[Show abstract][Hide abstract] ABSTRACT: Esophageal cancer is the sixth leading cause of cancer death worldwide; current early detection screening tests are inadequate. Esophageal balloon cytology successfully retrieves exfoliated and scraped superficial esophageal epithelial cells, but cytologic reading of these cells has poor sensitivity and specificity for detecting esophageal squamous dysplasia (ESD), the precursor lesion of esophageal squamous cell carcinoma (ESCC). Measuring telomere length, a marker for chromosomal instability, may improve the utility of balloon cytology for detecting ESD and early ESCC.
We examined balloon cytology specimens from 89 asymptomatic cases of ESD (37 low-grade and 52 high-grade) and 92 age- and sex-matched normal controls from an esophageal cancer early detection screening study. All subjects also underwent endoscopy and biopsy, and ESD was diagnosed histopathologically. DNA was extracted from the balloon cytology cells, and telomere length was measured by quantitative PCR. A receiver operating characteristic (ROC) curve was plotted for telomere length as a diagnostic marker for high-grade dysplasia.
Telomere lengths were comparable among the low- and high-grade dysplasia cases and controls, with means of 0.96, 0.96, and 0.92, respectively. The area under the receiver operating characteristic curve was 0.55 for telomere length as a diagnostic marker for high-grade dysplasia. Further adjustment for subject characteristics, including sex, age, smoking, drinking, hypertension, and body mass index did not improve the use of telomere length as a marker for ESD.
Telomere length of esophageal balloon cytology cells was not associated with ESCC precursor lesions. Therefore, telomere length shows little promise as an early detection marker for ESCC in esophageal balloon samples.
BMC Cancer 12/2013; 13(1):578. · 3.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Linzhou, China has one of the highest rates of esophageal squamous cell carcinoma in the world. Exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (BaP), may have a role in this increased risk. To better understand PAH sources, we measured PAHs in the air and food of 20 non-smokers over multiple days and compared the concentrations with a urinary PAH biomarker, 1-hydroxypyrene glucuronide (1-OHPG). Sampling occurred over 4 consecutive days. Kitchen air samples (days 2-3) and duplicate diet samples (days 1-4) were analyzed for 14 or more unique PAHs, including BaP. Daily urine samples (days 1-3) were analyzed for 1-OHPG. Mixed-effects models were used to evaluate the associations between air or food PAH concentrations and urine 1-OHPG concentrations. The median kitchen air BaP concentration was 10.2 ng/m(3) (interquartile range (IQR): 5.1-20.2 ng/m(3)). The median daily food BaP concentration and intake were 0.08 ng/g (IQR=0.04-0.16 ng/g) and 86 ng/day (IQR=41-142 ng/day), respectively. The median 1-OHPG concentration was 3.36 pmol/ml (IQR=2.09-6.98 pmol/ml). In mixed-effects models, 1-OHPG concentration increased with same-day concentration of food BaP (P=0.07). Although PAH concentrations in air were not associated with 1-OHPG concentrations, the high concentrations of PAHs in both air and food suggest that they are both important routes of exposure to PAHs in this population. Further evaluation of the role of PAH exposure from air and food in the elevated rates of esophageal cancer in this region is warranted.Journal of Exposure Science and Environmental Epidemiology advance online publication, 18 July 2012; doi:10.1038/jes.2012.73.
Journal of Exposure Science and Environmental Epidemiology 07/2012; · 3.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Esophageal squamous cell carcinomas (ESCC) are usually asymptomatic and go undetected until they are incurable. Cytological screening is one strategy to detect ESCC at an early stage and has shown promise in previous studies, although improvement in sensitivity and specificity are needed. Proteases modulate cancer progression by facilitating tumor invasion and metastasis. In the current study, matrix metalloproteinases (MMPs) were studied in a search for new early detection markers for ESCC.
Protein expression levels of MMPs were measured using zymography in 24 cases of paired normal esophagus and ESCC, and in the tumor-associated stroma and tumor epithelium in one sample after laser capture microdissection (LCM). MMP-3 and MMP-10 transcripts in both the epithelium and stroma in five cases were further analyzed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR).
