Combined genetic and epigenetic alterations of the TERT promoter affect clinical and biological behavior of bladder cancer.

In urothelial bladder cancer (UBC), risk stratification remains an important unmet need. Limitless self-renewal, governed by TERT expression and telomerase activation, is crucial for cancer progression. Thus, telomerase activation through the interplay of mutations (TERTpMut ) and epigenetic alterations in the TERT promoter may provide further insight into UBC behavior. Here, we investigated the combined effect of TERTpMut and the TERT Hypermethylated Oncological Region (THOR) status on telomerase activation and patient outcome in a UBC international cohort (n = 237). We verified that TERTpMut were frequent (76.8%) and present in all stages and grades of UBC. Hypermethylation of THOR was associated with higher TERT expression and higher-risk disease in nonmuscle invasive bladder cancers (NMIBC). TERTpMut alone predicted disease recurrence (HR: 3.18, 95%CI 1.84 to 5.51, p < 0.0001) but not progression in NMIBC. Combined THORhigh /TERTpMut increased the risk of disease recurrence (HR 5.12, p < 0.0001) and progression (HR 3.92, p = 0.025). Increased THOR hypermethylation doubled the risk of stage progression of both TERTpwt and TERTpMut NMIBC. These results highlight that both mechanisms are common and coexist in bladder cancer and while TERTpMut is an early event in bladder carcinogenesis THOR hypermethylation is a dynamic process that contributes to disease progression. While the absence of alterations comprises an extremely indolent phenotype, the combined genetic and epigenetic alterations of TERT bring additional prognostic value in NMIBC and provide a novel insight into telomere biology in cancer.

The TERT hypermethylated oncologic region predicts recurrence and survival in pancreatic cancer.

AIM: We explore the biomarker potential of the TERT hypermethylated oncologic region (THOR) in pancreatic cancer. MATERIALS & METHODS: We assessed the methylation status of THOR using the cancer genome atlas data on the cohort of pancreatic cancer (n = 193 patients). RESULTS: THOR was significantly hypermethylated in pancreatic tumor tissue when compared with the normal tissue used as control (p < 0.0001). Also, THOR hypermethylation could distinguish early stage I disease from normal tissue and was associated with worse prognosis. DISCUSSION:  We found that THOR is hypermethylated in pancreatic tumor tissue when compared with normal tissue and that THOR methylation correlates with TERT expression in tumor samples. CONCLUSION: Our preliminary findings support the diagnostic and prognostic values of THOR in pancreatic cancer.

Alternative lengthening of telomeres is enriched in, and impacts survival of TP53 mutant pediatric malignant brain tumors.

Although telomeres are maintained in most cancers by telomerase activation, a subset of tumors utilize alternative lengthening of telomeres (ALT) to sustain self-renewal capacity. In order to study the prevalence and significance of ALT in childhood brain tumors we screened 517 pediatric brain tumors using the novel C-circle assay. We examined the association of ALT with alterations in genes found to segregate with specific histological phenotypes and with clinical outcome. ALT was detected almost exclusively in malignant tumors (p = 0.001). ALT was highly enriched in primitive neuroectodermal tumors (12 %), choroid plexus carcinomas (23 %) and high-grade gliomas (22 %). Furthermore, in contrast to adult gliomas, pediatric low grade gliomas which progressed to high-grade tumors did not exhibit the ALT phenotype. Somatic but not germline TP53 mutations were highly associated with ALT (p = 1.01 × 10(-8)). Of the other alterations examined, only ATRX point mutations and reduced expression were associated with the ALT phenotype (p = 0.0005). Interestingly, ALT attenuated the poor outcome conferred by TP53 mutations in specific pediatric brain tumors. Due to very poor prognosis, one year overall survival was quantified in malignant gliomas, while in children with choroid plexus carcinoma, five year overall survival was investigated. For children with TP53 mutant malignant gliomas, one year overall survival was 63 ± 12 and 23 ± 10 % for ALT positive and negative tumors, respectively (p = 0.03), while for children with TP53 mutant choroid plexus carcinomas, 5 years overall survival was 67 ± 19 and 27 ± 13 % for ALT positive and negative tumors, respectively (p = 0.07). These observations suggest that the presence of ALT is limited to a specific group of childhood brain cancers which harbor somatic TP53 mutations and may influence the outcome of these patients. Analysis of ALT may contribute to risk stratification and targeted therapies to improve outcome for these children.

