Cytologic screening for esophageal cancer: results from 12,877 subjects from a high-risk population in China

Esophageal cancer in China: Practice and research in the new era

China, as the one of the largest developing countries in the world and with about one-fifth of the global population, is bearing an increasing burden on health from cancer. In the area of esophageal cancer (EC), China accounts for more than 50% of the global cases, with this disease being a particularly worse for those in disadvantaged populations. Along with China's socioeconomic condition, the epidemiology, diagnosis, therapeutics and research of EC have developed throughout the 21st century. In the current review, existing control measures for EC in China are outlined, including the incidence, mortality, screening, clinical diagnosis, multidisciplinary treatment and research landscape. EC in China are very different from those in some other parts of the world, especially in Western countries. Core measures that could contribute to the prevention of EC and improve clinical outcomes in patients of less developed countries and beyond are recommended. International cooperation among academia, government and industry is especially warranted in global EC control.

A multinational review: Oesophageal cancer in low to middle-income countries

Oesophageal cancer (OC) is an aggressive neoplasm that manifests in the gastrointestinal tract and is the result of numerous factors that can contribute to the development of the disease. These may include old age, nutritional deficiencies, oesophageal obstruction and food ingestion difficulties. Environmental factors serve a large role in increasing the risk of developing OC. Two factors that serve an increasing risk of developing OC are the use of tobacco and the consumption of alcohol. Genetic factors also exhibit a large effect on the risk of developing OC, for example, the causative genes in Black Africans differ from other races. OC is 3–4 times more common among men than women. OC has been previously reported in >450 000 individuals worldwide, and its incidence is increasing. The current review compares OC in low to middle-income countries with developed countries. The incidence of OC, particularly squamous cell carcinoma (SCC) is high in low and middle-income countries. In developed countries, the incidence of SCC is low compared with adenocarcinoma. The majority of OC cases are diagnosed in the late stages of the disease, leading to high mortality rates. The current review aimed to discuss factors that contribute to the development of this disease in different geographical areas and genetic mechanisms governing these findings. The current review also aims to discuss the preventative treatment options for the disease, and also discusses the diagnosis and surveillance in five LMICs, including South Africa, China, Tanzania, India and Brazil.

Role of TFF3 as an adjunct in the diagnosis of Barrett's esophagus using a minimally invasive esophageal sampling device-The CytospongeTM

The incidence of esophageal carcinoma continues to increase whilst its prognosis remains poor. The most dramatic reduction in mortality is likely to follow early diagnosis of the preinvasive precursor lesion, Barrett's esophagus (BE), coupled with treatment of dysplastic lesions. The major risk factor for BE is gastroesophageal reflux disease, however this is highly prevalent and only a small proportion of individuals have BE, therefore an endoscopy-based screening strategy to detect BE is unfeasible. Minimally invasive esophageal sampling devices offer an alternative, cost-effective strategy which can be deployed within an at-risk population in a primary care setting to identify individuals with probable BE who can then be referred for endoscopic confirmation. The device that has currently progressed furthest in clinical trials is the Cytosponge^TM which collects cells from the gastric cardia, gastroesophageal junction and along the whole esophageal length. The cell sample is processed into a formalin-fixed paraffin-embedded block and sections assessed for the presence of intestinal metaplasia. TFF3 immunohistochemistry has consistently been shown to be a valuable adjunct that increases the accuracy of the Cytosponge^TM test by highlighting early goblet cells which may be missed on morphological assessment and by allowing pseudogoblet cells to be differentiated from true goblet cells.

Combined EsophaCap cytology and MUC2 immunohistochemistry for screening of intestinal metaplasia, dysplasia and carcinoma

Purpose: The incidence of esophageal adenocarcinoma (EAC) has increased by 700% in Western countries over the last 30 years. Although clinical guidelines call for endoscopic surveillance for EAC among high-risk populations, fewer than 5% of new EAC patients are under surveillance at the time of diagnosis. We studied the accuracy of combined cytopathology and MUC2 immunohistochemistry (IHC) for screening of Intestinal Metaplasia (IM), dysplasia and EAC, using specimens collected from the EsophaCap swallowable encapsulated cytology sponge from Canada and United States. Patients and methods: By comparing the EsophaCap cytological diagnosis with concurrent endoscopic biopsies performed on the same patients in 28 cases, we first built up the cytology diagnostic categories and criteria. Based on these criteria, 136 cases were evaluated by both cytology and MUC2 IHC with blinded to patient biopsy diagnosis. Results: We first set up categories and criteria for cytological diagnosis of EscophaCap samples. Based on these, we divided our evaluated cytological samples into two groups: non-IM group and IM or dysplasia or adenocarcinoma group. Using the biopsy as our gold standard to screen IM, dysplasia and EAC by combined cytology and MUC2 IHC, the sensitivity and specificity were 68% and 91%, respectively, which is in the range of clinically useful cytological screening tests such as the cervical Pap smear. Conclusions: Combined EsophaCap cytology and MUC2 IHC could be a good screening test for IM and Beyond.

The National Cohort of Esophageal Cancer-Prospective Cohort Study of Esophageal Cancer and Precancerous Lesions based on High-Risk Population in China (NCEC-HRP): study protocol

INTRODUCTION

Oesophageal cancer (OC) is one of the most common cancers worldwide and about 50% of all new cases occurred in China. Population-based screening has been conducted in high-risk areas in China since 1970s, however, a few factors have limited the integration of the results from previous studies and the sharing of existing resources, such as the difference in screening methods and protocols, inconsistencies in questionnaires for risk factors investigation, lack of standards for sample collection and incomplete follow-up information.

