[Prevalence and clinical meaning of focal and incidental prostate cancers]

To calculate the proportion of focal and incidental prostate cancers (PCa) in our setting, to study their relationship with the findings in radical prostatectomy (RP) specimens, and to establish their clinical relevance in terms of progression and survival.

We selected patients with focal cancer, defined as a maximum extent of 3 mm in one or two adjacent prostate biopsy cores (transrectal ultrasound guided, sextant). In addition we included a group of patients with incidental T1a cancers (diagnosed after prostatectomy, nonpalpable, with less than 5% tumor in specimen). The proportion of those cancers over the total of tumors diagnosed in our health area was calculated. Also, clinical characteristics of such cancers were recorded (age, PSA, Gleason grade and score), and also therapy given. In cases that underwent RP, pathological findings were also recorded. Finally, survival analysis (Kaplan-Meier) was carried out to describe the natural history of these patients in terms of time to progression and time to death from PCa.

From 819 patients diagnosed of PCa, 46 (5.6%) presented with focal cancer and 23 (2.8%) with stage T1a tumors. None of the patients with incidental cancer (T1a) underwent RP opposed to 17 of 46 focal T1c cancers (37%). Although none of these cases showed extracapsular extension, seminal vesicle invasion, or lymph node invasion, relevant disease (stage pT2b or higher) was found in 15 cases (88.2%) and pathological Gleason score > 7 in 2 cases (2.9%). With a mean follow-up time of 37.6 months (standard error 4.26), the probability of being free from any progression was, for T1a cancers at 2 and 5 years, of 75.4% and 57.1% respectively, and 94.4% and 94.4% respectively for T1c cases. No PCa deaths were recorded in the presented cases during the mentioned follow-up period.

In our experience, the finding of microscopic or focal cancers in sextant prostate biopsy is related to a high proportion of clinically relevant tumors in RP specimens (88%). We think that expectant management of patients with such findings in prostate biopsy should be questioned.