Screening for Colorectal Cancer Leading into a New Decade: The "Roaring '20s" for Epigenetic Biomarkers?

Colorectal cancer (CRC) has an important bearing (top five) on cancer incidence and mortality in the world. The etiology of sporadic CRC is related to the accumulation of genetic and epigenetic alterations that result in the appearance of cancer hallmarks such as abnormal proliferation, evasion of immune destruction, resistance to apoptosis, replicative immortality, and others, contributing to cancer promotion, invasion, and metastasis. It is estimated that, each year, at least four million people are diagnosed with CRC in the world. Depending on CRC staging at diagnosis, many of these patients die, as CRC is in the top four causes of cancer death in the world. New and improved screening tests for CRC are needed to detect the disease at an early stage and adopt patient management strategies to decrease the death toll. The three pillars of CRC screening are endoscopy, radiological imaging, and molecular assays. Endoscopic procedures comprise traditional colonoscopy, and more recently, capsule-based endoscopy. The main imaging modality remains Computed Tomography (CT) of the colon. Molecular approaches continue to grow in the diversity of biomarkers and the sophistication of the technologies deployed to detect them. What started with simple fecal occult blood tests has expanded to an armamentarium, including mutation detection and identification of aberrant epigenetic signatures known to be oncogenic. Biomarker-based screening methods have critical advantages and are likely to eclipse the classical modalities of imaging and endoscopy in the future. For example, imaging methods are costly and require highly specialized medical personnel. In the case of endoscopy, their invasiveness limits compliance from large swaths of the population, especially those with average CRC risk. Beyond mere discomfort and fear, there are legitimate iatrogenic concerns associated with endoscopy. The risks of perforation and infection make endoscopy best suited for a confirmatory role in cases where there are positive results from other diagnostic tests. Biomarker-based screening methods are largely non-invasive and are growing in scope. Epigenetic biomarkers, in particular, can be detected in feces and blood, are less invasive to the average-risk patient, detect early-stage CRC, and have a demonstrably superior patient follow-up. Given the heterogeneity of CRC as it evolves, optimal screening may require a battery of blood and stool tests, where each can leverage different pathways perturbed during carcinogenesis. What follows is a comprehensive, systematic review of the literature pertaining to the screening and diagnostic protocols used in CRC. Relevant articles were retrieved from the PubMed database using keywords including: "Screening", "Diagnosis", and "Biomarkers for CRC". American and European clinical trials in progress were included as well.

DNA hypermethylation within TERT promoter upregulates TERT expression in cancer.

Replicative immortality is a hallmark of cancer cells governed by telomere maintenance. Approximately 90% of human cancers maintain their telomeres by activating telomerase, driven by the transcriptional upregulation of telomerase reverse transcriptase (TERT). Although TERT promoter mutations (TPMs) are a major cancer-associated genetic mechanism of TERT upregulation, many cancers exhibit TERT upregulation without TPMs. In this study, we describe the TERT hypermethylated oncological region (THOR), a 433-bp genomic region encompassing 52 CpG sites located immediately upstream of the TERT core promoter, as a cancer-associated epigenetic mechanism of TERT upregulation. Unmethylated THOR repressed TERT promoter activity regardless of TPM status, and hypermethylation of THOR counteracted this repressive function. THOR methylation analysis in 1,352 human tumors revealed frequent (>45%) cancer-associated DNA hypermethylation in 9 of 11 (82%) tumor types screened. Additionally, THOR hypermethylation, either independently or along with TPMs, accounted for how approximately 90% of human cancers can aberrantly activate telomerase. Thus, we propose that THOR hypermethylation is a prevalent telomerase-activating mechanism in cancer that can act independently of or in conjunction with TPMs, further supporting the utility of THOR hypermethylation as a prognostic biomarker.

Germline BRCA mutation in male carriers-ripe for precision oncology?