METHODS AND ANALYSIS

The National Cohort of Esophageal Cancer-Prospective Cohort Study of Esophageal Cancer and Precancerous Lesions based on High-Risk Population (NCEC-HRP) is a prospective cohort study of OC screening based on high-risk population in China supported by the National Key R&D Programme. Eight areas located at eastern, central and western China are selected as screening centres to represent three economical-geographical regions. All local residents aged 40-69 years in the selected areas are invited to take endoscopic examination and risk factors investigation unless they meet the exclusion criteria. The recruitment began on June 2017 and a total of 100 000 participants will be enrolled by December 2020 and all subjects will be followed for a long time. This study is designed as open-ended and has broad research aims. Summary statistics for baseline information will be reported after the completion of recruitment. We will develop a series of standards and guidelines for OC screening during the study. An open and shared research platform linked with epidemiological databases and biobank will be built up for further research.

ETHICS AND DISSEMINATION

The study is approved by the Ethics Committee of Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (approval number 16-171/1250). The findings of the study will be disseminated through scientific peer-reviewed journals as well as the public via the study website (http://www.ncec-china.cn).

TRIAL REGISTRATION NUMBER

ChiCTR-EOC-17010553; Pre-results.

History and Practice of Thyroid Fine-Needle Aspiration in China, Based on Retrospective Study of the Practice in Shandong University Qilu Hospital

Cytology in China developed from nothing and underwent a long journey from gynecologic cytology to that of all organs, laying a solid foundation for new developments in the 21st century. Thyroid fine-needle aspiration (FNA) was primarily developed in an endocrinology department and then in the clinical laboratory department or pathology department in the 1970-80s. Wrights staining is popular in endocrine and clinical laboratory departments, while hematoxylin and eosin staining is common in pathology. Liquid based cytology is not common in thyroid FNA cytology, while BRAF V600E mutation analysis has been the most popular molecular test. The history and practice of thyroid FNA practice in China were reviewed based on retrospective study of the practice in Qilu Hospital of Shandong University.

Epidemiology, etiology, and prevention of esophageal squamous cell carcinoma in China

Esophageal cancer is one of the most fatal diseases worldwide mainly because of its rapid progression and poor prognosis. Although the incidence of esophageal adenocarcinoma has markedly risen in North America and Europe in the past several decades, esophageal squamous cell carcinoma is still the predominant subtype of esophageal cancer, especially in China. It accounts for more than 90% of all esophageal squamous cell carcinoma cases in China. Geographical differentiation is one of the most distinctive characteristics of esophageal cancer. The progression, risk factors, and prognosis of these two subtypes of esophageal cancer differ. This study reviews the epidemiology, etiology, and prevention of esophageal squamous cell carcinoma in China, thereby providing systematic references for policy-makers who will decide on issues of esophageal cancer prevention and control.

DNA image cytometry test for primary screening of esophageal cancer: a population-based multi-center study in high-risk areas in China

OBJECTIVE

To evaluate the feasibility of DNA image cytometry (DNA-ICM) as a primary screening method for esophageal squamous cell cancer (ESCC).

METHODS

A total of 5,382 local residents aged 40-69 years from three high-risk areas in China (Linzhou in Henan province, Feicheng in Shandong province and Cixian in Hebei province) from 2008 to 2011 were recruited in this population-based screening study. And 2,526 subjects declined to receive endoscopic biopsy examination with Lugol's iodine staining, while 9 and 815 subjects were excluded from liquid-based cytology and DNA-ICM test respectively due to slide quality. Finally, 2,856, 5,373 and 4,567 subjects were enrolled in the analysis for endoscopic biopsy examination, liquid-based cytology and DNA-ICM test, respectively. Sensitivity (SE), specificity (SP), negative predictive values (NPV) and positive predictive values (PPV) as well as their 95% confidence intervals (95% CI) for DNA-ICM, liquid-based cytology and the combination of the two methods were calculated. Receiver operating characteristic (ROC) curves were applied to determine the cutoff point of DNA-ICM for esophageal cancer.

RESULTS

DNA-ICM results were significantly correlative with esophageal cancer and precancer lesions (χ(2)=18.016, P<0.001). The cutoff points were 5,802, 5,803 and 8,002 based on dissimilar pathological types of low grade intraepithelial neoplasia (LGIN), high grade intraepithelial neoplasia (HGIN), and ESCC, respectively, and 5,803 was chosen in this study considering the SE and SP. The SE, SP, PPV, NPV of DNA-ICM test (cutoff point 5,803) combined with liquid-based cytology [threshold atypical squamous cells of undetermined significance (ASCUS)] were separately 72.1% (95% CI: 70.3%-73.9%), 43.3% (95% CI: 41.3%-45.3%), 22.8% (95% CI: 21.1%-24.5%) and 87.0% (95% CI: 85.7%-88.3%) for LGIN, 85.7% (95% CI: 84.3%-87.1%), 41.3% (95% CI: 39.3%-43.3%), 4.6% (95% CI: 3.8%-5.4%) and 98.9% (95% CI: 98.5%-99.3%) for HGIN, and 96.0% (95% CI: 95.2%-96.8%), 40.8% (95% CI: 38.8%-42.8%), 1.7% (95% CI: 1.2%-2.2%) and 99.9% (95% CI: 99.8%-100.0%) for ESCC.

CONCLUSIONS

It is possible to use DNA-ICM test as a primary screening method before endoscopic screening for esophageal cancer.

Early esophageal cancer screening in China

In China, the incidence of esophageal cancer (EC) and its related mortality are high. Screening strategies aiming at early diagnosis can improve the prognosis. Researches on detection of early EC, especially in China are reviewed. Compared to esophageal balloon cytology or routine endoscopy, chromoendoscopy with Lugol's staining and biopsy appears to be the gold standard for early EC diagnosis in China today. Narrow-band imaging endoscopy, Confocal Laser endomicroscopy and other novel diagnostic approaches are more and more widely used in developed urban areas, but cost and lack of essential training to the endoscopists have made their use limited in rural areas. No specific biomarkers or serum markers were strongly commended to be used in screening strategies currently, which need to be evaluated in future. Trials on organized screening have been proposed in some regions of china with high disease prevalence. Screening in these areas has been shown to be cost effective.