Gelatin zymography showed bands corresponding in size to MMP-2, MMP-3, MMP-9, and MMP-10 enzymes in each of the 24 cancer cases. MMP levels tended to be higher in tumors than paired normal tissue; however, only the 45 kDa band that corresponds to the activated form of MMP-3 and MMP-10 was strongly expressed in all 24 tumors with little or no expression in the paired normal foci. LCM-based analysis showed the 45 kDA band to be present in both the stromal and epithelial components of the tumor microenvironment, and that MMP-3 and MMP-10 mRNA levels were higher in tumors than paired normal tissues for each compartment.
Increased levels of MMPs occur in ESCC suggesting their up-regulation is important in esophageal tumorigenesis. The up-regulated gene products have the potential to serve as early detection markers in the clinic.
Journal of Translational Medicine 10/2010; 8:91. · 3.46 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study represents a multiplex cytokine analysis of serum from a 10-month randomized, controlled trial of 238 subjects that investigated the effects of selenomethionine and/or celecoxib in subjects with mild or moderate esophageal squamous dysplasia. The original chemoprevention study found that, among those with mild dysplasia, selenomethionine treatment favorably altered dysplasia grade. The current analysis found that selenomethionine downregulated interleukin (IL)-2 by 9% (P = 0.04), whereas celecoxib downregulated IL-7 by 11% (P = 0.006) and upregulated IL-13 by 17% (P = 0.008). In addition, an increase in IL-7 tertile from baseline to t10 was significantly associated with an increase in dysplasia grade, both overall [odds ratio (OR), 1.47; P = 0.03] and among those with mild dysplasia at t0 (OR, 2.53; P = 0.001). An increase in IL-2 tertile from baseline to t10 was also nonsignificantly associated with worsening dysplasia for all participants (OR, 1.32; P = 0.098) and significantly associated with worsening dysplasia among those with mild dysplasia at baseline (OR, 2.0; P = 0.01). The association of increased IL-2 with worsening dysplasia remained significant in those on selenomethionine treatment who began the trial with mild dysplasia (OR, 2.52; P = 0.03). The current study shows that selenomethionine supplementation decreased serum IL-2 levels, whereas celecoxib treatment decreased IL-7 levels and increased IL-13 levels during a 10-month randomized chemoprevention trial. An increase in IL-2 or IL-7 was associated with increased severity of dysplasia over the course of the trial, especially in those who began the trial with mild dysplasia. The favorable effect of selenomethionine on esophageal dysplasia in the original trial may have been mediated in part by its effect in reducing the levels of IL-2.
Cancer Prevention Research 07/2010; 3(7):810-7. · 4.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Thousands of people in central Asia die every year from gastric cardia adenocarcinoma (GCA). GCA arises in the transformation zone between the esophagus and the stomach, similar to cervical and oropharyngeal carcinoma, which arise in areas with transformation zone characteristics. The analogous biology of the gastric cardia to the cervix and oropharynx, where human papillomavirus (HPV) is known to cause cancer, raises the possibility that GCA could be a HPV-associated cancer. Given the availability of an effective HPV vaccine and its potential to prevent HPV-associated cancer, we decided to evaluate the prevalence of HPV DNA in GCA.
We collected tumor tissue from 144 histopathologically confirmed GCA patients at Yaocun Commune Hospital (Linxian, China), with rigorous attention to prevent DNA contamination. We tested for the presence of HPV DNA in fresh-frozen tumor specimens using PCR with sensitive L1-, E6-, and E7-based primers.
DNA was adequate, as indicated by beta-globin positivity, in 108 cases. Of these, all (100%; 95% confidence interval, 97-100%) were negative for HPV DNA.
These results suggest that HPV does not contribute to gastric cardia carcinogenesis in north central China.
Because GCA does not seem to be a HPV-associated cancer, prophylactic HPV vaccination is unlikely to affect rates of GCA in China.
