[886] Insignificant Prostate Cancer: Analysis of Pathobiological Criteria and Predictive Factors

Isabel Hierro, Juan E Perez-Enriquez, Martina Alvarez, Cristobal Marchal, Luis Vicioso, Elena Gallego, Maria V Ortega, Lidia Perez-Villa, Francisco J Machuca, Alfredo Matilla. Virgen de la Victoria Hospital, Málaga, Spain

Background: Prostate specific antigen (PSA) screening and needle biopsy (NB) has been associated with a sharp increase in prostate cancer (PCa) detection as with decreased incidence of high-grade or high-risk PCa with a stage migration toward organ confined disease. Many of these patients will probably not require treatment because of the indolent course of the disease. The aim of this study is to evaluate in NB the predictive value of criteria of Epstein for insignificant PCa, as well as other clinical and immunohistochemical parameters, to identify patients that might benefit from active surveillance.
Design: We retrospectively studied 300 cases who subsequently underwent both early (8-12 cores) NB and radical prostactectomy from 2004 to 2010. Forty eight cases met predictive criteria of Epstein for insignificant PCa. Several clinical, histological and immunohistochemical parameters (table 1) as well as tumor length (mm) and uni-bilateral affectation were correlated with the findings of prostatectomy. We considered insignificant a tumor when it met the “classical” criteria of Epstein (PSAD < 0.15 ng/ml, volume ≤ 0.5cc of the entire gland, with a Gleason score ≤ 6, with no grades 4 or 5) and also when it met the “liberal” criteria (organ-confined disease).

Clinical, histological and immunohistochemical parameters in NB

Parameters	Value	Range
No. of patients	48 (16%)
Mean age (years)	61,4	46-71
Mean preoperative PSA (ng/ml)	6,7	3-15
Mean PSA density (ng/ml2)	0.10	0.03-0.15
Tumour volume (cc)	65.2	27-308
		No. cases (%)
No. of positive biopsy core	1	34 (70.8%)
	2	14 (29.2%)
% core involvement	0-15%	07 (14,6%)
	16-30%	12 (30,8%)
	31-45%	05 (12.6%)
Proliferation index (ki-67)	3.06%
p53 expression	Positive	-
	Negative	48 (100%)
Bcl2 expression	Positive	17 (14.6%)
	Negative	31 (85.4%)

Results: The prevalence of potentially insignificant PCa in NB in our experience was 16%. Only 10 cases (20.8%) met the “classical” criteria and 37 cases (77%) met the “liberal” criteria of insignificant tumor in prostatectomy specimen. None of the histological and immunohistochemical factors in the biopsy predicted the existence of insignificant tumor in radical prostatectomy considering both “classical” and “liberal” criteria.
Conclusions: We have not identified any factors: clinical, histological or immunohistochemical, that can predict with certainty the insignificant nature of a tumor and, therefore, useful to propose more conservative treatment options.
Category: Genitourinary (including renal tumors)

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 112, Wednesday Morning