Faculty Bibliography

Background: Low risk prostate cancers are amenable to active surveillance which can reduce harmful overtreatment of indolent disease. However there is great variability of criteria in urological practice for determination of active surveillance candidacy. The quantity of Gleason pattern 4 is an important prognostic parameter and may influence treatment decisions. A genomic classifier, the Oncotype DX Genomic Prostate Score has been used to predict both clinical risk and tumor aggressiveness in patients diagnosed on biopsy with low risk prostate cancer (Grade group (GG) 1 and 2). This study investigated whether Genomic Prostate Score (GPS) can predict unfavorable disease and correlates with percentage of Gleason pattern 4 in low grade prostate cancer.
Design(s): We searched our surgical pathology database for prostate biopsies with Oncotype DX Genomic Prostate Score reports (2016- 2019). Oncotype Dx was performed on the single core with worst disease (core with longest tumor and/or maximum percentage of pattern 4). Biopsy results including Gleason Score and length of the tumor and percentage of pattern 4 from the core submitted for Oncotype test were recorded. Follow-up repeat biopsy or prostatectomy, if performed, were also retrieved for review of Gleason Score. Oncotype GPS score and related clinical information were analyzed in the study.
Result(s): 306 prostate biopsy cases with Oncotype DX test report were included in the study. Among these cases, 124 cases were originally diagnosed as GG1 (Gleason Score 3 + 3) and 182 cases were GG2 (3 + 4). The average GPS in GG 2 is significantly higher than GG1 (28.52 +/- 11.80 vs 17.88 +/- 9.35, p < 0.0001). Forty cases in GG1 had follow up repeat biopsy or prostatectomy. Twenty cases were upgraded to GG2. Cases with higher GPS score are more likely to upgrade to GG2 (23.10 +/- 10.13 vs 16.55 +/- 8.22, p < 0.05) in follow up repeat biopsy or prostatectomy. In GG1 group, GPS score correlated with the maximum tumor length and tumor percentage (p < 0.01). In GG2, patients with Gleason pattern 4 greater than 30% received higher GPS score than patients with pattern 4 less than 30% (p < 0.05). GPS significantly correlated with percentage of Gleason pattern 4 but not length of pattern 4, length of tumor, PSA level or PSA density.
Conclusion(s): In GG1, Oncotype Dx GPS can predict the likelihood of unfavorable disease at follow up repeat biopsy or prostatectomy. In GG2, GPS score correlated with percentage of pattern 4, supporting its role as an auxiliary tool for clinical risk classification

Background: Recent clinical guidelines for management of prostate adenocarcinoma are aimed at expanding active surveillance (AS) to include men with intermediate-risk (Gleason score 3+4=7) disease on needle biopsy (NB). However, studies reported a large portion of men with Gleason 3+4=7 prostate cancer on biopsy, that harbored adverse surgical pathologic findings. It remains unclear which subset of intermediate-risk patients with Gleason score 7 cancers can be safely treated with AS. In this study we investigate whether the percentage of Gleason pattern 4 in NB with Gleason score 7 cancers is an indicator for stratifying risk.
Design(s): We retrospectively reviewed our electronic record database for patients that underwent core NB over a 6-year period. We included NB with Gleason score 3+3=6 (G336), 3+4=7 with <5% Gleason pattern 4 (G4%<5) and 3+4=7 with 6-49% maximum Gleason pattern 4 (G4%6-49); all cases had corresponding radical prostatectomy (RP) within 6 months of the biopsy. We defined adverse pathology (AP) as any RP with Gleason score equal to or greater than 4+3=7 and/or stage T3 or higher. We compare AP outcomes in final follow-up RP of three NB groups: G336, G4%<5 and G4%6-49.
Result(s): A total of 289 NB with corresponding radical prostatectomies were identified. The breakdown of Gleason groups is shown in Table 1. GS336 has an AP rate of 26.6%, while G4<5% an AP rate of 20%. In comparison, the group of patients with G4%6-49 exhibited a 42% rate of AP (Table 1). A Chi-square test performed comparing AP of G4%<5 and G%6-49 is statistically significant p= .0237 (Figure 1). Conversely, there is no statistical difference between the rate of AP in G4<5% and G336, p= 0.46. G336 and G4%<5 were aggregated into a new group G%0-5 with an AP rate of 25.2% compared to G%6-10 AP rate 39.6%, p= 0.0576 (Figure 2). G4%6-10 and G4%11-49 had comparable rates of AP, 39.6% and 43.1%, respectively (p=0.681). (Table presented)
Conclusion(s): Currently there is a paradigm shift amongst pathologist and the significance of minimal percentage pattern 4 on prostate biopsies. Our current data supports the recent literature publications that <5% maximal Gleason pattern 4 on a single core has a similar rate of adverse pathological outcomes as Gleason score 3+3=6 and can be considered for AS. Although we did not detect a statistical difference between the rate of AP between G4%0-5 and G4%6-10, the data is beginning to approach statistical significance and warrants further risk stratification

