Gastric-type adenocarcinoma of the uterine cervix presenting in urine cytology specimens: A case report and literature review

Gastric-type endocervical adenocarcinoma (GEA) is a rare type adenocarcinoma of the uterine cervix that is unrelated to human papillomavirus (HPV). GEA is difficult to diagnose due to its bland-looking morphological characteristics and is therefore often underdiagnosed. Although abnormal cells may be seen on cervical cytology specimens, they are rarely diagnosed as malignant and are often classified as atypical glandular cells. As a result, GEA may be diagnosed at advanced stages, with cytology samples from other organs after it has already invaded adjacent organs. Here, we report a case of GEA diagnosed by both cytological and histological examinations of urinary bladder and uterine cervix, after being identified as a non-urothelial malignancy on a urine cytology. We also review and summarize the differential diagnoses for non-urothelial lesions, particularly for glandular lesions observed on urinary cytology specimens, as well as the cytological and histological characteristics of GEA.

Usefulness of the human papillomavirus DNA chip test as a complementary method for cervical cytology

Objectives

As a convenient and economical method of screening cervical cancer and precancerous pathologies, the Papanicolaou smear (Pap smear) has been most widely used. Nevertheless, it requires cytological changes for making diagnoses and reportedly has a high false-negative rate. In this study, the usefulness of the human papillomavirus (HPV) DNA chip test as a complementary method that can compensate for the defect of the Pap smear was investigated.

Material and Methods

Of the 6516 patients who simultaneously underwent a Pap smear and an HPV DNA chip test at Chonnam National University Hospital between January 2015 and December 2016, 1897, an initial PAP smear-negative patients who had undergone an additional Pap smear during their 2-year follow-up period were selected for this study. Of the subject patients, 281 underwent a cervical biopsy.

Results

The Pap smear follow-up of an initial Pap smear-negative subjects showed 53 (75.7%) HPV high-risk positive cases in the cytology low-grade lesion group (70 cases) and 46 (97.8%) HPV high-risk positive cases in the cytology high-grade lesion group (47 cases). The 281 biopsy cases included 67 biopsy low-grade lesion cases and 74 biopsy high-grade lesion cases, of which there were 45 (67.2%) and 67 (90.5%) HPV high-risk positive cases, respectively. The follow-up cytology on the high-risk HPV-positive subjects showed that the ratio of their high-grade lesions was 260.8 times greater than that of the high-risk HPV-negative subjects (OR = 260.8 and 95% CI: 36.1 and 1886.1); and their biopsy showed that the ratio of their high-grade lesions was 102.7 times greater than that of the HPV-negative subjects (OR = 102.7 and 95% CI: 14.0 and 753.3).

Conclusion

The complementary use of the HPV DNA chip test may be useful in increasing the accuracy of screening examinations for the early diagnosis of uterine cervix cancer when combined with the Pap smear.

Clinical impact of intravascular ultrasound guidance in patients of ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention with drug eluting stent

Background

There is little data about clinical role of intravascular ultrasound (IVUS)-guided Percutaneous (PCI) in the setting of ST-segment elevation myocardial infarction (STEMI).

Methods

From 2005 to 2018, a total of 8,129 patients who underwent PCI with STEMI were investigated from the Korea Acute Myocardial Infarction Registry-National Institute of Health database. Patients with Non-ST segment elevation myocardial infarction, cardiogenic shock, bare metal stent implantation, thrombolytic treatment, and coronary artery bypass graft surgery were excluded. We categorized patients into two groups based on the treatment strategy: IVUS-guided PCI group (n=1,544), and coronary angiography guidance (CAG)-guided PCI group (n=6,585). The primary endpoint was composite of major adverse cardiovascular (MACE), including, cardiac death, myocardial infarction (MI), repeat target vessel revascularization (TVR) and stent thrombosis (ST).

Results

IVUS-guided PCI was performed in 19% patients (1544/8129). After propensity score matching, there were no statistically difference in the rate of cardiac death (0% in IVUS vs. 0.26% in CAG, p=0.947), MI (2.01% vs. 2.01%, p=0.408), TVR (1.23% vs. 0.91%, p=0.131), ST (0.32% vs. 0.45%, p=0.828) and composite of MACE at 1 year between two groups (2.01% vs. 2.40%, p=0.843). Independent risk factors for MACE were diabetes mellitus and multi-vessel disease, but not IVUS-guided PCI (HR 1.167, 95% CI, 0.896–1.520, p=0.251).

Conclusion

This study suggests that routine usage of IVUS in the setting of STEMI may not be necessary. Large-scaled random study will be needed for further evaluation.

Funding Acknowledgement

Type of funding sources: None.

Recent advances in vaccines and diagnostics against Middle East respiratory syndrome coronavirus

Middle East respiratory syndrome coronavirus (MERS-CoV) is an RNA virus that causes severe respiratory disease. Since it was identified in 2012, approximately 2500 MERS cases with high mortality have been confirmed in 27 countries. Although most cases have occurred in the Middle East, an outbreak in South Korea in 2015 showed that MERS could be a global threat via human-to-human transmission. There is no licensed vaccine against MERS. Thus, early detection is the best way to limit the spread of this fatal disease. In this review, we focus on transmission, the infection process, and scientific efforts in vaccine development and diagnostics for MERS-CoV. Keywords: Middle East respiratory syndrome coronavirus; epidemiology; virology; vaccine; diagnostics.

A case of large cell neuroendocrine carcinoma of the uterine cervix misdiagnosed as adenocarcinoma in Thinprep cytology test

Large cell neuroendocrine carcinoma (LCNEC) of uterine cervix is a rare malignancy with aggressive behavior and poor clinical outcome even in its early stage. Few cytopathologic features of cervical LCNEC have been reported previously. A 57-year-old postmenopausal African American female, presented to the local health department with a chief complaint of heavy vaginal bleeding. A 45-year-old female presented with 20 months of vaginal pruritus and foul odor. Cervical malignancy was suspected by pelvis magnetic resonance imaging. Thinprep cytology test demonstrated ball-like tumor cell clusters in a necrotic background. Cytologic diagnosis of adenocarcinoma was rendered. However, the histologic and immunohistochemical examination of cervical biopsy revealed the LCNEC of the uterine cervix. Due to its rarity, LCNEC may pose a diagnostic challenge in cervical cytology. Cytopathologists should pay attention to the cytological features of cervical LCNEC, such as rosettoid pattern, nuclear molding, and thin nuclear membrane for differentiation from other mimics.

