Tohru Yoneyama

Measurement of aberrant glycosylation of prostate specific antigen can improve specificity in early detection of prostate cancer

INTRODUCTION We previously identified prostate cancer (PCa)-associated aberrant glycosylation of PSA, where α2,3-linked sialylation is an additional terminal N-glycan on free PSA (S2,3PSA). We then developed a new assay system measuring S2,3PSA using a magnetic microbead-based immunoassay. We compared the diagnostic accuracy of conventional PSA and percent-free PSA (%fPSA) tests. METHODS We used MagPlex beads to measure serum S2,3PSA levels using anti-human fPSA monoclonal antibody (8A6) for capture and anti-α2,3-linked sialic acid monoclonal antibody (HYB4) for detection. We determined the cutoff values in a training test and measured serum S2,3PSA levels in 314 patients who underwent biopsy, including 138 PCa and 176 non-PCa patients with PSA of <10.0 ng/ml. Serum S2,3PSA levels were presented as mean fluorescence intensity (MFI). Receiver operating characteristic curves were used to evaluate the diagnostic accuracy of total PSA, %fPSA, and S2,3PSA. RESULTS We determined an MFI cutoff value of 1130 with a sensitivity of 95.0% and specificity of 72.0% for the diagnosis of PCa in the training test. In the validation study, the area under the curve for the detection of PCa with S2,3PSA was 0.84, which was significantly higher than that with PSA or %fPSA. CONCLUSIONS Although the present study is small and preliminary, these results suggest that the measurement of serum S2,3PSA using a magnetic microbead-based immunoassay may improve the accuracy of early detection of PCa and reduce unnecessary prostate biopsy.

Serum tri‐ and tetra‐antennary N‐glycan is a potential predictive biomarker for castration‐resistant prostate cancer

The U.S. FDA has approved several novel systemic agents including abiraterone acetate and taxoid cabazitaxel for metastatic castration‐resistant prostate cancer (CRPC) result in a complicated decision‐making while selecting an appropriate treatment. Therefore, a predictive biomarker for CRPC would provide useful information to physicians. The aim of this study is to evaluate the diagnostic potential of serum N‐glycan profiling in CRPC.

Serum N-glycan alteration associated with renal cell carcinoma detected by high throughput glycan analysis.

PURPOSE Biomarkers for the early detection and prediction of survival in patients with renal cell carcinoma have not been established. We developed what is to our knowledge a novel glycoblotting method that allows high throughput, comprehensive, quantitative analysis of glycans in human serum. In this study we identified alterations in serum N-glycans associated with renal cell carcinoma. MATERIALS AND METHODS We performed a comprehensive N-glycan structural analysis of serum from 64 patients with renal cell carcinoma and 34 age matched, healthy volunteers using glycoblotting methods and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The peak intensity of N-glycan was analyzed using logistic regression analysis and ROCs were used to select candidate N-glycans. Candidate N-glycans with a statistically significant relationship to renal cell carcinoma or overall survival were independently evaluated using a Cox regression model to determine superiority compared to other conventional renal cell carcinoma biomarkers. RESULTS We identified 56 types of N-glycans in serum from healthy volunteers and patients with renal cell carcinoma. Peaks 40 and 43 were significantly more intense in patients than in volunteers. Peak 19 intensity was significantly higher and peak 49 intensity was significantly lower in patients with renal cell carcinoma who survived for a longer period. Multivariate analysis revealed that peaks 19 and 49 were independent predictors of overall survival. CONCLUSIONS Serum N-glycan analysis is a promising approach to discovering new biomarkers for renal cell carcinoma. Further study is warranted to validate our results.

Recent progress and perspectives on prostate cancer biomarkers.

The application of prostate-specific antigen (PSA) in prostate cancer (PC) screening, diagnosis, and prognosis has improved the clinical management of PC patients. However, the PSA assay has been faced with criticism due to its potential association with over-diagnosis and subsequent overtreatment of patients with indolent disease. The United States Preventive Services Task Force incited much debate over PSA-based screening in 2012 by recommending against this approach. However, the PSA assay remains the first-line tool for the early detection of PC. This debate highlights the unmet need for non-invasive PC biomarkers with greater sensitivity and specificity that are capable of distinguishing aggressive disease from indolent disease, predicting treatment response, and guiding treatment decisions. Recent investigations into putative PC biomarkers have focused on PSA isoform assays (prostate health index, 4-kallikurein panel), PC-associated genes in the urine (PCA3 and TMPRSS2-ERG), glycan-associated biomarkers (S2, 3PSA, GCNT1, and tri- and tetra-antennary serum N-glycans), and circulating tumor cells. Although substantial efforts to identify novel PC biomarkers that might replace PSA have been put forth, the majority of the putative PC biomarkers reported in the last few years are still under investigation or validation. This review provides an overview of the current state of PC biomarker research and focuses on a few promising PC biomarkers in development.