[Show abstract][Hide abstract] ABSTRACT: Certain regions of China have high rates of esophageal squamous cell carcinoma (ESCC). Previous studies of human papillomavirus (HPV), a proposed causal factor, have produced highly variable results. We attempted to evaluate HPV and ESCC more definitively using extreme care to prevent DNA contamination. We collected tissue and serum in China from 272 histopathologically-confirmed ESCC cases with rigorous attention to good molecular biology technique. We tested for HPV DNA in fresh-frozen tumor tissue using PCR with PGMY L1 consensus primers and HPV16 and 18 type-specific E6 and E7 primers, and in formalin-fixed paraffin-embedded tumor tissue using SPF(10) L1 primers. In HPV-positive cases, we evaluated p16(INK4a) overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. beta-globin, and thus DNA, was adequate in 98.2% of the frozen tumor tissues (267/272). Of these, 99.6% (95% confidence interval (CI) = 97.9-100.0%) were negative for HPV DNA by PGMY, and 100% (95% CI = 98.6-100%) were negative by HPV16/18 E6/E7 PCR. In the corresponding formalin-fixed paraffin-embedded tumor specimens, 99.3% (95% CI = 97.3-99.9%) were HPV negative by SPF(10). By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF(10), 2 cases tested weakly positive: 1 for HPV16 and 1 for HPV31. No HPV DNA-positive case had evidence of HPV oncogene activity as measured by p16(INK4a) overexpression or E6/E7 seropositivity. This study provides the most definitive evidence to date that HPV is not involved in ESCC carcinogenesis in China. HPV DNA contamination cannot be ruled out as an explanation for high HPV prevalence in ESCC tissue studies with less stringent tissue procurement and processing protocols.
International Journal of Cancer 11/2009; 127(1):93-100. · 6.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pepsinogens are a class of endopeptidases that are secreted by the gastric epithelium and released into the circulation. Low serum pepsinogen I (PGI) and low serum pepsinogen I/pepsinogen II ratio (PGI/II ratio) are markers of gastric fundic atrophy, and have recently been shown to be associated with increased risk of esophageal squamous cell carcinoma (ESCC). We conducted the current study to test whether these markers are also associated with esophageal squamous dysplasia (ESD), the precursor lesion of ESCC. We measured serum PGI and PGII, using enzyme-linked immunosorbent assays, in 125 case subjects (patients with moderate or severe ESD) and 250 sex-matched control subjects (no ESD) selected from an endoscopic screening study in Linxian, China. We used conditional logistic regression models adjusted for age, smoking and place of residence to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). Serum PGI showed no statistically significant association with ESD, whether analyzed as a dichotomous, ordinal (quartiles) or continuous variable. Lower serum PGI/II ratio, however, showed a dose-response association with increased risk of ESD, with an adjusted OR (95% CI) of 2.12 (1.08-4.18), comparing the lowest versus the highest quartile. The association between the lower serum PGI/II ratio and log OR of ESD was nearly linear, and the p-value for the continuous association was 0.03. Lower serum PGI/II ratio was linearly associated with higher risk of ESD. This result is consistent with recent findings that gastric atrophy may increase the risk of ESCC.
International Journal of Cancer 11/2008; 124(2):456-60. · 6.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Molecular events associated with the initiation and progression of esophageal squamous cell carcinoma (ESCC) remain poorly understood but likely hold the key to effective early detection approaches for this almost invariably fatal cancer. CDC25B and LAMC2 are two promising early detection candidates emerging from new molecular studies of ESCC. To further elucidate the role of these two genes in esophageal carcinogenesis, we did a series of studies to (a) confirm RNA overexpression, (b) establish the prevalence of protein overexpression, (c) relate protein overexpression to survival, and (d) explore their potential as early detection biomarkers. Results of these studies indicated that CDC25B mRNA was overexpressed (>/=2-fold overexpression in tumor compared with normal) in 64% of the 73 ESCC cases evaluated, whereas LAMC2 mRNA was overexpressed in 89% of cases. CDC25B protein expression was categorized as positive in 59% (144 of 243) of ESCC cases on a tumor tissue microarray, and nonnegative LAMC2 patterns of protein expression were observed in 82% (225 of 275) of cases. Multivariate-adjusted proportional hazard regression models showed no association between CDC25B protein expression score and risk of death [hazard ratio (HR) for each unit increase in expression score, 1.00; P = 0.90]; however, several of the LAMC2 protein expression patterns strongly predicted survival. Using the cytoplasmic pattern as the reference (the pattern with the lowest mortality), cases with a diffuse pattern had a 254% increased risk of death (HR, 3.52; P = 0.007), cases with no LAMC2 expression had a 169% increased risk of death (HR, 2.69; P = 0.009), and cases with a peripheral pattern had a 130% greater risk of death (HR, 2.30; P = 0.02). CDC25B protein expression scores in subjects with esophageal biopsies diagnosed as normal (n = 35), dysplastic (n = 23), or ESCC (n = 32) increased significantly with morphologic progression. For LAMC2, all normal and dysplastic patients had a continuous pattern of protein expression, whereas all ESCCs showed alternative, noncontinuous patterns. This series of studies showed that both CDC25B and LAMC2 overexpress RNA and protein in a significant majority of ESCC cases. The strong relation of LAMC2 pattern of protein expression to survival suggests a role in prognosis, whereas the association of CDC25B with morphologic progression indicates a potential role as an early detection marker.