Long-Term Follow-Up of a Community Assignment, One-Time Endoscopic Screening Study of Esophageal Cancer in China

PURPOSE

There are no global screening recommendations for esophageal squamous cell carcinoma (ESCC). Endoscopic screening has been investigated in areas of high incidence in China since the 1970s. This study aimed to evaluate whether an endoscopic screening and intervention program could reduce mortality caused by ESCC.

METHODS

Residents age 40 to 69 years were recruited from communities with high rates of ESCC. Fourteen villages were selected as the intervention communities. Ten villages not geographically adjacent to intervention villages were selected for comparison. Participants in the intervention group were screened once by endoscopy with Lugol's iodine staining, and those with dysplasia or occult cancer were treated. All intervention participants and a sample consisting of one tenth of the control group completed questionnaires. We compared cumulative ESCC incidence and mortality between the two groups.

RESULTS

Three thousand three hundred nineteen volunteers (48.62%) from an eligible population of 6,827 were screened in the intervention group. Seven hundred ninety-seven volunteers from an eligible population of 6,200 in the control group were interviewed. Six hundred fifty-two incident and 542 fatal ESCCs were identified during the 10-year follow-up. A reduction in cumulative mortality in the intervention group versus the control group was apparent (3.35% v 5.05%, respectively; P < .001). Furthermore, the intervention group had a significantly lower cumulative incidence of ESCC versus the control group (4.17% v 5.92%, respectively; P < .001).

CONCLUSION

We showed that endoscopic screening and intervention significantly reduced mortality caused by esophageal cancer. Detection and treatment of preneoplastic lesions also led to a reduction in the incidence of this highly fatal cancer.

Esophageal cytology sponge diagnostic test results in kenyatta national referral hospital, kenya

OBJECTIVE

To describe the cytological findings of the esophagus using sponge cytology as a triage test in patients referred for esophageal endoscopy at Kenyatta National Hospital.

STUDY DESIGN

A cross-sectional descriptive study was undertaken to obtain specimens from the esophagus for cytological evaluation using a sponge. The cellular yield and pattern of esophageal cytological findings was described by cytopathologists using the Bethesda system. The cytological findings were compared with endoscopy findings and whenever possible with biopsy results.

RESULTS

All the participants (100%) swallowed the encapsulated sponge successfully and had smears with satisfactory material for evaluation. Negative smears for intraepithelial lesion or malignancy were the most common (86.6%), with intestinal metaplasia reported in 10% of all patients, high-grade squamous intraepithelial lesions in 1.7% and squamous cell carcinoma in 1.7%. There was good agreement between endoscopic and cytological findings.

CONCLUSION

Sponge cytology is a simple and inexpensive technique which seems to have promising results as a primary test as well as a triage test whenever there is any suspicion of an esophageal lesion, especially in clinical settings where endoscopic facilities and medical professionals are not available. Hence, further evaluation using a larger sample size is recommended.

Screening for oesophageal cancer

BACKGROUND

Oesophageal cancer is a global heath problem. The prognosis for advanced oesophageal cancer is generally unfavourable, but early-stage asymptomatic oesophageal cancer is basically curable and could achieve better survival rates. The two most commonly used tests are cytologic examination and endoscopy with mucosal iodine staining. The efficacy of the screening tests is controversial, and the true benefit and efficacy of screening remains uncertain because of the potential lead-time and length-time biases. This review was conducted to examine the evidence for the efficacy of screening for oesophageal cancer (squamous cell carcinoma and adenocarcinoma).

OBJECTIVES

To determine the efficacy of early screening, using endoscopy with iodine staining or cytologic examination, in reducing mortality from oesophageal cancer in asymptomatic individuals from high-risk and general populations.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 8), The Cochrane Library (2012, Issue 8), MEDLINE (1950 to August 2012), EMBASE (1980 to August 2012), Allied and Complementary Medicine (AMED) (1985 to August 2012), Chinese Biomedical Database (CBM) (January 1975 to August 2012), VIP Database (January 1989 to August 2012), China National Knowledge Infrastructure (CNKI) (January 1979 to August 2012), and the Internet. We also searched reference lists, conference proceedings, and databases of ongoing trials. There was no restriction on language or publication status in the search for trials.

SELECTION CRITERIA

We included only randomised controlled trials (RCT) of screening versus no screening for oesophageal cancer. Randomisation of groups or clusters of individuals was acceptable.

DATA COLLECTION AND ANALYSIS

Two review authors independently scanned the titles and abstracts from the initial search for potential trials for inclusion. We did not find any trials that met the inclusion criteria.

MAIN RESULTS

The electronic search identified 3482 studies. Two authors independently reviewed the references. The reports of 18 studies were retrieved for further investigation. None met the eligibility criteria for a RCT investigation of the effects of screening versus no screening for oesophageal cancer.

AUTHORS' CONCLUSIONS

There were no RCTs that determined the efficacy of screening for oesophageal cancer. Non-RCTs showed a high incidence and the reported better survival after screening could be caused by selection bias, lead-time and length-time biases. RCTs are needed to determine the efficacy of screening for oesophageal cancer.