BK Virus–Associated Urothelial Carcinoma of a Ureter Graft in a Renal Transplant Recipient: A Case Report

BACKGROUND Urothelial carcinomas of ureter grafts in renal transplant patients are rare. Here we report our experience with a case of BK virus-associated urothelial carcinoma in a ureter graft. CASE REPORT A 47-year-old man developed chronic renal failure secondary to diabetes mellitus and started maintenance hemodialysis in September 2007. Two months later, the patient received a renal transplant from his 70-year-old mother. The patient developed BK virus-associated nephropathy 1 year after transplantation and presented with a decline in renal function and hydronephrosis in the transplanted kidney 4 years 6 months after transplantation. Cystoscopy and retrograde pyelography revealed an irregular filling defect in the ureter graft. Cytologic diagnosis of his urine revealed a high-grade urothelial carcinoma. Computerized tomography showed a cT2 ureteral tumor and no involvement of other organs. The patient subsequently underwent a transplant nephroureterectomy with bladder cuff resection. Histopathologic findings revealed a high-grade urothelial carcinoma, pT2, in the ureter graft with SV40-positive staining. The patient was closely observed without adjuvant chemotherapy therapy and remained disease free 1 year after surgery. Renal transplant recipients with BK virus infection are at high risk of developing urologic malignancies. Close attention is necessary to diagnose post-transplantation urologica malignancies as early as possible.

Oncological outcomes of neoadjuvant chemotherapy in patients with locally advanced upper tract urothelial carcinoma: a multicenter study

Objective The clinical impact of neoadjuvant chemotherapy (NAC) on oncological outcomes in patients with locally advanced upper tract urothelial carcinoma (UTUC) remains unclear. We investigated the oncological outcomes of platinum-based NAC for locally advanced UTUC. Results Of 234 patients, 101 received NAC (NAC group) and 133 did not (Control [Ctrl] group). The regimens in the NAC group included gemcitabine and carboplatin (75%), and gemcitabine and cisplatin (21%). Pathological downstagings of the primary tumor and lymphovascular invasion were significantly improved in the NAC than in the Ctrl groups. NAC for locally advanced UTUC significantly prolonged recurrence-free and cancer-specific survival. Multivariate Cox regression analysis using an inverse probability of treatment weighted (IPTW) method showed that NAC was selected as an independent predictor for prolonged recurrence-free and cancer-specific survival. However, the influence of NAC on overall survival was not statistically significant. Materials and Methods A total of 426 patients who underwent radical nephroureterectomy at five medical centers between January 1995 and April 2017 were examined retrospectively. Of the 426 patients, 234 were treated for a high-risk disease (stages cT3–4 or locally advanced [cN+] disease) with or without NAC. NAC regimens were selected based on eligibility of cisplatin. We retrospectively evaluated post-therapy pathological downstaging, lymphovascular invasion, and prognosis stratified by NAC use. Multivariate Cox regression analysis was performed for independent factors for prognosis. Conclusions Platinum-based NAC for locally advanced UTUC potentially improves oncological outcomes. Further prospective studies are needed to clarify the clinical benefit of NAC for locally advanced UTUC.

Platinum-based Neoadjuvant Chemotherapy Improves Oncological Outcomes in Patients with Locally Advanced Upper Tract Urothelial Carcinoma

BACKGROUND Neoadjuvant chemotherapy (NAC) use for patients with locally advanced upper tract urothelial carcinoma (UTUC) is debatable. OBJECTIVE To investigate the efficacy and safety of platinum-based NAC for locally advanced UTUC. DESIGN, SETTINGS, AND PARTICIPANTS Of 233 consecutive patients who underwent radical nephroureterectomy, 55 patients received NAC (NAC group) and 138 patients did not (Ctrl group). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The two arms (Ctrl vs NAC) were matched using propensity scores to minimize selection bias. We retrospectively evaluated tumor response, post-therapy pathological downstaging, lymphovascular invasion, Ki67 status, and prognosis between pair-matched patients. Multivariate Cox regression analysis was performed for independent factors for prognosis. RESULTS AND LIMITATIONS We selected 51 pair-matched patients in each group. The regimens in the NAC group included gemcitabine and carboplatin, and gemcitabine and cisplatin. The median response rate in the NAC group was 28%. NAC-related adverse events were tolerable. Pathological downstaging of the primary tumor was significantly higher in the NAC group than in the Ctrl group. The MIB1 index (immunostaining for Ki67) was significantly higher in the NAC group. NAC for locally advanced UTUC significantly prolonged progression-free, cancer-specific, and overall survival. Multivariate Cox regression analysis using an inverse probability of treatment weighting method showed that NAC was selected as an independent predictor for prolonged cancer-specific survival. Limitations are the retrospective design and the small sample size. CONCLUSIONS Platinum-based NAC for advanced UTUC potentially improves oncological outcomes. Further prospective studies are needed. PATIENT SUMMARY Platinum-based neoadjuvant chemotherapy for locally advanced upper tract urothelial carcinoma was safe and potentially improves oncological outcomes. A carboplatin-based regimen may be used as an alternative in patients with impaired renal function.

