EBER Research Articles

Primary Intestinal Epstein-Barr Virus-associated Natural Killer/T-cell Lymphoproliferative Disorder: A Disease Mimicking Inflammatory Bowel Disease.

Primary intestinal Epstein-Barr virus [EBV]-associated natural killer/T-cell lymphoproliferative disorder [PIEBV+ NK/T-LPD] is a rare clinical entity, which is difficult to differentiate from inflammatory bowel disease [IBD]. We present a series of Chinese patients with PIEBV+ NK/T-LPD to increase awareness among clinicians of this condition. Patients diagnosed with PIEBV+ NK/T-LPD at West China hospital between 2014 and 2016 were included. Clinical and histopathological characteristics were reviewed, and key aspects of differential diagnosis were presented. Twelve patients diagnosed with PIEBV+ NK/T-LPD were identified. Initial symptoms included intermittent fever [11/12 patients], abdominal pain [9/12], haematochezia [8/12], and diarrhoea [3/12]. Main endoscopic findings included multisegmental irregular, variable-sized ulcers, isolated giant ulcers, and diffuse inflammation. Colon and ileocaecum were mainly affected in 11 patients. The main PIEBV+ NK/T-LPD immunophenotypic profile of the infiltrating cells was CD3ε-positive NK/T cells characterised by positive T-cell intracellular antigen-1 and granzyme B, with CD5 deletion. In situ hybridisation was positive for EBV-encoded small RNAs 1/2 in all patients. Eleven patients were misdiagnosed with ulcerative colitis [4/11], Crohn's disease [4/11], or tuberculosis [TB, 3/11], owing to the similar endoscopic and histopathological features. The mean number of endoscopic procedures performed before reaching the diagnosis of PIEBV+ NK/T-LPD was 3.58; in four patients, the diagnosis was confirmed only after surgical resection following complications. PIEBV+ NK/T-LPD may be difficult to differentiate from IBD or TB owing to overlapping endoscopic and pathological findings. Early identification of EBV reactivation in tissue samples is essential for the accurate diagnosis.

Epstein-Barr virus-associated smooth muscle tumor involving the spine of an HIV-infected patient: Case report and review of the literature

Within the last two decades, there have been multiple reports of Epstein-Barr virus (EBV)-associated smooth muscle tumors in immunocompromised patients. This includes HIV-infected patients, post-transplant patients, and patients with congenital defects of their immune systems. Here we report the case of a 24-year-old African American female with congenital HIV presenting with progressive lower extremity weakness, constipation, aching pain in her shoulders, and subcostal anesthesia. Magnetic resonance imaging (MRI) revealed a large circumferential lesion extending from T1-T3 and a smaller left paraspinal lesion at C6-C7. The T1-T3 mass was excised via a right-sided costotransversectomy with laminectomy and fusion from T1-T3. Highly active antiretroviral therapy (HAART) was started postoperatively, and adjuvant radiotherapy was initiated but patient was lost to follow-up. Surgical pathology demonstrated a smooth muscle tumor diffuse nuclear positivity for EBV-encoded small RNA 1 by in situ hybridization. Although eight studies have reported HIV patients with EBV-associated smooth muscle tumors of the spine, to the author’s knowledge, this is the first review comprised solely of patients with spinal involvement with the addition of our patient case.

Primary testicular NK/T cell lymphoma: a clinicopathologic analysis of six cases

Objective: To evaluate the clinicopathological features, diagnosis and management of primary testicular NK/T cell lymphoma (NKTCL). Methods: Six cases of primary testicular NKTCL at Beijing Friendship Hospital, Capital Medical University from January 2007 to December 2016 were retrospectively analyzed for the morphology, immunephenotype and outcome, and relevant literature was reviewed. Results: The median age of patients at diagnosis was 45 years(range 32-65 years). All patients presented with testicular masses as initial symptoms (6/6), five cases (5/6) were on the right. The lesions were confined to the testis. All patients were classified as Ann Arbor stage Ⅰ but the tumors exhibited aggressive clinical behavior. Two patients died of the disease within two months, three (3/6) had clinical remission, and one (1/6) was lost to follow-up. Morphologically, the lymphoma cells showed a diffuse growth pattern that largely effaced the interstitial tissues, and surrounded seminiferous tubules in all cases. There was also a prominent angioinvasive pattern, with focal necrosis and karyorrhexis(4/6). Cytologically, the medium-sized neoplastic cells showed scanty to moderate amount of cytoplasm and irregular folded nuclei. The immunophenotype was similar to that of nasal NKTCL: the neoplastic cells were positive for cytoplasmic CD3, CD56, cytotoxic molecules and EBV-encoded small RNA, the loss of CD5 antigen was seen in all cases. Conclusions: Primary testicular NKTCL is extremely rare, highly aggressive and is associated with a poor prognosis. There is no unified standard of treatment. Thus, at the time of diagnosis of testicular lymphoma, NKTCL should be included in the differential diagnosis.

