Feneley M R, Webb J A, McLean A, Kirby R S
Department of Urology, St Bartholomew's Hospital, London, UK.
Br J Urol. 1995 Jan;75(1):14-20. doi: 10.1111/j.1464-410x.1995.tb07225.x.
To examine the value of post-operative serum prostate-specific antigen (PSA), PSA density, incremental change in serial serum PSA (PSA slope) and transrectal ultrasound (TRUS) in the assessment of residual malignancy after the diagnosis of clinically unsuspected prostatic adenocarcinoma at transurethral resection of the prostate (TURP).
Forty-eight untreated patients with incidental carcinoma of the prostate, demonstrated at TURP for a clinically benign gland, were evaluated post-operatively with serum PSA and TRUS with multiple systematic prostatic biopsies. Prostatic volume was determined from TRUS measurements and PSA density was defined as serum PSA divided by gland volume. Those patients who did not undergo further treatment were monitored with serial PSA levels, and PSA slope was calculated as the overall annual percentage increase in serum PSA.
Among 36 patients staged T1A (A1), 11 (31%) had histologically proven residual carcinoma, and five of the 12 patients (42%) with T1B (A2) disease had no residual disease on biopsy. Serum PSA levels following TURP were greater in those patients with residual disease than those without (P = 0.001), but at a cut-off of 4.0 ng/mL--providing a sensitivity of 89%--the specificity of PSA alone was 57%. PSA density had an 83% sensitivity and a 67% specificity with a cut-off of 0.15 ng/mL/cm3. TRUS had a sensitivity of 63% and a specificity of 52%. An incremental rise in PSA exceeding 20% per year in untreated patients gave a sensitivity of 90% and specificity of 79% for biopsy proven residual malignancy.
This study demonstrates the inaccuracy of staging incidental prostatic malignancy by TURP. Although the performance of PSA density is better than that of PSA alone, the reliability of both are limited by the lack of specificity, and TRUS imaging lacks both sensitivity and specificity. The PSA slope has sufficient sensitivity and specificity to distinguish reliably most patients with biopsy proven residual malignancy. Although ultrasound-guided systematic biopsies provide a means for confirming residual malignancy, they may not be indicated in all patients with incidental carcinoma: for such patients, PSA progression may provide a rational basis for subsequent treatment.
探讨术后血清前列腺特异性抗原（PSA）、PSA密度、连续血清PSA的增量变化（PSA斜率）及经直肠超声（TRUS）在经尿道前列腺切除术（TURP）诊断临床未怀疑的前列腺腺癌后评估残留恶性肿瘤中的价值。
48例因临床诊断为良性前列腺而接受TURP手术的偶然发现前列腺癌患者，术后接受血清PSA检测、TRUS检查及多次系统性前列腺活检评估。根据TRUS测量确定前列腺体积，PSA密度定义为血清PSA除以腺体体积。未接受进一步治疗的患者通过连续PSA水平进行监测，PSA斜率计算为血清PSA的总体年度百分比增长。
在36例T1A（A1）期患者中，11例（31%）经组织学证实有残留癌，12例T1B（A2）期患者中有5例（42%）活检无残留疾病。有残留疾病的患者TURP术后血清PSA水平高于无残留疾病的患者（P = 0.001），但以4.0 ng/mL为临界值时，单独PSA的敏感性为89%，特异性为57%。PSA密度以0.15 ng/mL/cm³为临界值时，敏感性为83%，特异性为67%。TRUS的敏感性为63%，特异性为52%。未治疗患者中PSA每年增量超过20%对活检证实的残留恶性肿瘤的敏感性为90%，特异性为79%。
本研究表明TURP对偶然发现的前列腺恶性肿瘤进行分期不准确。虽然PSA密度的性能优于单独的PSA，但两者的可靠性均因缺乏特异性而受限，TRUS成像缺乏敏感性和特异性。PSA斜率具有足够的敏感性和特异性，能够可靠地区分大多数经活检证实有残留恶性肿瘤的患者。虽然超声引导下的系统性活检提供了确认残留恶性肿瘤的方法，但并非所有偶然发现癌症的患者都需要进行活检：对于此类患者，PSA进展可为后续治疗提供合理依据。
