Identification of fluorescence in situ hybridization assay markers for prediction of disease progression in prostate cancer patients on active surveillance.

BACKGROUND: Prostate Cancer (PCa) is the second most prevalent cancer among U.S. males. In recent decades many men with low risk PCa have been over diagnosed and over treated. Given significant co-morbidities associated with definitive treatments, maximizing patient quality of life while recognizing early signs of aggressive disease is essential. There remains a need to better stratify newly diagnosed men according to the risk of disease progression, identifying, with high sensitivity and specificity, candidates for active surveillance versus intervention therapy. The objective of this study was to select fluorescence in situ hybridization (FISH) panels that differentiate non-progressive from progressive disease in patients with low and intermediate risk PCa. METHODS: We performed a retrospective case-control study to evaluate FISH biomarkers on specimens from PCa patients with clinically localised disease (T1c-T2c) enrolled in Watchful waiting (WW)/Active Surveillance (AS). The patients were classified into cases (progressed to clinical intervention within 10 years), and controls (did not progress in 10 years). Receiver Operating Characteristic (ROC) curve analysis was performed to identify the best 3-5 probe combinations. FISH parameters were then combined with the clinical parameters ─ National Comprehensive Cancer Network (NNCN) risk categories ─ in the logistic regression model. RESULTS: Seven combinations of FISH parameters with the highest sensitivity and specificity for discriminating cases from controls were selected based on the ROC curve analysis. In the logistic regression model, these combinations contributed significantly to the prediction of PCa outcome. The combination of NCCN risk categories and FISH was additive to the clinical parameters or FISH alone in the final model, with odds ratios of 5.1 to 7.0 for the likelihood of the FISH-positive patients in the intended population to develop disease progression, as compared to the FISH-negative group. CONCLUSIONS: Combinations of FISH parameters discriminating progressive from non-progressive PCa were selected based on ROC curve analysis. The combination of clinical parameters and FISH outperformed clinical parameters alone, and was complimentary to clinical parameters in the final model, demonstrating potential utility of multi-colour FISH panels as an auxiliary tool for PCa risk stratification. Further studies with larger cohorts are planned to confirm these findings.

Analysis of genetic copy number changes in cervical disease progression.

BACKGROUND: Cervical dysplasia and tumorigenesis have been linked with numerous chromosomal aberrations. The goal of this study was to evaluate 35 genomic regions associated with cervical disease and to select those which were found to have the highest frequency of aberration for use as probes in fluorescent in-situ hybridization. METHODS: The frequency of gains and losses using fluorescence in-situ hybridization were assessed in these 35 regions on 30 paraffin-embedded cervical biopsy specimens. Based on this assessment, 6 candidate fluorescently labeled probes (8q24, Xp22, 20q13, 3p14, 3q26, CEP15) were selected for additional testing on a set of 106 cervical biopsy specimens diagnosed as Normal, CIN1, CIN2, CIN3, and SCC. The data were analyzed on the basis of signal mean, % change of signal mean between histological categories, and % positivity. RESULTS: The study revealed that the chromosomal regions with the highest frequency of copy number gains and highest combined sensitivity and specificity in high-grade cervical disease were 8q24 and 3q26. The cytological application of these two probes was then evaluated on 118 ThinPrep samples diagnosed as Normal, ASCUS, LSIL, HSIL and Cancer to determine utility as a tool for less invasive screening. Using gains of either 8q24 or 3q26 as a positivity criterion yielded specificity (Normal +LSIL+ASCUS) of 81.0% and sensitivity (HSIL+Cancer) of 92.3% based on a threshold of 4 positive cells. CONCLUSIONS: The application of a FISH assay comprised of chromosomal probes 8q24 and 3q26 to cervical cytology specimens confirms the positive correlation between increasing dysplasia and copy gains and shows promise as a marker in cervical disease progression.

Chromosomal biomarkers for detection of human papillomavirus associated genomic instability in epithelial cells of cervical cytology specimens.

The goal of this study was to compare how accumulation of chromosomal aberrations in human papillomavirus (HPV)-infected cells correlates with the severity of cervical dysplastic lesions. We assessed the frequency of genomic alterations for 35 different loci in a pilot biopsy study and selected two loci (3q26 and 8q24) with the highest frequency of copy number gains found in high-grade dysplasia and cancer. These probes were labeled with gold and red fluorophores and combined with HPV biotin-labeled probes for subsequent detection using a tyramide signal amplification system with a green fluorophore. Cells that were both HPV positive and chromosomally abnormal were designated as "double-positive cells." Cervical cytology specimens from 235 patients were used for this blinded study. The average number of double-positive cells increased from two cells in patients with a cytological interpretation of atypical squamous cells of undetermined significance to 22 cells in low-grade squamous intraepithelial lesion and 99 cells in high-grade squamous intraepithelial lesion, reflecting an accumulation of chromosomal abnormality with disease progression. Using a cutoff of four or more double-positive cells as the criterion for the presence of a cervical intraepithelial neoplasia 2 or 3 lesion, we demonstrated that low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion cytology specimens with underlying cervical intraepithelial neoplasia 2/3 histology showed positive test results in more than 80% of cases. Correlation of 3q26 and 8q24 aneusomy with concurrent HPV infection may thus serve as a biomarker of genetic instability in HPV-infected cells.

Evaluation of quantity and staining pattern of human papillomavirus (HPV)-infected epithelial cells in thin-layer cervical specimens using optimized HPV-CARD assay.

BACKGROUND: Testing for human papillomavirus (HPV) is used in the triage of women with a cervical cytology of atypical squamous cells of undetermined significance (ASCUS). A fluorescent in situ hybridization assay was developed for the detection of HPV using the catalyzed receptor deposition technique (HPV-CARD). In this study, the utility of this assay was tested for the detection of HPV in liquid-based cervical cytology specimens. METHODS: A total of 195 liquid-based cytology specimens were analyzed using the HPV-CARD assay. The results from the assay were compared with HPV polymerase chain reaction (PCR) and typing results. The number of HPV-infected cells and the staining pattern was correlated with the cytology classification. RESULTS: A 91% concordance between HPV-CARD and PCR was observed for the detection of high-risk HPV viruses. A 78% concordance was observed for specimens that were negative for HPV. In ASCUS, low-grade squamous intraepithelial lesion (LSIL), and high-grade squamous intraepithelial lesion (HSIL) categories, the average number of HPV-positive cells per slide was 19 cells, 127 cells, and 450 cells, respectively. The number of cells with a punctate staining, suggestive of HPV integration, was 21% in ASCUS, 34% in LSIL, and 46% in HSIL specimens. CONCLUSIONS: The results of the current study indicate positive correlations between the severity of the disease and the increased overall quantity of HPV-positive epithelial cells in cervical cytology specimens and accumulation of cells with punctate staining suggestive of integrated HPV. In summary, the developed HPV-CARD assay was found to provide novel information regarding the proportion and staining pattern of HPV-infected epithelial cells in different cytologic categories of cervical specimens.