The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial is a large randomized trial designed and sponsored by the National Cancer Institute (NCI) to determine the effects of screening on cancer-related mortality and secondary endpoints in men and women aged 55 to 74. The screening component of the trial was completed in 2006. Participants are being followed and additional data will be collected through 2015. In 2011, the follow up was streamlined and began being moved from the Screening Centers to the Centralized Data Coordinating Center (CDCC). Numerous epidemiologic and ancillary studies are also underway to answer related crucial questions.

The Etiology and Early Marker Studies (EEMS)

The Etiology and Early Marker Studies (EEMS) is an ongoing component of the PLCO Trial. By collecting biologic materials and risk factor information from trial participants before the diagnosis of disease, PLCO EEMS adds substantial value to the trial, providing a resource for cancer research, focused, in particular, on cancer etiology and early markers.

The Cancer Data Access System (CDAS) is a web portal that facilitates access to PLCO data other than the biospecimens in EEMS. CDAS provides extensive documentation including a summary of the trial, a description of the data collected, and a searchable list of research projects under way with the data and published results. Analytic data sets for prostate, lung, colorectal, ovarian and 14 other common sites of interest are available with nearly all the study data available for screening, incidence and mortality analyses.