The use of immunohistochemistry in metastatic prostatic adenocarcinoma to the breast

Prostate Cancer: Cases of Rare Presentation and Rare Metastasis

Prostate cancer is the second most common cancer in men. Diagnosis of early disease is based on prostate biopsy which is carried out because of symptoms of prostatism or asymptomatic rise in PSA. On the other side, advanced disease can locally invade and metastasise to lymph nodes, bones, lungs, etc. Initial presentation of prostate cancer in form of brain metastasis is extremely seldom. Similarly, prostate cancer, which metastasised to the breast, is very rare too. Here, we discuss two unique cases of prostate cancer, one of them had an initial presentation of brain metastasis from prostate adenocarcinoma and the other case had an established diagnosis of prostate cancer metastasised to the breast. In theory, cancer can cause metastatic spread to any part of the body; however diversity into such presentation or progression from prostate cancer has not been frequently noticed.

Prostate-specific antigen and hormone receptor expression in male and female breast carcinoma

Background

Prostate carcinoma is among the most common solid tumors to secondarily involve the male breast. Prostate specific antigen (PSA) and prostate-specific acid phosphatase (PSAP) are expressed in benign and malignant prostatic tissue, and immunohistochemical staining for these markers is often used to confirm the prostatic origin of metastatic carcinoma. PSA expression has been reported in male and female breast carcinoma and in gynecomastia, raising concerns about the utility of PSA for differentiating prostate carcinoma metastasis to the male breast from primary breast carcinoma. This study examined the frequency of PSA, PSAP, and hormone receptor expression in male breast carcinoma (MBC), female breast carcinoma (FBC), and gynecomastia.

Methods

Immunohistochemical staining for PSA, PSAP, AR, ER, and PR was performed on tissue microarrays representing six cases of gynecomastia, thirty MBC, and fifty-six FBC.

Results

PSA was positive in two of fifty-six FBC (3.7%), focally positive in one of thirty MBC (3.3%), and negative in the five examined cases of gynecomastia. PSAP expression was absent in MBC, FBC, and gynecomastia. Hormone receptor expression was similar in males and females (AR 74.1% in MBC vs. 67.9% in FBC, p = 0.62; ER 85.2% vs. 68.5%, p = 0.18; and PR 51.9% vs. 48.2%, p = 0.82).

Conclusions

PSA and PSAP are useful markers to distinguish primary breast carcinoma from prostate carcinoma metastatic to the male breast. Although PSA expression appeared to correlate with hormone receptor expression, the incidence of PSA expression in our population was too low to draw significant conclusions about an association between PSA expression and hormone receptor status in breast lesions.

Male breast cancer: a gender issue

The incidence of male breast cancer (MBC) is rising; however, mortality due to MBC has not changed, unlike female breast cancer. This lack of change is mostly attributable to a lack of major progress in the understanding and treatment of the disease. The treatment of MBC has been extrapolated from the knowledge of female breast cancer, despite the multiple differences in the pathogenesis, biology and genetics of these two disease entities, especially the differences with regard to the role of male hormones as well as estrogens in MBC compared with female disease. Although major advances in hormonal manipulation for the treatment of breast cancer are being developed, an improved understanding of the potential differences between male and female breast cancer is essential, as this would provide new opportunities for therapeutic intervention and probable improved outcome for MBC. This review aims at highlighting the major differences between male and female breast cancer with an emphasis on hormonal therapy, and discusses some of the recent advances in MBC.

Breast metastasis from prostate cancer and interpretation of immunoreactivity to prostate-specific antigen

A case of prostate cancer metastasized to the breast is presented, the latter being prostate-specific antigen (PSA) positive. This is the first of such cases reported in Hong Kong and China in the English literature. As PSA expression also can be found in primary breast cancer, prostatic acid phosphatase staining was employed to confirm the diagnosis. The relationship of PSA and non-prostatic tissues is reviewed. The differential diagnosis of breast enlargement in patients known to have prostate malignancy also is discussed.