Characteristic Histological Findings of Asymptomatic EBV-associated Lymphoproliferative Disorders in Tonsils

Recently, an in situ hybridization (ISH) and immunohistochemical study demonstrated that Epstein-Barr virus (EBV) infection may be involved in tonsillar hypertrophy and recurrent tonsillitis in children and young adolescents. The present study was based on 630 consecutive specimens from tonsillectomies performed at the Dokkyo University School of Medicine between 2002 and May 2017. Clinical findings were obtained from hospital records. Histologically, a “pale clear zone” was characterized by hyperplastic germinal centers with ill-defined borders and interfollicular expansion. Immunohistologically, the majority of immunoblasts were CD20-positive, whereas medium to large lymphoid cells usually expressed CD3. Among 14 lesions, numerous EBV-encoded small RNA (EBER)-positive cells were detected in 10. In 7 of these 10 lesions, EBER-positive cells were detected in germinal centers as well as in the interfollicular area. Based on our results, the “pale clear zone” suggests asymptomatic EBV infection of the tonsil. The present study demonstrated that “pale clear zones” should be taken into consideration when diagnosing asymptomatic EBV-associated LPDs in the tonsils of children and young adolescents as well as in middle-aged patients.

Induction of Interleukin-10 in the Stable Transformants of Human T-Cell Line Expressing Epstein-Barr Virus-Encoded Small RNAs

Induction of Interleukin-10 in the Stable Transformants of Human T-Cell Line Expressing Epstein-Barr Virus-Encoded Small RNAs

Identification of T-cell receptor expression in EBV-positive neoplastic cells in extranodal NK/T-cell lymphoma, nasal-type, and comparison with T-cell receptor gene rearrangement by BIOMED-2 assay

The cellular lineage of extranodal NK/T-cell lymphoma, nasal-type (ENKTL), is determined by expression of T-cell receptor (TR) or TR gene rearrangement. In ENKTL, from TR immunohistochemistry, it may often be difficult to decide whether TR-positive cells are tumor cells or not, especially when TR is expressed in a subset of tumor cells. To analyze TR expression pattern and TR rearrangement in T-lineage ENKTL, we performed double immunofluorescence staining for Epstein-Barr virus-encoded small RNAs (EBER)/T-cell receptor (TCR) βF1 and CD56/TCR βF1 in 12 cases of ENKTL that showed TCR βF1 expression in immunohistochemistry. TR gene rearrangement was analyzed using a commercial BIOMED-2 multiplex polymerase chain reaction system. Immunohistochemistry showed that all 12 cases expressed TCR βF1 in a wide range of infiltrating cells from 100% to <1%. Two of them expressed both TCR βF1 and TCR cγM1. EBER/TCR-βF1-positivity was confirmed in 10 cases by double staining. One case failed to show EBER/TCR-βF1-positive cells but showed a CD56/TCR βF1-positive result. Among 12 cases, 5 had poor-quality DNA, 3 of them showed no polymerase chain reaction product, and 2 cases showed nonspecific peak of low height. Five of 7 cases with good DNA quality demonstrated monoclonal TR gene rearrangement. Based on TR expression and TR gene rearrangement, 10 of 12 cases of ENKTL were decided as a T-lineage tumor. In conclusion, because of common TR silence and poor DNA quality, consideration of both immunohistochemistry and TR gene rearrangement is necessary to determine the lineage of ENKTL.

