Study
PLCO
(Learn more about this study)
Project ID
PLCO-758
Initial CDAS Request Approval
Mar 30, 2021
Title
When to schedule the first screening for women's ovarian cancer based on her age and other parameters?
Summary
A probability method is developed to decide when to initiate cancer screening for asymptomatic individuals. The probability of incidence is a function of screening sensitivity, time duration in the disease-free state and sojourn time in the pre-clinical state; and it is monotonically increasing as time increases, given a person's current age. So a unique solution of the first screening time can be found by limiting this probability to a small value, such as 10% or 20%. That is, with 90% or 80% probability, one will not be a clinical incident case before the first exam. The scheduling time/age will change with her current age, risk factors, sensitivity, sojourn time and transition density (the three key parameters), etc. After this scheduling time is found, we can further estimate the distribution of the lead time (diagnosis time advanced by screening) and probability of over-diagnosis if one would be diagnosed with cancer at the first exam. Simulations were carried out under different scenarios; and we plan to apply the new method to female's ovarian cancer screening cohorts using the PLCO ovarian data. The method is applicable to other kinds of cancer screening. We plan to develop user-friendly software for physicians for optimal scheduling. The proposed research may provide a theoretical and practical basis to guide individuals or physicians to make informed decision about ovarian screening time in the near future.
Aims
Aim 1: Apply the likelihood method we have developed to the PLCO ovarian cancer screening data, to obtain accurate estimation of screening sensitivity, sojourn time distribution and transition density from the disease-free state to the pre-clinical state. These three key parameters are the building blocks, since all other terms are functions of the three. And we need to extract these three key parameters first.
Aim 2: Apply the new probability method to find the optimal first screening time for ovarian cancer using the PLCO-ovarian screening data. That is, applying the new method by inserting the estimations of the three key parameters from the PLCO-ovarian screening data, to find the first screening time based on a woman's current age and other risk factors. Then, using the found optimal screening time, to estimate the probability of over-diagnosis and the lead time distribution if one would be diagnosed with cancer at the first screening exam.
Collaborators
