Several ancillary studies of PLCO data have been conducted and others are ongoing. For these studies, subsets of PLCO participants of interest were selected and additional data were ascertained through extra surveys, questionnaires, research and testing. Studies include a collaboration with a manufacturer regarding a free PSA assay, study center collaborations on cost-effectiveness and quality of life assessments, and a study of colonoscopy utilization.

For each dataset, a Data Dictionary that describes the data is publicly available. In order to obtain the actual data in SAS or CSV format, you must begin a data-only request. Data will be delivered once the project is approved and data transfer agreements are completed.

The following Ancillary Studies data are available by request:

1. Benign Ovarian Pathology
2. Free PSA
3. SCU
4. Contamination Survey
5. Chronic Conditions