Grant D. Stewart

Clinical Utility of an Epigenetic Assay to Detect Occult Prostate Cancer in Histopathologically Negative Biopsies: Results of the MATLOC Study

PURPOSE Concern about possible false-negative prostate biopsy histopathology findings often leads to rebiopsy. A quantitative methylation specific polymerase chain reaction assay panel, including GSTP1, APC and RASSF1, could increase the sensitivity of detecting cancer over that of pathological review alone, leading to a high negative predictive value and a decrease in unnecessary repeat biopsies. MATERIALS AND METHODS The MATLOC study blindly tested archived prostate biopsy needle core tissue samples of 498 subjects from the United Kingdom and Belgium with histopathologically negative prostate biopsies, followed by positive (cases) or negative (controls) repeat biopsy within 30 months. Clinical performance of the epigenetic marker panel, emphasizing negative predictive value, was assessed and cross-validated. Multivariate logistic regression was used to evaluate all risk factors. RESULTS The epigenetic assay performed on the first negative biopsies of this retrospective review cohort resulted in a negative predictive value of 90% (95% CI 87-93). In a multivariate model correcting for patient age, prostate specific antigen, digital rectal examination and first biopsy histopathological characteristics the epigenetic assay was a significant independent predictor of patient outcome (OR 3.17, 95% CI 1.81-5.53). CONCLUSIONS A multiplex quantitative methylation specific polymerase chain reaction assay determining the methylation status of GSTP1, APC and RASSF1 was strongly associated with repeat biopsy outcome up to 30 months after initial negative biopsy in men with suspicion of prostate cancer. Adding this epigenetic assay could improve the prostate cancer diagnostic process and decrease unnecessary repeat biopsies.

Ureteroscopic and percutaneous management of upper tract urothelial carcinoma (UTUC): systematic review.

Whats known on the subject? and What does the study add?

A comparison of the pathology of transitional cell carcinoma of the bladder and upper urinary tract.

To clarify the histopathological patterns of upper and lower urinary tract transitional cell carcinomas (TCCs), as previous reports suggest that upper urinary tract TCCs have a greater tendency towards high‐grade disease than bladder TCCs, of which most are low‐grade and low‐stage tumours.

The Effect of VEGF-Targeted Therapy on Biomarker Expression in Sequential Tissue from Patients with Metastatic Clear Cell Renal Cancer

Purpose: To investigate how biologically relevant markers change in response to antiangiogenic therapy in metastatic clear cell renal cancer (mRCC) and correlate these changes with outcome. Experimental Design: The study used sequential tumor tissue and functional imaging (taken at baseline and 12–16 weeks) obtained from three similar phase II studies. All three studies investigated the role of VEGF tyrosine kinase inhibitors (TKI) before planned nephrectomy in untreated mRCC (n = 85). The effect of targeted therapy on ten biomarkers was measured from sequential tissue. Comparative genomic hybridization (CGH) array and DNA methylation profiling (MethylCap-seq) was performed in matched frozen pairs. Biomarker expression was correlated with early progression (progression as best response) and delayed progression (between 12–16 weeks). Results: VEGF TKI treatment caused a significant reduction in vessel density (CD31), phospho-S6K expression, PDL-1 expression, and FOXP3 expression (P < 0.05 for each). It also caused a significant increase in cytoplasmic FGF-2, MET receptor expression in vessels, Fuhrman tumor grade, and Ki-67 (P < 0.05 for each). Higher levels of Ki-67 and CD31 were associated with delayed progression (P < 0.05). Multiple samples (n = 5) from the same tumor showed marked heterogeneity of tumor grade, which increased significantly with treatment. Array CGH showed extensive intrapatient variability, which did not occur in DNA methylation analysis. Conclusion: TKI treatment is associated with dynamic changes in relevant biomarkers, despite significant heterogeneity in chromosomal and protein, but not epigenetic expression. Changes to Ki-67 expression and tumor grade indicate that treatment is associated with an increase in the aggressive phenotype of the tumor. Clin Cancer Res; 19(24); 6924–34. ©2013 AACR.

