Smoking status, usual adult occupation, and risk of recurrent urothelial bladder carcinoma: data from The Cancer Genome Atlas (TCGA) Project

Inherited KDM6AA649T facilitates tumor-immune escape and exacerbates colorectal signet-ring cell carcinoma outcomes

Childhood onset of colorectal signet-ring cell carcinoma (CR-SRCC) is extremely rare and featured as highly malignant with poor prognosis. Here we reported a CR-SRCC case of 11-year-old boy with a novel inherited X-linked KDM6AA694T mutation. The H3K27me3 demethylase KDM6A was frequently mutated in varieties of tumors and acts as a tumor suppressor. In vivo H3K27me3 demethylation assay demonstrated that KDM6AA694T had dampened H3K27me3 demethylase activity. Overexpression of KDM6AA694T in SRCC cell line KATO3 promoted cell proliferation, invasion and migration, which were further confirmed in vivo by constructing orthotopic tumor growth and lung metastasis model. Besides, expression of KDM6AA694T in immune cells suppresses inflammatory macrophage response and effector T cell response. In conclusion, we characterized a novel inherited KDM6AA694T mutant from a childhood-onset SRCC case and demonstrated that the mutant with impaired H3K27me3 demethylase activity could potentiate tumor malignancy and suppress antitumor immunity.

Nitrated Polycyclic Aromatic Hydrocarbon (Nitro-PAH) Signatures and Somatic Mutations in Diesel Exhaust-Exposed Bladder Tumors

BACKGROUND

Diesel exhaust is a complex mixture, including polycyclic aromatic hydrocarbons (PAH) and nitrated PAHs (nitro-PAH), many of which are potent mutagens and possible bladder carcinogens. To explore the association between diesel exposure and bladder carcinogenesis, we examined the relationship between exposure and somatic mutations and mutational signatures in bladder tumors.

METHODS

Targeted sequencing was conducted in bladder tumors from the New England Bladder Cancer Study. Using data on 797 cases and 1,418 controls, two-stage polytomous logistic regression was used to evaluate etiologic heterogeneity between bladder cancer subtypes and quantitative, lifetime estimates of respirable elemental carbon (REC), a surrogate for diesel exposure. Poisson regression was used to evaluate associations between REC and mutational signatures.

RESULTS

We observed significant heterogeneity in the diesel-bladder cancer risk relationship, with a strong positive association among cases with high-grade, nonmuscle invasive TP53-mutated tumors compared with controls [ORTop Tertile vs.Unexposed, 4.8; 95% confidence interval (CI), 2.2-10.5; Ptrend < 0.001; Pheterogeneity = 0.002]. In muscle-invasive tumors, we observed a positive association between diesel exposure and the nitro-PAH signatures of 1,6-dintropyrene (RR, 1.93; 95% CI, 1.28-2.92) and 3-nitrobenzoic acid (RR, 1.97; 95% CI, 1.33-2.92).

CONCLUSIONS

The relationship between diesel exhaust and bladder cancer was heterogeneous based on the presence of TP53 mutations in tumors, further supporting the link between PAH exposure and TP53 mutations in carcinogenesis. Future studies that can identify nitro-PAH signatures in exposed tumors are warranted to add human data supporting the link between diesel and bladder cancer.

IMPACT

This study provides additional insight into the etiology and possible mechanisms related to diesel exhaust-induced bladder cancer.

Occupational asbestos exposure and survival among lung cancer patients

OBJECTIVE

This study investigated the association between occupational asbestos exposure (OAE) and survival in patients with histologically confirmed lung cancer (LC).

METHODS

This monocentric study was conducted in the Comprehensive Cancer Centre Léon Bérard, Lyon, France. A systematic screening has been in place since 2014 for occupational exposure to carcinogens using a self-assessment questionnaire sent to all patients newly diagnosed with histologically confirmed LC identified through the multidisciplinary LC board from 2014 to 2019. When the physician suspected a work-related exposure from the questionnaire including job history, an occupational cancer consultation was carried out to detail carcinogen exposures and assess if the LC was work-related. Demographics, clinical characteristics and survival data were extracted from medical records. The association between asbestos exposure and overall survival (hazard ratio and 95% confidence intervals) was estimated by Cox proportional hazards regression.