Surveillance for gastrointestinal malignancies

Gastrointestinal (GI) malignancies are notorious for frequently progressing to advanced stages even in the absence of serious symptoms, thus leading to delayed diagnoses and dismal prognoses. Secondary prevention of GI malignancies through early detection and treatment of cancer-precursor/premalignant lesions, therefore, is recognized as an effective cancer prevention strategy. In order to efficiently detect these lesions, systemic application of screening tests (surveillance) is needed. However, most of the currently used non-invasive screening tests for GI malignancies (for example, serum markers such as alpha-fetoprotein for hepatocellular carcinoma, and fecal occult blood test, for colon cancer) are only modestly effective necessitating the use of highly invasive endoscopy-based procedures, such as esophagogastroduodenoscopy and colonoscopy for screening purposes. Even for hepatocellular carcinoma where non-invasive imaging (ultrasonography) has become a standard screening tool, the need for repeated liver biopsies of suspicious liver nodules for histopathological confirmation can’t be avoided. The invasive nature and high-cost associated with these screening tools hinders implementation of GI cancer screening programs. Moreover, only a small fraction of general population is truly predisposed to developing GI malignancies, and indeed needs surveillance. To spare the average-risk individuals from superfluous invasive procedures and achieve an economically viable model of cancer prevention, it’s important to identify cohorts in general population that are at substantially high risk of developing GI malignancies (risk-stratification), and select suitable screening tests for surveillance in these cohorts. We herein provide a brief overview of such high-risk cohorts for different GI malignancies, and the screening strategies that have commonly been employed for surveillance purpose in them.

Screening for oesophageal cancer

Oesophageal cancer is a global health problem with high mortality due to the advanced nature of the disease at presentation; therefore, detection at an early stage significantly improves outcome. Oesophageal squamous-cell cancer is preceded by dysplasia and oesophageal adenocarcinoma is preceded by Barrett's oesophagus, which progresses to cancer via intermediate dysplastic stages. Screening to detect these preneoplastic lesions has the potential to substantially reduce mortality and morbidity. However, the risks and benefits of such programmes to individuals and to society need to be carefully weighed. Endoscopic screening is invasive, costly and error prone owing to sampling bias and the subjective diagnosis of dysplasia. Non-endoscopic cell-sampling methods are less invasive and more cost effective than endoscopy, but the sensitivity and specificity of cytological assessment of atypia has been disappointing. The use of biomarkers to analyse samples collected using pan-oesophageal cell-collection devices may improve diagnostic accuracy; however, further work is required to confirm this. The psychological and economic implications of screening as well as the feasibility of implementing such programmes must also be considered.

Population-based study of DNA image cytometry as screening method for esophageal cancer

AIM: To explore the DNA image cytometry (DNA-ICM) technique as a primary screening method for esophageal squamous precancerous lesions.

METHODS: This study was designed as a population-based screening study. A total of 582 local residents aged 40 years-69 years were recruited from Linzhou in Henan and Feicheng in Shandong. However, only 452 subjects had results of liquid-based cytology, DNA-ICM and pathology. The sensitivity and specificity of DNA-ICM were calculated and compared with liquid-based cytology in moderate dysplasia or worse.

RESULTS: Sensitivities of DNA-ICM ranging from at least 1 to 4 aneuploid cells were 90.91%, 86.36%, 79.55% and 77.27%, respectively, which were better than that of liquid-based cytology (75%). Specificities of DNA-ICM were 70.83%, 84.07%, 92.65% and 96.81%, but the specificity of liquid-based cytology was 91.91%. The sensitivity and specificity of a combination of liquid-based cytology and DNA-ICM were 84.09% and 85.78%, respectively.

CONCLUSION: It is possible to use DNA-ICM technique as a primary screening method for esophageal squamous precancerous lesions.

Cytological screening and 15 years' follow-up (1986-2001) for early esophageal squamous cell carcinoma and precancerous lesions in a high-risk population in Anyang County, Henan Province, Northern China

BACKGROUND

Anyang County and nearby Linzhou (formerly Linxian) in Henan, Northern China have been well recognized as the highest incidence area for esophageal squamous cell carcinoma (SCC) in the world. SCC remains the leading cause of cancer-related death in these areas and the natural history for esophageal precancerous lesions is not clear.

METHODS

In the present study, to determine the significance of cytological examination and natural history for SCC, esophageal balloon cytological screening and follow-up studies have been performed 2273 symptom-free subjects in Anyang County since 1986. Based on cellular morphological changes, esophageal epithelial cells were classified as normal (NOR), inflammation (IN), hyperplasia (HYP), dysplasia (grades I and II) (DYS I and DYS II), near squamous cell carcinoma (NSCC) and SCC.

RESULTS

The prevalence of NOR, IN, HYP, DYS I, DYS II, and NSCC was 22.7, 3.6, 33.6, 21.5, 10.7, and 3.8%, respectively, in males and 25.8, 5.7, 33, 18.9, 10.4, and 3.8%, respectively in females. No difference was observed between the male and female subjects (p > 0.05). Of the 2273 subjects examined, 2199 subjects entered the final follow-up analysis (97%). During the 15 years' follow-up on these subjects, 94 new cases (4.2%, 94/2199), including 91 with SCC (97%, 91/94, 58 males and 33 females) and 3 with GCA (3%, 3/94, one male and two females) were identified with a mean time of 8 +/- 4.6 years after entry of the follow-up. The incidence for SCC in males was higher than that in females (p < 0.05). The rate for SCC development increased apparently from the groups of NOR (2.4%) to DYS I (5%), DYS II (8.3%), and NSCC (10.3%) (p < 0.001). The prevalence of DYS and NSCC increased significantly with age.

CONCLUSIONS

The present results indicate that esophageal balloon cytology is a reliable approach for early SCC and precancerous lesions screening and that DYS and NSCC are important markers for high-risk subjects with predisposition to SCC. Close follow-up to the subjects with HYP, DYS and NSCC may shed light on the natural history for human esophageal carcinogenesis.

