A non-DRE, voided urine, genomic assay to diagnose prostate cancer and to assess its aggressiveness.

Abstract

e17145 Background: The standard clinical practice to diagnose the presence and aggressiveness of prostate cancer, (PCa) consists of measuring serum prostate specific antigen (PSA), and performing image guided biopsies for histopathology. Due to the invasive nature potential risks and costs associated with prostate biopsy, urine based assays have been developed that require digital rectal examination (DRE) and to ascertain certain biomarkers present in the urine. These assays are not commonly integrated into clinical practice due to low sensitivity and high cost. Our goal was to develop a simple, noninvasive, reliable and affordable assay by targeting VPAC, a genomic receptor, expressed in high density on PCa malignant cells (MC), shed in non-DRE voided urine. Methods: Non DRE-Voided urine samples were collected from consenting patients (N=62, 56 ± 72 yrs) with histologically confirmed PCa and scheduled for radical prostatectomy. Urine was cytocentrifuged, cells on a glass slide fixed, and incubated with 0.5µg TP4303, a fluorophore containing small biomolecule developed in our laboratory with a high (3.1x10 -8 M) Kd value for VPAC. The excess TP4303 was washed, cells air dried, treated with DAPI, coverslip placed, and cells were analyzed using Zeiss microscope which calculated the % MC and the fluorophore intensity around MC. Data were corroborated with prostate grade group (GG) as determined by histology. Voided urine was also collected from consenting subjects (N= 97) clinically diagnosed with benign prostatic hyperplasia (BPH), with PSA <1.5 ng/ml (0.7±0.4, 60 8+ 6.3 yrs.). Results: Given in Table 1, indicate that the VPAC voided urine test was positive for all (N=62) PCa patients with increasing % MC shed in urine and their fluorescence intensity ,with increasing severity (GG) of PCa. Although these data points are small for statistical evaluations, the trend is remarkable that as the aggressiveness of disease increased, also increased were the % MC shed and the fluorescence intensity around them indicating increased VPAC density per MC. For BPH, the specificity of the assay was 89.6% to exclude prostate cancer with PPV 0.00% and NPV 100%. Conclusions: The data indicate i) using non-DRE voided urine, VPAC can be targeted to detect PCa, ii) the assay may also predict aggressiveness of PCa, iii) can distinguish PCa from BPH and iv) the assay is worthy of further investigation. Support: NIH 5RO1,CA249921 (MLT, ET). Patient clinical characteristics and results. PCa Grade Group No. of patients Age (yrs) PSA (ng/mL) Total cells Malignant cells % Malignant cells Fluorescence intensity (Mean ± Standard Deviation) 1 10 63.2±5.9 6.5 ±4.1 8588.±11679 2929±3356 41±28 31.8±3.1 2 31 63.90±7.3 7.2±3.8 5562±5207 2140±2286 49±29 33.7±4.0 3 13 65±9.2 13.1±14.5 4892±4143 2363±2979 37+27 33.0±6.3 4 2 65.50±6.3 6.5±2.1 4685±2616 1558±1351 48±56 32.2±5.6 5 6 68.20±4.1 50.2±104.9 8961±9877 7009±8237 66±27 35.7±5.7