RESULTS

Overall, 702 patients were eligible to the present study, including 180 patients with OAE. In the crude analysis, LCs assessed as moderately or highly attributable to OAE were associated with decreased overall survival (HR = 1.32, 95 %CI 1.04-1.67) compared to LC without OAE or with a low degree of imputability to OAE (median follow-up 28.8 months). After adjustment for confounding (age at diagnosis, smoking status, stage, brain metastasis at diagnosis, and histology), the association of OAE with overall survival was no longer statistically significant (HR = 1.21, 95 %CI 0.94-1.56).

CONCLUSION

Overall survival in occupationally asbestos exposed LC patients may be decreased in comparison with non-exposed LC patients, warranting further investigations in larger studies.

DNA Repair Gene Polymorphisms and Susceptibility to Urothelial Carcinoma in a Southeastern European Population

Single nucleotide polymorphisms (SNPs) in DNA repair genes may predispose to urothelial carcinoma of the bladder (UCB). This study focused on three specific SNPs in a population with high exposure to environmental carcinogens including tobacco and alcohol. A case-control study design was used to assess for presence of XPC PAT +/-, XRCC3 Thr241Met, and ERCC2 Lys751Gln DNA repair gene SNPs in peripheral blood from patients with UCB and healthy individuals. One hundred patients and equal number of healthy subjects were enrolled. The XPC PAT +/+ genotype was associated with a 2-fold increased risk of UCB (OR = 2.16; 95%CI: 1.14-4; p = 0.01). The -/+ and +/+ XPC PAT genotypes were more frequently present in patients with multiple versus single tumors (p = 0.01). No association was detected between ERCC2 Lys751Gln genotypes/alleles, and risk for developing UCB. Presence of the XRCC3 TT genotype (OR = 0.14; 95%CI:0.07-0.25; p < 0.01) and of the T allele overall (OR = 0.26; 95%CI:0.16-0.41; p < 0.01) conferred a protective effect against developing UCB. The XPC PAT -/+ and XRCC3 Thr241Met SNPs are associated with predisposition to UCB. The XPC PAT -/+ SNP is also an indicator of bladder tumor multiplicity, which might require a more individualized surveillance and treatment.

The Dark Side of the Force: When the Immune System Is the Fuel of Tumor Onset

Nowadays, it is well accepted that inflammation is a critical player in cancer, being, in most cases, the main character of the process. Different types of tumor arise from sites of infection or chronic inflammation. This non-resolving inflammation is responsible for tumor development at different levels: it promotes tumor initiation, as well as tumor progression, stimulating both tumor growth and metastasis. Environmental factors, lifestyle and infections are the three main triggers of chronic immune activation that promote or increase the risk of many different cancers. In this review, we focus our attention on tumor onset; in particular, we summarize the knowledge about the cause and the mechanisms behind the inflammation-driven cancer development.

Knowledge of bladder cancer in the French population: results of the EDIFICE 6 survey

OBJECTIVE

To assess awareness of bladder cancer (BCa) in France.

METHODS

The French nationwide observational survey EDIFICE 6 was conducted online (26 June-28 July 2017) in 12,046 individuals (age, 18-69 years). The present analysis focuses on laypersons' knowledge of the severity and frequency of BCa, signs and symptoms, associated risk factors and screening tests. Quantitative data were expressed as means and standard deviation, and categorical data as percentages.

RESULTS

Analyses were conducted on 11,313 questionnaires. Among the top five acknowledged risk factors for BCa, tobacco was ranked as having the second lowest impact (5.9/10 [2.5]). Only 28% of the study population were aware that active tobacco smoking is a major risk factor for BCa (rating ≥8/10); 61% of the study population was unaware of the existence of any signs or symptoms of BCa, and 69% was not able to cite any of the most widely used diagnostic tests.

CONCLUSIONS

We found that the French population has a poor knowledge of BCa risk factors, early signs and diagnostic tests. Effective prevention of BCa requires dissemination of clear information and prevention messages to the lay population, focusing particularly on tobacco consumption and early signs of the disease.

Diesel exhaust and bladder cancer risk by pathologic stage and grade subtypes

BACKGROUND

The International Agency for Research on Cancer (IARC) classifies diesel engine exhaust as carcinogenic to humans based on sufficient evidence for lung cancer. IARC noted, however, an increased risk of bladder cancer (based on limited evidence).

OBJECTIVE

To evaluate the association between quantitative, lifetime occupational diesel exhaust exposure and risk of urothelial cell carcinoma of the bladder (UBC) overall and according to pathological subtypes.