[Show abstract][Hide abstract] ABSTRACT: The incidence of esophageal squamous cell carcinoma (ESCC) is very high in northern China. This cancer has a very poor prognosis, mostly because it is usually diagnosed at a late stage. Detection at an earlier stage can dramatically improve prognosis. Microscopic evaluation of esophageal balloon cytology (EBC) specimens has been the most common method for early detection of ESCC, but this technique is limited by low sensitivity and specificity. The use of molecular markers may improve these screening characteristics. This study evaluates whether measurement of gene methylation in EBC specimens may have utility for the detection of esophageal squamous dysplasia and early ESCC. We evaluated the presence of methylation in eight genes shown to be methylated in ESCC in previous studies in EBC specimens from 147 patients with endoscopic biopsy diagnoses ranging from normal mucosa to severe squamous dysplasia. Methylation status was determined using quantitative methylation-specific PCR techniques. The sensitivity and specificity of methylation of each individual gene and of combinations of these genes to detect biopsyproven high-grade (moderate or severe) squamous dysplasia were determined. For individual genes, the sensitivities ranged from 9% to 34% and the specificities ranged from 77% to 99%. Using a panel of four genes (AHRR, p16INK4a, MT1G, and CLDN3) resulted in sensitivity and specificity of 50% and 68%, respectively. This study suggests that evaluation of gene methylation in EBC samples may have utility for early detection of esophageal squamous dysplasia and early ESCC; however, identification of more sensitive methylation markers will be required for development of a clinically useful screening test.
Cancer Prevention Research 02/2008; 1(5):357-61. · 4.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Esophageal squamous cell carcinoma (ESCC) is associated with very high regional mortality rates in several countries. Our initial test of esophageal cytology screening devices found them not sensitive enough for an early detection program. The current study tested a newly designed "mechanical" balloon and a traditional Chinese inflatable balloon, followed by liquid-based cytology, to detect biopsy-proven squamous dysplasia and early cancer.
Participants were randomized to a cytologic sampler, followed by endoscopy with iodine staining. For each patient, the cytologic diagnosis (test) was compared with the worst endoscopic biopsy diagnosis (truth).
Seven hundred forty subjects completed both examinations. Approximately 30% showed atypical squamous cells of undetermined significance (ASCUS), and 10% showed squamous intraepithelial lesions. Seven hundred twenty-five subjects (98%) had satisfactory biopsies, and 32% had low grade dysplasia or worse disease. Defining > ASCUS, favor neoplastic, as a positive screening test, the sensitivities/specificities of the mechanical and inflatable balloons were 39%/85% and 46%/84%, respectively, for detecting any squamous dysplasia or cancer.
These esophageal cell samplers performed equivalently, but the accuracy was still too low for a primary screening test. These results highlight the need to develop new cytologic criteria or molecular markers that can better detect early squamous esophageal disease [corrected]
[Show abstract][Hide abstract] ABSTRACT: Previous studies have shown important effects of stromal elements in carcinogenesis. To explore the tumor-stromal relationship in esophageal neoplasia, we examined methylation of COX-2 (PTGS2), a gene etiologically associated with the development of gastrointestinal cancers, in adjacent foci of epithelium, subepithelial lymphocytes and non-lymphocytic stromal cells found in sections of normal squamous epithelium, squamous dysplasia and invasive esophageal squamous cell carcinoma.
Adjacent foci of epithelium, subepithelial lymphocytic aggregates and non-lymphocytic stromal tissues were laser microdissected from six fully embedded, ethanol fixed, esophagectomy samples from Shanxi, China, a high-risk region for esophageal cancer. Promoter CpG site-specific hypermethylation status of COX-2 was determined using real-time methylation-specific PCR (qMS-PCR) based on Taqman Chemistry. The methylation status of a subset of samples was confirmed by pyrosequencing.
Forty-nine microdissected foci were analyzed. COX-2 gene methylation was significantly more common in subepithelial lymphocytes (12/16 (75% of all foci)) than in epithelial foci (3/16 (19%)) or foci of non-lymphocytic stromal tissues (3/17 (18%)) (Fisher's exact p=0.05). Two of three epithelial samples and all three stromal samples that showed COX-2 methylation were adjacent to foci of methylated subepithelial lymphocytes. Pyrosequencing confirmed the methylation status in a subset of samples.