Diagnostic Utility of a Clonality Test for Lymphoproliferative Diseases in Koreans Using the BIOMED-2 PCR Assay

Background

A clonality test for immunoglobulin (IG) and T cell receptor (TCR) is a useful adjunctive method for the diagnosis of lymphoproliferative diseases (LPDs). Recently, the BIOMED-2 multiplex polymerase chain reaction (PCR) assay has been established as a standard method for assessing the clonality of LPDs. We tested clonality in LPDs in Koreans using the BIOMED-2 multiplex PCR and compared the results with those obtained in European, Taiwanese, and Thai participants. We also evaluated the usefulness of the test as an ancillary method for diagnosing LPDs.

Methods

Two hundred and nineteen specimens embedded in paraffin, including 78 B cell lymphomas, 80 T cell lymphomas and 61 cases of reactive lymphadenitis, were used for the clonality test.

Results

Mature B cell malignancies showed 95.7% clonality for IG, 2.9% co-existing clonality, and 4.3% polyclonality. Mature T cell malignancies exhibited 83.8% clonality for TCR, 8.1% co-existing clonality, and 16.2% polyclonality. Reactive lymphadenitis showed 93.4% polyclonality for IG and TCR. The majority of our results were similar to those obtained in Europeans. However, the clonality for IGK of B cell malignancies and TCRG of T cell malignancies was lower in Koreans than Europeans.

Conclusions

The BIOMED-2 multiplex PCR assay was a useful adjunctive method for diagnosing LPDs.

Harnessing the beneficial properties of adipogenic microbes for improving human health

Obesity is associated with numerous metabolic comorbidities. Weight loss is an effective measure for alleviating many of these metabolic abnormalities. However, considering the limited success of most medical weight-management approaches in producing a sustained weight loss, approaches that improve obesity-related metabolic abnormalities independent of weight loss would be extremely attractive and of practical benefit. Metabolically healthy obesity supports the notion that a better metabolic profile is possible despite obesity. Moreover, adequate expansion of adipose tissue appears to confer protection from obesity-induced metabolic comorbidities. To this end, the 10th Stock conference examined new approaches to improve metabolic comorbidities independent of weight loss. In particular, human adenovirus 36 (Ad36) and specific gut microbes were examined for their potential to influence lipid and glucose homeostasis in animals and humans. While these microbes possess some undesirable properties, research has identified attributes of adenovirus Ad36 and gut microbes that may be selectively harnessed to improve metabolic profile without the obligatory weight loss. Furthermore, identifying the host signalling pathways that these microbes recruit to improve the metabolic profile may offer new templates and targets, which may facilitate the development of novel treatment strategies for obesity-related metabolic conditions.

Multiple peripheral typical carcinoid tumors of the lung: associated with sclerosing hemangiomas

Abstract

This study presents a first case of multiple peripheral typical carcinoid tumors associated with sclerosing hemangiomas in the lung. A 52-year-old male presented with incidentally detected multiple pulmonary nodules on a simple chest X-ray during routine health check-up. A computed tomography (CT) scan of the chest showed multiple nodular lesions in the middle and lower lobes of the right lung. These were initially suspected as inflammatory lesions due to miliary tuberculosis. However, possibility of malignancy could not be excluded and right lower lobe lobectomy was performed. Histopathologically, some nodules including two largest nodules were composed of small round to spindle shaped cells with fine chromatin pattern, whereas the rest of the sclerotic nodules were composed of two epithelial cell types- surface cells and round cells. The final diagnosis of this case was multiple peripheral typical carcinoid tumors associated with sclerosing hemangiomas of the lung. For past three years of post-surgery follow up period, no new lesions or changes in the right middle lobe have been identified.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1511610609725790.

Interleukin-13/-4-induced oxidative stress contributes to death of hippocampal neurons in aβ1-42-treated hippocampus in vivo

AIMS

The present study examined whether Aβ(1-42) can induce endogenous expression of interleukin-13 (IL-13) or (IL-4) within activated microglia in the rat hippocampus in vivo. We further investigated whether these cytokines mediate ROS/RNS generation through activation of NADPH oxidase and/or inducible nitric oxide synthase (iNOS), and thus contribute to the degeneration of hippocampal neurons in vivo.

RESULTS

Here, we show that IL-13 and IL-4, endogenously expressed in Aβ(1-42)-activated microglia in hippocampus in vivo, contribute to degeneration of hippocampal neurons in vivo. Neutralization of IL-13 and IL-4 protected hippocampal neurons in vivo against neurotoxicity by inhibiting activation of microglial NADPH oxidase and iNOS, resulting in attenuation of ROS generation and oxidative damage of protein, lipid and DNA.

INNOVATION

To our knowledge, this is the first study to demonstrate the possible involvement of endogenously expressed IL-13 and/or IL-4 in activated microglia after Aβ(1-42) injection in the degeneration of hippocampal neurons in vivo. The current findings suggest that the deleterious effects of microglia-derived endogenous IL-13 and/or IL-4 are involved in oxidative stress-mediated neurodegenerative diseases, such as AD.

CONCLUSION

We carefully hypothesize that IL-13 and IL-4, well-known as anti-inflammatory cytokines might serve as neurotoxic mediators by enhancing microglia-derived oxidative stress in Aβ(1-42)-treated hippocampus in vivo.

Mucin-positive epithelial mesothelioma of the peritoneum: small bowel involvement

Mucin-positive epithelial mesothelioma has been reported in the peritoneum only once, and that mainly involved the stomach wall. We report the second peritoneal case and this is the first case mainly involving the small bowel wall. A 65-year-old man showed diffuse involvement from the duodenum to the ileum and metastatic masses in the left adrenal gland. Segmental resection of the small bowel was performed; 2 months later the patient died. Light microscopy showed diffusely anaplastic epithelioid cell proliferation and foci of glandular formation with granular mucinous materials in the cytoplasmic vacuoles or within glandular lumina. Histochemically, these mucin materials were PAS-positive and diastase-resistant. Immunohistochemically, the various mesothelial markers were positive, and a few adenocarcinoma markers were focally positive. Ultrastructurally, the tumor cells showed long slender microvilli on the apical surface, consistent with mesothelioma. Electron microscopy can play a decisive role in the case of ambiguous histochemical and immunohistochemical results.