Clinicopathologic analysis of micronodular thymoma with lymphoid stroma

Objective: To investigate the clinicopathologic features of micronodular thymoma with lymphoid stroma(MNT). Methods: Five cases of MNT diagnosed from January 2007 to December 2016 in Henan Provincial People's Hospital were collected.Hematoxylin-Eosin staining and immunohistochemistry were used to evaluate the histological and immunophenotypic characteristics in 5 MNT cases. Epstein-Barr virus (EBV) status was detected by in situ hybridization for EBV-encoded small RNA (EBER). Polymerase chain reaction was used to detect the rearrangement of immunoglobulin genes. Results: Five cases were MNT, including 3 male and 2 female patients, mean aged 59 years (from 43 to 63 years). All patients had ananterior mediastinal mass, with no myasthenia gravis and autoimmune diseases, and underwent surgical resection.Half to ten years follow-up showed no recurrence.Grossly, the tumors were solid in 4 cases, and cystic and solid in 1 case; the border was clear. Histologically, the tumors presented as a distribution of micronodules separated by abundant lymphoid stroma with prominent germinal centers. The nodules were composed of neoplastic spindle, oval cells containing bland, oval nuclei.Immunohistochemical study showed strong positivity of the tumor cells for CKpan, CK19, CK5/6 and p63. Stains for EMA, CD117, calretinin, TTF1 were negative in the tumor cells.Scattered CD3, CD1a, and TdT positive immature T lymphocytes were noted in and around tumor nodules. Many lymphocytes in the stroma, including germinal centers, were positive for CD20.The bcl-2 was also detected in lymphocytes in the stroma, mantle and marginal zone of lymphoid follicles, and in part of tumor cells. Tumor cells and lymphocytes were negative for EBER. Immunoglobulin genes rearrangement analysis showed that B lymphocytes were polyclonal. Conclusions: MNT is a rare thymoma, which occurs in the elderly and has no obvious symptom. After complete resection, the prognosis is very good. The diagnosis should be based on a combination of clinicopathologic features, and other types of thymoma should be excluded.

Methotrexate-associated lymphoproliferative disease with multiple pulmonary nodules in a patient with rheumatoid arthritis

A 62-year-old woman with rheumatoid arthritis and secondary Sjögren’s syndrome took methotrexate (MTX) 5 mg three times a week regularly but gradually developed an intermittent fever, oral ulcers and productive...

Clinical and pathological characterization of Epstein-Barr virus-associated gastric carcinomas in Portugal.

AIMTo determine the prevalence of Epstein-Barr virus (EBV)-associated gastric carcinomas in the North Region of Portugal and to study its clinicopathological characteristics.METHODSWe have performed a retrospective study including a total of 179 consecutive patients with gastric cancer (GC) submitted to gastrectomy during 2011 at the Portuguese Oncology Institute of Porto. Clinical and pathological data was collected from individual clinical records and inserted on a database with unique codification. Tumour tissues were collected from the institutional tumour bank. EBV was detected by in situ hybridization for the detection of EBV-encoded small RNAs (EBERs) and EBV latent proteins (LMP1 and LMP2A) were detected by immunohistochemistry.RESULTSThe analysis showed that EBV-associated gastric carcinomas (EBVaGC) represents 8.4% (15/179) of all GC cases, with a significant differential distribution among histological types (P < 0.001): 100% (3/3) of medullary carcinomas, 100% (1/1) of adenosquamous carcinoma, 8.7% (8/92) of tubular adenocarcinomas, 8.0% (2/25) of mixed carcinomas and 2% (1/51) in poorly cohesive carcinomas. The analysis revealed a higher predominance of EBVaGC in the upper third and middle (cardia, fundus and body) of the stomach (P = 0.041), a significant lower number of regional lymph nodes invasion (P = 0.025) and a tendency for better prognosis (P = 0.222). EBV latent protein expression revealed that all EBVaGC cases were LMP1-negative, nevertheless 6 cases (40%) expressed LPM2A, which reveals that these cases show a distinct EBV-Latency profile (latency II-like).CONCLUSIONEBVaGC represents 8.4% of all GC in the North Region of Portugal. The EBV-infected patients have specific clinic-pathological features that should be further explored to develop new strategies of management and treatment.

Is Epstein-Barr virus infection associated with the pathogenesis of microscopic colitis?

