• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2941-2946
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• 2016

Background: The limitations of total serum PSA values remain problematic, especially after an initial negative prostate biopsy. In this prospective study of Chilean men with a continued suspicion of prostate cancer due to a persistently elevated total serum PSA, abnormal digital rectal examination and initial negative prostate biopsy were compared with the use of the on-line Chun nomagram, detection of primary malignant circulating prostate cells (CPCs) and free percent PSA to predict a positive second prostate biopsy. We hypothesized that men negative for circulating prostate cells have a small risk of clinically significant prostate cancer and thus may be conservatively observed. Men positive for circulating prostate cells should undergo biopsy to confirm prostate cancer. Materials and Methods: Consecutive men with a continued suspicion of prostate cancer underwent 12 core TRUS prostate biopsy; age, total serum PSA and percentage free PSA and Chun nomagram scores were registered. Immediately before biopsy an 8ml blood simple was taken to detect primary mCPCs. Mononuclear cells were obtained by differential gel centrifugation and identified using double immunostaining with anti-PSA and anti-P504S. Biopsies were classifed as cancer/no-cancer, mCPC detecton test as negative/positive and the total number of cells/8ml registered. Areas under the curve (AUC) for percentage free PSA, Chun score and CPCs were calculated and compared. Diagnostic yields were calculated with reference to the number of possible biopsies that could be avoided and the number of clinically significant cancers that would be missed. Results: A total of 164 men underwent a second biopsy; 41 (25%) had cancer; the AUCs were 0.65 for free PSA, 0.76 for the Chun score and 0.87 for CPC detection, the last having a significantly superior prediction value (p=0.01). Using cut off values of free PSA <10%, Chun score >50% and ${\geq}1$ CPC detected, CPC detection had a higher diagnostic yield. Some 4/41 cancers complied with the criteria for active surveillance, free PSA and the Chun score missed a higher number of significant cancers when compared with CPC detection. Conclusions: Primary CPC detection outperformed the use of free PSA and the Chun nomagram in predicting clinically significant prostate cancer at repeat prostate biopsy.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9335-9339
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• 2014

Background: To determine the frequency of primary circulating prostate cells (CPC) detection according to age and serum PSA levels in a cohort of men undergoing screening for prostate cancer and to determine the diagnostic yield in those men complying with the criteria for prostate biopsy. Materials and Methods: A prospective study was carried out to analyze all men evaluated in a hospital prostate cancer screening program. Primary CPCs were obtained by differential gel centrifugation and detected using standard immunocytochemistry using anti-PSA, positive samples undergoing a second process with anti-P504S. A malignant primary CPC was defined as PSA+ P504S+, and a test positive if 1 cell/4ml was detected. The frequency of primary CPC detection was compared with age and serum PSA levels. Men with a PSA >4.0ng/ml and/or abnormal rectal examination underwent 12 core prostate biopsy, and the results were registered as cancer/no-cancer and compared with the presence/absence of primary CPCs to calculate the diagnostic yield. Results: A total of 1,117 men participated; there was an association of primary CPC detection with increasing age and increasing serum PSA. Some 559 men underwent initial prostate biopsy of whom 207/559 (37.0%) were positive for primary CPCs and 183/559 (32.0%) had prostate cancer detected. The diagnostic yield of primary CPCs had a sensitivity of 88.5%, a specificity of 88.0%, and positive and negative predictive values of 78.3% and 94.9%, respectively. Conclusions: The use of primary CPCs for testing is recommended, since its high negative predictive value could be used to avoid prostate biopsy in men with an elevated PSA and/or abnormal DRE. Men positive for primary CPCs should undergo prostate biopsy. It is a test that could be implemented in the routine immunocytochemical laboratory.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6615-6619
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• 2015

Background: The expression of HER-2 in prostate cancer has been linked to disease progression. We analysed the presence of HER-2 expression in primary tumors in men undergoing radical prostatectomy, its association with clinical and pathological findings, and its expression in secondary circulating prostate cells (CPCs) during follow up, as well as links with biochemical failure and the effects of androgen blockade. Materials and Methods: Consecutive men undergoing radical prostatectomy for histologically confirmed prostate cancer were analyzed. HER-2 expression in the primary tumor was assessed using the HercepTest(R), CPCs were identified from blood samples using standard immunocytochemistry with anti-PSA and positive samples with the HercepTest(R) to determine HER-2 expression. The influence of HER-2 expression on the frequency of biochemical failure and effects of androgen blockade was determined. Results: 144 men with a mean age of $64.8{\pm}10.3$ years participated, with a median follow up of 8.2 years. HER-2 was expressed in 20.8% of primary tumors; it was associated with vascular infiltration and older age, but not with other clinical pathological findings. Some 40.3% of men had secondary CPCs detected, of which 38% expressed HER-2. Men CPC (+) had a higher frequency of biochemical failure, but there was no difference in HER-2 expression of CPCs with the frequency of biochemical failure. After androgen blockade, men with HER-2 (+) positive secondary CPCs had a higher frequency of disease progression to castrate resistant disease. Conclusions: HER-2 plays a dual role in the progression of prostate cancer; firstly it may increase the potential of tumor cells to disseminate from the primary tumor via the blood by increasing vascular infiltration. In the presence of androgens, there is no survival advantage of expressing HER-2, but once biochemical failure has occurred and androgen blockade started, HER-2 positive cells are resistant to treatment, survive and grow leading to castration resistant disease.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3385-3390
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• 2016