METHODS

Data from personal interviews with 1944 UBC cases, as well as formalin-fixed paraffin-embedded tumor tissue blocks, and 2135 controls were pooled from two case-control studies conducted in the U.S. and Spain. Lifetime occupational histories combined with exposure-oriented questions were used to estimate cumulative exposure to respirable elemental carbon (REC), a primary surrogate for diesel exhaust. Unconditional logistic regression and two-stage polytomous logistic regression were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for smoking and other risk factors.

RESULTS

Exposure to cumulative REC was associated with an increased risk of UBC; workers with cumulative REC >396 μg/m³-years had an OR of 1.61 (95% CI, 1.08-2.40). At this level of cumulative exposure, similar results were observed in the U.S. and Spain, OR = 1.75 (95% CI, 0.97-3.15) and OR = 1.54 (95% CI, 0.89-2.68), respectively. In lagged analysis, we also observed a consistent increased risk among workers with cumulative REC >396 μg/m³-years (range of ORs = 1.52-1.93) for all lag intervals evaluated (5-40 years). When we accounted for tumor subtypes defined by stage and grade, a significant association between diesel exhaust exposure and UBC was apparent (global test for association p = 0.0019).

CONCLUSIONS

Combining data from two large epidemiologic studies, our results provide further evidence that diesel exhaust exposure increases the risk of UBC.

Identification of the Key Factors Related to Bladder Cancer by lncRNA-miRNA-mRNA Three-Layer Network

Bladder cancer is the most common malignant tumor of the urinary system, and it has high incidence, high degree of malignancy, and easy recurrence after surgery. The etiology and pathogenesis of bladder cancer are not fully understood, but more and more studies have shown that its development may be regulated by some core molecules. To identify key molecules in bladder cancer, we constructed a three-layer network by merging lncRNA-miRNA regulatory network, miRNA-mRNA regulatory network, and lncRNA-mRNA coexpression network, and further analyzed the topology attributes of the network including the degree, betweenness centrality and closeness centrality of nodes. We found that miRNA-93 and miRNA-195 are controllers for a three-layer network and regulators of numerous target genes associated with bladder cancer. Functional enrichment analysis of their target mRNAs revealed that miRNA-93 and miRNA-195 may be closely related to bladder cancer by disturbing the homeostasis of the cell cycle or HTLV-I infection. In addition, since E2F1 and E2F2 are enriched in various KEGG signaling pathways, we conclude that they are important target genes of miRNA-93, and participate in the apoptotic process by forming a complex with a certain protein or transcription factor activity, sequence-specific DNA binding in bladder cancer. Similarly, AKT3 is an important target gene of miRNA-195, its expression is associated with PI3K-Akt-mTOR signaling pathway and AMPK-mTOR signaling pathway. Therefore, we speculate that AKT3 may participate in proliferation and apoptosis of bladder cancer cells through these pathways, and ultimately affect the biological behavior of tumor cells. Furthermore, through survival analysis, we found that miRNA-195 and miRNA-93 are associated with poor prognosis of bladder cancer. And the Kaplan-Meier curve showed that 24 mRNAs and nine lncRNAs are closely related to overall survival of bladder cancer.

The histone demethylase UTX/KDM6A in cancer: Progress and puzzles

The lysine-specific demethylase 6A/UTX (gene name KDM6A) acts as a component of the COMPASS complex to control gene activation. UTX demethylates H3K27me2/3 at genes and enhancers. Deleterious mutations in KDM6A are found in many cancer types, prominently urothelial carcinoma and certain T-cell leukemias. In certain cancers, however, UTX supports oncogenic transcription factors, e.g. steroid hormone receptors in breast and prostate cancer. In fetal development, UTX regulates lineage choice and cell differentiation. Analogously, loss of UTX function in cancer may lead to metaplasia or impede differentiation. Likely because its function is contingent on its interacting transcription factors, the effects of UTX inactivation are not uniform and require detailed investigation in each cancer type. In urothelial carcinoma, in particular, the functional consequences of the frequent mutations in KDM6A and other COMPASS component genes are poorly understood. Nevertheless, UTX inactivation appears to sensitize many cancers to inhibitors of the H3K27 methyltransferase EZH2. Conversely, inhibitors of UTX enzymatic activity may be applicable in cancers with an oncogenic UTX function. Intriguingly, the fact that KDM6A is localized on the X-chromosome, but both copies are expressed, may account for gender-specific differences in cancer susceptibility. In conclusion, despite recent progress, many open questions need to be addressed, most importantly, the detailed mechanisms by which KDM6A inactivation promotes various cancers, but also with which proteins UTX interacts in and apart from the COMPASS complex, and to which extent its catalytic function is required for its tumor-suppressive function.

