Comparison of clinically nonpalpable prostate-specific antigen-detected (cT1c) versus palpable (cT2) prostate cancers in patients undergoing radical retropubic prostatectomy

Abstract

Objectives. Serum prostate-specific antigen (PSA) testing has led to increased detection of clinically localized prostate cancer. We analyzed the clinical characteristics and outcome of digitally palpable (cT2) and PSA detected (cT1c) prostate cancers. Methods. We evaluated 4453 patients with clinically localized prostate cancer who underwent radical retropubic prostatectomy (RRP) between 1987 and 1995 at the Mayo Clinic. Overall, 1041 (23.4%), 1076 (24.2%), and 2336 (52.5%) patients had cT1c, cT2a, and cT2b/c disease, respectively. Patients were analyzed with regard to Gleason score, preoperative PSA, pathologic stage, deoxyribonucleic acid (DNA) ploidy, margin status, tumor volume, and adjuvant treatment. Survival outcomes at 5 and 7 years were estimated using the Kaplan-Meier method with respect to the end points of systemic/local clinical progression and clinical and/or PSA progression (greater than 0.2 μg/mL). Multivariate analysis was employed to estimate the relative risk of progression associated with each clinical stage when adjusted for the above factors. Results. Clinical T1c tumors were more likely to be organ confined (76% versus 54%), have a Gleason score less than 7 (75% versus 61%), and be diploid (80% versus 70%) than cT2b/c tumors ( P <0.001). Clinical T1c disease closely resembled cT2b/c disease with respect to preoperative PSA. Considering pathologic stage, DNA ploidy, and tumor volume, cT1c tumors were comparable to cT2a lesions. Of the patients with T1c cancers, 96.2% had clinically significant cancer on the basis of pathologic grade and tumor volume. The 5 (and 7 year) systemic/local clinical progression-free and PSA progression-free survivals for cT1c tumors were 97.7 ± 0.7% (96.4 ± 1.1%) and 82.2 ± 1.7% (72.9 ± 3.8%), respectively. There was a significant survival advantage at 5 and 7 years regarding both end points for cT1c and cT2a compared with cT2b/c tumors ( P <0.001). Multivariate analysis revealed a continued benefit in PSA and systemic/local clinical progression for cT1c tumors compared with cT2b/c tumors adjusting for the above factors. Conclusions. Clinical T1c tumors are clinically significant cancers. When compared with digitally palpable tumors, progression-free survival rates for cT1c tumors are similar to cT2a lesions, but are significantly better than cT2b/c lesions. This supports continued use of serum PSA to detect potentially curable prostate cancer.