High-grade oncocytic mucoepidermoid carcinoma of the minor salivary gland origin: a case report with immunohistochemical study

An oncocytic mucoepidermoid carcinoma arising from the minor salivary gland origin is extremely rare. We report on a 44-year-old man with a high-grade oncocytic mucoepidermoid carcinoma originating in the minor salivary gland of the posterior mandible. All tumor cells showed the expected pattern of immunoreactivity, with positive results for the antimitochondrial antibody and p63, and negative results for the androgenic receptor antibody. Microscopically, the tumor was considered to be a high-grade carcinoma in the grading systems of the Armed Forces Institute of Pathology and Brandwein. The patient underwent a partial mandibulectomy, and the lesion was reconstructed with a right fibula osteofasciocutaneous flap under general anesthesia. The patient is currently under long-term follow-up.

All-trans retinoic acid inhibits the differentiation, maturation, and function of human monocyte-derived dendritic cells

All-trans retinoic acid (ATRA) affects on the function of antigen presenting cells with somewhat controversies. We investigated the effects of ATRA on differentiation, maturation and function of human monocyte-derived dendritic cells (DCs). Low dose (10(-14)M) or high dose (10(-6)M) of ATRA was added either when monocytes were differentiated into immature DCs (imDCs) or mature DCs (mDCs) were induced. Apoptotic cell populations were dramatically increased in imDCs or mDCs with increasing concentration of ATRA. The productions of IL-12p40 and IL-12p70 were significantly suppressed in imDCs or mDCs induced by the addition of ATRA in the dose-dependent manner, whereas IL-10 was increased. DCs cultured with ATRA induced the differentiation of naïve T cells towards a helper T cell type 2 (Th2) response and expansion of CD4(+)CD25(+)Foxp3(+) regulatory T cells. Allostimulatory capacity of DCs was suppressed with increasing concentration of ATRA. These findings suggest that ATRA inhibits the effects on the differentiation, maturation and function of human monocyte-derived DCs in vitro and also enhance the differentiation of naïve T cell toward the Th2 type.

Immunocytochemical panel for distinguishing between adenocarcinomas and reactive mesothelial cells in effusion cell blocks

The aim of our study was to determine the value of a panel that consisted of one epithelial marker (MOC-31) and two mesothelial markers (D2-40 and calretinin) for distinguishing between reactive mesothelial cells (RMCs) and adenocarcinomas (ACs) in effusion fluids. A total of 118 cell block specimens from pleural and peritoneal effusions, including 88 ACs and 30 benign effusions with RMCs were stained with antibodies against MOC-31, D2-40, and calretinin. MOC-31 membranous activity was observed in all samples from ACs, regardless of the primary tumor site. All benign effusion samples with RMCs were negative for MOC-31. All benign effusion samples with RMCs exhibited membranous staining for D2-40, and one AC case had focal reactivity for D2-40. Almost all benign effusions reacted positively with calretinin. Staining was noted in both the cytoplasm and the nucleus in the majority of cases. Scattered tumor cells had weak calretinin positivity in two AC cases. Background RMCs in AC effusions were consistently positive for D2-40 and calretinin. In general, D2-40 identified more RMCs than calretinin. The staining combination of positive for MOC-31 and negative for D2-40 or calretinin were 100% specific and 99% sensitive for ACs. Our data suggest that immunohistochemical studies performed on cell blocks with MOC-31, D2-40, and calretinin were useful in the differentiation between ACs and RMCs. D2-40 was a more sensitive marker for RMCs than calretinin.

Abundant cartilage formation of congenital pulmonary airway malformation--a case report

Congenital pulmonary airway malformation (CPAM) of the lung is an uncommon developmental anomaly. We report an unusual case of type 1 CPAM with abundant cartilage in a 5-year-old boy. On chest radiography, a left lung mass was detected incidentally, and tumor resection was performed under the impression of a benign tumor. The pathological examination of the mass revealed abundant cartilage in the walls of malformed bronchioles with partially cystic dilatation. We think that this case represents a cartilaginous variant of CPAM. The cartilaginous variant of CPAM should be differentiated pathologically from other pulmonary neoplasms containing abundant cartilage, such as chondroid hamartoma.

Small cell carcinoma of the uterine cervix: clinicopathologic study of 20 cases in a single center

PURPOSE

To investigate clinicopathologic findings of patients with small cell carcinoma of the uterine cervix (SCCUC), and evaluate their prognosis.

METHODS

We retrospectively reviewed the medical records of 20 patients with histologically confirmed SCCUC treated between October 1996 and December 2004 at Asan Medical Center, Korea. The review included demographic data, pathologic findings, treatments, and outcomes.

RESULTS

Of 1,358 invasive cervical carcinoma, the incidence of SCCUC was 1.5%. Median age was 45.5 years. The clinical stages were Ib in 11, IIa in two, IIb in one, IIIa in one, IIIb in one, IVa in three and IVb in one. Fourteen patients underwent radical hysterectomy. Ten patients are alive and nine show no evidence of disease. Median overall survival was 77.0 months and 5-year overall survival rate was 50%. There was significant difference in overall survival with FIGO stage and tumor mass size.

CONCLUSION

Advanced FIGO stage and tumor mass size are poor prognostic factors for overall survival in patients with SCCUC. Even though SCCUC is a highly aggressive neoplasm, early diagnosis and combined therapeutic modalities may lead to longer survival in some patients.

Monocyte-derived dendritic cells from HLA-matched allogeneic donors showed a greater ability to induce leukemic cell-specific T cells in comparison to leukemic cell-derived dendritic cells or monocyte-derived dendritic cells from AML patients

We investigated the usefulness of allogeneic monocyte-derived dendritic cells (allogeneic mDCs) pulsed with leukemic lysates in acute myeloid leukemia (AML). Allogeneic mDCs showed higher expressions of several molecules (HLA-DR, CD80, CD83 or CD86), higher production of IL-12 and higher capacity to stimulate allogeneic T cells compared to both leukemic DCs and autologous mDCs. Autologous T cells primed by allogeneic mDCs displayed a larger number of interferon-gamma-secreting cells against leukemic cells than those primed by either leukemic DCs or autologous mDCs. These results suggest that monocyte-derived DCs from HLA-matched allogeneic donors can be used as an alternative to generate leukemia-specific cytotoxic T cells and to overcome the limitation of leukemic DCs or autologous mDCs.