BackgroundEpstein-Barr virus (EBV) has been associated with inflammation in the colon, particularly in patients with inflammatory bowel disease (IBD). Even if a relevant plasmocytosis, similar to IBD, is present in microscopic colitis (MC), the frequency of EBV infection in this setting is unknown. ObjectivesWe aimed to compare the frequency of colonic EBV infection in patients with MC, ulcerative colitis (UC), and irritable bowel syndrome (IBS). Study designThe frequency of colonic EBV infection in biopsies of 30 patients with MC, 30 patients with UC, and 30 controls with IBS was retrospectively assessed. PCR was performed to detect viral EBV DNA in colonic biopsies. In situ hybridization was also performed to identify and localize EBV-encoded small RNA1 and 2 (EBERs) within cells. ResultsThe presence of EBV DNA was detected in 27 out of 30 MC patients, in 20 out of 30 UC cases, and in none of IBS group. The frequency of EBV DNA in MC was significantly higher compared with that reported in UC (90.0% vs. 66.7%, p=0.03). EBERs+ cells were observed in 18 out of 30 MC patients, in only 3 out of 30 UC patients (60.0% vs. 10.0%, p<0.001), and in none of IBS group. ConclusionsEBV infection is almost always detectable in the colonic mucosa of patients with MC. Further studies are necessary to confirm this association and to clarify the role of EBV in MC and, more generally, in colonic inflammation.

Comparison of Clinicopathologic Parameters and Survivals Between Epstein-Barr Virus–positive and Her2-positive Gastric Cancers

Gastric carcinomas are highly mortal neoplasms for which new therapeutic options are being searched. The molecular subtyping of gastric adenocarcinomas was proposed recently, and the relationship between etiopathogenetic types is still under investigation. Here we compared histopathologic, prognostic, and survival differences between Epstein-Barr virus (EBV)-positive and Her2-positive gastric adenocarcinomas. In a retrospective design, we searched the EBV status with Epstein Barr Virus encoded small RNA (EBER) in situ hybridization, and the Her2 status both by immunohistochemistry and by chromogenic in situ hybridization of 106 gastrectomized gastric carcinomas. Histologic and clinical prognostic parameters and survival information were determined, and retrieved from archival tissues and clinical notes. The Her2 positivity rate was 12.3% and the EBV positivity rate was 7.6%. Among EBER-positive cases, Her2 positivity was not detected. Her2 positivity was detected more in intestinal differentiated tumors, whereas EBER positivity was detected in undifferentiated tumors (P=0.003). There was no correlation of Her2 or EBER positivity with the tumor stage. Median survivals of EBER-positive, Her2-positive, and both negative cases were 11.5, 18, and 20.5 months, respectively. The tumor stage and distant metastasis were found to be significant for survival in the multivariate analysis. In our 106 gastrectomized gastric carcinoma cases, EBV-positive and Her2-positive groups were found to be unrelated as proposed in the upcoming classification of gastric carcinomas.

Epstein-Barr virus in tumor-infiltrating B cells of myasthenia gravis thymoma: an innocent bystander or an autoimmunity mediator?

The thymus plays a key role in myasthenia gravis (MG), a B cell-mediated autoimmune disorder affecting neuromuscular junction. Most MG patients have thymic abnormalities, including hyperplasia and thymoma, a neoplasm of thymic epithelial cells. Epstein-Barr virus (EBV) is associated with autoimmune diseases and tumors. Recently, we showed EBV persistence and reactivation in hyperplastic MG thymuses, suggesting that EBV might contribute to intra-thymic B cell dysregulation in MG patients. Here, we investigated EBV involvement in thymoma-associated MG, by searching for EBV markers in MG (n=26) and non-MG (n=14) thymomas. EBV DNA and EBV-encoded small nuclear RNA (EBER) 1 transcript were detected in 14/26 (53.8%) and 22/26 (84.6%) MG thymomas, and only in 3 of 14 (21.4%) non-MG thymomas. Latent EBNA2 and late gp350/220 lytic transcripts were undetectable in all, but one, thymomas, and early lytic BZLF1 transcript was absent in all samples, suggesting that early infection events and EBV reactivation were very rare in thymomas. EBER1 and 2-positive cells were detected in MG, but not in non-MG, thymomas, as well as cells expressing EBV latency proteins (EBNA1, LMP1, LMP2A), that were mainly of B cell phenotype, indicating EBV association with MG rather than with thymoma. Toll-like receptor (TLR) 3 transcriptional levels were higher in MG than non-MG thymomas and positively correlated with EBER1 levels, suggesting a role for EBERs in TLR3 activation. Our findings show that EBV is commonly present in thymoma-infiltrating B cells of myasthenic patients, indicating a contribution of EBV to B cell-mediated autoreactivity in MG associated with thymic tumor.

Epstein-Barr virus-encoded small RNAs in idiopathic orbital inflammatory pseudotumor tissues: a comparative case series.

