Prostate cancer laterality as a rationale of focal ablative therapy for the treatment of clinically localized prostate cancer.

BACKGROUND

Early detection of small-volume prostate cancer (PCa) has led to the concept of focal therapy to treat PCa as an organ-sparing, minimally invasive procedure. The authors sought to determine the frequency of unilateral cancers in the contemporary prostate-specific antigen (PSA) era to determine the percentage of patients who would be candidates for hemiablation of the prostate by using focal therapy while preserving the contralateral lobe.

METHODS

Paraffin-embedded radical prostatectomy specimens (1184 specimens) from consecutive patients between 2002 and 2006 with pathologic organ confined PCa were analyzed. Pathologic assessment focused on tumor laterality and percentage of tumor involvement (PTI) along with other routine parameters such as pathological T-classification (pT), pathological Gleason Score (pGS), extracapsular extension (ECE), and surgical margins (SM). Clinical and pathologic parameters were analyzed by univariate and multivariate methods.

RESULTS

Completely unilateral cancers were identified in 227 (19.2%) of 1184 patients. Of these patients, 164 (72.2%) had PTI of < or =5%, 40 (17.6%) had a PTI of 5.01%-10%, 9 (4.0%) had a PTI of 10.01%-15%, and 14 (6.2%) had a PTI of > 15%, respectively (P < .0005). African-American men had bilateral cancers more commonly that non-African-American men, eg, 90.8% versus 79.2%, respectively (P < .0005). Race, PTI, pGS, and SM were independent predictors by multivariate logistic regression (P < or = .05).

CONCLUSIONS

This study suggests that 1 in 5 men diagnosed with PCa have small volume, completely unilateral cancers that may be amenable to hemiablation of the prostate. Further study is needed to develop predictive models to select candidates for focal therapy.