Background: Allelic counterparts of biallelically expressed genes display an epigenetic symmetry normally manifested by synchronous replication, different from genes subjected to monoallelic expression, which normally are characterized by an asynchronous mode of replication (well exemplified by the SNRPN imprinted locus). Malignancy was documented to be associated with gross modifications in the inherent replication-timing coordination between allelic counterparts of imprinted genes as well as of biallelically expressed loci. The cancer-related allelic replication timing aberrations are non-disease specific and appear in peripheral blood cells of cancer patients, including those with solid tumors. As such they offer potential blood markers for non-invasive cancer test. The present study was aimed to gain some insight into the mechanism leading to the replication timing alterations of genes in blood lymphocytes of cancer patients. Methods: Peripheral blood samples derived from patients with prostate cancer were chosen to represent the cancerous status, and samples taken from patients with no cancer but with benign prostate hyperplasia were used to portray the normal status. Fluorescence In Situ Hybridization (FISH) replication assay, applied to phytohemagglutinin (PHA)-stimulated blood lymphocytes, was used to evaluate the temporal order (either synchronous or asynchronous) of genes in the patients' cells. Results: We demonstrated that: (i) the aberrant epigenetic profile, as delineated by the cancer status, is a reversible modification, evidenced by our ability to restore the normal patterns of replication in three unrelated loci (CEN15, SNRPN and RB1) by introducing an archetypical demethylating agent, 5-azacytidine; (ii) following the rehabilitating effect of demethylation, an imprinted gene (SNRPN) retains its original parental imprint; and (iii) the choice of an allele between early or late replication in the aberrant asynchronous replication, delineated by the cancer status, is not random but is independent of the parental origin. Conclusion: The non-disease specific aberrant epigenetic profile displayed in peripheral blood cells of patients with a solid tumour (unlike genetic aberrations) can be reversed, by an epigenetic drug applied in vitro, to the normal. It appears that the cancerous status differentiates between two allelic counterparts in a non-random manner, but independent of the parental origin
Purpose: to evaluate a unique subpopulation of radical prostatectomy (RP) candidates with “negative” prostate 68Ga-labeled prostate-specific membrane antigen (PSMA) positron emission tomography (PET) computed tomography (CT) imaging scans and to characterize the clinical implications of misleading findings. Materials and Methods: This case-control retrospective study compared the final histological outcomes of patients with “negative” pre-RP PSMA PET/CT prostate scans (with a prostate maximal standardized uptake value [SUVmax] below the physiologic uptake) to those with an “intense” prostatic tracer uptake (with a SUVmax above the physiologic uptake). The patients underwent an RP between March 2015 and July 2019 in five academic centers. Data on the demographics, comorbidities, prostate-specific antigen (PSA) and rectal exam findings, prior biopsies, imaging results, biopsies, and RP histology results were collected. Results: Ninety-seven of the 392 patients who underwent an RP had PSMA PET/CT imaging preoperatively. Fifty-two (54%) had a “negative” uptake (in the study group), and 45 (46%) had a “positive” uptake (in the control group). Only the lesion size and SUVmax values on the PSMA PET/CT differed between the groups preoperatively. On the histological analysis, only the ISUP score, seminal vesicles invasion, T stage, and positive margin rates differed between the groups (p < 0.05), while 50 (96%) study group patients harbored clinically significant disease (ISUP ≥ 2), with an extra-prostatic disease in 24 (46%), perineural invasion in 35 (67%), and positive lymph nodes in 4 (8%). Conclusions: Disease aggressiveness generally correlated with an intense PSMA uptake on the preoperative PSMA PET/CT, but a subpopulation of patients with clinically significant cancer and aggressive characteristics showed a deceptively weak PSMA uptake. These data raise a concern about the unqualified application of PSMA PET/CT for staging RP candidates.
Up-to-date guidelines on the management of upper tract urothelial carcinoma (UTUC) are continuously published. We aim to assess the variability of diagnosis and treatment strategies in the endoscopic management of UTUC and adherence to European Association of Urology and National Comprehensive Cancer Network guidelines. A 15-question survey was designed to query practitioners on approaches to clinical practice and knowledge about endoscopic treatment indications and techniques. It was emailed to all members of the Endourologic Society through the society’s office, and to all Israeli non-member endourologists. Eighty-eight urologists participated in the survey. Adherence to guidelines on indications for endoscopic management was only 51%. Most of the survey respondents (87.5%) use holmium laser for tumor ablation, and ~50% use forceps for biopsy while the other half use baskets. Only 50% stated that they would use Jelmyto® for specific indications. Most (80%) indicated that they repeat the ureteroscopy 3 months after the first one, and 52.3% continue with follow-up ureteroscopy every 3 months during the first year after diagnosis. There is vast variability among endourologists in the technical aspects of UTUC, the indications for endoscopic management, and adherence to the available guidelines for managing UTUC.