Invasive carcinomas of the male breast: a morphologic study of the distribution of histologic subtypes and metastatic patterns in 778 cases

The current investigation was conducted to evaluate the proportional distribution of the various histologic subtypes (including newly recognized variants) of male breast carcinomas, to determine whether any histologic subtypes occur with a frequency that is markedly discordant with the expected frequencies from published data on parallel female breast tumors. We also aimed to document the distribution of malignancies metastatic to the breast. Seven hundred fifty-nine archived cases of primary invasive carcinoma involving the male breast were retrieved and subcategorized into histologic subtypes according to contemporary criteria. Six hundred forty-three (84.7%) tumors were pure infiltrating ductal carcinoma (IDC) not otherwise specified. The most common of the remainder included papillary carcinoma with invasion in the form of IDC (n = 34), mixed IDC and mucinous carcinoma (n = 26), and pure mucinous carcinoma (n = 21). In 19 cases, metastases from other sites involved the breast, most commonly (58%) cutaneous melanoma. Invasive carcinoma of the male breast appears to display a morphologic spectrum and distribution of histologic subtypes that is comparable to those of the female breast, with some expected variation. Compared with published experience on their female counterparts, there is a two-fold increase in the frequency of invasive papillary carcinoma in the male breast. Finally, the most common tumor metastatic to the male breast in this series was cutaneous melanoma.

Expression of androgen receptor and prostate-specific antigen in male breast carcinoma

BACKGROUND

The androgen-regulated proteins prostate-specific antigen (PSA) and prostate-specific acid phosphatase (PSAP) are present in high concentrations in normal prostate and prostatic cancer and are considered to be tissue-specific to prostate. These markers are commonly used to diagnose metastatic prostate carcinoma at various sites including the male breast. However, expression of these two proteins in tumors arising in tissues regulated by androgens such as male breast carcinoma has not been thoroughly evaluated.

METHODS

In this study we analyzed the expression of PSA, PSAP and androgen receptor (AR) by immunohistochemistry in 26 cases of male breast carcinomas and correlated these with the expression of other prognostic markers.

RESULTS

AR, PSA and PSAP expression was observed in 81%, 23% and 0% of carcinomas, respectively. Combined expression of AR and PSA was observed in only four tumors.

CONCLUSION

Although the biological significance of PSA expression in male breast carcinomas is not clear, caution should be exercised when it is used as a diagnostic marker of metastatic prostate carcinoma.

Immunohistochemical localization of prostate-specific antigen in ductal epithelium of male breast. Potential diagnostic pitfall in patients with gynecomastia

Enlargement of the male breast is frequently encountered in the course of adjuvant antiandrogen therapy for advanced prostate carcinoma. The clinical differential diagnosis in this setting includes hormonal imbalance-induced gynecomastia, primary breast carcinoma, and metastasis of prostatic carcinoma. Biopsy of the lesion with the identification of prostate-specific antigen (PSA) plays an important role in establishing the correct diagnosis. Recent studies showed that female mammary epithelium may be a significant source of PSA, but its expression in male breasts has not been sufficiently studied. We found that normal and hyperplastic duct epithelium in gynecomastia exhibited focal, strong (+3) PSA immunoreactivity in 5 of 18 cases (28%). In contrast, no PSA reactivity was found in eight cases of male breast carcinoma. No reactivity was seen with antiprostatic acid phosphatase (PsAP) antibody, in either benign or malignant epithelium. Frequent expression of PSA in gynecomastia may, in an appropriate clinical setting, cause confusion with metastatic prostatic carcinoma. The lack of immunoreactivity for PsAP in male breast epithelium indicates its usefulness in the differential diagnosis.

Prostatic adenocarcinoma metastatic to the breasts: report of a case with diagnosis by fine needle aspiration biopsy

Metastases of tumors of extramammary origin to the breast are extremely uncommon. We report the case of an 81-year-old man with a history of prostatic adenocarcinoma treated with adjuvant estrogen therapy, who presented with bilateral palpable mammary masses. Mammographic study showed irregular solid nodules. Fine needle aspiration (FNA) biopsy was performed. The aspiration smears showed single cells with high nuclear/cytoplasmic ratios, prominent nucleoli, and rare acinar formations. Immunocytochemical studies using antibodies against prostate-specific antigen and prostate-specific acid phosphatase confirmed the diagnosis of metastatic prostatic adenocarcinoma, allowing appropriate treatment.

