[Small volume (<0.5 cc) prostate cancer: characteristics and clinical implications]

INTRODUCTION. It is not well known how many Small Volume Prostate Cancers (SVPC) may host high grade (Gleason pattern 4/5) or have extraprostatic extension in particular in the national setting. Features of SVPC are very interesting since they raise controversies in diagnosis and have important clinical implications in treatment strategies. The diagnosis may be difficult and the treatment ranges from active surveillance to radical surgery. AIM. We evaluate clinical and pathological features of SVPC in surgical specimens of patients who underwent biopsy and radical prostatectomy. METHODS. We analysed a consecutive series of 849 radical prostatectomies performed between 2005 and 2008. Inclusion criteria were: biopsy specimen available, pathological tumor volume analysis according to standard criteria, whole-mount section 3 mm step analysis according to Stanford protocol, clinical parameters (PSA, DRE, number of core biopsy taken).

any hormonal manipulation before surgery and cT1A/B stage. Data were analysed using SPSS for statistical comparison. RESULTS. 238 patients were evaluated. SVPC<0.5 cc was observed in 58 (24.3%). Overall in 17/58 (29.3%) a clinical/pathological relevant disease was observed. In 16/58 (27.5%) pathological Gleason Score (GS) was 7-8, in 5/58 (9%) pathological stage was T3. The number of tumor foci was >1 in 78.3%, tumor-involving in both lobes in 55%. Unifocal disease was observed in 22%. Clinically relevant disease is significantly associated with total cancer volume (0.20 versus 0.31, p 0.007), but not to tumor foci (2.5 versus 2.0). PSA, age, no. of positive cores, DRE were not predictive of clinical relevant disease. Six of 17 (35%) cases with SVPC - who were in the low risk category (PSA <10, biopsy Gleason score <7 and negative DRE), had clinical relevant disease. CONCLUSION. SVPC are clinically relevant in 29.3% since they have a Gleason pattern 4 (27.5%) or have only pathological T3 (9%). Early diagnosis techniques and treatments have to consider that SVPC prostate cancer may contain high risk disease in 1/4 of cases. Clinical parameters are not useful to accurately detect high risk SVPC.