Adenosquamous carcinoma of the prostate: case report with DNA analysis, immunohistochemistry, and literature review

GATA3 Expression in Prostatic Adenosquamous Carcinoma: A Potential Diagnostic Pitfall

Urothelial carcinoma and prostatic adenocarcinoma can have overlapping histologic features and in some instances pose challenges to pathologists. GATA binding protein 3 (GATA3) immunohistochemistry (IHC) is a well-established tool to aid in this specific diagnostic dilemma as it has been shown to be a sensitive marker for urothelial carcinoma and a putatively specific marker in excluding prostatic adenocarcinoma. However, in encountering an index tumor of prostatic adenosquamous carcinoma positive for GATA3, herein we sought to investigate this potential diagnostic pitfall in a larger series of tumors. In this study, we retrospectively reviewed prostatic adenosquamous carcinomas diagnosed in 17 patients across the authors' institutions and personal consult collections in the past 10 years. GATA3 IHC was either reviewed or performed on tumors not previously tested. We also recorded other immunostains that were performed at initial diagnosis. Positivity for GATA3 was found in 9 of 17 (53%) tumors, all within squamous regions (2 tumors also showed concomitant moderate GATA3 positivity within glandular elements). The GATA3 positive tumors were all positive for p63 in the 7 tumors where p63 was also performed. Of all tumors tested, NKX3.1 was positive in 100% (13/13) of the glandular elements (3 tumors also showed NKX3.1 concomitant positivity within squamous regions). In summary, when encountering a carcinoma with mixed glandular/squamous features in which prostatic origin is being considered, awareness of GATA3 immunoreactivity in a subset of prostatic adenosquamous carcinoma is critical to avoid diagnostic pitfalls.

Genomic analysis of circulating tumor cells in adenosquamous carcinoma of the prostate: a case report

BACKGROUND

Adenosquamous carcinoma of the prostate (ASCP) is an extremely rare and aggressive prostate cancer variant, whose genomic characteristics have not been elucidated. Although liquid biopsy of circulating tumor cells (CTCs) is an emerging topic in oncology, no study has assessed CTCs in patients with ASCP.

CASE PRESENTATION

A 76-year-old man presented with discomfort in his urethra. His prostate-specific antigen (PSA) level was 13.37 ng/mL. A computed tomography (CT) scan indicated a prostate mass with multiple lymph node and lung metastases. The patient underwent transurethral resection of the prostate and prostatic needle biopsy; both specimens demonstrated Gleason grade group 5 acinar adenocarcinoma of the prostate. Bone scintigraphy indicated bone metastasis in the ischium. Combined androgen blockade was implemented, and his serum PSA level rapidly decreased to 0.01 ng/mL. However, a CT scan 6 months after the initial diagnosis revealed worsening of the disease. The patient therefore underwent repeated prostatic needle biopsy; its specimen demonstrated prostatic adenocarcinoma together with squamous carcinoma components. As immunohistochemical analyses showed the tumor cells to be negative for CD56, chromogranin A, synaptophysin, and PSA, the definitive diagnosis was ASCP. Although the patient underwent chemotherapy (docetaxel and cabazitaxel), he died of the disease 3 months after the diagnosis of ASCP, or 13 months after the initial diagnosis of prostatic adenocarcinoma. His PSA values remained ≤ 0.2 ng/mL. CTCs from the patient's blood (collected before starting docetaxel) were analyzed and genomically assessed. It showed 5 cytokeratin (CK)+ CTCs, 14 CK- CTCs, and 8 CTC clusters, per 10 mL. Next-generation sequencing identified a total of 14 mutations in 8 oncogenes or tumor suppressor genes: PIK3CB, APC, CDKN2A, PTEN, BRCA2, RB1, TP53, and CDK12. Of 14 mutations, 9 (64%) were detected on CK- CTCs and 5 (36%) were detected on CK+ CTCs.

CONCLUSIONS

This is the first report of CTC analysis and genomic assessment in ASCP. Although the prognosis of ASCP is dismal due to lack of effective treatment, genomic analysis of CTCs might lead to effective treatment options and improved survival.

Transformation of a prostatic adenocarcinoma into squamous cell carcinoma after luteinizing hormone-releasing hormone (LHRH) agonist and radiotherapy treatment

Squamous cell carcinoma of the prostate is rare and represents 0.5% to 1% of prostatic carcinomas. Transformation of prostatic adenocarcinoma into squamous cell carcinoma after LH-RH agonist intake has been reported in only 8 cases in the literature. To our knowledge, our case is the second pure squamous cell carcinoma observed after hormonotherapy and radiotherapy. We reported a case of a patient with prostatic adenocarcinoma treated by radical prostatectomy followed by radiotherapy. Eleven years later, he had a vesical recurrence of prostatic adenocarcinoma. Our patient had an endoscopic resection followed by injections of Triptorelin. Six months later, he developed a local recurrence of a squamous cell carcinoma.

Pathological transition as the arising mechanism for drug resistance in lung cancer

Despite the tremendous efforts for improving therapeutics of lung cancer patients, its prognosis remains disappointing. This can be largely attributed to the lack of comprehensive understanding of drug resistance leading to insufficient development of effective therapeutics in clinic. Based on the current progresses of lung cancer research, we classify drug resistance mechanisms into three different levels: molecular, cellular and pathological level. All these three levels have significantly contributed to the acquisition and evolution of drug resistance in clinic. Our understanding on drug resistance mechanisms has begun to change the way of clinical practice and improve patient prognosis. In this review, we focus on discussing the pathological changes linking to drug resistance as this has been largely overlooked in the past decades.