Role of cytology in the diagnosis of Barrett's esophagus and associated neoplasia

We studied 327 consecutive paired esophageal biopsies and brushing specimens obtained during the same endoscopic session to evaluate the role of cytology for the diagnosis of Barrett's esophagus (BE) and/or surveillance for associated dysplasia. A diagnosis of BE was based on the cytologic presence of goblet cells. Cases were reviewed and categorized into: 1) benign esophageal lesions (125 cases), with 48 cases of Candida (32 cases diagnosed by both techniques and 16 diagnosed only by cytology), 3 cases of herpes simplex with only 1 case diagnosed by cytology, and 74 cases of inflammation and/or repair; 2) benign BE (141 cases), with 74 cases (52%) diagnosed by both techniques, 11 cases by cytology only (8%), and 56 cases (40%) by histology only; 3) low-grade dysplasia (LGD, 30 cases), with 5 cases (17%) diagnosed with both specimens, one case (3%) by cytology only, and 24 cases (80%) by histology only; 4) high-grade dysplasia (HGD, 10 cases), with 8 cases (80%) diagnosed with both specimens, 1 case (10%) by cytology, and 1 case (10%) by histology; and 5) carcinomas (23 cases), with 20 cases (87%) diagnosed with both specimens, 2 cases (9%) by cytology only, and 1 case (4%) by histology only. Our results support the high degree of diagnostic accuracy of cytology for the diagnosis of Barrett's-associated HGD and/or carcinoma, and moderate sensitivity for BE.

Gastrointestinal tract cytology: advancing horizons

Tide and ebb of interest in gastrointestinal tract cytology has followed technical advances in this field over the last 60 years. Cytologic samples can be obtained using gastric lavage, abrasive balloons, mucosal brushing, and fine needle aspiration (under percutaneous image guidance, endoscope and endoscopic ultrasound guidance). These advances now allow simultaneous performance of brushing the abnormal mucosa, obtaining fine needle aspirates and excising mucosal biopsy samples for evaluation. Use of endoscopic ultrasound guided fine needle aspirates now help to obtain diagnosis of submucosal lesions, preoperative staging of gastrointestinal tract malignancies and help determine further management of patients. Such advances have brought pathologists to the forefront of the patient management team for the treatment of gastrointestinal tract lesions. This manuscript reviews the advantages and limitations of each cytology associated technique as well as reviews the salient diagnostic features, differential diagnosis and diagnostic pitfalls of gastrointestinal tract lesions. Finally, it suggests the modalities best suited to obtain diagnosis for various gastrointestinal tract lesions.

Cytology in Barrett's esophagus

Brush cytology is complementary to endoscopic biopsy and is recommended by some to be part of the routine endoscopic surveillance of patients with BE. Advantages of cytology include the ability to sample a greater area of involved epithelium, preferential exfoliation of the less cohesive dysplastic cells, simplicity, and lower cost. There are clear cytologic criteria for dysplasia, and biomarker studies can be performed on cytologic specimens. Despite these advantages, cytology is used by only 17% of gastroenterologists in the United States today. Limited data are available on the usefulness of cytology in the diagnosis and surveillance of BE. Cytology has good sensitivity for the detection of adenocarcinoma and HGD and good specificity for the detection of IM without dysplasia. Furthermore, cytology may detect abnormalities missed by biopsy. Cytology has problems in the detection of LGD, however. For cytology to become a useful surveillance option, its sensitivity for low-grade lesions must be improved. One potential way to accomplish this is to add biomarkers to routine cytologic specimens to define patients at increased risk of progression to cancer. If simple prognostic biomarkers could be developed and validated in histology and cytologic specimens, this would provide additional support for the utility of cytologic brushings in the surveillance of BE. Cytology could then conceivably accomplish the goals of improved efficiency, risk stratification, and decreased costs in BE surveillance programs.

Absence of association between HPV DNA, TP53 codon 72 polymorphism, and risk of oesophageal cancer in a high-risk area of China

We analyzed TP53 codon 72 polymorphism, HPV DNA in 32 subjects with oesophageal cancer and 57 healthy subjects with normal oesophageal cytology from an area of China with a high prevalence for this cancer (Linxian County, Henan Province). The frequency of the proline allele (0.63) was significantly higher in the Chinese population than in most European or American populations. No significant association was found between TP53 codon 72 genotype and cancer. We also found a low prevalence of HPV DNA (6.7%) in both cancer cases and healthy subjects. Our findings do not support the association between risk of oesophageal cancer, human papilloma virus infection, and TP53 codon 72 polymorphism in a Chinese population at high risk of oesophageal cancer.

Mxi1 is a potential cellular target of carcinogens and frequently mutated in experimental rat tumors and tumor cell lines

Mxi1, a member of the Myc family of transcription factors, negatively regulates Myc oncoprotein activity and thus may be a tumor suppressor gene. It is mutated in a few human prostate cancers. Rat Mxi1 was isolated as a selective overexpressive message in rat esophageal cancer induced by N-nitrososarcosine ethyl ester using differential display and polymerase chain reaction cloning. Reverse transcription, single-strand conformation polymorphism analysis and subsequent DNA sequencing were used to screen mutations for the rat Mxi1 coding region including the functional domains, Sin3-interacting, helix-loop-helix and leucine zipper in samples from 24 rat tumor tissues and various cell lines. Seven mutations were revealed to exist in six rat tumors (including two esophageal tumors and a breast cancer), and three rat tumor cell lines: Leydig cell tumor, osteogenic sarcoma, and pituitary tumor. No coding changes were detected in 34 samples of human sporadic gastric adenocarcinoma. A silent base substitution (GAG to GAA) at codon 131 was also identified in six rat tumors as well as in one human gastric cancer. Our results indicate that Mxi1 is often mutated in experimental rat tumors but mutations are rare in human sporadic cancers. The Mxi1 tumor suppressor gene may be a cellular target of strong carcinogens. Considering the frequency of mutations in chemical carcinogen-induced tumors, searches for Mxi1 mutation in human tumors should be directed toward patients with a specific epidemiological background.

Early detection of esophageal squamous cell carcinoma and its effects on therapy: an overview

Squamous cell carcinoma of the esophagus shows a wide variation in incidence worldwide. It is the fifth leading cause of cancer-related death in men and usually diagnosed at an advanced stage with unsatisfactory therapeutic results. The techniques available for early detection of esophageal carcinoma are reviewed in this paper, as well as its overall effect on survival. For the time being, only surgical resection at a very early stage may improve survival of the disease. Esophageal cancer can be treated at an earlier stage when it is diagnosed by mass screening detection. However, despite a high survival rate at 5 years, local recurrences and distal metastases may still occur even 10 years after treatment. Prevention and therapeutic intervention at an earlier stage before the oncologic process has resulted in cancer changes is necessary to alter the natural evolution of the disease.

