Immunohistochemical diagnosis of prostatic cancer with metastasis

Abstract

An immunohistochemical method for detecting prostatic acid phosphatase is described for the diagnosis of metastatic prostatic carcinoma. The specific antiserum against prostatic acid phosphatase was prepared from rabbit by injection of acid phosphatase purified from seminal fluid. This method gives a selective staining of the cytoplasm of the glandular epithelial cells of prostatic tissue specimens on paraffin section. Most of the non-prostatic tissues were negative except for occasional weak staining in granulocytes, islet cells of pancreas, parietal cells of stomach, tubular epithelial cells of kidney, and liver cells. Also examined were 50 consecutive cases of metastatic tumor involving the bone marrow and 5 cases of metastatic prostatic carcinoma involving the lymph node or lung. All 20 cases with prostatic primary lesion showed positive staining. All other cases were negative, except 5 of the 14 cases of metastatic breast carcinoma in women showing weakly positive results. The method is fairly specific for identification of metastatic prostatic carcinoma. Occasional positive staining in breast tumor needs further study to establish whether the staining is due to the same isoenzyme or to certain cross immunoreactivity.

A novel hybridoma antibody (PASE/4LJ) to human prostatic acid phosphatase suitable for immunohistochemistry

“…With the PASE/4LJ monoclonal antibody no staining was seen in granulocytes (Yam et al, 1981), osteoclasts (Jobsis et al, 1981), parietal cells of the stomach, liver cells, renal cell or breast carcinomas (Li et al, 1980;Yam et al, 1981).…”

Prostatic acid phosphatase expression in human tissues

“…The studies have generally confirmed that the preponderance of PAP expression is in the prostate, though several studies have noted some extra-prostatic expression. PAP expression has been reported in liver cells, normal adult kidney [11,15]; granulocytes, parietal cells of the stomach [15]; urethral glands [16,17]; anal gland non-mucosal epithelium, rectal tissue [16]; salivary glands [18]; and ectopic prostate tissue in both uterine cervix and vagina [19].…”

“…In contrast, several studies failed to observe PAP staining in normal tissues, including bladder, breast, colon/rectum, epidermis, kidney, liver, lung, ovary, salivary glands, stomach, testes, and urethra [11,12,15,16]. Using qPCR to measure relative levels of PAP mRNA transcripts, Cunha and colleagues [14] found that, relative to prostate, PAP mRNA was expressed at low levels in several normal tissues, most notably in placenta, kidney, and testis.…”

“…Relative to prostate tissue extracts, normal pancreatic tissue had low but detectable PAP, as measured by electrophoresis [20]. Li and coworkers observed weak occasional PAP IHC staining of pancreatic islets cells [15]. Likewise, Cohen et al found weak diffuse PAP immunostaining in islets cells, but concluded the weak PAP signal was non-specific [21].…”

“…There is renewed interest in PAP as a prognostic tissue marker for T4 tumors [22], as a serum marker in clinical staging of prostate cancer [23], and for predicting recurrence after radical prostatectomy [24]. PAP is expressed in > 95% of the primary prostate adenocarcinomas as determined by IHC [11,12,15]. Goldstein observed that 80% (176 of 219) of PAP positive prostate adenocarcinomas from patients with Gleason scores of 6 to 10 expressed PAP in more than 25% of the malignant cells [25].…”