Testicular metastasis of prostate cancer: a case report.

The incidence of secondary neoplasms of the testis during autopsies is approximately 2.5%. Although most secondary testicular metastases are due to prostate cancer, only a few patients with prostate cancer have clinically manifested testicular metastasis. We report the case of a prostate cancer patient with testicular metastasis who was diagnosed after the presence of a palpable mass in the right testis. A 56-year-old Japanese male presented to our hospital with an elevated serum prostate-specific antigen (PSA) level of 137 ng/ml. He was diagnosed with stage IV (T3N1M1b) prostate cancer and received androgen deprivation therapy, followed by various hormonal manipulations. His serum PSA level was undetectable for 1 year. No distant metastases were detected during imaging examinations. He received radiation therapy; however, his serum PSA level increased gradually. Four months later, he presented with right testicular swelling. Computed tomography revealed a heterogenous mass in the right testis and a right high inguinal orchiectomy was performed. Histopathological analysis showed that the right testis was infiltrated with metastatic adenocarcinoma with a Gleason score of 8. This is a rare case of right testicular metastasis in a patient with prostate cancer. Testicular metastasis of prostate cancer can be aggressive and metastasize.

Detecting asymptomatic recurrence after radical cystectomy contributes to better prognosis in patients with muscle-invasive bladder cancer

AbstractThe prognostic benefit of oncological follow-up to detect asymptomatic recurrence after radical cystectomy (RC) remains unclear. We aimed to assess whether routine follow-up to detect asymptomatic recurrence after RC improves patient survival. We retrospectively analyzed 581 RC cases for muscle-invasive bladder cancer at four hospitals between May 1996 and February 2017. All patients had regular follow-up examinations with urine cytology, blood biochemical tests, and computed tomography after RC. We investigated the first site and date of tumor recurrence. Overall survival in patients with recurrence stratified by the mode of recurrence (asymptomatic group vs. symptomatic group) was estimated using the Kaplan–Meier method with the log-rank test. Cox proportional hazards regression analysis via inverse probability of treatment weighting (IPTW) was used to evaluate the impact of the mode of diagnosing recurrence on survival. Of the 581 patients, 175 experienced relapse. Among those, 12 without adequate data were excluded. Of the remaining 163 patients, 76 (47%) were asymptomatic and 87 (53%) were symptomatic at the time of diagnosis. The most common recurrence site and symptom were lymph nodes (47%) and pain (53%), respectively. Time of overall survival after RC and from recurrence to death was significantly longer in the asymptomatic group than in the symptomatic group. A multivariate Cox regression analysis using IPTW showed that in the patients with symptomatic recurrence was an independent risk factor for overall survival after RC and survival from recurrence to death. Routine oncological follow-up for detection of asymptomatic recurrence contributes to a better prognosis after RC.

Detection of Core2 β-1,6-N-Acetylglucosaminyltransferase in Post-Digital Rectal Examination Urine Is a Reliable Indicator for Extracapsular Extension of Prostate Cancer.

To identify appropriate candidates for aggressive treatment such as radical prostatectomy or radiation therapy of localized prostate cancer (PCa), novel predictive biomarkers of PCa aggressiveness are essential. Core2 β-1,6-N-acetylglucosaminyltransferase-1 (GCNT1) is a key enzyme that forms core 2-branched O-glycans. Its expression is associated with the progression of several cancers. We established a mouse IgG monoclonal antibody (mAb) against GCNT1 and examined the relationship of GCNT1 expression to the clinicopathological status of PCa. Paraffin-embedded PCa specimens were analyzed by immunohistochemistry for GCNT1 expression using a newly established mouse anti-GCNT1 mAb by ourselves. GCNT1-positive tumor showed significantly higher Gleason score and larger tumor volume. The number of GCNT1-positive cases was significantly lower in cases of organ-confined disease than in cases of extracapsular extension. GCNT1-negative tumors were associated with significantly better prostate-specific antigen (PSA)-free survival compared with GCNT1-positive tumors. Multivariate analysis revealed that detection of GCNT1 expression was an independent risk factor for PSA recurrence. We established new methods for GCNT1 detection from PCa specimens. Immunoblotting was used to examine post-digital rectal examination (DRE) urine from PCa patients. Over 90% of GCNT1-positive PCa patients with high concentrations of PSA showed extracapsular extension. In conclusion, GCNT1 expression closely associates with the aggressive potential of PCa. Further research aims to develop GCNT1 detection in post-DRE urine as a marker for PCa aggressiveness.