In these esophageal cancer patients, COX-2 gene methylation was more common in subepithelial lymphocytes than in adjacent epithelial or stromal cells in both grades of dysplasia and in foci of invasive cancer. These findings raise the possibility that methylation of subepithelial lymphocytes may be important for tumorigenesis. Future studies of gene methylation should consider separate evaluation of epithelial and non-epithelial cell populations.
Cancer Detection and Prevention 01/2008; 32(2):135-9. · 2.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Squamous dysplasia is the precursor lesion for esophageal squamous cell carcinoma, and nutritional factors play an important role in the etiology of this cancer. Previous studies using a variety of measures for vitamin D exposure have reached different conclusions about the association between vitamin D and the risk of developing esophageal cancer.
We measured serum 25-hydroxyvitamin D [25(OH)D] concentrations in a cross-sectional analysis of 720 subjects from Linxian, China, a population at high risk for developing esophageal squamous cell carcinoma. All subjects underwent endoscopy and biopsy and were categorized by the presence or absence of histologic squamous dysplasia. We used crude and multivariate-adjusted generalized linear models to estimate the relative risks (RR) and 95% confidence intervals (95% CI) for the association between squamous dysplasia and sex-specific quartiles of serum 25(OH)D concentration.
Two-hundred and thirty of 720 subjects (32%) had squamous dysplasia. Subjects with dysplasia had significantly higher median serum 25(OH)D concentrations than subjects without dysplasia, 36.5 and 31.5 nmol/L, respectively (Wilcoxon two-sample test, P = 0.0004). In multivariate-adjusted models, subjects in the highest compared with the lowest quartiles were at a significantly increased risk of squamous dysplasia (RR, 1.86; 95% CI, 1.35-2.62). Increased risks were similar when examined in men and women separately: men (RR, 1.74; 95% CI, 1.08-2.93); women (RR, 1.96; 95% CI, 1.28-3.18).
Higher serum 25(OH)D concentrations were associated with significantly increased risk of squamous dysplasia. No obvious source of measured or unmeasured confounding explains this finding.
[Show abstract][Hide abstract] ABSTRACT: Polymorphisms in genes encoding polycyclic aromatic hydrocarbon (PAH) metabolizing enzymes may alter metabolism of these carcinogens and contribute to inter-individual difference in urine concentrations. We investigated the influence of genetic polymorphism on PAH metabolism in urine from 199 healthy subjects from Southern Brazil. We measured urine 1-hydroxypyrene glucuronide (1-OHPG) concentrations using immunoaffinity chromatography and synchronous fluorescence spectroscopy and genotyped subjects using standard methods. Genetic variants in CYP1B1 (rs1056827, rs1800440, rs10012) were strongly associated with urine 1-OHPG with P-values < 0.010. Variants in aryl hydrocarbon receptor (Ahr) (rs4986826), CYP1A1 (rs1799814) and CYP1A2 (rs2069514) were also, although less strongly, associated with changes in urine 1-OHPG concentrations. These variants had P-values of 0.074, 0.040 and 0.025, respectively. The median urine 1-OHPG concentrations (pmol/ml) in the homozygous wild-type and homozygous variants for CYP1B1 (rs10012) and the Ahr, CYP1A1 and CYP1A2 variants listed above were 2.16 and 0.10, 2.16 and 0.41, 2.03 and 0.46, 2.19 and 2.79, respectively. We found no effect of deletions in GST M1 or GST T1, or different alleles of UGT1A1*28. Adjusting for age, sex, place of residence, tobacco smoke exposure, maté drinking, cachaça and barbeque preparation had only a minor impact on the associations. A model containing just exposure variables had an r2 of 0.21; a model with single genotypes for Ahr, CYP1A1, CYP1A2 and CYP1B1 had an r2 of 0.10; and a model combining both exposure and genotype information had a total r2 of 0.33. Our results suggest that CYP1B1 genotypes are strongly associated with urine 1-OHPG concentrations in this population.
[Show abstract][Hide abstract] ABSTRACT: The oral health status of rural residents in the People's Republic of China has not been extensively studied and the relationship between poor oral health and esophageal cancer (EC) is unclear. We aim to report the oral health status of adults participating in an EC screening study conducted in a rural high-risk EC area of China and to explore the relationship between oral health and esophageal dysplasia.