Effectiveness of sputum cytology using ThinPrep method for evaluation of lung cancer

Sputum cytology is a non-invasive test for evaluating lung cancer. But, its sensitivity is yet lower than other tests. ThinPrep (TP) is an automated cytopreparatory method that has mucolytic and hemolysing effects. We compared 955 sputum specimens that were prepared by both TP and conventional preparation (CP). The nuclear details were more preserved on the TP slides, while the obscuring materials were more eliminated on the TP slides as compared with the CP. The cytologic rates of TP were 2.7% unsatisfactory, 4.7% normal, 81.0% benign, 2.4% suspicious, and 9.1% malignancy. The rates of CP were 7.9% unsatisfactory, 1.6% normal, 84.8% benign, 1.8% suspicious, and 4.0% malignancy. The false negative rates, relative to the histologic data for 352 cases which the tissue diagnosis was available, were 49.6% (TP) and 69.4% (CP). Sputum cytology using the TP method improves the diagnostic accuracy for evaluating lung cancer by reducing the unsatisfactory and false-negative rates.

Real-time RT-PCR of Hantaan virus RNA used for the detection of virus response to antiviral drugs

Hantaan virus (HTN) is an important cause of hemorrhagic fever with renal syndrome (HFRS) in Korea. HTN RNA can be detected with the RT-PCR and the quantity of HTN RNA in infected cells can be measured by competitive RT-PCR. The current study used the real-time RT-PCR for the detection of viral RNA S gene in a more detailed fashion than in the previous study (Nam et al., Virus Genes 26, 31-38, 2003). A standard curve was generated with serial 10-fold dilutions of the HTN RNA. The sensitivity of RNA detection was approximately 10 PFU of HTN. The cells infected with HTN were treated with the antiviral drugs ribavirin, zidovudine, and amantadine. 24 hrs after infection, real-time RT-PCR was used to detect the HTN RNA synthesized in the infected cells. No viral RNA was detected in the HTN-infected cells treated with antiviral drugs, but HTN RNA was detected in untreated HTN-infected cells. This finding suggested that real-time RTPCR should be used for the detection of antiviral activity against HTN.

Optimization and limitation of calcium ionophore to generate DCs from acute myeloid leukemic cells

PURPOSE

Calcium ionophore (CI) is used to generate dendritic cells (DCs) from progenitor cells, monocytes, or leukemic cells. The aim of this study was to determine the optimal dose of CI and the appropriate length of cell culture required for acute myeloid leukemia (AML) cells and to evaluate the limitations associated with CI.

MATERIALS AND METHODS

To generate leukemic DCs, leukemic cells (4x10(6) cells) from six AML patients were cultured with various concentrations of CI and/or IL-4 for 1, 2 or 3 days.

RESULTS

Potent leukemic DCs were successfully generated from all AML patients, with an average number of 1.2x10(6) cells produced in the presence of CI (270 ng/ml) for 2 days. Several surface molecules were clearly upregulated in AML cells supplemented with CI and IL-4, but not CD11c. Leukemic DCs cultured with CI had a higher allogeneic T cell stimulatory capacity than untreated AML cells, but the addition of IL-4 did not augment the MLR activity of these cells. AML cells cultured with CI in the presence or absence of IL-4 showed increased levels of apoptosis in comparison to primary cultures of AML cells.

CONCLUSION

Although CI appears to be advantageous in terms of time and cost effectiveness, the results of the present study suggest that the marked induction of apoptosis by CI limits its application to the generation of DCs from AML cells.

Association of CD94/NKG2A, CD94/NKG2C, and its ligand HLA-E polymorphisms with Behcet's disease

Inhibitory CD94/NKG2A and activating CD94/NKG2C receptors are expressed on natural killer, CD4, and CD8 T cells and recognize human leukocyte antigen (HLA)-E, resulting in the modulation of cytotoxic activity and cytokine production. An imbalance in cytotoxic activity and cytokine production has been implicated in Behcet's disease (BD). The results of this study showed that the NKG2A c.-4258*C, c.338-90*G, and CD94 c.-134*T alleles (P= 0.015, OR = 0.8; P < 0.0001, OR = 0.5; and P= 0.034, OR = 0.8, respectively) were associated with decreased risk and that NKG2A c.284-67_-62del, c.1077*C, and the activating receptor, NKG2C c.305*T were not associated with 345 patients with BD. But a significant difference in NKG2C c.305*T was detected among BD patients with ocular lesions and arthritis (P < 0.0001, OR = 2.1 and P= 0.0001, OR = 1.8, respectively). We already showed in our previous research that HLA-E*0101 also appears to contribute to a reduction in risk through the inhibitory CD94/NKG2A-mediated immune response. This result led us to the analyses of the combined risk of the HLA-E and the NKG2A for BD. Individuals harboring HLA-E*0101, NKG2A c.-4258*C, and c.338-90*G evidenced a reduced risk of BD compared with healthy controls (21.1% vs 40.1%, P < 0.0001, OR = 0.4). By way of contrast, individuals without the HLA-E*0101, NKG2A c.-4258*C, and c.338-90*G alleles evidenced a twofold increased risk of BD (P= 0.014, OR = 2.0). Individuals without HLA-E*0101, NKG2A c.-4258*G/*G, and c.338-90*G evidenced a 4.8-fold increase in BD risk (P= 0.0002, OR = 4.8). Although the effects of these single nucleotide polymorphisms (SNPs) remain unclear, our results indicate that the SNPs of the inhibitory receptor CD94/NKG2A and its haplotypes, as well as its ligand HLA-E, are associated with BD immune systems.

