Clinical and Economic Impact of Gene Expression Testing in Localized Prostate Cancer

E. David Crawford, MD

Biopsy-based cell cycle progression (CCP) gene expression testing can aid in the stratification of patients with localized prostate cancer based on disease aggressiveness. This enhanced stratification method could lead to improved patient outcomes and lower costs by guiding treatment selection, specifically the utilization of active surveillance.

E. David Crawford, MD, presented an evaluation of the economic impact of the CCP assay in localized prostate cancer in a poster session at the 15th Annual Meeting of the Society of Urologic Oncology (SUO).¹ This study suggested that CCP testing could reduce costs by $2,850 per patient over 10 years. Given current health plan sizes, this could translate to over $16 million in savings.

OncLive: How can CCP assays be used to guide treatment decisions?

The PROCEDE 1000 study² looked specifically at the impact of testing on treatment decisions. Can you tell us more about this study?

To gain further insight into the intricacies of these findings, OncLive interviewed Crawford, of the University of Colorado at Denver, on the main takeaway points from the study, which specifically looked at the Prolaris CCP assay.Crawford: There are many new genomic tests that hold promise in helping the community oncologist with treatment decisions in patients with newly diagnosed prostate cancer. Some of these tests can increase the positive biopsy rate, decrease the need for second biopsies, and for patients who are at higher risk, can be helpful in deciding whether to choose surveillance or to choose treatment. To be useful, the results of these tests should provoke some decision from the clinician.Untreated patients who were newly diagnosed with localized prostate cancer were enrolled in the PROCEDE 1000 trial. Clinicians recorded their initial treatment recommendations, before the test was administered, based on clinical parameters. The CCP test was then conducted on the patient’s prostate biopsy tissue. We then had the physician fill out 3 consecutive post-CCP questionnaires and recorded the physician’s revised treatment recommendations. The physician also shared the results of the CCP test with the patient and we recorded the consensus treatment decision. Finally, we recorded the actual treatment administered after clinical follow-up.

What are some of the economic advantages associated with testing?

We demonstrated that nearly half the time (44%), the physicians changed their treatment decisions based on the results of the CCP test, with 72% of decisions resulting in a reduction in treatment. Reductions occurred in radical prostatectomy (27%), radiation therapy (44% primary; 56% adjuvant), brachytherapy (46% interstitial; 66% high-dose rate), and hormonal therapy (33% neoadjuvant; 68% concurrent) treatments. On the other hand, 12% of patients received more aggressive treatment based on their test score.We did a study that quantified the economic impact the test results had on a commercial insurer by following a hypothetical cohort of prostate cancer patients with localized disease for 10 years.¹ We calculated the total cost of care, which served as a reference scenario, and a test scenario in which patient management was altered based on CCP test results.

Our group analyzed different disease states, attaching costs for each diagnostic, surgical, radiotherapy procedures, and pharmacological treatments based on published costs of care. The total cost of care was compared between the two scenarios to determine the overall economic affect. We tracked the cost savings when each input was either lowered or increased.

Over a period of 10 years, the CCP test could reduce costs by $2850 per patient. For an insurer with 10 million members, this would translate to over $16 million in savings. Two-thirds of the savings would be achieved in the first year after testing.

Why is localized prostate cancer an ideal setting for this type of testing?

We demonstrated savings when greater use of active surveillance was used in low- and intermediate-risk patients. We also saw savings from reduced progression rates in high-risk patients with more aggressive disease who use more multimodality therapy.Stratifying local disease based on prostate cancer aggressiveness is a challenge for the clinician. Estimating the level of aggressiveness of the cancer can result in overtreatment of low-risk patients and under treatment of high-risk patients. Results from the CCP test can help physicians in predicting prostate cancer aggressiveness, leading to more appropriate patient management.

References

1. Crawford ED, Gustavsen G, Cole D, et al. Evaluation of the economic impact of the CCP assay in localized prostate cancer. Presented at: 15th Annual Meeting of the Society of Urologic Oncology. Dec 3-5, 2014. Poster #74.
2. Gonzalgo M, Boczko J, Kella N, et al. Impact of CCP test on personalizing treatment decisions: results from a large prospective registry of newly diagnosed prostate cancer patients. Presented at: 15th Annual Meeting of the Society of Urologic Oncology. Dec 3-5, 2014. Poster #73.