National Health and Nutrition Examination Survey (NHANES) oral health examination procedures and the Modified Gingival Index (MGI) were used in a clinical study designed to examine risk factors for esophageal cancer and to test a new esophageal cytology sampling device. This study was conducted in three rural villages in China with high rates of EC in 2002 and was a collaborative effort involving investigators from the National Institutes of Health and the Cancer Institute of the Chinese Academy of Medical Sciences.
Nearly 17% of the study participants aged 40-67 years old were edentulous. Overall, the mean number of adjusted missing teeth (including third molars and retained dental roots) was 13.8 and 35% had 7 contacts or less. Women were more likely to experience greater tooth loss than men. The average age at the time of first tooth loss for those with no posterior functional contacts was approximately 41 years for men and 36 years for women. The mean DMFT (decayed, missing, and filled teeth) score for the study population was 8.5. Older persons, females, and individuals having lower educational attainment had higher DMFT scores. The prevalence of periodontal disease (defined as at least one site with 3 mm of attachment loss and 4 mm of pocket depth) was 44.7%, and 36.7% of the study participants had at least one site with 6 mm or more of attachment loss. Results from a parsimonious multivariate model indicate that participants with poor oral health wemore likely to have esophageal dysplasia (OR = 1.59; 95% CI 1.06, 2.39).
This report describes the first use of NHANES oral health protocols employed in a clinical study conducted outside of the United States. The extent and severity of poor oral health in this Chinese study group may be an important health problem and contributing factor to the prevalence of EC.
BMC Oral Health 02/2007; 7:10. · 1.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to determine whether immunologic competence, as measured by lymphocyte stimulation indices from three different ex vivo challenges, is associated with subsequent risk of cancer or total mortality in Linzhou, China, a population at high risk for upper gastrointestinal cancers. Cellular immune function tests were conducted on a subgroup of 381 trial participants after 5.25 years of intervention to evaluate whether nutrient supplementation affected the cellular immune system and found significantly higher T-lymphocyte mitogenic responsiveness to phytohemagglutinin-M among men receiving daily supplementation of beta-carotene (15 mg) plus selenium (50 mug) plus alpha-tocopherol (30 mg) (supplementation factor D) compared with those who did not receive this supplement (P<0.05). The current analysis reports 10 years of post-trial prospective follow-up of these 381 trial participants and identifies 53 incident cancers, 48 (92%) of which were upper gastrointestinal cancers, including 22 esophageal cancers, 22 gastric cardia cancers, and four noncardia gastric cancers. Ninety-one deaths occurred among the 381 participants, including 33 upper gastrointestinal cancer deaths, 23 heart disease deaths, 16 stroke deaths, and seven fatal accidents. Multivariate Cox proportional hazards models including variables for age at time of tests, sex, tobacco smoking, alcohol drinking, and original trial treatment group showed no significant associations between phytohemagglutinin-M, concanavalin-A, or anti-CD3 stimulation indices and subsequent cancer incidence or total mortality. This implies that immune competence, as measured by these stimulation indices, is not associated with incident cancer or total mortality in this population.
European Journal of Cancer Prevention 12/2006; 15(6):548-50. · 2.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Esophageal cancer is a leading cause of cancer death, especially in developing countries. In high-risk regions, squamous cell carcinoma is the most common type of esophageal cancer, and its etiology remains poorly understood. The purpose of this study was to evaluate the association between human papillomavirus (HPV) infection and esophageal squamous cell carcinoma (ESCC) and related precursor lesions in a high-risk area of China. We conducted a cross-sectional study among adult inhabitants of Linxian, China. All subjects were interviewed about potential risk factors, had the length of their esophagus sampled by a balloon cytology examination and underwent endoscopy with mucosal iodine staining and biopsy of all unstained lesions. A multivalent HPV hybridization probe, Digene Hybrid Capture II (Gaithersburg, MD), which recognizes high-risk types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68, was used to determine the HPV infection status of the cytologic specimens, and the endoscopic biopsies were used to classify each subject's esophageal disease. 740 subjects completed the cytologic and endoscopic exams, and 702 had adequate cytologic and biopsy specimens. Using a cutpoint of > or =3.0 pg/ml of HPV DNA to define a positive test, HPV positivity was identified in 13% (61/475) of subjects without squamous dysplasia, 8% (8/102) with mild dysplasia, 7% (6/83) with moderate dysplasia, 16% (6/38) with severe dysplasia and zero (0/4) with invasive ESCC. Changing the cutpoint defining a positive test did not change the association of HPV infection and dysplasia grade. In this high-risk population, infection of esophageal cells with high-risk HPV types occurs in 13% of asymptomatic adults with no evidence of squamous dysplasia and a similar proportion of individuals with mild, moderate or severe dysplasia. This suggests that HPV infection is not a major risk factor for ESCC in this high-risk Chinese population. Further studies are warranted to determine if infection with this agent is associated with neoplastic progression in a subset of cases.
