Can genetic test help guide prostate cancer patients’ treatment decisions?

Dr. Peter Gann, professor of pathology, UIC College of Medicine. Photo: Joshua Clark/UIC Photo Services. Click on image to download file.

Funded by a three-year, $2.8 million grant from the Defense Department’s Prostate Cancer Research Program, Chicago researchers hope to see if a new test that “scores” the aggressiveness of prostate cancers by measuring the activity of certain genes can help guide patients’ treatment decisions and improve their psychological state.

“We want to know whether having this gene-expression profile of the tumor improves patient and provider confidence in choice of treatment,” says Peter Gann, professor of pathology in the University of Illinois at Chicago College of Medicine and principal investigator on the grant.

The study will look at whether the new test leads more men with newly-diagnosed, early-stage prostate cancer to choose active surveillance, or “watchful waiting,” over immediate treatment with surgery or radiation, which has its own risks and side-effects.

Discriminating between aggressive prostate cancers that need immediate treatment and low-risk cancers that can be managed by active surveillance is a major challenge, Gann said. PSA testing, which measures the blood levels of a molecule produced by prostate cancers, along with standard biopsy procedures, is exquisitely sensitive and detects even slow-growing cancers that produce no symptoms and are not life-threatening.

“Many prostate cancers that are diagnosed have a small likelihood of progressing, and these men could be better off being monitored instead of treated,” Gann said. “But the diagnostic tools we have today leave a lot of room for uncertainty. Any additional information that can help men more confidently decide whether to undergo immediate treatment or active surveillance is very valuable.”

The new test — the Oncotype DX Prostate Cancer Assay, made by Genomic Health Inc. — measures the activity of 17 genes from biopsy samples. The test’s score indicates the probability that early-stage prostate cancer will become aggressive. Although the test’s ability to predict aggressive prostate cancer is proven, its impact on patients’ decision-making regarding treatment has not been studied.

The study will enroll 300 men with newly diagnosed, low-to-intermediate risk prostate cancer at three Chicago hospitals: the University of Illinois Hospital & Health Sciences System, the Jesse Brown VA Medical Center and the John H. Stroger Jr. Hospital of Cook County. Half the patients will receive standard counseling on treatment options, while the other half will also undergo the genetic testing and discuss those scores with their physicians.

Gann expects approximately three-quarters of the enrolled men to be African-American, based on the patient populations of the three institutions involved in the study. Among major ethnic groups, African American men have the highest incidence of prostate cancer and the highest mortality risk from prostate cancer.

All patients will fill out questionnaires on their anxiety, mood and outcome-fears related to their new prostate cancer diagnosis before and after counseling. They will be queried about decision-conflict and decision-regret.

The researchers will determine if discussing genetic test scores affects African American men differently than other men in their decision-making; if it reduces overtreatment of low-risk cancers; and if it contributes to men’s comfort with their treatment decisions.

“The prostate cancer group at UIC, with support from the University of Illinois Cancer Center and the department of urology, has been intensely involved in clinical and research efforts to reduce the excessive mortality associated with prostate cancer that disproportionately affect the communities we serve,” Gann said. “This project is an important step towards that goal.”

Co-investigators on the Biomarker Development Award from the Department of Defense Prostate Cancer Research Program are Drs. Michael Abern, Kameron Matthews and Andre Balla of UIC; Dr. Courtney Hollowell of Stroger Hospital; Dr. Roohallah Sharifi of the Jesse Brown VA Medical Center; and Dr. Adam Murphy of Northwestern University’s Feinberg School of Medicine. Carol Ferrans and Lisa Sharp of UIC will provide expertise in psychometrics and counseling.