Background: Clear cell papillary renal cell carcinoma (ccpRCC) is a relatively new entity and it has been described as an indolent renal neoplasm. ccpRCC shares features of clear cell RCC (ccRCC) and papillary RCC (pRCC) morphologically and immunohistochemically, even though it carries a very different prognostic potential. Epigenetic alterations play a significant role in the development and progression of human tumors. A large scale sequencing efforts demonstrated that hypermethylation in RCC tumors is associated with poor prognosis and may dictate treatment options. However, ccpRCC has not been included and further molecular elucidation is to be done. In this study, we attempt to investigate the methylation patterns in ccpRCC and test if differential patterns can be correlated with histologic subtypes and known biological behaviors.
Design(s): Nephrectomy specimens from our institution were reviewed and 8 cases from 2017-2019 were selected and confirmed as ccpRCC by three pathologists. Tumors were microdissected and DNA from FFPE was extracted and profiled using the Illumina MethylationEPIC array. Methylation data were analyzed with the R Bioconductor package minfi, including quality control, data normalization and differentially methylated CpG site analysis. Subsequent filtering was performed using a p-value cutoff = 0.01 and a minimum mean difference of the Beta-value of 0.1. Clustering was performed using tSNE analysis. Copy numbers were analyzed using conumee package. The methylation data were compared to ccRCC and pRCC from publicly available TCGA dataset.
Result(s): All 8 cases passed QC metrics on bisulfite conversion, hybridization and signal intensity confirming that the DNA quality was optimal for methylation study. ccpRCC clustered very tightly together illustrating that they represented a homogeneous group of tumors. When this cluster was compared to the TCGA dataset, ccpRCC was found to be located in between ccRCC and pRCC which might explain the characteristic features of this tumor subtype (figure 1). (Figure presented)
Conclusion(s): 1. DNA methylation is a useful molecular hallmark of many cancers including renal cancers and is increasingly utilized in diagnosis, prognostication, and clinical trials (epigenetic therapy). 2. Morphologically and immunohistochemically confirmed ccpRCC forms a tight cluster validating the use of methylation assay for future studies. 3. Promotor and pathway specific methylation patterns will be further studied which can distinguish the indolent clinical behavior

BACKGROUND:Differentiating parathyroid from thyroid lesions can be difficult on fine-needle aspiration (FNA) due to overlapping cytomorphologic features. While the traditional parathyroid hormone (PTH) assays can help in the distinction, these tests may be cumbersome, particularly when the lesion is unexpected clinically and a needle wash is not collected at the time of FNA. Therefore, we chose to investigate the application of immunohistochemical staining (IHC) with GATA 3 and thyroid transcription factor-1 (TTF-1) on air-dried cytology smears to distinguish parathyroid and thyroid lesions. METHODS:Air-dried touch preparation (TP) slides were prepared from consecutively selected parathyroid and thyroid specimens. Thirteen FNA cases with the clinical concern for parathyroid lesions were also included in the study. IHC was performed on unstained and ultrafast Papanicolaou (UFP) stained air-dried slides. RESULTS:On TP slides, GATA 3 expression was observed in all cases of parathyroid origin but no immunoreactivity was present in thyroid lesions. TTF-1 expression was observed in all cases of thyroid origin but not in parathyroid lesions. GATA 3 and TTF-1 expression of 13 FNA cases were consistent with the clinical impression or concurrent PTH tests. CONCLUSIONS:IHC with GATA 3 and TTF-1 on air-dried cytology smears is a simple and effective way to differentiate parathyroid vs thyroid lesions on FNA. Air-dried unstained and UFP-stained slides perform equally well with IHC, but UFP-stained slides provide the added benefit of morphologic evaluation and assessment of smear cellularity prior to IHC.