Identification of stromally expressed molecules in the prostate by tag-profiling of cancer-associated fibroblasts, normal fibroblasts and fetal prostate

The stromal microenvironment has key roles in prostate development and cancer, and cancer-associated fibroblasts (CAFs) stimulate tumourigenesis via several mechanisms including the expression of pro-tumourigenic factors. Mesenchyme (embryonic stroma) controls prostate organogenesis, and in some circumstances can re-differentiate prostate tumours. We have applied next-generation Tag profiling to fetal human prostate, normal human prostate fibroblasts (NPFs) and CAFs to identify molecules expressed in prostatic stroma. Comparison of gene expression profiles of a patient-matched pair of NPFs vs CAFs identified 671 transcripts that were enriched in CAFs and 356 transcripts whose levels were decreased, relative to NPFs. Gene ontology analysis revealed that CAF-enriched transcripts were associated with prostate morphogenesis and CAF-depleted transcripts were associated with cell cycle. We selected mRNAs to follow-up by comparison of our data sets with published prostate cancer fibroblast microarray profiles as well as by focusing on transcripts encoding secreted and peripheral membrane proteins, as well as mesenchymal transcripts identified in a previous study from our group. We confirmed differential transcript expression between CAFs and NPFs using QrtPCR, and defined protein localization using immunohistochemistry in fetal prostate, adult prostate and prostate cancer. We demonstrated that ASPN, CAV1, CFH, CTSK, DCN, FBLN1, FHL1, FN, NKTR, OGN, PARVA, S100A6, SPARC, STC1 and ZEB1 proteins showed specific and varied expression patterns in fetal human prostate and in prostate cancer. Colocalization studies suggested that some stromally expressed molecules were also expressed in subsets of tumour epithelia, indicating that they may be novel markers of EMT. Additionally, two molecules (ASPN and STC1) marked overlapping and distinct subregions of stroma associated with tumour epithelia and may represent new CAF markers.

Long-term endoscopic management of upper tract urothelial carcinoma: 20-year single-centre experience

Study Type – Therapy (case series)

Is There a Human Homologue to the Murine Proteolysis-Inducing Factor?

Purpose: A tumor-derived proteolysis-inducing factor (PIF) is suggested to be a potent catabolic factor in skeletal muscle of mice and humans. We aimed to establish the clinical significance of PIF in cancer patients and to elucidate its structural features. Experimental Design: PIF was detected in human urine using a monoclonal antibody (mAb) and related to clinical outcomes. PIF immunoaffinity-purified using the mAb was purified/separated using reverse-phase high-performance liquid chromatography and two-dimensional electrophoresis. Ten human cancer cell lines were tested for expression of mRNA encoding PIF core peptide. Results: PIF immunoreactivity was present in 160 of 262 patients with advanced cancers of the lung, esophagus/stomach, and other organs. In a Kaplan-Meier survival analysis of 181 lung cancer patients, PIF was unrelated to survival; PIF status was also unrelated to skeletal muscle loss confirmed by computed tomography imaging. PIF was seen in 16 of 24 patients with chronic heart failure and thus is not exclusive to malignant disease. In-gel digestion and mass spectrometric analysis of immunoaffinity purified PIF from cancer patients consistently identified human albumin and immunoglobulins. We showed nonspecific binding of purified albumin and immunoglobulins to the anti-PIF mAb, which is thus not a useful tool for PIF detection or purification in humans. Finally, the human PIF core peptide was detected in human cancer cell lines using reverse transcription-PCR and nucleotide sequencing; however, none of the amplified products had a site for the glycosylation critical to the proteolysis-inducing activity of murine PIF. Conclusions: A putative human homologue of murine PIF and its role in human cancer cachexia cannot be verified.

Endoscopic Versus Laparoscopic Management of Noninvasive Upper Tract Urothelial Carcinoma: 20-Year Single Center Experience

PURPOSE We compare the outcomes of endoscopic surgery to laparoscopic nephroureterectomy for the management of specifically noninvasive upper tract urothelial carcinoma. MATERIALS AND METHODS A retrospective database review identified consecutive patients with clinically noninvasive upper tract urothelial carcinoma who underwent endoscopic surgery (59, via ureteroscopic ablation or percutaneous resection) or laparoscopic nephroureterectomy (70) at a single center during 20 years (1991 to 2011). Overall survival, upper tract urothelial carcinoma specific survival, upper tract recurrence-free survival, intravesical recurrence-free survival, progression-free survival and renal unit survival were estimated using Kaplan-Meier methods, with differences assessed using the log rank test. RESULTS Median age and followup were 74.8 years and 50 months, respectively. Overall renal preservation in the endoscopic group was high (5-year renal unit survival 82.5%), although this came at a cost of high local recurrence (endoscopic surgery 5-year recurrence-free survival 49.3%, laparoscopic nephroureterectomy 100%, p <0.0001). For G1 upper tract urothelial carcinoma, endoscopic surgery 5-year disease specific survival (100%) was equivalent to that of laparoscopic nephroureterectomy (100%). However, laparoscopic nephroureterectomy demonstrated superior disease specific survival to endoscopic surgery for G2 disease (91.7% vs 62.5%, p = 0.037) and superior progression-free survival for G3 disease (88.9% vs 55.6%, p = 0.033). CONCLUSIONS For G1 upper tract urothelial carcinoma, endoscopic management can provide effective oncologic control and renal preservation. However, endoscopic management should not be considered for higher grade disease except in compelling imperative cases or in patients with poor life expectancy as oncologic outcomes are inferior to those of laparoscopic nephroureterectomy.

