Contrast-enhanced ultrasound and pre-contrast imaging increased detection of prostate cancer, but the addition of dutasteride to these imaging techniques did not increase detection, according to study results.
Previous studies have indicated that pretreatment with a 5-alpha-reductase inhibitor may help increase microvessel density in prostate cancer. This, in turn, can improve the efficiency of contrast-enhanced ultrasound targeted biopsy.
Ethan J. Halpern, MD, a professor and vice chairman for research at Jefferson University Hospitals, and colleagues conducted a randomized, double blind, placebo-controlled study to determine whether a short-term regimen of dutasteride (Avodart, GlaxoSmithKline) could improve prostate cancer detection with contrast-enhanced ultrasound.
The investigators graded ultrasound findings and used the findings to direct targeted biopsy (up to six cores per prostate). Each patient then underwent a masked 12-core systematic biopsy based on standard medial and lateral sampling of each sextant.
The final analysis included 272 participants.
There were 276 positive biopsies from 3,264 systematic cores and 203 positive biopsies from 1,237 targeted cores (OR=2.1; 95% CI, 1.7–2.6).
Researchers observed an increase in diagnostic accuracy between pre-contrast imaging and contrast-enhanced ultrasound, according to results of the receiver operating characteristic (ROC) analysis (area under the ROC curve, 0.60 vs. 0.64; P.005).
High-grade cancer was defined as Gleason score of at least 7. ROC analysis results indicated improved accuracy for pre-contrast imaging (area under the ROC curve, 0.74) and contrast-enhanced ultrasound (area under the ROC curve, 0.8; P.0005) in these cancers.
Pre-contrast imaging (area under the ROC curve, 0.83) and contrast-enhanced ultrasound (area under the ROC curve, 0.9) demonstrated accuracy in detecting high-grade cancer with greater than 50% biopsy core involvement (P.001).
The results show dutasteride therapy was not associated with a significant impact on prostate cancer detection (P.97).
“Prostate cancer screening remains controversial in large part because the risks of prostate biopsy and subsequent therapy may outweigh the benefits of treatment among the many men diagnosed with localized, low-grade cancer,” Halpern and colleagues wrote. “This study demonstrates that a targeted biopsy based on contrast-enhanced ultrasound selectively detects high-grade/high-volume cancers, and may be a more appropriate approach to screening for clinically important prostate cancer. Although contrast-enhanced ultrasound does add cost to the biopsy procedure, this additional cost is minimal compared to the cost of treating clinically insignificant prostate cancer.”