Occupational variation in bladder cancer in Nordic males adjusted with approximated smoking prevalence

BACKGROUND

Occupational exposure has been identified as the most important risk factor for bladder cancer second to smoking. The objective of this study was to estimate the occupational variation in risk of bladder cancer that is not attributable to smoking.

MATERIAL AND METHODS

In the Nordic Occupational Cancer study (NOCCA), 111,458 cases of bladder cancer and 208,297 cases of lung cancer cases were observed among men in Denmark, Finland, Iceland, Norway and Sweden during 1961-2005. Relative smoking prevalence in an occupation was estimated based on standardized incidence ratio (SIR) for lung cancer in the given occupation. Crude and smoking-adjusted SIRs with 95% confidence intervals (CI) for bladder cancer were calculated for each occupation.

RESULTS

The smoking-adjusted SIR for most of the occupations was closer to 1.00 than the unadjusted SIR. The highest statistically significant smoking-adjusted SIRs were observed among chimney sweeps (SIR 1.29, 95% CI 1.05-1.56), waiters (1.22, 1.07-1.38) hairdressers (1.14, 1.02-1.26), cooks and stewards (1.12, 1.01-1.25), printers (1.11, 1.04-1.18) and seamen (1.09, 1.03-1.14).

CONCLUSIONS

Smoking is a strong risk factor for bladder cancer but there may also be other factors in some specific occupations in addition to smoking. The occupational variation in risk of bladder cancer is small when adjusted for smoking, but risk increasing factors are indicated in some occupations.

Novel therapies in urothelial carcinoma: a biomarker-driven approach

Urothelial malignancies, including carcinomas of the bladder, ureters, and renal pelvis comprised ∼8% of new cancer cases in the USA in 2016. In the metastatic setting, 15% of patients exhibit long-term survival following cisplatin-based chemotherapy and in patients with recurrent disease, response rates to second-line chemotherapy are generally 15%-20% with a 3-month progression-free survival. However, recent advances in immunotherapy represent an opportunity to significantly improve patient outcomes. Moreover, the advent of next-generation sequencing has resulted in both an improved understanding of the fundamental genetic changes that characterize urothelial carcinoma (UC) and identification of several candidate biomarkers of response to various therapies. Incorporation of prospective genotyping into clinical trials will allow for the identification and enrichment of patients most likely to respond to specific targeted therapies and chemotherapy. Combining different therapeutic classes to enhance outcomes is also an area of active research in UC.

The association between smoking cessation before and after diagnosis and non-muscle-invasive bladder cancer recurrence: a prospective cohort study

BACKGROUND

Smoking is a major risk factor for bladder cancer, but the relationship between smoking cessation after initial treatment and bladder cancer recurrence has been investigated less frequently and not prospectively yet.

METHODS

722 non-muscle-invasive bladder cancer (NMIBC) patients (pTa, pT1, and CIS) from the prospective Bladder Cancer Prognosis Programme (BCPP) cohort, selected in the UK between 2005 and 2011, provided complete data on smoking behavior before and up to 5 years after diagnosis. The impact of smoking behavior on NMIBC recurrence was explored by multivariable Cox regression models investigating time-to-first NMIBC recurrence.

RESULTS

Over a median follow-up period of 4.21 years, 403 pathologically confirmed NMIBC recurrences occurred in 210 patients. Only 25 current smokers at diagnosis quit smoking (14%) during follow-up and smoking cessation after diagnosis did not decrease risk of recurrence compared to continuing smokers (p = 0.352).

CONCLUSIONS

Although quitting smoking after diagnosis might reduce the risk of recurrence based on retrospective evidence, this is not confirmed in this prospective study because the number of NMIBC patients quitting smoking before their first recurrence was too low. Nevertheless, this indicates an important role for urologists and other health care professionals in promoting smoking cessation in NMIBC.

Urine cytology screening of French workers exposed to occupational urinary tract carcinogens: a prospective cohort study over a 20-year period

OBJECTIVES

To demonstrate that urine cytology screening can provide relevant epidemiological data for earlier detection of urothelial cancer caused by occupational exposure.

DESIGN

Prospective cohort study.

SETTING

Industries using urothelial carcinogens in France. Urine samples were collected on site, after a work week and were analysed at the University Hospital of Clermont-Ferrand, France.

