Purpose: The majority of impalpable prostate cancers (state T1c) are biologically significant. We report the interim results in 257 patients with stage T1c prostate cancer treated with radical prostatectomy.
Materials and methods: Prostate specific antigen progression-free survival was assessed by the Kaplan-Meier method. Multivariate analyses were performed to determine which clinical and pathological variables independently correlated with progression. Comparisons among the various clinical substages (T1a to T2b/c) were calculated.
Results: Of the patients with stage T1c cancers 51% had stage pT2c or less and 91% had clinically significant tumors on the basis of pathological grade, deoxyribonucleic acid ploidy and tumor volume. High preoperative prostate specific antigen, poorly differentiated tumors and nondiploid status were strong independent predictors of progression. The 5-year survival rate free of progression was 84%. Patients with clinical stage T1c cancers had a significant progression-free survival advantage compared to those with clinical stage T2b/c disease (p = 0.0005).
Conclusions: Impalpable tumors should not be regarded as insignificant or innocuous on the basis of pathological analysis. Disease-free survival in the stage T1c group was similar to that in the clinical stages T1a to T2a group but significantly better than that in the T2b/c group.