Representation of Low-Grade Prostate Cancer in Metastatic Prostate Cancer Trials

Lead Investigator: Yaw Nyame, University of Washington Medical Center
Title of Proposal Research: Representation of Low-Grade Prostate Cancer in Metastatic Prostate Cancer Trials
Vivli Data Request: 5872
Funding Source: None
Potential Conflicts of Interest: None

Summary of the Proposed Research:

Prostate cancer is the most common non-skin cancer in men affecting roughly 1 in 7 men in the US during the course of their lifetime. As a disease, prostate cancer demonstrates a wide range of aggressiveness and outcomes. Currently, there is debate whether low-grade/low-risk (i.e., Gleason score 6) prostate cancers can spread in the body and be fatal. In 1994, researchers from Johns Hopkins University identified a group of clinically ‘insignificant’ prostate cancers characterized by very small and low-grade tumors that did not spread or cause death in men treated with surgery. The classification of these low-risk cancers is the basis of modern-day active surveillance, which is the primary mode of managing low-risk cancers. In fact, some clinicians and researchers are advocating for removing the title of cancer from these low risk tumors.

In this study, we aim to characterize the baseline aggressiveness of men who were treated in large clinical trials for advanced (i.e., metastatic or stage IV) prostate cancer. We hypothesize that an insignificant proportion of men in these trials were diagnosed with low-grade/low-risk cancers. We will aggregate data from multiple trials to report the proportions of low-, intermediate- and high- risk cancer from the various clinical trials over the last last 4 decades.

Statistical Analysis Plan:

We have identified 36 Phase III clinical trials evaluating various treatments for metastatic prostate cancer from 1982 to present. We will perform a simple descriptive analysis that will focus on aggregating clinical grade among the men in the trials. We aim to report the proportion of low (Gleason 2-6), intermediate (7), and high (8-10) grade prostate cancer over various time points; recognizing that there was a significant change in the grade classification of prostate cancer in 2005. We will not be performing any comparative analysis and therefore will not require any bivariate or multivariate analyses. We recognize that there will be bias associated with selection, and hope to minimize some of these selection biases by including and aggregating data from as many of the trials identified that have grade at diagnosis available from their respective cohort. All analyses will be performed using STATA for data curation and chart development.

Requested Studies:

A Safety and Efficacy Study of Oral MDV3100 in Chemotherapy-Naive Patients With Progressive Metastatic Prostate Cancer (PREVAIL)
Sponsor: Pfizer
Study ID: NCT01212991

Summary of Results:

We were unable to proceed with this project due to insufficient availability of critical data from other randomized studies. We did not complete the study and have no results or publications to share.