HLA-E*0101 and HLA-G*010101 reduce the risk of Behcet's disease

The nonclassical human leukocyte antigen (HLA)-E and -G molecules have previously been shown to inhibit natural killer- and cytotoxic T-lymphocyte-mediated cell lysis and have also been shown to prevent the proliferation of CD4 T cells and secrete cytokines that appear to be important in the modulation of the Behcet's disease (BD) immune systems. Polymorphisms in the HLA-E and HLA-G genes have been associated with differential expression and function. Thus, we conducted an analysis of the HLA-E and HLA-G alleles using Amplification Refractory Mutation System-polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism techniques in a study comprising 312 patients with BD and 486 controls. The HLA-E*0101 and HLA-G*010101 alleles were associated with a reduced risk of BD (P = 0.0002, odds ratio (OR) = 0.7 and P = 0.002, OR = 0.7, respectively). By way of contrast, the variants HLA-E*010302, HLA-G*010102, G*0105N alleles and 3741_3754ins14bp were all associated with an increased risk of BD (P < 0.0001, OR = 1.6; P = 0.002, OR = 1.8; P = 0.024, OR = 2.0 and P = 0.003, OR = 1.4, respectively). Individuals carrying both the HLA-E*0101 and the HLA-G*010101 alleles evidenced significantly lower frequency in the patients than in the controls (35.6% vs 49.6%; P < 0.0001, OR = 0.6). These results indicate that variant HLA-E and HLA-G molecules appear to function independently and synergistically, increasing the risk of BD, and may result in an imbalance of lymphocytic functions, which may culminate in the development of BD.

Human papillomavirus genotyping using HPV DNA chip analysis in Korean women

This study was designed to investigate the genotypes of human papillomavirus (HPV) in Korean women who had abnormal cervical cytology and to evaluate the clinical accuracy of HPV DNA chip analysis for the diagnosis of cervical neoplasia. Liquid-based cytology preparations, HPV DNA chip analysis, and cervical biopsy were performed in 2358 women. High-risk HPV was identified in 23.5% of 1650 histologically confirmed normal samples (including cervicitis and squamous metaplasia) and in 81.8% of 708 samples with cervical intraepithelial neoplasia (CIN) and carcinoma (P< 0.01). The major prevalent high-risk HPV genotypes in 381 samples of CIN II/III were HPV-16, -58, -33, and -31, in order of prevalence rate (average overall, 78.0%), and HPV-16, -18, -58, and -33 (average overall, 81.2%) in 133 samples of squamous cell carcinoma (SCC). The infection rate of HPV-16 was significantly higher than that of other high-risk HPV genotypes in all normal, CIN, and SCC cases (P< 0.01) and increased with more advanced squamous cervical lesions (P< 0.01). The detection accuracy of high-risk HPV using HPV DNA chip analysis for CIN II or worse was as follows: sensitivity 84% (81–87%), specificity 72% (70–74%), positive predictive value 47% (44–50%), and negative predictive value 94% (92–95%). These results suggest that HPV DNA chip analysis may be a reliable diagnostic tool for the detection of cervical neoplasia and that there are geographic differences in the distribution of high-risk HPV genotypes.

Down-regulation of cellular vascular endothelial growth factor levels induces differentiation of leukemic cells to functional leukemic-dendritic cells in acute myeloid leukemia

We examined the effect of cellular vascular endothelial growth factor (VEGF) levels on the generation of leukemic dendritic cells (DCs). Leukemic DCs were successfully generated in vitro from bone marrow cells of 16 of 21 acute myeloid leukemia (AML) patients, and the cellular VEGF concentrations in the leukemic cells and the neutralization of VEGF with anti-VEGF antibody were determined. AML cells that failed to generate leukemic DCs showed significantly higher cellular VEGF levels compared with generated leukemic DCs, and down-regulation of cellular VEGF levels induced the generation of leukemic DCs from AML cells. Inhibition of cellular VEGF levels increased interleukin (IL)-12 production and the allostimulatory capacity of leukemic DCs. These results suggest that the generation of leukemic DCs from AML cells is inversely related to the VEGF production of the cells and that the down-regulation of cellular VEGF levels can induce potential differentiation of leukemic cells to functional leukemic DCs in patients with AML.

Optimization of the concentration of autologous serum for generation of leukemic dendritic cells from acute myeloid leukemic cells for clinical immunotherapy

Clinical application of immunotherapy for acute myeloid leukemia (AML) requires the efficient induction of dendritic cells (DCs) from AML blast cells using in vitro culture. We examined the effect of autologous serum on the properties of leukemic DCs derived from leukemic cells of AML patients by culture in AIM-V medium with GM-CSF, IL-4, TNF-alpha, and 0, 2, 5, or 10% human autologous serum. The expressions of CD80, CD83, CD86, and HLA-DR were upregulated under all culture conditions; however, 10% autologous serum induced the highest expression levels of several molecules. The capacity of leukemic DCs to stimulate allogeneic T cells increased with increasing serum concentration. Stimulation of autologous CD3(+) T cells with leukemic DCs grown in the presence of various concentrations of autologous serum resulted in induction of more IFN-gamma-secreting cells than was the case for unprimed CD3(+) T cells. Leukemic DCs cultured with 10% autologous serum induced the highest numbers of IFN-gamma-secreting cells and CD8(+)CD56(+) T cells from autologous T cells. These results suggest that culture of AML blast cells in the presence of autologous serum could be used to generate leukemic DCs for immunotherapy against AML. The highest serum concentration appeared optimal for generating the most potent leukemic DCs.

Minimization of immunosuppressive therapy after islet transplantation: combined action of heme oxygenase-1 and PEGylation to islet

We previously established a type of PEGylated islets to attenuate cellular immune reactions by immobilizing polyethylene glycol (PEG) molecules on islet surfaces, thereby synergistically reducing the dose of immunosuppressant cyclosporine A (CsA; 3 mg/kg/day) to protect transplanted islets. However, higher doses of immunosuppressants should be administered after islet transplantation due to nonspecific inflammation. This study documents that PEGylated islets can be cooperatively protected by the systemic overexpression of heme oxygenase-1 (HO-1), which has a potent cytoprotective function in preventing nonspecific inflammation during an early stage following islet transplantation. Under this scheme, the viability of PEGylated islets was improved; that is, PEG molecules could block cellular immunity and HO-1 could exert its cytoprotective property against inflammation. Interestingly, when employed with a low dose of CsA (1 mg/kg/day), a cooperative action of PEG molecules and HO-1 in immune reactions could result in the complete survival of transplanted islets for 100 days without islet function impairment. However, unmodified islets (control) were completely rejected within 2 weeks despite cotreatment with HO-1 expression and CsA. These results demonstrated that the combinatorial protocol of initial induction of HO-1 expression, followed by the daily administration of a low dose CsA after transplantation of PEGylated islets can be employed as a successful cell therapy in clinical islet transplantation.

