[867] Neuroendocrine Differentiation in High Gleason Score Prostatic Adenocarcinoma and Response to Radiation Treatment

S Hayek, D Krauss, A Martinez, L Kestin, S Zadora, M Amin. William Beaumont Hospital, Royal Oak, MI

Background: Radiation treatment is often the treatment of choice for patients with high Gleason score prostate carcinoma (PCa). There is a concern among the treating physicians about presence of small cell carcinoma/neuroendocrine (NE) differentiation, and possible lack of response to standard modalities of treatment. The concern for a pathologist is that high grade prostate carcinoma often has areas that may mimic or actually possess neuroendocrine components. The aim of our study was to examine for presence of NE component in high Gleason score PCa, and correlate with clinical outcome in patients treated primarily with radiation therapy.
Design: We studied a cohort of 95 PCa patients with Gleason scores 8-10, who received radiation treatment (external beam and/or high boost brachytherapy) as their primary treatment. The diagnostic H&E stained needle biopsies were reviewed and traditional clinical and pathologic prognostic parameters studied. Immunostaining with chromogranin, synaptophysin and CD56 was performed on representative sections. Staining results were graded for intensity (1-4+) and extent (0 staining; < 1% cells positive; 1-10% positive and: >10% cells positive). The examined parameters were correlated for clinical outcome.
Results: The mean age of patients was 74 years. The mean pre-radiotherapy PSA value was 19.77. 25% patients were stage I, 64% - stage II and 11% - stage III. The mean follow-up time was 6 years (range 0.3 - 18.9 years). Univariate analysis showed maximum tumor length in a core and the highest percent of tumor involvement in any core in a patient to be statistically significant for biochemical failure, overall survival, cause specific survival, distant metastasis and local recurrence. Presence of any staining with antibodies to chromogranin, synaptophysin and CD56 was noted in 44%, 47% and 27% cases respectively. Staining results with these NE markers showed some trends but was not statistically significant for clinical outcome.
Conclusions: We found neuroendocrine differentiation in approx 50% of high Gleason score prostate cancer. The role of NE differentiation reported in literature with regards to outcome is controversial. In this cohort of patients that were treated primarily with radiation treatment, NE differentiation does not appear to be statistically signifcant as regards clinical outcome.
Category: Genitourinary (including renal tumors)

Monday, March 22, 2010 1:00 PM

Poster Session II # 113, Monday Afternoon

 

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