Background: Sequential use of circulating prostate cell (CPC) detection has been reported to potentially decrease the number of unnecessary prostate biopsies in men suspected of prostate cancer. In order to determine the real world effectiveness of the test, we present a prospective study of men referred to two hospitals from primary care physicians, one using CPC detection to determine the necessity of prostate biopsy the other not doing so. Materials and Methods: Men with a suspicion of prostate cancer because of elevated PSA >4.0ng/ml or abnormal DRE were referred to Hospitals A or B. In Hospital A all underwent 12 core TRUS biopsy, in Hospital B only men CPC (+), with mononuclear cells obtained by differential gel centrifugation identified using double immunomarking with anti-PSA and anti-P504S, were recommended to undergo TRUS biopsy. Biopsies were classifed as cancer or no-cancer. Diagnostic yields were calculated, including the number of posible biopsies that could be avoided and the number of clinically significant cancers that would be missed. Results: Totals of 649 men attended Hospital A, and 552 men attended Hospital B; there were no significant differences in age or serum PSA levels. In Hospital A, 228 (35.1%) men had prostate cancer detected, CPC detection had a sensitivity of 80.7%, a specificity of 88.6%, and a negative predictive value of 89.5%. Some 39/44 men CPC negative with a positive biopsy had low grade small volume tumors. In Hospital B, 316 (57.2%) underwent biopsy. There were no significant differences between populations in terms of CPC and biopsy results. The reduction in the number of biopsies was 40%. Conclusions: The use of sequential CPC testing in the real world gives a clear decision structure for patient management and can reduce the number of biopsies considerably.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5365-5370
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• 2015

Background: Combining risk factors for prostate cancer into a predictive tool may improve the detection of prostate cancer while decreasing the number of benign biopsies. We compare one such tool, age multiplied by prostate volume divided by total serum PSA (PSA-AV) with PSA density and detection of primary malignant circulating prostate cells (CPCs) in a Chilean prostate cancer screening program. The objectives were not only to determine the predictive values of each, but to determine the number of clinically significant cancers that would have been detected or missed. Materials and Methods: A prospective study was conducted of all men undergoing 12 core ultrasound guided prostate biopsy for suspicion of cancer attending the Hospital DIPRECA and Hospital de Carabineros de Chile. Total serum PSA was registered, prostate volumecalculated at the moment of biopsy, and an 8ml blood simple taken immediately before the biopsy procedure. Mononuclear cells were obtained from the blood simple using differential gel centrifugation and CPCs identified using immunocytchemistry with anti-PSA and anti-P504S. Biopsy results were classed as positive or negative for cancer and if positive the Gleason score, number of positive cores and percent infiltration recorded. Results: A total of 664 men participated, of whom 234 (35.2%) had cancer detected. They were older, had higher mean PSA, PSA density and lower PSA-AV. Detection of CPCs had high predictive score, sensitivity, sensibility and positive and negative predictive values, PSA-AV was not significantly different from PSA density in this population. The use of CPC detection avoided more biopsies and missed fewer significant cancers.Conclusions: In this screening population the use of CPC detection predicted the presence of clinically significant prostate cancer better than the other parameters. The high negative predictive value would allow men CPC negative to avoid biopsy but remain in follow up. The formula PSA-AV did not add to the predictive performance using PSA density.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.601-606
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• 2015

Background: Prostate cancer is predominately a disease of older men, with a median age of diagnosis of 68 years and 71% of cancer deaths occurring in those over 75 years of age. While prostate cancer screening is not recommended for men >70 years, fit elderly men with controlled comorbidities may have a relatively long life expectancy. We compare the use of age related PSA with the detection of primary malignant circulating prostate cells mCPCs to detect clinically significant PC in this population. Materials and Methods: All men undergoing PC screening with a PSA >4.0ng/ml underwent TRUS 12 core prostate biopsy (PB). Age, PSA, PB results defined as cancer/no-cancer, Gleason, number of positive cores and percentage infiltration were registered. Men had an 8ml blood sample taken for mCPC detection; mononuclear cells were obtained using differential gel centrifugation and mCPCs were identified using immunocytochemistry with anti-PSA and anti-P504S. A mCPC was defined as a cell expressing PSA and P504S; a positive test as at least one mCPC detected/sample. Diagnostic yields for subgroups were calculated and the number of avoided PBs registered. Esptein criteria were used to define small grade tumours. Results: A total of 610 men underwent PB, 398 of whom were aged <70yrs. Men over 70 yrs had: a higher median PSA, 6.24ng/ml versus 5.59ng/ml (p=0.04); and a higher frequency of cancer detected 90/212 (43%) versus 134/398 (34%) (p=0.032). Some 34/134 cancers in men <70yrs versus 22/90 (24%) of men >70yrs complied with criteria for active surveillance. CPC detection: 154/398 (39%) men <70yrs were CPC (+), specificity for cancer 86%, sensitivity 88%, 14/16 with a false (-) result had a small low grade PC. In men >70 years, 88/212 (42%) were CPC (+); specificity 92%, sensitivity 87%, 10/12 with a false (-) had small low grade tumours. False (+) results were more common in younger men 36/154 versus 10/88 (p<0.02). With a PSA cutoff of 6.5ng/ml, in men <70yrs, 108 PB would be avoided, missing 56 cancers of which 48 were clinically significant. Using CPC detection, 124 biopsies would be avoided, missing only 2 clinically significant cancers. In men >70 yrs using a PSA >6.5ng/ml would have resulted in 108 PB with 34 PC detected, of which 14(41%) were small low grade tumours. Conclusions: The use of CPC detection in the fit elderly significantly decreases the number of PBs without missing clinically significant cancers, indicating superiority to the use of age-related PSA.