NO-sulindac inhibits the hypoxia response of PC-3 prostate cancer cells via the Akt signalling pathway

Nitric oxide‐donating non‐steroidal anti‐inflammatory drugs are safer than traditional NSAIDs and inhibit the growth of prostate cancer cells with greater potency than NSAIDs. In vivo, prostate cancer deposits are found in a hypoxic environment which induces resistance to chemotherapy. The aim of this study was to assess the effects and mechanism of action of a NO‐NSAID called NO‐sulindac on the PC‐3 prostate cancer cell line under hypoxic conditions. NO‐sulindac was found to have pro‐apoptotic, cytotoxic, and anti‐invasive effect on PC‐3 cells under normoxia and hypoxia. NO‐sulindac was significantly more cytotoxic than sulindac at all oxygen levels. The sulindac/linker and NO‐releasing subunits both contributed to the cytotoxic effects of NO‐sulindac. Resistance of PC‐3 cells to NO‐sulindac was induced as the oxygen concentration declined. Hypoxia‐induced chemoresistance was reversed by knocking‐down hypoxia‐inducible factor‐1α (HIF‐1α) mRNA using RNAi. Nuclear HIF‐1α levels were upregulated at 0.2% oxygen but reduced by treatment with NO‐sulindac, as was Akt phosphorylation. NO‐sulindac treatment of hypoxic PC‐3 cells transfected with a reporter construct, downregulated activation of the hypoxia response element (HRE) promoter. Co‐transfection of PC‐3 cells with the HRE promoter reporter construct and myr‐Akt (constitutively active Akt) plasmids reversed the NO‐sulindac induced reduction in HRE activation. Real‐time polymerase chain reaction analysis of hypoxic, NO‐sulindac treated PC‐3 cells showed downregulation of lysyl oxidase and carbonic anhydrase IX mRNA expression. Collectively, these novel findings demonstrate that NO‐sulindac directly inhibits the hypoxia response of PC‐3 prostate cancer cells by inhibiting HIF‐1α translation via the Akt signalling pathway. The ability of NO‐sulindac to inhibit tumour adaption to hypoxia has considerable relevance to the future management of prostate cancer with the same cellular properties as PC‐3.

Long-term comparative outcomes of open versus laparoscopic nephroureterectomy for upper urinary tract urothelial-cell carcinoma after a median follow-up of 13 years*.

BACKGROUND AND PURPOSE Open nephroureterectomy (ONU) rather than laparoscopic nephroureterectomy (LNU) is still regarded as the standard of care for extirpative surgical management of upper urinary tract urothelial-cell carcinoma (UUT-UCC). The longest published follow-up of LNU is 7 years. We report outcomes for patients having surgery ≥10 years ago. PATIENTS AND METHODS Consecutive patients with UUT-UCC who were treated with ONU (n=39) or LNU (n=23) between April 1992 to September 2000 were included. Preoperative, tumor, operative and postoperative characteristics, recurrence, and outcomes were collated. Survival was estimated using the Kaplan-Meier method. RESULTS Median follow-up of censored patients was 163 months (13.6 y). Estimated mean overall survival (OS) was 111 months for ONU and 103 months for LNU. Mean progression free survival (PFS) was 175 months for ONU and 143 months for LNU. Probability of PFS at 10 years was 79% for ONU and 76% for LNU and was unchanged at 15 years. There was no significant difference between ONU and LNU in terms of OS (P=0.51, log-rank test), PFS (P=0.70) or cancer-specific survival (CSS; P=0.43). There were no prognostic differences between ONU and LNU after correcting for confounding variables. There was no increase in the probability of a bladder cancer recurrence from 10 to 15 years postoperation. CONCLUSION Long-term follow-up of patients who were operated on more than 10 years ago suggests that LNU has oncologic equivalence to ONU because there were no significant differences in OS, PFS, or CSS between ONU and LNU patients followed for a median of 13 years.