impact of Competing Risks on the Risk Estimation of Multiple Cancers in Family Studies
Yun-hee Choi
University of Western Ontario
Laurent Briollais
Lunenfeld-Tanenbaum Research Institute
In cancer family studies, families are often ascertained through affected individuals (i.e. the probands) where those affected individuals can have multiple cancers. Estimating the risk of first and successive cancers in these families could depend on the occurrence of multiple cancers among the probands as well as their mutation status. The goal of our study is to investigate the impact of ascertainment on risk estimation of a first and a second cancer in family studies. We propose here a general framework based on a progressive multistate model where the progression to a specific cancer stage can have multiple competing risk events to deal with complex ascertainment and provide unbiased risk estimates for first and successive cancers in family studies. We illustrate the method by an analysis of lynch syndrome families identified through the colon cancer family registries, a NIH-funded initiative. These families harbour a mutation in mismatched repair genes and members of those families are at high risk of developing multiple cancers over their lifetime including colorectal, endometrial, ovarian, stomach.