False‐positive prostatic‐specific antigen in the serum of a man with renal cell carcinoma

Abstract

Fig. 1. A, Diagnostic MRI and, B, 1 year after treatment shows almost complete involution of an orbital metastasis of a prostatic adenocarcinoma. Case reports Cases 1 and 2A 76-year-old man (patient A) and an 83-year-old man (patient B) were examined in 1993 by the ophthalmologist because of diplopia due to progressive unilateral exophthalmus. CT and MRI in both instances showed locally destructive tumours in the right (patient A) and left (patient B) orbital bony and soft tissues. Biopsies revealed adenocarcinomas, which were positive for PSA and PAP on immunohistochemistry. Both patients had high levels of PSA in the serum, 211 ng/mL in patient A and 131.6 ng/mL in patient B. The serum alkaline phosphatase values were normal, although bone scintigraphy showed multiple 'hot spots'. In both cases, a DRE indicated grossly extra-prostatic disease of TNM-stage T4; moreover, TRUS showed multiple hypoechoic lesions, extracapsular disease and seminal vesicle invasion. The TRUS-guided prostate needle biopsies in both patients revealed poorly differentiated adenocarcinomas. Patient A was treated with bilateral subcapsular orchidectomy. One month later the orbital tumour was clearly regressing and the serum PSA level had decreased to 15.4 ng/mL, with a testosterone level of 0.8 nmol/L. A follow-up MRI scan at one year showed almost complete involution of the orbital metastatic process (Fig. 1) and all the visual variables improved to near normality. However, follow-up bone scintigraphy revealed new 'hot spots' in the lumbar vertebral region, while the patient remained in good condition with no pain and an active daily life. The serum PSA level stabilized, with a final value of 14.0 ng/mL. The total follow-up after diagnosis has been 25 months.Patient B was treated with local radiation of the orbital metastasis and chemical castration using the LHRHanalogue goserelin (Zoladex) in 3.6 mg monthly subcutaneous depots after initial pretreatment with cyproterone acetate (Androcur) 100 mg three times daily for 4 weeks. Several weeks after initiation, the serum PSA level was 62.7 ng/mL and the serum testosterone was 0.6 nmol/L. The impaired visual variables showed no improvement.© 1997 British Journal of Urology 288

Pre- and post-analytical factors that may influence use of serum prostate specific antigen and its isoforms in a screening programme for prostate cancer

“…Of note is the study by Douville and Tiberi, 70 which demonstrated normal total PSA concentrations but signi®cantly higher free PSA levels in patients on chronic haemodialysis, suggesting that the cut-off value established for non-renal patients may be inappropriate. Raised levels of PSA have been detected in the serum of men 71 and women 72 with renal cell carcinoma, PSA levels returning to normal following nephrectomy. Interference by other kallikreins may be implicated in the ®rst of these reports, as polyclonal antibody was used in the assay.…”

“…Interference by other kallikreins may be implicated in the ®rst of these reports, as polyclonal antibody was used in the assay. 71 A report by Garcia Reboll et al 73 suggested that the hypogonadism associated with renal failure may reduce prostatic growth. It might be expected that PSA would be lost through the kidney in nephrotic syndrome (and proteinlosing enteropathy) but no cases have been found in the literature.…”