BACKGROUND: Prostate cancer (PC) is one of the known heritable cancers with individual variations attributed to genetic factors. BRCA1 and BRCA2 are tumour suppressor genes with crucial roles in repairing DNA and thereby maintaining genomic integrity. Germline BRCA mutations predispose to multiple familial tumour types including PC. METHODS: We performed a Pubmed database search along with review of reference lists from prominent articles to capture papers exploring the association between BRCA mtuations and prostate cancer risk and prognosis. Articles were retrieved until May 2017 and filtered for relevance, and publication type. RESULTS: We explored familial PC genetics; discussed the discovery and magnitude of the association between BRCA mutations and PC risk and outcome; examined implications of factoring BRCA mutations into PC screening; and discussed the rationale for chemoprevention in this high-risk population. We confirmed that BRCA1/2 mutations confer an up to 4.5-fold and 8.3-fold increased risk of PC, respectively. BRCA2 mutations are associated with an increased risk of high-grade disease, progression to metastatic castration-resistant disease, and 5-year cancer-specific survival rates of 50 to 60%. CONCLUSION: Despite the growing body of research on DNA repair genes, deeper analysis is needed to understand the aetiological role of germline BRCA mutations in the natural history of PC. There is a need for awareness to screen for this marker of PC risk. There is similarly an opportunity for structured PC screening programs for BRCA mutation carriers. Finally, further research is required to identify potential chemopreventive strategies for this high-risk subgroup.

Breast Cancer and HIV in Sub-Saharan Africa: A Complex Relationship.

INTRODUCTION: The number and lifespan of individuals living with HIV have increased significantly with the scale-up of antiretroviral therapy. Furthermore, the incidence of breast cancer in women with HIV is growing, especially in sub-Saharan Africa (SSA). However, the association between HIV infection and breast cancer is not well understood. METHODS: A literature search was performed to identify articles published in journals pertaining to breast cancer and HIV, with an emphasis on SSA. Selected US-based studies were also identified for comparison. RESULTS: Among the 56 studies reviewed, the largest study examined 314 patients with breast cancer and HIV in the United States. There is no consensus on whether HIV infection acts as a pro-oncogenic or antioncogenic factor in breast cancer, and it may have no relation to breast cancer. A higher incidence of breast cancer is reported in high-income countries than in SSA, although breast cancer in SSA presents at a younger age and at a more advanced stage. Some studies show that patients with breast cancer and HIV experience worse chemotherapy toxicity than do patients without HIV. Data on treatment outcomes are limited. The largest study showed worse treatment outcomes in patients with HIV, compared with their counterparts without HIV. CONCLUSION: HIV infection has not been associated with different clinical presentation of breast cancer. However, some evidence suggests that concurrent diagnosis of HIV with breast cancer is associated with increased therapy-related toxicity and worse outcomes. Systematic prospective studies are needed to establish whether there is a specific association between breast cancer and HIV.

The power of integration: radiotherapy and global palliative care.

Radiotherapy (RT) is a powerful tool for the palliation of the symptoms of advanced cancer, although access to it is limited or absent in many low- and middle-income countries (LMICs). There are multiple factors contributing to this, including assumptions about the economic feasibility of RT in LMICs, the logical challenges of building capacity to deliver it in those regions, and the lack of political support to drive change of this kind. It is encouraging that the problem of RT access has begun to be included in the global discourse on cancer control and that palliative care and RT have been incorporated into national cancer control plans in some LMICs. Further, RT twinning programs involving high- and low-resource settings have been established to improve knowledge transfer and exchange. However, without large-scale action, the consequences of limited access to RT in LMICs will become dire. The number of new cancer cases around the world is expected to double by 2030, with twice as many deaths occurring in LMICs as in high-income countries (HICs). A sustained and coordinated effort involving research, education, and advocacy is required to engage global institutions, universities, health care providers, policymakers, and private industry in the urgent need to build RT capacity and delivery in LMICs.

A cancer specific hypermethylation signature of the TERT promoter predicts biochemical relapse in prostate cancer: a retrospective cohort study.