To investigate the positive rate and types of cells that express Epstein-Barr virus-encoded small RNAs (EBERs) and to determine the distribution of EBER-expressing cells in idiopathic orbital inflammatory pseudotumor (IOIP) tissues. We retrospectively examined 40 archived paraffin specimens from two teaching hospitals in Southern China between January 2007 and January 2015 that were pathologically determined to exhibit IOIP. Eleven concurrent paraffin specimens of thyroid-associated ophthalmopathy (TAO) composed the control group. In situ hybridization was performed to detect EBERs. Immunohistochemistry was employed to detect CD3, CD20, Vimentin, and smooth muscle actin (SMA), and the positive rate, types of positive cells, and distribution and location of EBERs were evaluated. The positive expression rate of EBERs was 47.5% (19/40) in the IOIP group, which was significantly higher than that in the TAO group [0 (0/11), P=0.011]. In the IOIP group, the lymphocyte infiltrative subtype, fibrotic subtype, and mixed subtype exhibited EBER-positive rates of 57.1% (12/21), 12.5% (1/8), and 54.5% (6/11), respectively, and no significant differences were found between these subtypes (P=0.085). Positive signals of EBERs were mainly present in medium-small lymphocytes between or around follicles and in the nuclei of activated immunoblasts (14/19). The positive rate, types, and distribution of EBER-expressing cells in IOIP have been documented. These findings are conducive for a better understanding of the underlying mechanisms of Epstein-Barr virus infection in IOIP pathogenesis.

Interparietal (Inca) bone: A case report!

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare variant of intrahepatic cholangiocarcinoma. Epstein-Barr virus (EBV) was reported to be associated with LELCC in approximately 70% of cases by EBV-encoded small non-polyadenylated RNA (EBER) in situ hybridization. In reviewing literature, the treatment experience of advanced LELCC are lacking. In this study, we reported a young female patient diagnosed with locally advanced EBV-associated LELCC with elevated EBV DNA titer and treated with systemic chemotherapy.

Standardizing the MCAO model for increased post-stroke survival

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare variant of intrahepatic cholangiocarcinoma. Epstein-Barr virus (EBV) was reported to be associated with LELCC in approximately 70% of cases by EBV-encoded small non-polyadenylated RNA (EBER) in situ hybridization. In reviewing literature, the treatment experience of advanced LELCC are lacking. In this study, we reported a young female patient diagnosed with locally advanced EBV-associated LELCC with elevated EBV DNA titer and treated with systemic chemotherapy.

Anencephalic fetus with cranial rachischisis and associated anomalies: A case report

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare variant of intrahepatic cholangiocarcinoma. Epstein-Barr virus (EBV) was reported to be associated with LELCC in approximately 70% of cases by EBV-encoded small non-polyadenylated RNA (EBER) in situ hybridization. In reviewing literature, the treatment experience of advanced LELCC are lacking. In this study, we reported a young female patient diagnosed with locally advanced EBV-associated LELCC with elevated EBV DNA titer and treated with systemic chemotherapy.

Variable branching pattern of brachial artery – A cadaveric study

Lymphoepithelioma-like cholangiocarcinoma (LELCC) is a rare variant of intrahepatic cholangiocarcinoma. Epstein-Barr virus (EBV) was reported to be associated with LELCC in approximately 70% of cases by EBV-encoded small non-polyadenylated RNA (EBER) in situ hybridization. In reviewing literature, the treatment experience of advanced LELCC are lacking. In this study, we reported a young female patient diagnosed with locally advanced EBV-associated LELCC with elevated EBV DNA titer and treated with systemic chemotherapy.

Epstein-Barr virus positivity is associated with angiogenesis in, and poorer survival of, patients receiving standard treatment for classical Hodgkin's lymphoma.

Epstein-Barr virus (EBV) is a significant contributor to the development of classical Hodgkin's lymphoma (cHL). Recent studies have documented associations between angiogenesis and EBV-associated malignancies. No study has yet examined the associations among, and prognostic implications of, EBV infection, vascular endothelial growth factor (VEGF) expression, and microvessel density (MVD) in cHL patients. Diagnostic tissues from 135 cHL patients treated with adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) were retrospectively evaluated by in situ hybridization of EBV-encoded small RNA (EBER) and immunohistochemical staining for VEGF and CD31 (a measure of MVD). EBER and VEGF expression were positively correlated (P=0.038). The mean MVD value of EBER-positive tumors was significantly higher than that of EBER-negative tumors (P=0.034). The mean MVD of tumors positive for both EBER and VEGF was significantly higher than that of tumors negative for both markers (P=0.008). EBER-positive patients had a lower 5-year overall survival (OS) rate than EBER-negative patients (P=0.046). A high MVD was also associated with a poorer OS (P=0.01); multivariate analysis showed that this was a significant and independent prognostic factor (P=0.026). We found positive correlations between EBER and VEGF levels, and the MVD, indicating that EBV plays an important role in tumor angiogenesis. Targeting of both angiogenesis and EBV may be important when treating cHL patients who are EBER-positive and/or have a high MVD.