Fine needle aspiration cytology in male breast carcinoma

A veterans' hospital-based retrospective, clinicopathological study was undertaken to evaluate fine needle aspiration cytology (FNAC) in the diagnosis of male breast carcinoma. Two hundred and forty histologically proven cases of breast carcinoma spanning a period 17 yrs were identified and 13 of these were in males. Nine of these male patients had FNAC performed and were reported by the same cytopathologist (L.I.B.). In 8 of these cases FNAC was diagnostic of carcinoma. No material from FNA was obtained for diagnosis from one of these patients. We concluded that FNA is a useful technique in the diagnosis of male breast carcinoma.

Prostatic specific antigen

PSA is a 34-kDa 240-amino-acid glycoprotein produced exclusively by prostatic epithelial cells. PSA is a serine protease, is a member of the kallikrein gene family, and has a high sequence homology with human glandular kallikrein. It has chymotrypsin-, trypsin-, and esterase-like activities. In the serum it is present mainly in a complex form with alpha 1-antichymotrypsin. It is secreted in the seminal plasma and is responsible for liquefaction of the seminal coagulum. The production of PSA proteins appears to be under the control of circulating androgens acting through the androgen receptors. The PSA gene is up-regulated predominantly by androgens at both the protein and mRNA levels. DRE causes minimal changes in the PSA level, while prostate massage, ultrasonography, systoscopic examination, and prostate biopsy can all cause clinically significant elevations. Other conditions, such as prostatitis, prostate intraepithelial neoplasia, acute urinary retention, and renal failure can also elevate the PSA level. The value of PSA as a screening tool is questionable because of the great deal of overlap in PSA levels between BPH and prostate cancer. However, if used in men over 50, in conjunction with DRE and/or ultrasonography, it may become a vital part of the early detection program. PSA's role in determining the clinical and pathological stage is also limited, in spite of the direct correlation between the pathological stage and the PSA level, because of great overlap in the PSA levels in various stages. The most important clinical utility of PSA is in monitoring patients after definitive therapy. PSA is most sensitive and reliable in the detection of a residual tumor, possibly recurrence, or disease progression following treatment, irrespective of the treatment modality. PSA can accurately predict the tumor status and can detect recurrence several months before its detection by any other method. PSA is also a very sensitive and specific immunohistochemical marker for tumors of prostatic origin. Compared to PAP, PSA is a more precise and meaningful marker in all clinical situations. With the development of ultrasensitive assays and the adoption of an international standard PSA calibrator, so that results from multicenter studies can be compared, PSA could become one of the most useful tumor marker in cancer biology.

Fine-needle aspiration cytology of the male breast in a cancer center

All fine-needle aspirates (FNA) performed on the male breast at The University of Texas M. D. Anderson Cancer Center from 1985 to 1992 were reviewed, totaling 64. The patients' ages ranged from 19 to 86 years, with a mean of 56 years. Thirty-three patients had a history of an extramammary malignancy. The diagnoses established by FNA were gynecomastia (45), mammary carcinomas (6), neoplasms metastatic to the breast (5), suspicious for carcinoma (1), intra-mammary lymph node (1), and lipoma (1). In five cases the aspirates were nondiagnostic. Two of these proved to be gynecomastia on subsequent histologic examination. Of the six FNA cases initially thought to represent primary breast carcinomas, two were found to be secondary because of involvement of the underlying chest wall by mesothelioma (1), and mucinous adenocarcinoma, unknown primary (1). No false-positive diagnosis was rendered. We conclude that fine-needle aspiration of the male breast is a reliable means of assessment; however, unique problems may be encountered compared with aspiration of the female breast. These include the epithelial hyperplasia frequently associated with gynecomastia, the relatively equal frequency of primary and metastatic breast lesions when a malignant process is discovered, and chest wall lesions masquerading as breast lesions.