Expression of cyclooxygenase-2 in breast carcinogenesis and its relation to HER-2/neu and p53 protein expression in invasive ductal carcinoma

The purpose of this study was to evaluate cyclooxygenase-2 (COX-2) expression in the successive steps of breast carcinogenesis and to determine its correlation with HER-2/neu and p53 expression in invasive ductal carcinomas of the breast. Immunohistochemical staining with anti-COX-2 antibody was performed in normal breast tissue, usual hyperplasia, ductal carcinoma in situ, and invasive ductal carcinoma. Expression of COX-2 in invasive ductal carcinoma was correlated with immunohistochemical expression of HER-2/neu and p53 protein. COX-2 expression was found to be progressively elevated along the continuum from normal breast tissue to invasive ductal carcinoma (P<0.001). COX-2 expression significantly correlated with p53 and HER-2/neu protein expression (P<0.05 and P<0.001). On multivariate analysis, only TNM stage and elevated COX-2 expression correlated with survival. Our results suggest that COX-2 may be involved in the carcinogenesis of the breast and may be an independent prognostic indicator in patients with invasive ductal carcinoma. HER-2/neu and p53 are likely to be involved in the regulation of COX-2 expression in invasive ductal carcinomas of the breast.

Primary peritoneal carcinoma: experience with cytoreductive surgery and combination chemotherapy

The objective of this study was to review the clinical outcome and prognosis of patients with primary peritoneal carcinoma (PPC) treated with cytoreductive surgery and combination chemotherapy. We retrospectively reviewed the charts of 27 patients with histologically confirmed PPC, treated between March 1990 and February 2004 at Asan Medical Center, South Korea. The review included demographic data, pathologic findings, treatments, and outcomes. The mean age of the 27 patients was 57.5 +/- 7.2 years, and the rate of optimal cytoreduction was 70.4%. Seven patients had stage IIIB, 17 had stage IIIC, and 3 had stage IV; all patients received adjuvant chemotherapy. There were 4 patients with progressive disease, 5 partial responders, and 15 complete responders; the remaining 3 patients were nonevaluable. At the time of the review, 10 patients were alive without evidence of disease, 3 were alive with disease, and 14 had died from disease. The median overall survival time was 41 months, and the overall 5-year survival rate was 18.1%. Patients who had optimal cytoreduction had a longer median survival (42 months) than those who had suboptimal cytoreduction (10 months; P < 0.05). Combination chemotherapy after optimal cytoreductive surgery may be effective in the treatment of patients with PPC.

Adult granulosa cell tumor of the ovary: 35 cases in a single Korean Institute

BACKGROUND

Adult granulosa cell tumor of the ovary is an uncommon neoplasm. The overall prognosis is favorable. The prognostic factors that are related to survival have not been well defined and are discussed in the literature amidst controversy.

METHODS

Thirty-five patients diagnosed with adult granulosa cell tumor of the ovary were reviewed retrospectively. Demographic data, pathologic findings, treatments, and survival times were reviewed and analyzed for prognostic significance.

RESULTS

Of the 35 cases, there were 30 cases representing stage I tumors, one case at stage II, four cases at stage III, and no cases at stage IV. The mean overall survival time of all patients was 140.3 months. The 5- and 10-year survival rates were 92.0% and 85.8% respectively. The FIGO stage was the only independent prognostic factor.

CONCLUSIONS

Despite the small number of patients, the study showed that the less advanced stage is the only favorable prognostic factor of significance.

Expression of cyclooxygenase-2 in epithelial ovarian tumors and its relation to vascular endothelial growth factor and p53 expression

The purpose of this study was to evaluate cyclooxygenase-2 (COX-2) expression in epithelial ovarian tumors and its correlation with vascular endothelial growth factor (VEGF) and p53 expression. Immunohistochemical studies with anti-COX-2, anti-VEGF, and anti-p53 antibodies were carried out in 54 malignant and 23 borderline epithelial ovarian tumors. Elevated COX-2 expression was detected in 77.8% of ovarian carcinomas, which was significantly higher than that of borderline tumors (26.1%) (P < 0.001). In ovarian carcinomas, there was no significant correlation between COX-2 expression and other clinicopathologic features. Elevated VEGF expression was detected in 74.1% of ovarian carcinomas, and p53 expression was found in 64.8% of ovarian carcinomas. COX-2 expression was statistically correlated with elevated VEGF expression (P < 0.001) and p53 positivity (P < 0.05). On a univariate analysis, FIGO stage (P < 0.0001), histologic type (P= 0.0104), and COX-2 expression (P= 0.0135) were significant prognostic factors for overall survival. In a multivariate analysis, FIGO stage (P < 0.0001) was the only independent prognostic factor for poor survival. These findings suggest that COX-2 may play a role in the progression of epithelial ovarian tumors and that COX-2 expression may contribute to ovarian tumor angiogenesis by stimulating VEGF expression. p53 may be responsible for the regulation of COX-2 expression.

Malignant mixed mullerian tumors of the ovary: experience with cytoreductive surgery and platinum-based combination chemotherapy

This study reviews the clinical outcome and prognosis of patients with malignant mixed müllerian tumors (MMMTs) of the ovary treated with optimal cytoreductive surgery, leaving no residual disease, and platinum-based chemotherapy. Ten patients diagnosed with MMMT of the ovary after complete surgical staging from February 1993 to February 2004 at Asan Medical Center in Korea were studied retrospectively. All ten patients were treated with optimal cytoreductive surgery, leaving no gross residual disease. Seven patients received ifosfamide/cisplatin chemotherapy, and the remaining three patients received other platinum-based combination chemotherapy. Demographic data, pathologic findings, treatments, and survival time were reviewed. Of the ten patients, two were scored at FIGO stage IIC, seven were at stage IIIC, and one was at stage IV. The median survival time of all ten patients was 46 months. The overall survival rate was 60.0% at 1 year, 40.0% at 2 years, and 20.0% at 5 years. Platinum-based combination chemotherapy after optimal cytoreductive surgery may be effective in the treatment of ovarian MMMT.