Screening for cancer: future potential

Much progress has been made in cancer screening over the past decade, but a great deal more needs to be done if screening is to make a major impact on worldwide cancer mortality. Where fully implemented, cytological screening for cervical precursor lesions has had a major impact on mortality. However, the cost and required infrastructure levels are high, and new approaches are needed if screening is to be effective in the developing world. Testing for the human papillomavirus and automated liquid based cytology offer great promise to improve quality, reduce overall cost and make screening more viable generally. Breast screening has been less successful, although useful mortality benefits have been achieved in women aged over 50 years. Full implementation in countries that can afford it will save lives, but radical new approaches will be needed to conquer breast cancer. Colorectal cancer screening offers the best hope of a major reduction in cancer mortality over the next decade. Less certainty exists about screening for other major cancers such as lung, prostate and ovary, but a range of potential approaches merit investigation.

Abrasive esophageal cytology for the oncological follow-up of patients with head and neck cancer

OBJECTIVES

The occurrence of a second primary cancer in the esophagus in patients with head and neck squamous cell carcinoma is frequent and is associated with a poor prognosis. The aim of this study was to evaluate the yield of abrasive esophageal cytology as a means of screening for metachronous cancer of the upper aerodigestive tract.

STUDY DESIGN

We retrospectively reviewed the results of abrasive esophageal cytology performed twice yearly for the screening of patients with prior head and neck cancer.

METHODS

From 1987 to 1996, 320 patients treated for head and neck cancer underwent 1,673 abrasive cytology examinations of the esophagus during a mean follow-up period of 4 years. Cytological results were classified as negative, suspect, or positive for malignancy.

RESULTS

Twenty-five patients without symptoms had one or more suspect or positive cytologic findings, leading to 29 endoscopic examinations. These revealed 20 premalignant or early malignant lesions of the esophagus (2 dysplasias, 18 squamous cell carcinomas), 2 glandular carcinomas, and 10 clinically unsuspected oral or pharyngeal carcinomas. In seven patients, positive cytological results were associated with clinically visible head and neck cancer. Of the 34 patients with suspect cytological results for malignancy, 10 had no evidence of tumor at endoscopy and 24 had no endoscopic examination because of refusal or because suspected cells were not found in additional examinations. Negative results on cytological examination were found for 254 patients throughout their follow-up, and none of them developed esophageal cancer during a mean follow-up period of 3 years.

CONCLUSIONS

For patients with head and neck cancer, abrasive sponge cytology is useful for detecting esophageal cancer at an early stage. In addition, it may reveal unsuspected second primaries or recurrences in the head and neck region.

Screening for cancer: future potential

Much progress has been made in cancer screening over the past decade, but a great deal more needs to be done if screening is to make a major impact on worldwide cancer mortality. Where fully implemented, cytological screening for cervical precursor lesions has had a major impact on mortality. However, the cost and required infrastructure levels are high, and new approaches are needed if screening is to be effective in the developing world. Testing for the human papillomavirus and automated liquid based cytology offer great promise to improve quality, reduce overall cost and make screening more viable generally. Breast screening has been less successful, although useful mortality benefits have been achieved in women aged over 50 years. Full implementation in countries that can afford it will save lives, but radical new approaches will be needed to conquer breast cancer. Colorectal cancer screening offers the best hope of a major reduction in cancer mortality over the next decade. Less certainty exists about screening for other major cancers such as lung, prostate and ovary, but a range of potential approaches merit investigation.

Mucosal iodine staining improves endoscopic visualization of squamous dysplasia and squamous cell carcinoma of the esophagus in Linxian, China

BACKGROUND

In previous studies in the high risk population of Linxian, China, the majority of foci of high grade (moderate and severe) squamous dysplasia (HGD) and invasive squamous carcinoma (CA) of the esophagus were associated with endoscopically visible lesions that could be targeted for biopsy, but some foci of HGD were missed by routine endoscopic examination. This study examined whether spraying the mucosa with Lugol's iodine solution, which stains normal epithelium brown but leaves dysplasia and carcinoma unstained, could improve endoscopic detection and delineation of these lesions.

METHODS

Two hundred twenty-five Linxian adults with balloon cytologic evidence of dysplasia or carcinoma underwent endoscopy. All visible lesions were described and photographed before and after staining with 1.2% Lugol's iodine solution. Biopsies were taken from all lesions visible before staining, from all unstained lesions (USLs) after applying the stain, and from representative control areas of stained mucosa.

RESULTS

Two hundred fifty-three USLs and 255 control sites were biopsied. No complications occurred. Ninety-four biopsy sites contained HGD and 20 contained CA. Before staining, the sensitivity of visible lesions for identifying HGD or CA was 62%, and the specificity was 79%. After staining, the sensitivity of USLs for identifying HGD or CA was 96%, and the specificity was 63%. Eighty-eight percent of the HGD and CA lesions were larger or more clearly defined after staining. The diagnostic lesions in 17 of 31 patients with moderate dysplasia (55%), 8 of 35 patients with severe dysplasia (23%), and none of the 19 patients with invasive carcinoma (0%) were identified only after staining.

CONCLUSIONS

Mucosal iodine staining improved endoscopic detection and delineation of HGD and CA in these patients. This simple technique is highly sensitive for identifying these precursor and invasive squamous lesions, and it should be used whenever optimal visualization of squamous mucosal abnormalities is required.

Is the cytologic diagnosis of esophageal glandular dysplasia feasible?