Prevalence and characteristics of Epstein\u2013Barr virus-associated gastric carcinomas in Portugal

BackgroundGastric cancer (GC) is one of the most common malignant tumors of the digestive tract and is the third leading cause of cancer death worldwide. Epstein–Barr virus (EBV) has been associated with approximately 10% of the total cases of gastric carcinomas. No previous study has analyzed the prevalence of EBV infection in gastric cancer of the Portuguese population.MethodsIn the present study, we have analyzed 82 gastric carcinoma cases and 33 healthy individuals (control group) from Coimbra region for the presence of EBV by polymerase chain reaction (PCR) and by in situ hybridization (ISH) for EBV-encoded small RNAs (EBERs). The status of H. pylori infection was assessed by serology and by PCR.ResultsEBV was detected by PCR in 90.2% of stomach cancer cases, whereas EBERs were detected in 11%. In our series, EBV-associated gastric carcinoma (EBVaGC) were significantly associated with gender and the majority of them presented lymph node metastasis. These cases were generally graded in more advanced pTNM stages and, non-surprisingly, showed worse survival. H. pylori infection was detected in 62.2% of the gastric cancers and 64.7% of these patients were CagA+. On the other hand, the H. pylori prevalence was higher in the EBV-negative gastric carcinomas (64.4%) than in those carcinoma cases with EBV+ (44.4%).ConclusionsThe present study shows that prevalence of EBVaGC among Portuguese population is in accordance with the worldwide prevalence. EBV infection seems to be associated to poorer prognostic and no relation to H. pylori infection has been found. Conversely, the presence of H. pylori seems to have a favourable impact on patient’s survival. Our results emphasize that geographic variation can contribute with new epidemiological data on the association of EBV with gastric cancer.

Abstract 3776: Examination of ERCC1 status in circulating tumor cells as a prognostic tool for patients with nasopharyngeal carcinoma

Abstract Investigation of the expression pattern of DNA-repair protein excision repair cross-complementation group 1 (ERCC1) has been reported to allow selection of patients with non-small cell lung cancer who are likely to benefit from cisplatin-based therapy. Recent evidence suggests that ERCC1 expression may also find prognostic use in patients with nasopharyngeal carcinoma (NPC). We evaluated ERCC1 expression and genotype from NPC tissues and peripheral blood mononuclear cells of patients with NPC. ERCC1 expression was detected in 61/77 cases (79.2%) with varying intensities, where high ERCC1 expression significantly associated with worse relapse-free survival (RFS) (HR 2.34, 1.06-5.16, p=0.036). In addition, the presence of ERCC1 C118T genotype was significantly associated with favorable RFS and overall survival (OS) in a subgroup of patients with undetectable post-treatment plasma EBV DNA. These findings support a prognostic role for ERCC1 examination in NPC. However, the invasive nature of obtaining biopsy samples for tumor marker studies is a major hindrance of this approach. To facilitate the investigation of ERCC1 expression in a noninvasive manner, we have developed a negative selection immunomagnetic method for isolating circulating tumor cells from patient blood. Cell line spike-in experiments reveal a mean recovery rate of 66% for NPC cells with greater than 99% removal of non-targeted blood cells. Specificity of CTC identification was confirmed by detection of the expression of the Epstein-Barr virus encoded small RNA (EBER) in the CTCs. This method also allowed the simultaneous analysis of the expression of multiple protein markers including CD45, cytokeratin and ERCC1. It is expected that the development of noninvasive methodologies for tumor marker studies will facilitate their clinical application for improved patient care and monitoring in the future. Note: This abstract was not presented at the meeting. Citation Format: Edwin P. Hui, Brigette BY Ma, KC Allen Chan, Charles ML Chan, SC Cesar Wong, Ka Fai To, Herbert HF Loong, Frankie KF Mo, Roger KC Ngan, Anthony TC Chan. Examination of ERCC1 status in circulating tumor cells as a prognostic tool for patients with nasopharyngeal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3776. doi:10.1158/1538-7445.AM2017-3776