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Principal Investigator
Eric Miller
Position Title
About this CDAS Project
PLCO (Learn more about this study)
Project ID
Initial CDAS Request Approval
Jan 22, 2024
Evolution of cancer stage and mortality in the PLCO trial (NCI Version)
The interim 10 yr results from the NordICC colonoscopy study were recently reported in the NEJM (bretthauer, M. NEJM 2022). In the intention to screen analysis, the crossover in incidence from increased rate in the screening group compared to control occurred around year 6, later than that observed in PLCO and the other flexible sigmoidoscopy trials (years 3-5). Moreover, no appreciable effect on CRC mortality was observed through 10 years of follow up. The reasons for the lack of an observable effect on CRC mortality are unclear. In the flexible sigmoidoscopy trials, a consistent and predictable effect on mortality was observed. The divergence in the mortality curves begins rather early on. We propose to study the PLCO chronological evolution of cancer incidence, stage and mortality in granular detail. it is assumed that in the screening arm in the initial years of the trial, early-stage prevalent cancers are identified, and those early-stage lesions and less likely to lead to CRC mortality, contributing to the initial divergence of the CRC mortality curves. Subsequently, the effect of polypectomy on reducing incident CRC disease emerges, and absolute reductions in CRC incidence emerge.

1. To examine in detail the CRC stage in screening and control arms by time to characterize the emergence of cancer in a trial which showed an effect.
2. To examine which tumors contribute to CRC mortality by time.


Robert E. Schoen, M.D., M.P.H
Uri Ladabaum, M.D., M.S.
Reinier Meester, PhD
Paul Pinsky, PhD