Barrett's esophagus is a premalignant condition in which the normal stratified squamous epithelium of the esophagus is replaced by metaplastic glandular epithelium. Patients with Barrett's esophagus are at increased risk for the development of esophageal adenocarcinoma. Because dysplasia precedes the development of frank adenocarcinoma, the cytologic detection of esophageal glandular dysplasia represents a potentially inexpensive and efficient means of monitoring disease progression to adenocarcinoma and identifying high-risk patients. This article discusses the current status of exfoliative cytology as a screening test for glandular dysplasia of the esophagus.

Identification of cytokeratin subspecies altered in rat experimental esophageal tumors by subtractive cloning

By using the subtractive hybridization method, two complementary DNA clones differently expressed in rat normal esophageal epithelium and squamous cell carcinoma induced by administration of precursors of N-nitrososarcosine ethyl ester were isolated. A rat homologue of the human 50-kDa type I cytokeratin 14 was cloned for the first time and shown to be expressed preferentially in squamous cell papillomas and carcinomas, whereas it was weakly expressed or absent in normal squamous epithelial cells and in hyperplastic lesions. A rat homologue of the mouse 57-kDa type II cytokeratin showed strong expression in both normal and tumor tissues. These results are well consistent with the reported alteration of keratin subspecies in human esophageal cancers, therefore, encouraging us to use this experimental system as a model for human esophageal carcinogenesis.

High prevalence of p53 protein overexpression in patients with esophageal cancer in Linxian, China and its relationship to progression and prognosis

BACKGROUND

Linxian is the highest endemic area of esophageal squamous cell carcinoma (ESCC) in China and one of the highest incidence areas in the world. The relationship of p53 protein accumulation to geographic variation, pathologic findings, and prognosis has not been investigated extensively.

METHODS

Formalin fixed, paraffin embedded ESCC tissues from 100 patients who underwent esophagectomy between 1973 and 1983 were immunostained by using monoclonal antibody pAB1801.

RESULTS

p53 overexpression was observed in 41 (87.2%) of 47 tumors of patients in Linxian and in 16 (64%) of 25 additional patients outside Linxian. Its prevalence in the noncancerous epithelium (11/72, 15.3%) and carcinoma in situ (1/7, 14.3%) was lower than that in invasive lesions (64/93, 68.8%). Its immunostaining intensity increased with the depth of cancer invasion. Of 30 primary carcinomas with lymph node metastasis, 29 (96.7%) were positive. However, only 36 (51.4%) of 70 primary lesions without metastasis were positive, and a higher intensity was noticed in the metastases. There was a lower expression rate in tumors of patients surviving more than 10 years (25/52, 48.1%) than in those surviving less than 3 years (40/48, 83.3%). Overall and nonadvanced or metastasis-free cumulative survival rates were both significantly different in patients with and without p53 protein overexpression.

CONCLUSIONS

There is a higher expression rate of p53 protein in ESCC in tumors of patients from Linxian than in those from the surrounding area. The accumulation of p53 protein is related to the invasiveness and capability for metastases of cancer cells and appears to be a useful prognostic factor for patients with ESCC.

Squamous esophageal histology and subsequent risk of squamous cell carcinoma of the esophagus. A prospective follow-up study from Linxian, China

BACKGROUND

Linxian, China, has some of the highest rates of esophageal cancer in the world. Previous authors have proposed that esophagitis, atrophy, and dysplasia may be precursor lesions of esophageal cancer in such high risk populations.

METHODS

To examine the relationship between squamous esophageal histology and subsequent esophageal cancer in Linxian, the authors prospectively followed 682 participants of a 1987 endoscopic survey for 3.5 years and compared their initial biopsy diagnoses with the occurrence of squamous cell carcinoma during this follow-up period.

RESULTS

Squamous cell carcinoma of the esophagus was identified in 52 (7.6%) of the participants during the follow-up period. After adjusting for potential confounding factors, relative risks (95% confidence intervals) for squamous cell carcinoma incidence by initial histologic diagnoses were as follows: normal, 1.0 (reference); basal cell hyperplasia, 2.1 (0.4-9.8); mild dysplasia, 2.2 (0.7-7.5); moderate dysplasia, 15.8 (5.9-42.2); severe dysplasia, 72.6 (29.8-176.9); dysplasia not otherwise specified, 22.9 (6.7-78.0); and carcinoma in situ, 62.5 (24.1-161.9).

CONCLUSION

In this study, moderate dysplasia, severe dysplasia, and carcinoma in situ were the only histologic lesions associated with a significantly increased risk of developing squamous cell carcinoma of the esophagus within 3.5 years after endoscopy. Increasing grades of dysplasia were associated with increasing risk, but severe dysplasia were associated with increasing risk, but severe dysplasia and carcinoma in situ had similar degrees of risk, findings that suggest a continuous spectrum of esophageal intraepithelial neoplasia, without morphologically distinguishable dysplasia and in situ carcinoma. A longer follow-up will be necessary to fully evaluate the less severe diagnostic categories, which may take more than 3.5 years to affect the occurrence of squamous cell carcinoma in this high risk population.

Squamous esophageal histology and subsequent risk of squamous cell carcinoma of the esophagus. A prospective follow-up study from Linxian, China

BACKGROUND

Linxian, China, has some of the highest rates of esophageal cancer in the world. Previous authors have proposed that esophagitis, atrophy, and dysplasia may be precursor lesions of esophageal cancer in such high risk populations.

METHODS

To examine the relationship between squamous esophageal histology and subsequent esophageal cancer in Linxian, the authors prospectively followed 682 participants of a 1987 endoscopic survey for 3.5 years and compared their initial biopsy diagnoses with the occurrence of squamous cell carcinoma during this follow-up period.

RESULTS

Squamous cell carcinoma of the esophagus was identified in 52 (7.6%) of the participants during the follow-up period. After adjusting for potential confounding factors, relative risks (95% confidence intervals) for squamous cell carcinoma incidence by initial histologic diagnoses were as follows: normal, 1.0 (reference); basal cell hyperplasia, 2.1 (0.4-9.8); mild dysplasia, 2.2 (0.7-7.5); moderate dysplasia, 15.8 (5.9-42.2); severe dysplasia, 72.6 (29.8-176.9); dysplasia not otherwise specified, 22.9 (6.7-78.0); and carcinoma in situ, 62.5 (24.1-161.9).