Association of HYPA haplotype in the mannose-binding lectin gene-2 with Behçet's disease

Behcet's disease (BD) is a multisystemic, recurrent inflammatory disease caused by the combinations of multiple genetic and environmental factors. Moreover, the MBL2 gene single-nucleotide polymorphisms and haplotypes are known to increase the susceptibility to inflammatory disease and to alter the serum levels of mannose-binding lectin (MBL. We postulated that the haplotypes of the MBL2 gene influence therapeutic response in BD, thus affecting the clinical symptoms in 282 BD patients. The promoter region, MBL2-550*C/*C (L/L) homozygote was found to have a lower frequency in BD patients than that in controls. No difference was observed in the allele frequencies of G-221C (Y/X), C+4T (P/Q) or Gly54Asp (A/B) of the MBL2 gene in BD patients and in controls. The HYPA haplotype contributed to BD occurrence, whereas the LYPA haplotype was negatively associated with BD. BD patients with several symptoms and with an earlier disease-onset age had a higher HYPA haplotype frequency. BD patients showing poor response (S) to therapy had a higher HYPA frequency than those showing good response (M). It seems that possessing HYPA increases the risk of BD and that the MBL2 HYPA haplotype plays a role in MBL levels and increases the susceptibility to BD.

Detection of HPV genotypes in cervical lesions by the HPV DNA Chip and sequencing

OBJECTIVE

A newly introduced HPV detection technique in cervical lesion, the HPV DNA Chip test, contains 24 HPV probes and has the advantage of being able to detect 24 HPV types at once. We performed HPV DNA sequencing and compared the results with that of the HPV DNA Chip for evaluation of the accuracy of the DNA Chip test.

METHODS

The HPV DNA sequencing was performed in samples of 282 patients, where specific HPV type had been shown in HPV DNA Chip test. The sixteen cases where multiple HPV types had been found in HPV DNA Chip test were included in 282 cases. The sequencing was also performed in HPV-other type samples of 95 patients, where positive in HPV-PCR, but specific HPV type had not been found.

RESULTS

In 257 cases (91.1%) of 282 cases, the HPV types of the HPV DNA sequencing test were in agreement with types of the HPV DNA Chip. In 16 cases (5.7%), the sequencing types were different from the types of HPV DNA Chip. But, in 9 of 16 cases, types in HPV DNA sequencing were absent types in HPV DNA Chip test. The interpretation of HPV DNA sequencing was impossible in nine cases (3.2%). The HPV DNA sequencing test of 95 cases of HPV-other type showed that the sequencing types from 94 cases (98.9%) were absent types in HPV DNA Chip test. In sequencing test of HPV-other type, HPV-81 (20.0%), HPV-62 (14.7%), HPV-84 (13.7%), and HPV-61 (13.7%) were frequently detected.

CONCLUSION

HPV DNA Chip is an accurate method for detecting the 24 HPV genotypes.

Efficacy assessment of CellSlide in liquid-based gynecologic cytology

OBJECTIVE

To evaluate the efficacy of CellSlidetrade mark (CS) method in liquid-based gynecologic cytology.

METHODS

We compared 1221 specimens prepared by both CS and conventional techniques to evaluate specimen adequacy and cytologic diagnoses. Sensitivity and specificity of these techniques were analyzed in 54 cases using the available histological data.

RESULTS

Quality limiting factors, such as obscuring inflammation or blood, were markedly reduced in CS (0.2%) compared to the conventional smear (4.9%). There was a complete agreement in the Bethesda 2001 diagnosis between these methods in 1132 cases (92.7%) out of 1221. 16.7% more ASC cases and 37.5% more low-grade squamous intraepithelial lesions (LSIL) and 21.4% more high-grade SIL (HSIL) were detected on the CS slides than on the conventional smears. Sensitivity rates, relative to histological data, were 91.4% (CS) and 74.3% (conventional) and specificity rates were same (89.5%) for ASC and more severe lesions. Infectious organisms (Trichomonas and Candida, etc.) were readily identifiable in both methods.

CONCLUSIONS

CS preparation is more sensitive and equally specific in detecting epithelial abnormalities when compared to the conventional smear. In addition, it has a lower incidence of unsatisfactory results with hypocellularity or >75% obscuration of cells.

Immunotherapy using autologous monocyte-derived dendritic cells pulsed with leukemic cell lysates for acute myeloid leukemia relapse after autologous peripheral blood stem cell transplantation

Although a second stem cell transplantation (SCT) can be used as salvage therapy in patients with relapsing leukemia after SCT, most of these patients have a poor outcome. We tried clinical vaccination using monocyte-derived dendritic cells (DCs) pulsed with leukemic lysates to treat relapsing acute myeloid leukemia (AML) after autologous SCT. To generate DCs, CD14+ cells isolated from peripheral blood stem cell products were cultured in AIM-V in the presence of GM-CSF and IL-4. Adding TNF-alpha on day 6 induced maturation of the DCs, which were harvested on day 8 or 9. The DCs were incubated with tumor lysate and KLH for 2 hr at 37 degrees C. After certifying the absence of microorganisms and endotoxins, the patients received four DC vaccinations at two- to three-week intervals. Two patients received four DC vaccinations with means of 7.8 x 10(6) and 9 x 10(6) DCs at two- to three-week intervals. The DC vaccinations were well tolerated with no apparent side effects. After the vaccinations, the patients showed immunological responses with positive delayed-type hypersensitivity skin reaction and increasing autologous T cells stimulatory capacity to the DCs; however, the BM blast percentage of the patients did not improve. The results suggest that DCs are a feasible cellular therapy for relapsing AML after autologous SCT.

The role of ERK1/2 activation in the infection of HeLa cells with Human coxsackievirus B3

Human coxsackievirus B3 (CVB3) is known to trigger in host cells a biphasic activation of extracellular signal-regulated kinase (ERK1/2); i.e., early transient and late sustained activation. In this study, we explored (i) the role of ERK1/2 activation in virus entry into cells and virus replication and (ii) cellular genes influenced by this activation in CVB3-infected HeLa cells. Pretreatment of the cells with an ERK1/2 inhibitor, PD98059 showed that early transient ERK1/2 activation is not be related to virus entry, but late sustained ERK1/2 activation plays a role in virus replication. To identify which cellular genes are influenced by the ERK1/2 activation after virus infection, a cDNA microarray analysis was performed. In HeLa cells pretreated with PD98059 and then infected with the virus, the number of influenced cellular genes was higher compared to that in infected cells not pretreated with the inhibitor (15 vs 77 at 10 mins post infection (p.i.) and 347 vs 91 at 9 hrs p.i. Thus the virus infection affected several host genes through ERK1/2 activation.