The identification of new biomarkers to differentiate between indolent and aggressive prostate tumors is an important unmet need. We examined the role of THOR (TERT Hypermethylated Oncological Region) as a diagnostic and prognostic biomarker in prostate cancer (PCa).We analyzed THOR in common cancers using genome-wide methylation arrays. Methylation status of the whole TERT gene in benign and malignant prostate samples was determined by MeDIP-Seq. The prognostic role of THOR in PCa was assessed by pyrosequencing on discovery and validation cohorts from patients who underwent radical prostatectomy with long-term follow-up data.Most cancers (n = 3056) including PCa (n = 300) exhibited hypermethylation of THOR. THOR was the only region within the TERT gene that is differentially methylated between normal and malignant prostate tissue (p < 0.0001). Also, THOR was significantly hypermethylated in PCa when compared to paired benign tissues (n = 164, p < 0.0001). THOR hypermethylation correlated with Gleason scores and was associated with tumor invasiveness (p = 0.0147). Five years biochemical progression free survival (BPFS) for PCa patients in the discovery cohort was 87% (95% CI 73-100) and 65% (95% CI 52-78) for THOR non-hypermethylated and hypermethylated cancers respectively (p = 0.01). Similar differences in BPFS were noted in the validation cohort (p = 0.03). Importantly, THOR was able to predict outcome in the challenging (Gleason 6 and 7 (3 + 4)) PCa (p = 0.007). For this group, THOR was an independent risk factor for BPFS with a hazard-ratio of 3.685 (p = 0.0247). Finally, THOR hypermethylation more than doubled the risk of recurrence across all PSA levels (OR 2.5, p = 0.02).

Evolving surgical techniques of and indications for corneal transplantation in Ontario: 2000 - 2012.

OBJECTIVE: To evaluate trends in indications for and preferred surgical techniques of corneal transplantation in Ontario over a 12-year period. DESIGN: Retrospective review of recipient information forms collected by Eye Bank of Canada (Ontario Division). PARTICIPANTS: Patients who received corneal transplantation in Ontario between 2000 and 2012, totaling 11,725 corneal transplants performed. METHODS: Database containing information collected from recipient information forms maintained by the Eye Bank of Canada (Ontario Division) was reviewed. Corneal transplants performed between July 1, 2000, and June 30, 2012, in Ontario were analyzed. Surgeons complete recipient information forms at the time of corneal transplant surgery. Of the 11,725 available recipient information forms, 10,906 (93%) were sufficiently complete to meet the inclusion criteria and were included in the study. RESULTS: Since 2009, Fuchs endothelial dystrophy overtook pseudophakic corneal edema as the leading indication for corneal transplantation. Since the shift toward lamellar keratoplasty in 2006, there has been a significant decrease in number of corneal transplants performed with penetrating keratoplasty (PKP; p = 0.0016) and a significant increase in Descemet stripping automated endothelial keratoplasty (DSAEK; p = 0.0069) and deep anterior lamellar keratoplasty (p = 0.0108). The gap between number of PKPs and DSAEKs performed each year is progressively narrowing. From July 1, 2011, to June 30, 2012, 514 PKPs were performed compared with 420 DSAEKs. From 2011 to 2012, 83% of corneal transplants indicated by Fuchs endothelial dystrophy were performed with DSAEK, whereas only 13% were performed with PKP. CONCLUSIONS: Six years since initial implementation, partial thickness transplantation continues to increase in popularity. Corneal tissue supply and demand will need to reflect these changes in the field of corneal transplantation.

Sequential pterygium excision with conjunctival autograft in the management of primary double-headed pterygia.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of sequential pterygium excision with conjunctival autograft (PECA) in the management of double-headed pterygia. METHODS: All patients who underwent a sequential PECA procedure for double-headed pterygia from 2004 to 2009 were included in this retrospective, noncomparative, interventional case series. The recurrence rate and visual outcomes after this procedure were determined. RESULTS: Nine eyes of 8 patients with doubled-headed pterygia undergoing sequential PECA were identified. Of 18 PECA procedures, 1 recurrence (5.56%) was found. The single recurrence was observed nasally in the right eye (first site operated) of a female patient 55 months after the second PECA procedure. None of the operated eyes lost any lines of corrected distance visual acuity, and 22% gained at least 1 line of corrected distance visual acuity. CONCLUSIONS: In this series, harvesting the conjunctival autograft from the same site several months later does not appear to increase the rate of recurrence. Sequential PECA is a safe and effective method of addressing double-headed pterygia.