Electronic-cigarettes (E-cigs) are marketed as a safe alternative to tobacco to deliver the stimulant nicotine, and their use is gaining in popularity, particularly among the younger population. We recently showed that mice exposed to short-term (12 wk) E-cig smoke (ECS) sustained extensive DNA damage in lungs, heart, and bladder mucosa and diminished DNA repair in lungs. Nicotine and its nitrosation product, nicotine-derived nitrosamine ketone, cause the same deleterious effects in human lung epithelial and bladder urothelial cells. These findings raise the possibility that ECS is a lung and bladder carcinogen in addition to nicotine. Given the fact that E-cig use has become popular in the past decade, epidemiological data on the relationship between ECS and human cancer may not be known for a decade to come. In this study, the carcinogenicity of ECS was tested in mice. We found that mice exposed to ECS for 54 wk developed lung adenocarcinomas (9 of 40 mice, 22.5%) and bladder urothelial hyperplasia (23 of 40 mice, 57.5%). These lesions were extremely rare in mice exposed to vehicle control or filtered air. Current observations that ECS induces lung adenocarcinomas and bladder urothelial hyperplasia, combined with our previous findings that ECS induces DNA damage in the lungs and bladder and inhibits DNA repair in lung tissues, implicate ECS as a lung and potential bladder carcinogen in mice. While it is well established that tobacco smoke poses a huge threat to human health, whether ECS poses any threat to humans is not yet known and warrants careful investigation.

BACKGROUND:DHX15 is a member of the DEAH-box (DHX) RNA helicase family. Our previous study identified it as an AR coactivator which contributes to prostate cancer progression. METHODS:We investigated DHX15 expression in castration resistant prostate cancer specimens and the influence of DHX15 on the responsiveness of prostate cancer cells to DHT stimulation. We also explored the role DHX15 played in enzalutamide resistance and the interacting domain in DHX15 with AR. DHX15 expression level in human CRPC specimens and prostate cancer specimens was detected by tissue microarray (TMA) immunostaining analysis. Colony formation assay was performed to determine the proliferation of cells treated with enzalutamide or DHT. siRNAs were used to knockdown DHX15. The interactions between DHX15 and AR were detected using co-immunoprecipitation assay. RESULTS:The expression level of DHX15 was upregulated in human CRPC specimens compared with hormone naïve prostate cancer specimens. DHX15 knockdown reduced AR sensitivity to low DHT concentrations in C4-2 cells. Inactivation of DHX15 sensitizes the enzalutamide treatment in C4-2 cells. Deletion mutagenesis indicated that DHX1 5 interacts with AR through its N terminal domain. CONCLUSIONS:These findings suggest that DHX15 contributes to prostate cancer progression. DHX15 is required for androgen receptor sensitivity to low DHT concentrations and contributes to enzalutamide resistance in C4-2 cells. Targeting DHX15 may improve the ADT treatment.

CONTEXT/BACKGROUND:- In Gleason score GS (7) prostate cancers, the quantity of Gleason pattern 4 (GP 4) is an important prognostic factor and influences treatment decisions. Magnetic resonance imaging (MRI)-targeted biopsy has been increasingly used in clinical practice. OBJECTIVE:- To investigate whether MRI-targeted biopsy may detect GS 7 prostate cancer with greater GP 4 quantity, and whether it improves biopsy/radical prostatectomy GS concordance. DESIGN/METHODS:- A total of 243 paired standard and MRI-targeted biopsies with cancer in either standard or targeted or both were studied, 65 of which had subsequent radical prostatectomy. The biopsy findings, including GS and tumor volume, were correlated with the radical prostatectomy findings. RESULTS:- More prostate cancers detected by MRI-targeted biopsy were GS 7 or higher. Mean GP 4 percentage in GS 7 cancers was 31.0% ± 29.3% by MRI-targeted biopsy versus 25.1% ± 29.5% by standard biopsy. A total of 122 of 218 (56.0%) and 96 of 217 (44.2%) prostate cancers diagnosed on targeted biopsy and standard biopsy, respectively, had a GP 4 of 10% or greater ( P = .01). Gleason upgrading was seen in 12 of 59 cases (20.3%) from MRI-targeted biopsy and in 24 of 57 cases (42.1%) from standard biopsy ( P = .01). Gleason upgrading correlated with the biopsy cancer volume inversely and GP 4 of 30% or less in standard biopsy. Such correlation was not found in MRI-targeted biopsy. CONCLUSIONS:- Magnetic resonance imaging-targeted biopsy may detect more aggressive prostate cancers and reduce the risk of Gleason upgrading in radical prostatectomy. This study supports a potential role for MRI-targeted biopsy in the workup of prostate cancer and inclusion of percentage of GP 4 in the prostate biopsy reports.