Study Type – Diagnostic (exploratory cohort)
Level of Evidence 2b
What's known on the subject? and What does the study add?
Focal therapy is an emergent therapeutic option for prostate cancer. Focal therapy includes a variety of therapeutic approaches ranging from lesion treatment to sub‐total gland treatment. In this context, an accurate selection of patients having unilateral prostate cancer is closely related to the success of these strategies, especially when a hemi‐ablative approach is considered. As prostate cancer is often multifocal, the critical issue is whether it is possible to preoperatively predict a clinically significant unifocal and/or unilateral lesion with sufficient accuracy to recommend focal or hemi‐ablative therapy, relying on clinical characteristics and pathological data derived from the biopsy.
Our study clearly demonstrates that the prediction of unilateral prostate cancer is not accurate, based on preoperative variables (predictive accuracy 52.3%). Our study is the first study based on an extended biopsy template. Even in patients diagnosed with extended biopsy, the accuracy of the available predictors is far from the ideal prediction. To date, there is no way of correctly identifying patients who will harbour unilateral prostate cancer based on routinely available variables.
OBJECTIVE
To establish the predictors of unilateral prostate cancer in a population of patients with low risk prostate cancer, diagnosed with extended biopsy and submitted to radical prostatectomy, potentially candidates for focal therapy.
PATIENTS AND METHODS
The study included 321 consecutive patients with low risk (clinical stage T1, Gleason score 3 + 3 or less, prostate‐specific antigen [PSA] < 10 ng/mL) unilateral prostate cancer diagnosed after extended biopsy who were subsequently treated with radical prostatectomy between 2002 and 2009 at a single institution.
We evaluated the rate of unilateral prostate cancers at final pathology following radical prostatectomy, defined as pT2a or pT2b stage.
Univariable and multivariable logistic regression analyses were used to identify predictors of unilateral prostate cancers. Predictive accuracy was assessed with estimates of the area under the receiver operating characteristic curve, which were subjected to 200 bootstraps to reduce overfit bias.
RESULTS
At final pathology only 29.3% patients harboured unilateral prostate cancer. No significant differences in terms of age, preoperative PSA, prostate volume and percentage of positive cores were recorded between patients with unilateral prostate cancer and patients with more advanced stage (all P≥ 0.07).
Patients harbouring unilateral prostate cancer had a smaller number of positive biopsy cores (2.8 vs 3.2, P= 0.056) compared with patients with stage pT2c or higher at final pathology. Patients with unilateral prostate cancer had a higher rate of Gleason sum 6 compared with patients with more advanced pathological stage (pT2c or higher: 85.1% vs 65.6%; P= 0.002).
On multivariable analyses, only the percentage of po...