Abstract:
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We are interested in developing a dynamic risk model that uses multiple longitudinal biomarkers to improve precancer risk estimation. Currently, Pap cytology is used to identify HPV-positive (HPV+) women at high-risk of cervical precancer, but it lacks accuracy and reproducibility. HPV DNA methylation is closely linked to the carcinogenic process and may show promise of improved risk stratification. We propose a joint model to link both the continuous methylation biomarker and a binary cytology biomarker to the time to precancer outcome using shared random effects. The model uses a discretization of the time scale to allow for closed-form likelihood expressions, thereby avoiding potential high dimensional integration of the random effects. The method handles an interval-censored time-to-event outcome due to intermittent clinical visits, incorporates sampling weights to deal with stratified sampling data, and can provide immediate and 5-year risk estimates that may inform clinical decision-making. Applying the method to longitudinally measured HPV methylation data may/can improve risk stratification of HPV+ women.
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