The authors have previously assessed the diagnostic utility of the urinary PCA3 test in the grey zone of PSA 4-10 ng/mL, but in this study they assess the cost effectiveness of such a test. It is more expensive than PSA testing.
Economic modeling was used to assess two diagnostic strategies:
1) PSA testing alone – biopsy for PSA > 4 ng/mL
2) PSA testing followed by PCA3 testing if PSA between 4-10, biopsy if PCA3 also abnormal (cutoff not indicated)
For the model, 1000 patients with PSA between 4-10 ng/mL were included. They used data from 20984 biopsy specimens of patients with PSA between 4-10. The following values were utilized for PCA3 accuracy: 73.5% sensitivity and 90.6% specificity. Costs were based on Russian standards.
Strategy 1 demonstrated 6992 false positives, while strategy 2 identified only 657 false positives and 2211 true positives. Urinary PCA3 avoided 90.6% unnecessary biopsies, but 26.5% of PCa was missed. Strategy 1 was 1.5 fold more expensive than Strategy 2.
While the cost was improved, the high rate of missed cancers is concerning. The authors understand this and feel need additional work is needed before adopting this strategy. However, if the 26.5% of cancers missed with low-volume Gleason 6, it may still be a worthwhile strategy.
Sequencing studies to improve outcomes and reduce cost are important in this area. However, all cost effectiveness studies are limited by utility outside the country it was conducted in.
Presented by: Andrey Sivkov
Affiliation: National Medical Radiology Research Center, Russia
Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre.Twitter: @GoldbergHanan at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal