Polygenic risk-stratified screening for nasopharyngeal carcinoma in high-risk endemic areas of China: a cost-effectiveness study.

Background: Nasopharyngeal carcinoma (NPC) has an extremely high incidence rate in Southern China, resulting in a severe disease burden for the local population. Current EBV serologic screening is limited by false positives, and there is opportunity to integrate polygenic risk scores for personalized screening which may enhance cost-effectiveness and resource utilization. Methods: A Markov model was developed based on epidemiological and genetic data specific to endemic areas of China, and further compared polygenic risk-stratified screening [subjects with a 10-year absolute risk (AR) greater than a threshold risk underwent EBV serological screening] to age-based screening (EBV serological screening for all subjects). For each initial screening age (30-34, 35-39, 40-44, 45-49, 50-54, 55-59, 60-64, and 65-69 years), a modeled cohort of 100,000 participants was screened until age 69, and then followed until age 79. Results: Among subjects aged 30 to 54 years, polygenic risk-stratified screening strategies were more cost-effective than age-based screening strategies, and almost comprised the cost-effectiveness efficiency frontier. For men, screening strategies with a 1-year frequency and a 10-year absolute risk (AR) threshold of 0.7% or higher were cost-effective, with an incremental cost-effectiveness ratio (ICER) below the willingness to pay (¥203,810, twice the local per capita GDP). Specifically, the strategies with a 10-year AR threshold of 0.7% or 0.8% are the most cost-effective strategies, with an ICER ranging from ¥159,752 to ¥201,738 compared to lower-cost non-dominated strategies on the cost-effectiveness frontiers. The optimal strategies have a higher probability (29.4-35.8%) of being cost-effective compared to other strategies on the frontier. Additionally, they reduce the need for nasopharyngoscopies by 5.1-27.7% compared to optimal age-based strategies. Likewise, for women aged 30-54 years, the optimal strategy with a 0.3% threshold showed similar results. Among subjects aged 55 to 69 years, age-based screening strategies were more cost-effective for men, while no screening may be preferred for women. Conclusion: Our economic evaluation found that the polygenic risk-stratified screening could improve the cost-effectiveness among individuals aged 30-54, providing valuable guidance for NPC prevention and control policies in endemic areas of China.

Monitoring hepatocellular carcinoma using tumor content in circulating cell-free DNA.

PURPOSE: To evaluate the utility of tumor content in circulating cell-free DNA (ccfDNA) for monitoring hepatocellular carcinoma (HCC) throughout its natural history. METHODS: We included 67 hepatitis B virus (HBV)-related HCC patients, of whom 17 had paired pre- and post-treatment samples, and 90 controls. Additionally, in a prospective cohort with HBV surface antigen-positive participants recruited in 2012 and followed up biannually with blood sample collections until 2019, we included 270 repeated samples before diagnosis from 63 participants who later developed HCC (pre-HCC samples). Shallow whole-genome sequencing and the ichorCNA method were used to analyze genome-wide copy number and tumor content in ccfDNA. RESULTS: High tumor content was associated with advanced tumor stage (P < 0.001) and a poor survival after HCC diagnosis (HR=12.35; 95% confidence interval [CI]=1.413-107.9; P = 0.023). Tumor content turned negative after surgery (P = 0.027), while remained positive after transarterial chemoembolization treatment (P = 0.578). In non-HCC samples, the mean tumor content (±SD) was 0.011 (±0.007) and had a specificity of 97.8% (95%CI=92.2%-99.7%). In pre-HCC samples, tumor content increased from 0.014 in 4 years before diagnosis to 0.026 in 1 year before diagnosis. The sensitivity of tumor content in detecting HCC increased from 22.7% (95%CI=11.5%-37.8%) within one year before diagnosis to 30.4% (95%CI=13.2%-52.9%) at BCLC stage 0/A, 81.8% (95%CI=59.7%-94.8%) at stage B, and 95.5% (95%CI=77.2%-99.9%) at stage C. CONCLUSIONS: The tumor content in ccfDNA is correlated with tumor burden and may help in monitoring HCC one year earlier than clinical diagnosis and in predicting patient prognosis.

Circulating DNA genome-wide fragmentation in early detection and disease monitoring of hepatocellular carcinoma.

Genome-wide circulating cell-free DNA (ccfDNA) fragmentation for cancer detection has been rarely evaluated using blood samples collected before cancer diagnosis. To evaluate ccfDNA fragmentation for detecting early hepatocellular carcinoma (HCC), we first modeled and tested using hospitalized HCC patients and then evaluated in a population-based study. A total of 427 samples were analyzed, including 270 samples collected prior to HCC diagnosis from a population-based study. Our model distinguished hospital HCC patients from controls excellently (area under curve 0.999). A high ccfDNA fragmentation score was highly associated with an advanced tumor stage and a shorter survival. In evaluation, the model showed increasing sensitivities in detecting HCC using 'pre-samples' collected ≥4 years (8.3%), 3-4 years (20.0%), 2-3 years (31.0%), 1-2 years (35.0%), and 0-1 year (36.4%) before diagnosis. These findings suggested ccfDNA fragmentation is sensitive in clinical HCC detection and might be helpful in screening early HCC.

Anti-Epstein-Barr Virus BNLF2b for Mass Screening for Nasopharyngeal Cancer.

BACKGROUND: Population screening of asymptomatic persons with Epstein-Barr virus (EBV) DNA or antibodies has improved the diagnosis of nasopharyngeal carcinoma and survival among affected persons. However, the positive predictive value of current screening strategies is unsatisfactory even in areas where nasopharyngeal carcinoma is endemic. METHODS: We designed a peptide library representing highly ranked B-cell epitopes of EBV coding sequences to identify novel serologic biomarkers for nasopharyngeal carcinoma. After a retrospective case-control study, the performance of the novel biomarker anti-BNLF2b total antibody (P85-Ab) was validated through a large-scale prospective screening program and compared with that of the standard two-antibody-based screening method (EBV nuclear antigen 1 [EBNA1]-IgA and EBV-specific viral capsid antigen [VCA]-IgA). RESULTS: P85-Ab was the most promising biomarker for nasopharyngeal carcinoma screening, with high sensitivity (94.4%; 95% confidence interval [CI], 86.4 to 97.8) and specificity (99.6%; 95% CI, 97.8 to 99.9) in the retrospective case-control study. Among the 24,852 eligible participants in the prospective cohort, 47 cases of nasopharyngeal carcinoma (38 at an early stage) were identified. P85-Ab showed higher sensitivity than the two-antibody method (97.9% vs. 72.3%; ratio, 1.4 [95% CI, 1.1 to 1.6]), higher specificity (98.3% vs. 97.0%; ratio, 1.01 [95% CI, 1.01 to 1.02]), and a higher positive predictive value (10.0% vs. 4.3%; ratio, 2.3 [95% CI, 1.8 to 2.8]). The combination of P85-Ab and the two-antibody method markedly increased the positive predictive value to 44.6% (95% CI, 33.8 to 55.9), with sensitivity of 70.2% (95% CI, 56.0 to 81.4). CONCLUSIONS: Our results suggest that P85-Ab is a promising novel biomarker for nasopharyngeal carcinoma screening, with higher sensitivity, specificity, and positive predictive value than the standard two-antibody method. (Funded by the National Key Research and Development Program of China and others; ClinicalTrials.gov number, NCT04085900.).

EBV antibody and gastric cancer risk: a population-based nested case-control study in southern China.

BACKGROUND: We aim to clarify the controversial associations between EBV-related antibodies and gastric cancer risk. METHODS: We analysed the associations between serological Epstein-Barr nuclear antigen 1 immunoglobulin A (EBNA1-IgA) and viral capsid antigen immunoglobulin A (VCA-IgA) by enzyme-linked immunosorbent assay and the risk of gastric cancer in a nested case-control study originated from a population-based nasopharyngeal carcinoma (NPC) screening cohort in Zhongshan, a city of southern China, including 18 gastric cancer cases and 444 controls. Conditional logistic regression was used to calculate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs). RESULTS: All the sera of cases were sampled before diagnosis and the median time interval was 3.04 (range: 0.04, 7.59) years. Both increased relative optical density (rOD) values of EBNA1-IgA and VCA-IgA were associated with higher risks of gastric cancer with age adjusted ORs of 1.99 (95%CI: 1.07, 3.70) and 2.64 (95%CI: 1.33, 5.23), respectively. Each participant was further classified as high or medium/low risk based on a combination of two anti-EBV antibody levels. Participants in the high-risk group had substantially higher odds of developing gastric cancer than that in the medium/low risk group with an age adjusted OR of 6.53 (95%CI: 1.69, 25.26). CONCLUSIONS: Our research reveals positive associations between EBNA1-IgA and VCA-IgA and gastric cancer risk in southern China. We thus postulate that EBNA1-IgA and VCA-IgA might appear to be potential biomarkers for gastric cancer. More research to further validate the results among diverse populations and investigate its underlying biological mechanism is needed.

Pre-diagnostic anti-EBV antibodies and primary liver cancer risk: a population-based nested case-control study in southern China.

BACKGROUND: We aimed to investigate associations between pre-diagnostic anti-Epstein-Barr virus (EBV) antibodies, including interactions with hepatitis B virus (HBV), and risk of primary liver cancer in southern China. METHODS: In a population-based nested case-control study, we measured pre-diagnostic immunoglobulin A (IgA) against EBV nuclear antigen 1 (EBNA1) and viral capsid antigen (VCA) in 125 primary liver cancer cases and 2077 matched controls. We also explored the interaction between HBV surface antigen (HBsAg) and anti-EBV antibodies. RESULTS: Participants with positive EBNA1-IgA, positive VCA-IgA or single-positive anti-EBV antibodies had two-fold odds of developing liver cancer, compared with seronegative subjects. The odds ratios (ORs) between the relative optical density of EBNA1-IgA and VCA-IgA and primary cancer, controlling for age and HBsAg, were 1.59 (95% confidence interval (CI): 1.17, 2.14) and 1.60 (95% CI: 1.07, 2.41), respectively. Subjects with both HBsAg and anti-EBV antibody seropositivity were at 50-fold increased risk compared with those negative for both biomarkers (OR: 50.67, 95% CI: 18.28, 140.46), yielding a relative excess risk due to interaction of 30.81 (95% CI: 3.42, 114.93). CONCLUSION: Pre-diagnostic seropositivity for EBNA1-IgA and/or VCA-IgA was positively associated with primary liver cancer risk, especially in combination with HBsAg positivity. EBV may interact with HBV in the development of primary liver cancer, and anti-EBV antibodies might be potential biomarkers for primary liver cancer in this high-risk population.

Recommendations for Epstein-Barr virus-based screening for nasopharyngeal cancer in high- and intermediate-risk regions.

A meeting of experts was held in November 2021 to review and discuss available data on performance of Epstein-Barr virus (EBV)-based approaches to screen for early stage nasopharyngeal carcinoma (NPC) and methods for the investigation and management of screen-positive individuals. Serum EBV antibody and plasma EBV DNA testing methods were considered. Both approaches were found to have favorable performance characteristics and to be cost-effective in high-risk populations. In addition to endoscopy, use of magnetic resonance imaging (MRI) to investigate screen-positive individuals was found to increase the sensitivity of NPC detection with minimal impact on cost-effectiveness of the screening program.

A polygenic risk score for nasopharyngeal carcinoma shows potential for risk stratification and personalized screening.

Polygenic risk scores (PRS) have the potential to identify individuals at risk of diseases, optimizing treatment, and predicting survival outcomes. Here, we construct and validate a genome-wide association study (GWAS) derived PRS for nasopharyngeal carcinoma (NPC), using a multi-center study of six populations (6 059 NPC cases and 7 582 controls), and evaluate its utility in a nested case-control study. We show that the PRS enables effective identification of NPC high-risk individuals (AUC = 0.65) and improves the risk prediction with the PRS incremental deciles in each population (Ptrend ranging from 2.79 × 10-7 to 4.79 × 10-44). By incorporating the PRS into EBV-serology-based NPC screening, the test's positive predictive value (PPV) is increased from an average of 4.84% to 8.38% and 11.91% in the top 10% and 5% PRS, respectively. In summary, the GWAS-derived PRS, together with the EBV test, significantly improves NPC risk stratification and informs personalized screening.

Dynamic Observation of Lung Nodules on Chest CT Before Diagnosis of Early Lung Cancer.

Objective: Early recognition and diagnosis of lung cancer can help improve the prognosis of patients. However, early imaging patterns of malignant lung nodules are not fully clear. To understand the early imaging signs of malignant lung cancer nodules, the changes of the lung nodules before diagnosis were dynamically observed and analyzed. Materials and Methods: This retrospective study observed dynamic changes of lung nodules before pathological confirmation with consecutive regular chest CT examination from January 2003 to December 2018. At least 3 follow-up CT scans were performed in all cases, and the interval between each follow-up was about 1 year. The size, density, and morphological signs of the nodules were evaluated based on the CT axial image, and a reverse line chart or scatter plot with the diagnosis time as coordinate origin was constructed. Results: A total of 55 lung nodules in 53 patients (mean age, 58.40 years ±11.43 [standard deviation]; 20 women) were accessed. The follow-up time was 5.96 ± 2.68 years. The average diameters in maximum slice of the lesion at baseline and last scan were 6.83 ± 2.92 mm and 16.65 ± 7.34 mm, respectively. According to the reverse line chart, the nodule growth curve segments within 4 years from the last scan showed an ascending shape, and those beyond 4 years showed a flat shape. There are 90.9% (50/55) GGN and 9.1% (5/55) SN when the lesion first appears, and 21.8% (12/55) GGN, 38.2% (21/55) PSN, and 40% (22/55) SN in the last scan. There are 12.7% (7/55) and 98.2% (54/55) nodules with poor morphological signs at baseline and last scan, respectively. Conclusion: At the time node close to the diagnosis, the growth curve showed an upward pattern; the proportion of PSN and SN rose as the main density types; and the appearance of poor morphological signs of nodules increased. When a persistent lung nodule starts to show a malignant change, a further diagnostic workup is warranted.

Inflammatory-miR-301a circuitry drives mTOR and Stat3-dependent PSC activation in chronic pancreatitis and PanIN.

Activated pancreatic stellate cells (PSCs) are the main cells involved in chronic pancreatitis and pancreatic intraepithelial neoplasia lesion (PanIN). Fine-tuning the precise molecular targets in PSC activation might help the development of PSC-specific therapeutic strategies to tackle progression of pancreatic cancer-related fibrosis. miR-301a is a pro-inflammatory microRNA known to be activated by multiple inflammatory factors in the tumor stroma. Here, we show that miR-301a is highly expressed in activated PSCs in mice, sustained tissue fibrosis in caerulein-induced chronic pancreatitis, and accelerated PanIN formation. Genetic ablation of miR-301a reduced pancreatic fibrosis in mouse models with chronic pancreatitis and PanIN. Cell proliferation and activation of PSCs was inhibited by downregulation of miR-301a via two of its targets, Tsc1 and Gadd45g. Moreover, aberrant PSC expression of miR-301a and Gadd45g restricted the interplay between PSCs and pancreatic cancer cells in tumorigenesis. Our findings suggest that miR-301a activates two major cell proliferation pathways, Tsc1/mTOR and Gadd45g/Stat3, in vivo, to facilitate development of inflammatory-induced PanIN and maintenance of PSC activation and desmoplasia in pancreatic cancer.

Prospective assessment of a nasopharyngeal carcinoma risk score in a population undergoing screening.

Despite evidence suggesting the utility of Epstein-Barr virus (EBV) markers to stratify individuals with respect to nasopharyngeal carcinoma (NPC) risk in NPC high-risk regions, no validated NPC risk prediction model exists. We aimed to validate an EBV-based NPC risk score in an endemic population undergoing screening for NPC. This prospective study was embedded within an ongoing NPC screening trial in southern China initiated in 2008, with 51 235 adult participants. We assessed the score's discriminatory ability (area under the receiver-operator-characteristics curve, AUC). A new model incorporating the EBV score, sex and family history was developed using logistic regression and internally validated using cross-validation. AUCs were compared. We also calculated absolute NPC risk combining the risk score with population incidence and competing mortality data. A total of 151 NPC cases were detected in 2008 to 2016. The EBV-based score was highly discriminating, with AUC = 0.95 (95% CI = 0.93-0.97). For 90% specificity, the score had 87.4% sensitivity (95% CI = 81.0-92.3%). As specificity increased from 90% to 99%, the positive predictive value increased from 2.4% (95% CI = 1.9-3.0%) to 12.5% (9.9-15.5%). Correspondingly, the number of positive tests per detected NPC case decreased from 272 (95% CI = 255-290) to 50 (41-59). Combining the score with other risk factors (sex, first-degree family history of NPC) did not improve AUC. Men aged 55 to 59 years with the highest risk profile had the highest 5-year absolute NPC risk of 6.5%. We externally validated the discriminatory accuracy of a previously developed EBV score in a high-risk population. Adding nonviral risk factors did not improve NPC prediction.

Efficacy of Chemiluminescence Immunoassays on VCA-IgA and EBNA1-IgA Antibodies of Epstein-Barr Virus in Diagnosing Nasopharyngeal Carcinoma.

Background: IgA antibodies against Epstein-Barr virus (EBV) capsid antigen (VCA) and nuclear antigen 1 (EBNA1) have been proposed to facilitate the diagnosis and early detection of nasopharyngeal carcinoma (NPC) in high-incidence regions. However, while new methodologies and new platforms for the detection of VCA-IgA and EBNA1-IgA have become available, proper interassay simultaneous comparisons have not been carried out. The study was to compare the performance of the chemiluminescent immunoassays (CLIA) and enzyme-linked immunosorbent assay (ELISA) for VCA-IgA and EBNA1-IgA antibodies, and to evaluate the levels of EBV antibodies in healthy population from different areas of China. Methods: CLIA and ELISA for VCA-IgA and EBNA1-IgA were performed in NPC and healthy populations from high-incidence areas of NPC in South China (N=555), medium-incidence areas of NPC in Central China (N=318) and low-incidence areas of NPC in North China (N=379), and the results were compared and analyzed. Results: (1) The highest sensitivity in total, early and advanced NPC were 91.5% (CLIA for VCA-IgA), 86.4% (CLIA and ELISA-2 for EBNA1-IgA) and 93.6% (CLIA for VCA-IgA). However, the specificity of EBV-IgA measured by CLIA was relatively lower than ELISA. The top three seromarkers with the largest AUC was CLIA for VCA-IgA (AUC: 0.929, 95% CI: 0.905-0.953), ELISA-2 for EBNA1-IgA (AUC: 0.922, 95% CI: 0.896-0.947) and CLIA for EBNA1-IgA (AUC:0.919, 95% CI: 0.893-0.945), respectively. The positive and negative coincidence rates of the two EBNA1-IgA kits were 69.5% and 91.9%, respectively. However, the coincidence rates of VCA-IgA were relatively low. CLIA kits had good repeatability between different laboratories. (2) The positive rates of EBV-IgA antibodies were relatively high in high-incidence areas of NPC (P < 0.017), while there was no significant difference in the antibody positive rates between medium-incidence areas and low-incidence areas of NPC (P > 0.05). Conclusions: The performance of EBV-IgA antibodies measured by CLIA has good repeatability, higher sensitivity and similar specificity. The higher EBV-IgA positive rate in healthy subjects by CLIA raises concern about its suitability for NPC-risk screening and requires further analysis.

Autocrine INSL5 promotes tumor progression and glycolysis via activation of STAT5 signaling.

Metabolic reprogramming plays important roles in development and progression of nasopharyngeal carcinoma (NPC), but the underlying mechanism has not been completely defined. In this work, we found INSL5 was elevated in NPC tumor tissue and the plasma of NPC patients. Plasma INSL5 could serve as a novel diagnostic marker for NPC, especially for serum VCA-IgA-negative patients. Moreover, higher plasma INSL5 level was associated with poor disease outcome. Functionally, INSL5 overexpression increased, whereas knockdown of its receptor GPCR142 or inhibition of INSL5 reduced cell proliferation, colony formation, and cell invasion in vitro and tumorigenicity in vivo. Mechanistically, INSL5 enhanced phosphorylation and nuclear translocation of STAT5 and promoted glycolytic gene expression, leading to induced glycolysis in cancer cells. Pharmaceutical inhibition of glycolysis by 2-DG or blockade of INSL5 by a neutralizing antibody reversed INSL5-induced proliferation and invasion, indicating that INSL5 can be a potential therapeutic target in NPC. In conclusion, INSL5 enhances NPC progression by regulating cancer cell metabolic reprogramming and is a potential diagnostic and prognostic marker as well as a therapeutic target for NPC.

Long-Term Survival After Nasopharyngeal Carcinoma Treatment in a Local Prefecture-Level Hospital in Southern China.

PURPOSE: NPC is a malignant and invasive tumor with the incidence rate of 19/100,000 per year in Zhongshan City, a prefecture city in southern China. Long-term survival analysis on intensity-modulated radiotherapy (IMRT)-based treatment in local prefecture-level hospitals have not been investigated. We aimed to evaluate the 5-year clinical outcomes and prognostic factors of NPC treated with IMRT in Zhongshan City People's Hospital (ZSPH), a prefecture-level hospital in South China. PATIENTS AND METHODS: The number of 149 newly diagnosed non-metastatic NPC cases treated with IMRT were included from Zhongshan City People's Hospital between January 2010 and December 2011. The survival outcomes, treatment toxicities and prognostic factors were analyzed by Kaplan-Meier method and Cox proportional hazards model. RESULTS: With a median follow-up period of 65 months for the cohort, the 5-year local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS) and distant metastasis-free survival (DMFS) and overall survival (OS) were 86.80%, 94.80%, 86.10% and 80.50%, respectively. The 5-year OS rates were 100%, 95.2%, 87% and 67.2% for stage I, II, II and IVa-b, respectively (P=0.004). The 5-year LRFS rates were 97.2%, 96.0%, 90.4% and 72.0% for T1, T2, T3 and T4, respectively (P=0.001); the 5-year DMFS rates were 100% for T1, 96.8% for T2, 81.9% for T3 and 74.6% for T4 (P=0.022). A multivariate analysis revealed tumor stage as an independent prognostic factor for LRFS, DMFS and OS. No patients died from acute toxicities. Late toxicities were observed for 130 (87.2%) patients, and most late toxicities were graded I/II. CONCLUSION: NPC treatment effect in a prefecture-level hospital in South China was comparable to international results and toxicities were tolerable. Tumour stage was an independent prognostic factor for survival outcome. More NPC survival data from local and remote places are needed.

Simultaneous Detection of Gene Fusions and Base Mutations in Cancer Tissue Biopsies by Sequencing Dual Nucleic Acid Templates in Unified Reaction.

BACKGROUND: Targeted next-generation sequencing is a powerful method to comprehensively identify biomarkers for cancer. Starting material is currently either DNA or RNA for different variations, but splitting to 2 assays is burdensome and sometimes unpractical, causing delay or complete lack of detection of critical events, in particular, potent and targetable fusion events. An assay that analyzes both templates in a streamlined process is eagerly needed. METHODS: We developed a single-tube, dual-template assay and an integrated bioinformatics pipeline for relevant variant calling. RNA was used for fusion detection, whereas DNA was used for single-nucleotide variations (SNVs) and insertion and deletions (indels). The reaction chemistry featured barcoded adaptor ligation, multiplexed linear amplification, and multiplexed PCR for noise reduction and novel fusion detection. An auxiliary quality control assay was also developed. RESULTS: In a 1000-sample lung tumor cohort, we identified all major SNV/indel hotspots and fusions, as well as MET exon 14 skipping and several novel or rare fusions. The occurrence frequencies were in line with previous reports and were verified by Sanger sequencing. One noteworthy fusion event was HLA-DRB1-MET that constituted the second intergenic MET fusion ever detected in lung cancer. CONCLUSIONS: This method should benefit not only a majority of patients carrying core actionable targets but also those with rare variations. Future extension of this assay to RNA expression and DNA copy number profiling of target genes such as programmed death-ligand 1 may provide additional biomarkers for immune checkpoint therapies.

Rationally engineered Staphylococcus aureus Cas9 nucleases with high genome-wide specificity.

RNA-guided CRISPR-Cas9 proteins have been widely used for genome editing, but their off-target activities limit broad application. The minimal Cas9 ortholog from Staphylococcus aureus (SaCas9) is commonly used for in vivo genome editing; however, no variant conferring high genome-wide specificity is available. Here, we report rationally engineered SaCas9 variants with highly specific genome-wide activity in human cells without compromising on-target efficiency. One engineered variant, referred to as SaCas9-HF, dramatically improved genome-wide targeting accuracy based on the genome-wide unbiased identification of double-stranded breaks enabled by sequencing (GUIDE-seq) method and targeted deep sequencing analyses. Among 15 tested human endogenous sites with the canonical NNGRRT protospacer adjacent motif (PAM), SaCas9-HF rendered no detectable off-target activities at 9 sites, minimal off-target activities at 6 sites, and comparable on-target efficiencies to those of wild-type SaCas9. Furthermore, among 4 known promiscuous targeting sites, SaCas9-HF profoundly reduced off-target activities compared with wild type. When delivered by an adeno-associated virus vector, SaCas9-HF also showed reduced off-target effects when targeting VEGFA in a human retinal pigmented epithelium cell line compared with wild type. Then, we further altered a previously described variant named KKH-SaCas9 that has a wider PAM recognition range. Similarly, the resulting KKH-HF remarkably reduced off-target activities and increased on- to off-target editing ratios. Our finding provides an alternative to wild-type SaCas9 for genome editing applications requiring exceptional genome-wide precision.

A Retrospective Cohort Study of Nasopharyngeal Carcinoma Screening and Hepatocellular Carcinoma Screening in Zhongshang City.

Background: Nasopharyngeal carcinoma (NPC) and hepatocellular carcinoma (HCC) have remained a major burden of public health in Southern China. The screening for early disease in asymptomatic individuals has potentially been the most promising tool to improve cancer treatment outcomes. The present study aims to evaluate the compliance rates and characteristics of cancer incidence in the population of NPC and HCC screening. Methods: Enzyme-linked immunsorbent assay (ELISA) for Epstein-Barr virus (EBV) antibodies and Hepatitis B surface antigen (HBsAg) was performed in this population. NPC high/medium risk and HCC high risk individuals were followed-up for a number of years. The compliance rate, cancer incidence and early diagnosis rate of the screened population were statistically analyzed. Results: (1) In the preliminary screening, the compliance rate for NPC screening was significantly higher than that for HCC screening (29.3% vs. 26.2%; P<0.05). The compliance rates for screening were positively associated with age in these two screenings (P<0.01). (2) In the NPC screening, the compliance rates for the first year follow-up among NPC high/medium risk individuals were 74.9%, which was higher than that (60.2%) for the second year follow-up (P<0.05). The compliance rates for fiberoptic endoscopy among high risk individuals decreased along with the frequency of screening (P<0.016). The rates of missed diagnosis by non-compliance and the poor diagnostic accuracy of indicators were 3.3% and 3.3%, respectively. The average annual incidence and early diagnosis rate of the compliers were higher than those of the non-compliers (94.3 per 100,000 vs. 29.0 per 100,000; P<0.05 and 77.8% vs. 18.5%; P<0.05). (3) In the preliminary HCC screening, the compliance rate for ultrasonography among high risk individuals was 61.8%. The compliance rates for the follow-up were unsatisfactory. The rates of missed diagnosis by non-compliance and the poor diagnostic accuracy of indicators were 12.3% and 24.6%, respectively. There was no significant differences in average annual incidence and the rate of early diagnosis between compliers and non-compliers (79.4 per 100,000 vs. 54.6 per 100,000, P>0.05; 49.1% vs. 38.5%, P>0.05). Conclusion: The compliance rates for NPC and HCC screening needs to be improved. In particular, public health policies for HCC should be implemented. The present NPC screening could be the preferred strategy. However, the efficiency of HCC screening remains substantially unsatisfactory and needs to be further discussed.

Intermittent abortive reactivation of Epstein-Barr virus during the progression of nasopharyngeal cancer as indicated by elevated antibody levels.

The development of nasopharyngeal carcinoma (NPC), a common cancer in Southeastern Asia, is closely associated with Epstein-Barr virus (EBV) infection; however, the aetiological role of EBV in NPC pathogenesis remains enigmatic. The life cycle of EBV in NPC patients is defined as latency II, while the antibodies specific to lytic phase proteins, as well as lytic genes, were highly expressed in NPC patients. The correlation between antibody levels and the progression of NPC has been reported in some studies; however, most of these studies focused on IgA antibodies, and the results in different articles were not consistent. In this study, we concurrently determined the levels of IgA and IgG antibodies specific to six purified recombinant EBV antigens associated with different replication statuses of EBV: EBNA1 associated with latency II; the non-structural antigens Zta, TK, EA-D and EA-R associated with immediate-early and early lytic phases; and the EBV matrix protein VCA p18, which is involved in late lytic phase. Levels of antibodies specific to immediate-early and early antigens were correlated with the tumour progression, especially tumour size. The levels of antibodies specific to some lytic phase antigens were also correlated with lymph node inclusion and metastasis. However, the antibody specific to the latency II antigen EBNA1 was not correlated with either tumour size or metastasis. Consistent with previous transcriptome studies, the results suggested both the expression of lytic phase genes at the protein level and the intermittent reactivation of EBV in NPC patients.

Mass screening for liver cancer: results from a demonstration screening project in Zhongshan City, China.

Current Chinese national guidelines recommend routine screening for liver cancer in patients positive for HBsAg, irrespective of fibrosis status, age, or family history of liver cancer. We aim to evaluate whether the recommended screening strategy could reduce liver-cancer-specific mortality. We conducted a liver cancer mass screening trial in Xiaolan Town, Zhongshan City, China, among residents aged 35-64 years in 2012. All volunteers were offered serological testing for hepatitis B virus surface antigen (HBsAg). We proposed biannual screening using serum alpha-fetoprotein (AFP) and ultrasonography examination for subjects positive for HBsAg. Among 17,966 participants (26.2% of 68,510 eligible residents) who were free of liver cancer at baseline in 2012, we identified 57 incident cases of liver cancer within the first 4 years of follow-up (i.e., 43 among 2,848 HBsAg-positive participants and 14 among 15,118 HBsAg-negative participants), compared with 104 cases identified in non-participants (N = 50,544). A total of 207 participants had the recommended number of ultrasonography examinations (every 6 months) during the screening period. Compared with cases identified from non-participants, the cases arising among participants were more likely to be at early stage and had better survival than those among non-participants. However, we did not observe a reduction in liver cancer-specific mortality rate among participants (relative risk = 1.04, 95% confidence interval = 0.68, 1.58, P = 0.856). Our demonstration screening study does not show a reduction in liver cancer mortality within the first 4 years of follow-up according to current guidance in China, although long-term efficacy remains to be evaluated. Targeted surveillance among high-risk individuals as recommended by international guidelines, along with measures to improve compliance, should be evaluated in the Chinese population.