Can prostate biopsies predict suitability for nerve‐sparing radical prostatectomy?

Discordance between location of positive cores in biopsy and location of positive surgical margin following radical prostatectomy

Purpose

We compared location of positive cores in biopsy and location of positive surgical margin (PSM) following radical prostatectomy.

Materials and Methods

This retrospective analysis included patients who were diagnosed as prostate cancer by standard 12-core transrectal ultrasonography guided prostate biopsy, and who have PSM after radical prostatectomy. After exclusion of number of biopsy cores <12, and lack of biopsy location data, 46 patients with PSM were identified. Locations of PSM in pathologic specimen were reported as 6 difference sites (apex, base and lateral in both sides). Discordance of biopsy result and PSM was defined when no positive cores in biopsy was identified at the location of PSM.

Results

Most common location of PSM were right apex (n=21) and left apex (n=15). Multiple PSM was reported in 21 specimens (45.7%). In 32 specimens (69.6%) with PSM, one or more concordant positive biopsy cores were identified, but 14 specimens (28%) had no concordant biopsy cores at PSM location. When discordant rate was separated by locations of PSM, right apex PSM had highest rate of discordant (38%). The discordant group had significantly lower prostate volume and lower number of positive cores in biopsy than concordant group.

Conclusions

This study showed that one fourth of PSM occurred at location where tumor was not detected at biopsy and that apex PSM had highest rate of discordant. Careful dissection to avoid PSM should be performed in every location, including where tumor was not identified in biopsy.

Discrepancy in prostate cancer localization between biopsy and prostatectomy specimens in patients with unilateral positive biopsy: implications for focal therapy

BACKGROUND

Unilateral ablative strategy success depends on reliable prediction of prostate cancer (PCA) location. We evaluated the discrepancy in PCA localization between unilateral positive biopsy (PBx) and radical prostatectomy (RP).

METHODS

Between 2004 and 2008, 431 patients were diagnosed with unilateral PCA by 12-core PBx; 179 underwent RP and constituted our study cohort. Specimens were reviewed to map tumor outline and determine number of cancer foci, tumor volume, Gleason score (GS), zone of origin, localization, and pathologic stage.

RESULTS

In 50 men, biopsy and prostatectomy findings correlated (unilateral tumor); in 129, PCA was detected in the contralateral side of the prostate. In 52 patients, 54 clinically significant tumors were missed by biopsy. When patients with true unilateral and missed contralateral disease at RP were compared with respect to prognostic parameters no significant differences were detected. Sixty-one of the 88 patients with preoperative low-risk disease had true unilateral (n = 21) or missed insignificant contralateral (n = 40) PCA; 27 had missed significant contralateral PCA at RP. PSA > 4 ng/ml predicted presence of significant bilateral disease in low-risk population (P = 0.004). Twenty-four of 27 patients with significant bilateral cancer had PSA > 4, although 33/61 with unilateral or bilateral insignificant cancer had similar elevated PSA values.

CONCLUSIONS

Twelve-core biopsy is inadequate to identify candidates for organ-sparing therapy. Most men with unilateral positive biopsies have bilateral cancer at prostatectomy. Tumors missed by biopsy were clinically significant in 40% of patients, but no prognostic parameters could predict unilateral disease. Hemi-ablative treatment might fail to eradicate significant lesions in the contralateral side.

The clinical significance and therapeutic implications of extraprostatic invasion

Invasion of the prostatic margin by cancer establishes a higher risk of disease progression and treatment failure depending upon its extent and other clinical factors. Pathological stage is the most important single prognostic indicator, but determined reliably only in patients having radical prostatectomy. Tumour beyond the prostatic margin or its invasion into the seminal vesicle defines the local stage category as T3, and when confirmed by pathological examination the extent of prostatic margin involvement has prognostic significance. Prediction of extraprostatic invasion may influence therapeutic decisions, but can be difficult to determine for the individual patient prior to treatment. In some individuals having radical prostatectomy, the finding of extraprostatic invasion is unsuspected, and fortunately for the majority of these men the treatment remains curative. On the other hand, when extraprostatic invasion is suspected prior to or at surgery, wide excision may be necessary to achieve negative surgical margins, with other factors contributing independently to the likelihood of subsequent progression. Radiotherapy is an effective alternative treatment for clinical stage T3 and high-risk clinically localized cancer. Recent technological advances and use of combination modality treatment with radiation and hormone manipulation have improved survival outcomes and reduced side-effects. Radiation also has its place as adjuvant treatment following radical prostatectomy in high-risk disease, or as salvage following PSA recurrence, with ongoing trials evaluating potential benefit and toxicity. For clinically localised stage T3 prostate cancer, treatment with surgery or radiotherapy may be highly effective, but multimodality interventions are increasingly being used for primary treatment where clinical assessment indicates that there would otherwise be a high risk for disease progression and therapeutic failure.

Impact of nerve sparing on surgical margins and biochemical recurrence: results from the SEARCH database

The effects of nerve sparing on the risk of positive surgical margins (PSMs) and biochemical recurrence after radical prostatectomy (RP) remain controversial. We examined data from 1018 men treated by RP between 1988 and 2006 at five centers in the Shared Equal Access Regional Cancer Hospital database. Neither bilateral nor unilateral nerve-sparing techniques were associated with a higher risk of PSM; on multivariate analysis of individual sides, the risk of PSM on either side was not increased by nerve sparing on either side. The risk for biochemical recurrence was not affected by bilateral or unilateral nerve sparing. When used on appropriately selected patients, nerve sparing does not increase the probability of PSM or biochemical recurrence after RP.

Predicting unilateral prostate cancer based on biopsy features: implications for focal ablative therapy--results from the SEARCH database

PURPOSE

For men with low risk prostate cancer it was recently proposed that ablative treatment to the affected side may decrease morbidity, while maintaining good oncological outcomes. However, few studies have assessed the correlation between biopsy parameters and pathological outcome (unilateral vs bilateral disease).

MATERIALS AND METHODS

Using the Shared Equal Access Regional Cancer Hospital Database of men treated with radical prostatectomy at multiple equal access medical centers we retrospectively examined the records of 261 men with clinical stage T1c or T2a prostate cancer, prostate specific antigen less than 10 ng/ml, Gleason sum 6 or less and only 1 or 2 ipsilateral positive cores on at least sextant biopsy. We compared clinical characteristics between men with pathologically unilateral disease or less (pT2b or less) and men with pathologically bilateral disease or extraprostatic extension (pT2c or greater). To determine the significant predictors of pT2c or greater disease we used a multivariate logistic regression model.

RESULTS

Of the cohort of 261 men with low risk prostate cancer only 93 (35.1%) had unilateral or no evidence of disease following examination of radical prostatectomy specimens. Men with pathologically unilateral or less disease did not differ from those with bilateral or more advanced disease by age, prostate specific antigen, clinical stage, body mass index or number of positive biopsy cores (1 vs 2). On multivariate analysis no clinical feature was significantly related to pathologically unilateral or less vs bilateral or greater disease.

CONCLUSIONS

The majority of men with low risk prostate cancer and 1 or 2 ipsilateral positive biopsy cores have pathologically bilateral disease. Therefore, strategies for unilateral treatment of prostate cancer are unlikely to be curative for these men.