Volume 1, Number 2 ----- Fall/Winter 1998

Notes from the National Cancer Institute's PLCO Project Office

---

Meet John Gohagan

John Gohagan, Ph.D. is the NCI project officer for the PLCO trial. He directs all components of the trial and manages all staff members.

"I am very pleased with the progress of the trial. PLCO has been endorsed by the American Cancer Society. It is a very important trial: the four PLCO cancers (prostate, lung, colorectal, and ovarian) account for about half of all U.S. cancer deaths. Because of its depth and scope, it is a complicated effort requiring the cooperation of thousands of people -- both participants and staff."

Dr. Gohagan knows the trial is working well for two reasons:

First, the dedication of PLCO staff across the nation. "We estimate over 200 people are working on PLCO -- this might be a record number of staff for a clinical trial! Staff at the screening centers, especially clinic coordinators, recruiters, and data managers are to be commended."

Second, the willingness of all the PLCO participants to enroll in and adhere to study requests. "PLCO participants have made a long-term investment in the health of future generations of Americans. Their continued participation -- carefully following requests to fill out questionnaires and/or attend clinic visits -- will make it possible to advance cancer prevention."

"To answer the medical questions about PLCO screening tests, we need to reach our enrollment goal of 148,000 participants," notes Dr. Gohagan. He urges participants to spread the word about the PLCO study to their friends and family members. "The sooner we have the full number of participants, the sooner we will have the answers."

Meet Phil Prorok

 Phil Prorok, Ph.D., a co-PLCO project officer at NCI, is a biostatistician. He oversees all data analysis for the PLCO trial.

Though many people find statistics dry, statistical analysis is at the heart of scientific discovery. Dr. Prorok explains, "Careful statistical design and analysis is the only way we can answer the medical questions of the PLCO trial: whether PLCO screening tests reduce the number of lives lost to PLCO cancers." NCI constantly monitors the progress of the trial and incoming data. "Ongoing analysis alerts us to any necessary mid-course adjustments we should make to protect participants and/or enhance the trial." In fact, results of recent statistical analyses suggested some changes. The following changes to the protocol, which were supported by the trial's steering committees and an independent monitoring panel, will begin this winter:

• Extend the follow-up for three years so that all participants will be followed at least 13 years;
• Delay the second sigmoidoscopy exam for two years;
• Eliminate the ovarian palpation exam;
• Stop performing the chest x-ray for non-smokers after the third year; and
• Add a PSA or CA125 blood test during the fourth and fifth years.

These changes are being made to strengthen the scientific results of the trial.