Small-cell neuroendocrine carcinoma as a variant form of prostate cancer recurrence: a case report and short literature review.
BACKGROUND
Small-cell neuroendocrine carcinoma has been recognized as a rare histologic variant occurring in only 0.5% to 2% of prostatic primary tumors. However, recent autopsy studies suggest development to this phenotype in up to 10% to 20% of the cases with hormone-refractory disease.


METHODS
A case of conventional adenocarcinoma before androgen-ablation therapy but showing progression to small-cell neuroendocrine carcinoma at the recurrence. The immunohistochemistry of the tumor showed strong positive staining for progastrin-releasing peptide (ProGRP), a carboxy terminal region common to 3 precursors for gastrin-releasing peptide, but almost negative staining for chromogranin-A and prostate-specific antigen. Combination chemotherapy based on cisplatin and etoposide was effective for controlling the tumor progression for 7 months, and the serum ProGRP level correlated well to the clinical course. Neither objective nor subjective responses were observed to somatostatin analogue therapy performed in the late stage of disease.


CONCLUSIONS
The present case reminds the urologist that small-cell neuroendocrine carcinoma may be a variant form of disease recurrence during androgen ablation in advanced prostate cancer. A strategic approach for this phenotype evaluating serum neuroendocrine markers, such as ProGRP, should be taken when serum prostate-specific antigen does not reflect the disease state. This approach would allow one to choose alternative therapies targeting neuroendocrine cells other than androgen ablation.
Yashi
Masahiro
M
Department of Urology, Jichi Medical School, Tochigi 3290498, Japan. yashi@jichi.ac.jp
Terauchi
Fumihito
F
Nukui
Akinori
A
Ochi
Masanori
M
Yuzawa
Masayuki
M
Hara
Yosuke
Y
Morita
Tatsuo
T
D000368:Aged; D018288:Carcinoma, Small Cell / Q000097:blood / Q000188:drug therapy / Q000473:pathology*; D053379:Chromogranin A; D002864:Chromogranins / Q000097:blood; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D010455:Peptides / Q000097:blood; D010751:Phosphopyruvate Hydratase / Q000097:blood; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000473:pathology*; D011498:Protein Precursors / Q000097:blood
D053379:Chromogranin A; D002864:Chromogranins; D010455:Peptides; D011498:Protein Precursors; C047897:gastrin-releasing peptide precursor; D017430:Prostate-Specific Antigen; D010751:Phosphopyruvate Hydratase