PARTICIPANTS

Participants were workers exposed to urothelial carcinogens. Women and current smokers at time of study recruitment were exclusion criteria.

OUTCOMES

Urine cells atypia were ranged into three classes: negative/normal, atypical/suspicious/dysplasia or positive/malignant.

RESULTS

We included 2020 workers over a period of 20 years from 1993 to 2013: 606 worked in rubber manufacturing, 692 from metal processing, 245 in chemical industry and 477 in roadwork and building industry. Workers had a mean exposure of 15.2±10.4 years before their first urine cytology screening. There was a mean of 3.4±4.3 urine cytology screenings per worker between 1993 and 2013. 6478 cytology were normal, 462 suspicious and 13 malignant. Suspicious and malignant cytology occurred in 4.8% of workers exposed for 1-10 years, 6.2% for 11-20 years of exposure, 7.6% for 21-30 years and 8.6% for >30 years (p<0.001). Using exposure for 1-10 years as reference, the adjusted OR of receiving a suspicious or malignant diagnosis increased with duration of exposure: OR=1.50 (95% CI 1.10 to 2.05, p=0.01) for 21-30 years and OR=1.78 (95% CI 1.23 to 2.56, p=0.002) for >30 years of exposure. Using metal processing as reference, the risk of pathological urine cytology results increased for rubber manufacturing (OR=1.32, 95% CI 1.05 to 1.65, p=0.02), with a trend for roadwork and building industry (OR=1.39, 95% CI 0.98 to 1.97, p=0.07) and for chemical industry (OR=1.34, 95% CI 0.94 to 1.93, p=0.11).

CONCLUSIONS

Urine cytology is a useful tool in occupational medicine. We promote new guidelines with an early screening of urothelial cancer by cytology, starting with beginning of exposure.

The association of rs710886 in lncRNA PCAT1 with bladder cancer risk in a Chinese population

OBJECTIVE

The long noncoding RNA PCAT1 is an important gene involved in urinary tumors. In this study, we aimed to explore the association between polymorphisms in PCAT1 and bladder cancer susceptibility.

METHODS

A two-stage case-control study was conducted to assess the association between four tagging SNPs (i.e., rs4871771, rs1902432, rs16901904 and rs710886) and bladder cancer risk. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated with unconditional univariate and multivariate logistic regression.

RESULTS

At the first stage of discovery, we identified that SNP rs710886A>G was significantly associated with bladder cancer risk (OR=0.86, 95% CI=0.74-0.99, P=0.046). At the following stage of validation, individuals with GG genotype were found to have a significant reduction in bladder cancer risk compared with those carrying AA genotype (adjusted OR=0.83, 95% CI=0.74-0.93, P=0.001). Furthermore, stratified analyses showed that protective effect of rs710886 was more pronounced in subgroup of age>60 and never smoking, and had little to do with sex. Besides, rs710886 was identified as an eQTL for PCAT1. G allele was consistent with lower PCAT1 expression.

CONCLUSION

This study indicates that genetic variants in lncRNA PCAT1 were associated with bladder cancer susceptibility and the SNP rs710886 may act as a potential biomarker for bladder cancer risk.

Epidemiology of urothelial carcinoma

The epithelium lining is defined as the mucosal surfaces of the renal collecting tubules, calyces and pelvis, as well as the ureter, bladder and urethra. The term "urothelium" is used to refer to these surfaces. Upper tract urothelial carcinoma is a rare subset of urothelial cancers with a poor prognosis. Urinary bladder cancer is the most common malignancy involving the urinary system. Upper tract urothelial carcinoma is more common in men than in women, with a male-to-female ratio of 2:1. The incidence of urinary bladder cancer is also higher in men. Cigarette smoking and occupational exposure are the main upper tract urothelial carcinoma and urinary bladder cancer risk factors, while other factors are more specific to the carcinogenesis of upper tract urothelial carcinoma (i.e. Balkan endemic nephropathy, Chinese herb nephropathy). In Egypt until recent years, urinary bladder cancer was the most frequently diagnosed cancer due to Schistosoma haematobium. Substantial knowledge exists regarding the causes of upper tract urothelial carcinoma and urinary bladder cancer, and epidemiological studies have identified various chemical carcinogens that are believed to be responsible for most cases of urothelial carcinoma. In the era of precision medicine, genetic effects might play a direct role in the initiation and progression of urothelial carcinoma.