[Clinicopathological analysis of transition zone cancer of the prostate: the clinical significance of coexistent non-transition zone cancer foci].

Background: Dominant cancer of transition zone origin of the prostate (TZ cancer) has been frequently detected, because ultrasound-guided systematic biopsies have been generalized. In cases of TZ cancer, we attempted to determine clinical significance of coexistent non-TZ cancer foci.

Materials And Methods: Twenty cases with TZ cancer who underwent radical prostatectomy or cystoprostatectomy were clinicopathologically evaluated using step-sectioned specimens.

Results: In TZ cancer foci, there were extraprostatic extension in 5 cases (25%), seminal vesicle invasion in 2 cases (10%), positive surgical margin in 6 cases (30%) and bladder neck invasion in 4 cases (20%). The extraprostatic extension and the positive surgical margin occurred at the anterior or anterioapical portion of the prostate in all the cases. On the other hand, 17 (85%) had coexistent non-TZ cancer foci. In non-TZ cancer foci, there were extraprostatic extension in 3 cases (15%), seminal vesicle invasion in 1 case (5%) and positive surgical margin in 1 case (5%). The extraprostatic extension and the positive surgical margin occurred at the posteriolateral portion of the prostate in all the cases. In 3 cases a coexistent non-TZ cancer focus showed the extraprostatic extension, the seminal vesicle invasion or the positive surgical margin, although a TZ cancer focus were organ-confined.

Conclusion: We should add attention to coexistent non-TZ cancer foci in TZ cancer cases. Particularly, we believe that pre-operative evaluation of non-TZ cancer foci is needed in TZ cancer cases of the candidates for nerve-sparing radical prostatectomy.