title: Neuroendocrine differentiation in prostatic carcinoma during hormonal treatment.
abstract: OBJECTIVE
  Neuroendocrine differentiation (NED) is a common feature in adenocarcinoma of the prostate. Several studies suggest that NED may have a major impact on cancer progression as neuroendocrine (NE) secretory products have been shown to possess growth stimulatory effects. NED has also been proposed to constitute part of the mechanism by which a prostate cancer cell progresses toward androgen independence as NE tumor cells have been demonstrated to be devoid of androgen receptor immunoreactivity. In this retrospective study, we evaluated NED status in prostate cancer specimens from patients undergoing androgen ablation therapy.
  
  
  METHODS
  The degree of NED in transurethral resection of the prostate (TURP) samples from 53 patients with prostate cancer was investigated by immunocytochemistry using polyclonal rabbit immunoglobin G (IgG) against chromogranin A (CgA). Changes in NED with time were determined by a manual semiquantitative cell counting method.
  
  
  RESULTS
  During androgen withdrawal therapy, 21 tumors (40%) displayed increased NED concomitant with histopathologic tumor progression, whereas 29 carcinomas (55%) showed no change in NED status. However, a majority of the histopathologically unchanged tumors displayed marked NED at the first TURP and an increase in NED was by definition not possible. In only 3 cases (5%) was a decrease in NED observed with time.
  
  
  CONCLUSIONS
  Androgen ablation therapy may be a contributing factor to the increase in NED of prostatic adenocarcinoma with time, and our findings imply that androgen withdrawal therapy enhances the selection and progression of NED, androgen-independent tumor cells.
authors.affiliation: Department of Urology, University Hospital, Malmö, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Jiborn
authors.forename: A
authors.initials: A
authors.lastname: Bjartell
authors.forename: P A
authors.initials: PA
authors.lastname: Abrahamsson
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000628:therapy*; D000368:Aged; D000369:Aged, 80 and over; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology; D009919:Orchiectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000628:therapy*