[Clinicopathological study of nonpalpable and nonvisible (stage T1c) prostate cancer].

Clinical and pathologic characteristics of stage T1c disease (nonpalpable and nonvisible cancer) was studied retrospectively in men who underwent radical prostatectomy in order to better understand this disease entity. Findings in stage T1c disease (16 patients) were directly compared with those in stage T2b disease (11 patients). No significant difference was observed between these groups with regard to age, preoperative serum prostatic acid phosphatase level, prostatic weight, numbers of tumor foci, total tumor volume, volume of index cancer and tumor grade (p > 0.05). Preoperative prostate specific antigen concentration was significantly lower in stage T1c group (p < 0.05). Substantially larger number of patients with stage T1c disease had pathologically organ confined disease when compared with T2b group (86.7% versus 45.5%, p < 0.05). Seventy-five percent (12/16) of stage T1c and 90.9% (10/11) of stage T2b disease were considered clinically significant. Most of stage T1c disease is organ confined and clinically significant. Clinical and pathologic features of these tumors are similar to those in T2b disease. Twenty-five percent of stage T1c disease, however, are small and thus may potentially be overtreated. Enhanced detection of prostate cancer achieved with modern technology can lead to undesirable treatment of clinically insignificant tumors. Preoperative diagnostic modalities which can reliably distinguish groups of tumor with different biological potential are needed to overcome this contradiction.