CONCLUSION

In this study, moderate dysplasia, severe dysplasia, and carcinoma in situ were the only histologic lesions associated with a significantly increased risk of developing squamous cell carcinoma of the esophagus within 3.5 years after endoscopy. Increasing grades of dysplasia were associated with increasing risk, but severe dysplasia were associated with increasing risk, but severe dysplasia and carcinoma in situ had similar degrees of risk, findings that suggest a continuous spectrum of esophageal intraepithelial neoplasia, without morphologically distinguishable dysplasia and in situ carcinoma. A longer follow-up will be necessary to fully evaluate the less severe diagnostic categories, which may take more than 3.5 years to affect the occurrence of squamous cell carcinoma in this high risk population.

Esophageal balloon cytology and subsequent risk of esophageal and gastric-cardia cancer in a high-risk Chinese population

Linxian, China has some of the highest rates of esophageal/gastric cardia cancer in the world. In 1983, esophageal balloon cytology screening was performed in 3 communes in northern Linxian. Of the participants, 10,066 with no evidence of cancer were followed prospectively for 7 1/2 years to evaluate the ability of the initial cytologic diagnoses to identify individuals at increased risk for developing cancer of the esophagus or gastric cardia. A total of 747 incident cases of esophageal or cardia cancer and 322 deaths due to these tumors were identified during the follow-up period and used in this analysis. The risks for esophageal or cardia cancer incidence and mortality increased in parallel with the presumed severity of the 1983 Chinese cytologic diagnoses. After adjusting for potential confounding factors, relative risks for esophageal or cardia cancer incidence, by initial cytologic diagnosis, were normal = 1.00 (reference), hyperplasia = 1.25, dysplasia 1 = 2.20, dysplasia 2 = 4.22 and near-cancer = 5.96. Our results suggest that esophageal balloon cytology, as performed and interpreted in Linxian in 1983, successfully identified individuals at increased risk for developing cancer of the esophagus or gastric cardia.

The effect of vitamin and mineral supplementation on esophageal cytology: results from the Linxian Dysplasia Trial

The population of Linxian in China has one of the world's highest rates for esophageal/gastric cardia cancer, as well as documented nutritional deficiencies. To determine whether dietary supplementation with a multi-vitamin multi-mineral preparation could reduce the risk of esophageal cancer and favorably influence precursor lesions, 3,318 individuals age 40-69 with cytologically determined grade 1 or grade 2 esophageal dysplasia were randomly assigned to receive either an active multi-vitamin multi-mineral supplement or a placebo. Pills were distributed at monthly visits and incident cancers or deaths were recorded. At 30 and 72 months subsequent to randomization all living participants without a known incident cancer were asked to undergo repeat cytological examination of their esophagus. Based on these procedures participants were classified as having no dysplasia, dysplasia grade 1, dysplasia grade 2 or near cancer dysplasia. Diagnoses of cancer were based on the cytology findings plus available histologic, radiologic and clinical materials. At the end of the study there was little overall difference in cumulative risk of esophageal cancer between those receiving vitamin/mineral supplementation and those receiving placebo. There was, however, a significant increase in reversion to non-dysplastic cytology among the group receiving the active treatment. The odds of not having any dysplasia at the two post-randomization screens was 1.23 times higher in the active treatment group than in the placebo group. Within each treatment group higher categories of dysplasia were associated with higher rates of cancer.

Esophageal morphology from Linxian, China. Squamous histologic findings in 754 patients

BACKGROUND

Linxian, China, has one of the highest rates of esophageal cancer in the world. Other authors have described high prevalences of histologic esophagitis, atrophy, and dysplasia in Linxian and have suggested that these findings may represent precancerous lesions in this population. In 1987, a new endoscopic survey allowed the authors to make an independent study of esophageal histology in Linxian.

METHODS

There were 1567 satisfactory squamous esophageal biopsies available from 754 patients. These biopsies were classified as normal, atrophy, acanthosis, esophagitis, squamous dysplasia, or squamous cancer.

RESULTS

Classified by their worst diagnosis, 56.5% of the 754 patients had normal mucosa, 0.0% atrophy, 11.5% acanthosis, 4.6% esophagitis, 22.7% squamous dysplasia, and 4.6% squamous cancer.

CONCLUSIONS

The results show a different distribution of esophageal squamous diagnoses than has been reported previously from this population. The authors believe that the major reason for this discrepancy was differences in histologic criteria. In this survey, seemingly small differences in criteria could cause large differences in apparent disease prevalence; this was especially true for esophagitis. By the criteria used in this study, histologic esophagitis and atrophy are uncommon findings in Linxian, raising questions about their significance as precursor lesions of esophageal cancer in this population.

Linxian nutrition intervention trials. Design, methods, participant characteristics, and compliance

Two nutrition intervention trials were conducted in Linxian, China, where the esophageal/gastric cardia cancer mortality rates are among the highest in the world and there is suspicion that the population's chronic deficiencies of multiple nutrients are etiologically involved. Both trials were randomized, double-blind, and placebo-controlled, and tested the effect of multiple-vitamin and multiple-mineral supplements in lowering the rates of cancer. In the first trial, the Dysplasia Trial, 3318 individuals with a cytologic diagnosis of esophageal dysplasia received daily vitamin and mineral supplements or placebos for 6 years. The second trial, the General Population Trial, involved 29,584 individuals and used a one-half replicate of a 2(4) fractional factorial design, which enabled the testing of daily supplementation of four different vitamin and mineral combinations and placebo for a period 5 1/4 years. This article describes the design and methods of these studies as well as the baseline characteristics and compliance behavior of the participants in these two trials, the largest cancer chemoprevention studies reported to date.