title: Prostate cancer with small-cell morphology: an immunophenotypic subdivision.
abstract: OBJECTIVE
  To study the immunophenotypic characteristics and clinical outcome of morphologically undifferentiated prostatic carcinoma with small-cell morphology (U-PC-SCM).
  
  
  METHODS
  Sixteen patients with U-PC-SCM were enrolled. The streptavidin-biotin complex immunohistochemical method was used on paraffin-embedded tissue sections to test positivity for prostate-specific antigen, prostate-specific acid phosphatase, CD57, androgen receptors, CK8-18, epithelial membrane antigen, carcinoembryonic antigen, CD56, neuron-specific enolase, chromogranin, synaptophysin, serotonin, various hormones, thyroid transcriptional factor-1 and Ki-67/MIB1.
  
  
  RESULTS
  Based on immunophenotypic criteria, we identified two groups of patients. The final diagnosis was U-PC (Gleason score 10) in Group 1 (n=9) and pure or mixed neuroendocrine small-cell carcinoma in Group 2 (n=7). Group 1 underwent total androgen blockade (TAB) with no major response and had a median survival of 9 months. In Group 2, three patients underwent TAB, two of whom died of progressive disease. The third patient showed a partial response (PR) for 18 months but eventually relapsed with liver metastatic lesions. He was then treated with cisplatin + etoposide and showed a PR for 3 months and survived for 5 months after the initiation of the second-line chemotherapy (CTH) treatment. The other four patients received six cycles of cisplatin + etoposide. There were two complete responses of >14 and >22 months, respectively and 2 PRs of 11 and 17 months, respectively, the partial responders surviving for 14 and 21 months, respectively.
  
  
  CONCLUSIONS
  U-PC-SCM with a neuroendocrine immunophenotype is a histogenetically distinct entity with different clinical and laboratory manifestations which responds well to a cisplatin + etoposide CTH regimen.
authors.affiliation: Department of Pathology, Evangelismos Hospital, Athens, Greece. nellitsa@vip.gr
authors.forename: Constantina
authors.initials: C
authors.lastname: Petraki
authors.forename: Michael
authors.initials: M
authors.lastname: Vaslamatzis
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Petraki
authors.forename: Kyriakos
authors.initials: K
authors.lastname: Revelos
authors.forename: Nektarios
authors.initials: N
authors.lastname: Alevizopoulos
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Papanastasiou
authors.forename: Alkiviadis
authors.initials: A
authors.lastname: Gregorakis
mesh_terms: D000135:Acid Phosphatase; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000276:immunology* / Q000378:metabolism; D001706:Biopsy; D018959:CD57 Antigens / Q000276:immunology / Q000378:metabolism; D018288:Carcinoma, Small Cell / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000276:immunology / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D017027:Protein Tyrosine Phosphatases / Q000276:immunology / Q000378:metabolism; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D018959:CD57 Antigens; D000135:Acid Phosphatase; C428439:prostatic acid phosphatase; D017027:Protein Tyrosine Phosphatases; D017430:Prostate-Specific Antigen