TY - JOUR
T1 - Rb loss is characteristic of prostatic small cell neuroendocrine carcinoma
AU - Tan, Hsueh Li
AU - Sood, Akshay
AU - Rahimi, Hameed A.
AU - Wang, Wenle
AU - Gupta, Nilesh
AU - Hicks, Jessica
AU - Mosier, Stacy
AU - Gocke, Christopher D.
AU - Epstein, Jonathan I.
AU - Netto, George J.
AU - Liu, Wennuan
AU - Isaacs, William B.
AU - De Marzo, Angelo M.
AU - Lotan, Tamara L.
PY - 2014
Y1 - 2014
N2 - Purpose: Small cell neuroendocrine carcinoma of the prostate is likely to become increasingly common with recent advances in pharmacologic androgen suppression. Thus, developing molecular markers of small cell differentiation in prostate cancer will be important to guide the diagnosis and therapy of this aggressive tumor. Experimental Design: We examined the status of RB1, TP53, and PTEN in prostatic small cell and acinar carcinomas via immunohistochemistry (IHC), copy-number alteration analysis, and sequencing of formalin- fixed paraffin-embedded specimens. Results: We found retinoblastoma (Rb) protein loss in 90% of small cell carcinoma cases (26 of 29) with RB1 allelic loss in 85% of cases (11 of 13). Of acinar tumors occurring concurrently with prostatic small cell carcinoma, 43% (3 of 7) showed Rb protein loss. In contrast, only 7% of primary high-grade acinar carcinomas (10 of 150), 11% of primary acinar carcinomas with neuroendocrine differentiation (4 of 35), and 15% of metastatic castrate-resistant acinar carcinomas (2 of 13) showed Rb protein loss. Loss of PTEN protein was seen in63% of small cell carcinomas (17 of 27), with38% (5 of 13) showing allelic loss. By IHC, accumulation of p53 was observed in 56% of small cell carcinomas (14 of 25), with 60% of cases (6 of 10) showing TP53 mutation. Conclusions: Loss of RB1 by deletion is a common event in prostatic small cell carcinoma and can be detected by a validated IHC assay. As Rb protein loss rarely occurs in high-grade acinar tumors, these data suggest that Rb loss is a critical event in the development of small cell carcinomas and may be a useful diagnostic and potential therapeutic target.
AB - Purpose: Small cell neuroendocrine carcinoma of the prostate is likely to become increasingly common with recent advances in pharmacologic androgen suppression. Thus, developing molecular markers of small cell differentiation in prostate cancer will be important to guide the diagnosis and therapy of this aggressive tumor. Experimental Design: We examined the status of RB1, TP53, and PTEN in prostatic small cell and acinar carcinomas via immunohistochemistry (IHC), copy-number alteration analysis, and sequencing of formalin- fixed paraffin-embedded specimens. Results: We found retinoblastoma (Rb) protein loss in 90% of small cell carcinoma cases (26 of 29) with RB1 allelic loss in 85% of cases (11 of 13). Of acinar tumors occurring concurrently with prostatic small cell carcinoma, 43% (3 of 7) showed Rb protein loss. In contrast, only 7% of primary high-grade acinar carcinomas (10 of 150), 11% of primary acinar carcinomas with neuroendocrine differentiation (4 of 35), and 15% of metastatic castrate-resistant acinar carcinomas (2 of 13) showed Rb protein loss. Loss of PTEN protein was seen in63% of small cell carcinomas (17 of 27), with38% (5 of 13) showing allelic loss. By IHC, accumulation of p53 was observed in 56% of small cell carcinomas (14 of 25), with 60% of cases (6 of 10) showing TP53 mutation. Conclusions: Loss of RB1 by deletion is a common event in prostatic small cell carcinoma and can be detected by a validated IHC assay. As Rb protein loss rarely occurs in high-grade acinar tumors, these data suggest that Rb loss is a critical event in the development of small cell carcinomas and may be a useful diagnostic and potential therapeutic target.
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U2 - 10.1158/1078-0432.CCR-13-1982
DO - 10.1158/1078-0432.CCR-13-1982
M3 - Article
C2 - 24323898
AN - SCOPUS:84896715260
SN - 1078-0432
VL - 20
SP - 890
EP - 903
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 4
ER -