Contemporary impact of transrectal ultrasound lesions for prostate cancer detection

Transrectal ultrasound (TRUS) guided systematic biopsy of the prostate is the gold standard diagnostic modality for prostate cancer. Consequently, the value of discrete hypoechoic lesions on TRUS lesions considered suspicious for cancer deserves meticulous reevaluation, specifically in the prostate specific antigen era when the majority of tumors diagnosed are nonpalpable. We studied whether the predictability of a biopsy core changes if the tissue comes from an isoechoic vs hypoechoic lesion.

Prospective data were collected on 3,912 consecutive patients referred to our medical center between 1993 and 1999 for biopsy of the prostate. A sextant technique (apex, mid gland and base) with an additional core biopsy from the transitional zone was used. If a hypoechoic lesion was identified, the biopsy was taken from the lesion. Correlation between hypoechoic lesions, isoechoic areas and cancer detection for each core was performed.

A total of 31,296 cores were obtained from the cohort. Overall 2,642 (68%) cores had at least 1 hypoechoic lesion ultrasonographically. Cancer was detected in 675 (25.5%) and 323 (25.4%) patients with or without hypoechoic lesions (p = 0.97). The per core cancer detection was fairly uniform and averaged 9.3% and 10.4% for hypoechoic and isoechoic areas, respectively. The difference was not statistically significant (p = 0.3). Gleason scores were less than 7, 7 and greater than 7 in 46%, 34% and 20% of cases, respectively.

Despite the higher prevalence of cancers discovered in prostates with hypoechoic areas, the hypoechoic lesion itself was not associated with increased cancer prevalence compared with biopsy cores from isoechoic areas. For impalpable tumors TRUS findings are not contributory for staging.