International Journal of Cancer 10/2006; 119(6):1354-9. · 6.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Esophageal squamous cell carcinoma (ESCC) is a common cancer with a very poor prognosis. New methods are needed to screen high-risk populations and identify curable tumors and precursor lesions early. Molecular markers may be useful in such screening efforts. This study was designed to determine the prevalence of p16, MGMT, RARbeta2, CLDN3, CRBP and MT1G gene methylation in patients with ESCC to evaluate the variation of gene methylation across a spectrum of preneoplastic lesions, and assess the feasibility of using gene methylation in a primary screening test utilizing frozen esophageal cells collected by balloon cytology samplers. Samples were obtained from high-risk subjects from north central China. These samples included 11 foci of histologically normal mucosa, 8 foci of low-grade squamous dysplasia, 7 foci of high-grade squamous dysplasia, and 13 foci of ESCC from 6 fully embedded resection specimens; endoscopic biopsies from 6 individuals with no histological evidence of disease; and frozen esophageal balloon samples from 12 asymptomatic subjects. Promoter CpG site-specific hypermethylation status was determined for each gene using real-time methylation-specific PCR (qMS-PCR) based on Taqman chemistry. Of the 6 ESCC patients, 5 showed methylation of at least one gene. For most genes, methylation occurred with increasing frequency during neoplastic progression, with the largest increase found between low- and high-grade dysplasia. There was considerable variation in methylation patterns among different foci of the same histological grade, even within individual patients, but 16/20 (80%) of high-grade dysplastic and cancer foci had >or= 2 methylated genes, while 17/19 (89%) of normal and low-grade dysplastic foci had <2 methylated genes. These genes were rarely methylated in histologically normal mucosa from patients with or without ESCC. Gene methylation was common and easily detectable in the frozen esophageal cells collected by balloon cytology samplers. Our data suggest that methylation of p16, MGMT, RARbeta2, CLDN3, CRBP, and MT1G is common in the esophageal mucosa of patients with ESCC in this high-risk population, and tends to increase in prevalence in foci with increasing histological severity of disease. Methylation data from panels of genes may be able to identify patients with high-grade lesions. Balloon cytology may be able to screen the length of the esophagus effectively for a subset of cells with abnormal methylation, and may be useful in a primary screening test for ESCC and its precursor lesions.
[Show abstract][Hide abstract] ABSTRACT: Basal cell carcinoma (BCC) of the plantar surface of the foot is rare, with only 22 previously reported cases. This clinico-pathologic study is based on 20 cases pf BCC of the plantar surface and plantar-like surfaces from adjacent lower lateral and medial aspects of the foot, submitted to a large podiatric laboratory from 1986 through June 1992 (total specimens for this period = 518,624; total BCC of lower extremities, below knee = 53). There were 15 women and 5 men. The average patient age was 73 years, with a range from 52 to 92 years. The duration of the lesion before diagnosis was 2 months to 12 years, with an average of 2 years. Three patients had a history of trauma. Podiatric clinical diagnoses included BCC (4), SCC (3), soft tissue tumor (2), nevus (1), granuloma (1), keratosis (2), verucca (1), and psoriasis (1). Follow-up information was available on 10 patients; all were free of disease up to 64 months, with an average follow-up of 15.7 months. Three of 20 BCC showed predominant histologic patterns characteristic of fibroepithelioma of Pinkus (FEP). An additional three BCC showed focal or suggestive patterns of FEP. Fourteen tumors showed ordinary BCC histologic patterns. No multicentric-superficial or morphea like BCC were observed. The relatively high incidence of FEP in BCC of the sole correlates with abundant sweat glands and lack of hair follicles on the plantar surface, in accordance with the recent proposal that FEP derives its histologic pattern from the spread of BCC down eccrine ducts, eventually replacing them with solid strands of tumor.