Molecular profiling stratifies diverse phenotypes of treatment-refractory metastatic castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is a heterogeneous disease with diverse drivers of disease progression and mechanisms of therapeutic resistance. We conducted deep phenotypic characterization of CRPC metastases and patient-derived xenograft (PDX) lines using whole genome RNA sequencing, gene set enrichment analysis and immunohistochemistry. Our analyses revealed five mCRPC phenotypes based on the expression of well-characterized androgen receptor (AR) or neuroendocrine (NE) genes: (i) AR-high tumors (ARPC), (ii) AR-low tumors (ARLPC), (iii) amphicrine tumors composed of cells co-expressing AR and NE genes (AMPC), (iv) double-negative tumors (i.e. AR-/NE-; DNPC) and (v) tumors with small cell or NE gene expression without AR activity (SCNPC). RE1-silencing transcription factor (REST) activity, which suppresses NE gene expression, was lost in AMPC and SCNPC PDX models. However, knockdown of REST in cell lines revealed that attenuated REST activity drives the AMPC phenotype but is not sufficient for SCNPC conversion. We also identified a subtype of DNPC tumors with squamous differentiation and generated an encompassing 26-gene transcriptional signature that distinguished the five mCRPC phenotypes. Together, our data highlight the central role of AR and REST in classifying treatment-resistant mCRPC phenotypes. These molecular classifications could potentially guide future therapeutic studies and clinical trial design.

Diagnostic dilemmas of squamous differentiation in prostate carcinoma case report and review of the literature

We report a case of pure squamous cell carcinoma involving the prostate and urinary bladder and describe the diagnostic dilemmas that we faced in trying to determine its origin. The patient was diagnosed ten years ago with prostatic adenocarcinoma treated with radioactive seed implantation. During the last year he also underwent a TURP procedure for urinary obstruction complicated by multiple infections. Postsurgery, the patient developed colo-urethral fistula and decision to perform cystoprostatectomy was taken. Excision illustrated a tumor mass replacing the entire prostate that microscopically proved to be squamous cell carcinoma. The challenge that we encountered was to determine its origin, the possibilities being divergent differentiation from adenocarcinoma post radiation therapy, de novo neoplasm or urothelial carcinoma with extensive squamous differentiation. Our literature review showed also that the etiology of prostatic squamous carcinoma is still unclear. We present our approach in an attempt to solve this dilemma.

Clinical features and outcomes of 25 patients with primary adenosquamous cell carcinoma of the prostate

The aim of the present study was to examine the epidemiology, natural history, treatment and long-term survival of patients with adenosquamous cell carcinoma of the prostate. The Surveillance, Epidemiology, and End Results (SEER) Program database was used to identify ASCC of prostate cases between January 1973 and December 2006. Survival probabilities were estimated using the Kaplan-Meier methods and compared using the log-rank test. A total of 25 patients with adenosquamous cell carcinoma of the prostate were identified during the study period. The median age was 74 years (range 53–98). Twenty percent of study subjects presented with metastatic disease. Among those patients with known grade (n=16), 75% had poorly or undifferentiated histology. A total of 40% of study subjects received radical prostatectomy, while 24% of the patients had primary radiation therapy. The 1-, 3-, and 5-year cancer specific survival rates for the entire cohort were 55.2%, 37.8%, and 30.3%, respectively. For patients who underwent prostatectomy, the 1-, 3-, and 5-year survival rates were 78%, 78%, and 63%, respectively. For the patients who did not receive prostatectomy, the 1-year survival rates were 38.7% and none survived to three years. Adenosquamous cell carcinoma is a rare aggressive subtype of prostate cancer with poor cancer specific survival. The development of new therapeutic approaches for this aggressive tumor is urgently needed.

Adenosquamous carcinoma of the prostate

Adenosquamous carcinoma of the prostate is an unusual histological variant of prostate cancer. The histogenesis of this tumor remains uncertain. The stimulus for the development of the squamous metaplastic cells had been thought to be related to hormone and/or radiation therapy. This report presents a case of adenosquamous carcinoma of the prostate with abscence of previous hormone or radiation therapy. The case showed negative prostate-specific antigen and high molecular weight cytokeratin staining of the adenocarcinoma component, and negative prostate-specific antigen and positive high molecular weight cytokeratin staining of the squamous cell carcinoma component. The adenocarcinoma component stained intraluminally with periodic acid schiff. The staining features and the distinct localizations of the components with intermingling, but no transition, are against the collision-type tumor theory and support the theory that the adenocarcinoma and squamous components arise de novo from pluripotent stem cells. The patient had a rapid downhill clinical course and died 3 weeks after the diagnosis was made.

Unusual subtypes of prostate cancer

The vast majority of prostatic tumors developing in adult males are adenocarcinomas. For the most part, variations in histology have not received specific designations and, from a practical approach, have had any specific prognostic implications handled through application of the Gleason grading system. Nonetheless, some of the adenocarcinoma variants have specific clinical features and differential diagnoses. Furthermore, there has been some controversy regarding the appropriate application of the Gleason grading scheme in these tumors. In addition, there are carcinomas that are in fact not adenocarcinomas and that should be kept as distinct entities. In this paper, the histologic variants of adenocarcinoma are reviewed with emphasis on clinicopathologic features and the clinical relevance of these subtypes. Other carcinomas that occur in the prostate gland are also discussed again with a focus on the clinicopathologic characteristics.