The generation of leukemic dendritic cells from acute myeloid leukemia cells is potentiated by the addition of CD40L at the terminal maturation stage

Leukemic dendritic cells (DCs) that are derived from acute myeloid leukemia (AML) cells display low-level expression of several key molecules. We investigated the optimal combination of cytokines needed to generate potent leukemic DCs from AML cells in vitro. AML cells were cultured in the presence of the following combinations of cytokines: Group A, granulocyte-macrophage colony-stimulating factor (GM-CSF) + interleukin-4 (IL-4) + tumor necrosis factor-alpha (TNF-alpha); Group B, GM-CSF + IL-4 + CD40L; and Group C, CD40L addition at the terminal maturation point of cells that were grown as for Group A. The AML cells showed clear upregulation of CD80, CD83, CD86, CD40, and HLA-DR expression under all culture conditions, without significant differences between these groups. However, the addition of CD40L (as in Group C) showed a slight upregulation in the expression of CD83 and CD86 on leukemic DCs. The leukemic DCs in Groups A and B had higher allogeneic T-cell stimulatory capacities than untreated AML cells, and the addition of CD40L (Group C) enhanced this effect. The function of the cytotoxicity-stimulating autologous T cells was also augmented by the addition of CD40L (Group C). These results suggest that AML cells may be used to generate leukemic DCs using various cytokine combinations, and that the most potent, mature leukemic DCs are generated by the addition of CD40L to terminal-stage AML cultures that are grown in the presence of conventional cytokine combinations.

Intercellular adhesion molecule-1 polymorphisms in Korean patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by synovial proliferation and the accumulation of inflammatory cells in the affected joints. Intercellular adhesion molecule-1 (ICAM-1) is readily detected in RA synovial tissues and helps recruit inflammatory cells to the joint. ICAM-1 shows genetic polymorphisms at codons 241 (R241G) and 469 (K469E). In order to investigate the association between ICAM-1 gene polymorphisms and RA, we genotyped ICAM-1 R241G and ICAM-1 K469E polymorphisms in 143 Korean patients with RA, and in 138 healthy controls, by using the polymerase chain reaction-restriction fragment length polymorphism method. No polymorphism of R241G was found in Korean subjects. However, the frequency of the K469 allele was found to be significantly lower in RA patients than in healthy controls. Allele frequency of K469 was lower in RA patient group, compared to that in healthy controls, regardless of the shared epitope status. Distribution of K469E allele frequencies was not different whether the patient had rheumatoid factor, radiographic erosion or extra-articular complications. In conclusion, this study shows lower frequency of the ICAM-1 K469E allele in Korean patients with RA than that in healthy controls.

A comparison of modified MonoPrep2™ of liquid-based cytology with ThinPrep® Pap test

OBJECTIVE

The purpose of this study is to evaluate a modified MonoPrep2 (MP) of liquid-based cytology (LBC) to search for a less expensive alternative technique usable for screening of cervical cancers.

STUDY DESIGN

Cervicovaginal direct-to-vial samples from 1218 consecutive patients were processed with the modified MP technique and the results were compared with those of currently popular ThinPrep Pap test (TP) technique.

RESULTS

Both MP and TP methods provide uniformly spread thin layers of cells without cellular overlap or significant obscuring elements. The diameter of the circular area was 20 mm in MP and 22 mm in TP. Obscuring factors were slightly more frequent in MP but not enough to affect interpretation. Thirteen specimens were excluded from the study because of poor specimen quality in MP. In 1205 patients, there was an absolute agreement in results (the Bethesda diagnosis system) between the two methods, and discordances were observed in only 18 (1.5%) in 1187 cases (98.5%). Furthermore, there was no significant difference in diagnostic accuracy in histopathologic correlation between the two methods. The sensitivity of MP was slightly lower than that of TP, and the specificity of MP was higher than that of TP. A human papillomavirus (HPV) test with polymerase chain reaction (PCR) using broad-spectrum probes has yielded good results in both MP and TP samples.

CONCLUSIONS

The modification of the MP method gave comparable results to those of TP in terms of smear quality, cytologic diagnostic evaluation, and biopsy correlation with much less cost. The modified MP offers a cost-effective alternative to the currently popular expensive techniques of liquid-based cytology practical for cervical cancer screening.

Frequent CpG island methylation in precursor lesions and early gastric adenocarcinomas

Gastric carcinogenesis involves multiple genetic and epigenetic alterations. Epigenetic silencing of tumor-related genes due to CpG island methylation (CIM) has been recently reported in gastric cancer, but the role in precursor lesions is not well understood. We analysed the methylation status of the tumor suppressor gene p16, the DNA mismatch repair gene hMLH1, and four CpG islands (MINT1, MINT2, MINT25, and MINT31) using methylation-specific polymerase chain reaction in 35 polypoid adenomas and 46 flat dysplasias unassociated with carcinoma, 34 early adenocarcinomas (T1N0M0) and associated adenomas/dysplasias, and corresponding adjacent non-neoplastic mucosa. The extent of CIM was defined by the fraction of methylated loci (methylation index), and compared with previously characterized genetic alterations (microsatellite instability (MSI) and APC gene mutation). We found that methylation of p16 was more frequent in adenocarcinoma-associated dysplasias/adenomas (29%) and adenocarcinomas (44%) as compared to flat dysplasias (4%) and adenomas (18%) unassociated with adenocarcinoma (P=0.001). The mean methylation index increased from normal/chronic gastritis (CG) mucosa (0.09) to intestinal metaplasia (IM) (0.16), flat dysplasias (0.40) or polypoid adenomas (0.41) unassociated with carcinoma, dysplasias/adenomas associated with carcinoma (0.44), and adenocarcinomas (0.44). There was no difference in frequencies of high-level CpG island methylation (CIM-H, methylation index > or =0.5) among flat dysplasias (50%) and polypoid adenomas (51%) unassociated with carcinoma, dysplasias/adenomas associated with adenocarcinoma (47%), and adenocarcinoma (47%). CIM-H was present in 15% of IM, but not in normal/CG mucosa. There was a significant correlation between methylation of hMLH1 and high-level of microsatellite instability (MSI-H): methylation of hMLH1 was present in 71% of MSI-H tumors, but only 8% of MSI-low tumors and 13% of microsatellite-stable tumors (P=0.0001). There was no statistical difference between methylation index and APC mutation. Our results indicate that concurrent promoter methylation is an early and frequent event in gastric tumorigenesis, including both MSI-H and microsatellite-stable neoplasms. Methylation of the p16 gene may contribute to the malignant transformation of gastric precursor lesions.