Impact of primary prophylaxis by pegfilgrastim in diffuse large B-cell lymphoma treated with R-CHOP.

Febrile neutropenia (FN) and chemotherapy-induced neutropenia (CIN) are common conditions that lead to dose reduction or delayed chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL). Primary prophylaxis (PP) with long-acting granulocyte colony-stimulating factor (G-CSF) was introduced in South Korea in 2014. We aimed to investigate the effects of PP on FN-related hospitalization and death in patients with DLBCL receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Korean individuals (n = 11,491) with incident DLBCL and receiving R-CHOP during 2010-2016 were followed for FN-related hospitalization and mortality. The PP exposure group (patients during 2014-2015, n = 3599), patients during 2010-2016 (n = 11,491), and patients receiving PP during 2014-2016 (n = 4421) were compared with the non-exposure group (patients during July 2011-June 2013, n = 3017), patients in 2013 (n = 1596), and patients not receiving PP during 2014-2016 (n = 1289), respectively. Multivariable-adjusted hazard ratios (HRs) were calculated using the Cox model. The PP exposure group had 16% lower FN-related hospitalizations than the non-exposure group (HR = 0.84, P < 0.001). PP exposure had no beneficial effect on 1-year (HR = 0.98, P = 0.782) and 5-year mortality (HR = 0.97, P = 0.474). Patients in 2014 (HR = 0.85, P < 0.001), 2015 (HR = 0.88, P = 0.003), and 2016 (HR = 0.80, P < 0.001) had a decreased risk of FN-related hospitalizations compared with those in 2013. Among patients receiving their first R-CHOP cycle during 2014-2016, the HR for FN-related hospitalization was 0.90 (P = 0.014) in PP users compared with non-users. PP with a long-acting G-CSF lowered the FN-related hospitalization risk but did not benefit survival in patients with DLBCL receiving R-CHOP.

A Randomized, Open-Label, Phase II Study Comparing Pemetrexed Plus Cisplatin Followed by Maintenance Pemetrexed versus Pemetrexed Alone in Patients with Epidermal Growth Factor Receptor (EGFR)-Mutant Non-small Cell Lung Cancer after Failure of First-Line EGFR Tyrosine Kinase Inhibitor: KCSG-LU12-13.

PURPOSE: The optimal cytotoxic regimens have not been established for patients with non-small cell lung cancer (NSCLC) who develop disease progression on first-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). MATERIALS AND METHODS: We conducted a multi-center randomized phase II trial to compare the clinical outcomes between pemetrexed plus cisplatin combination therapy followed by maintenance pemetrexed (PC) and pemetrexed monotherapy (P) after failure of first-line EGFR-TKI. The primary objective was progression-free survival (PFS), and secondary objectives included overall response rate (ORR), overall survival (OS), health-related quality of life (HRQOL), and safety and toxicity profiles. RESULTS: A total of 96 patientswere randomized, and 91 patientswere treated at 14 centers in Korea. The ORR was 34.8% (16/46) for the PC arm and 17.8% (8/45) for the P arm (p=0.066). With 23.4 months of follow-up, the median PFS was 5.4 months in the PC arm and 6.4 months in the P arm (p=0.114). The median OS was 17.9 months and 15.7 months in PC and P arms, respectively (p=0.787). Adverse events ≥ grade 3 were reported in 12 patients (26.1%) in the PC arm and nine patients (20.0%) in the P arm (p=0.491). The overall time trends of HRQOL were not significantly different between the two arms. CONCLUSION: The outcomes of pemetrexed therapy in NSCLC patients with disease progression after firstline EGFR-TKI might not be improved by adding cisplatin.

Primary central nervous system lymphoma: a new prognostic model for patients with diffuse large B-cell histology.

BACKGROUND: Age and performance status are important prognostic factors in primary central nervous system (CNS) lymphoma. Although several prognostic models have been proposed, there is no consensus on the optimal model for patients with diffuse large B-cell histology. METHODS: Seventy-seven patients with primary CNS diffuse large B-cell lymphoma were retrospectively analyzed to determine factors affecting survival. Three Western models were applied to our eligible patients; we devised a novel model based on our findings. RESULTS: The median patient age was 59 years (range, 29-77); the median event-free and overall survival (OS) durations were 35.9 and 12.6 months, respectively. Nottingham/Barcelona and Memorial Sloan Kettering Cancer Center models were applicable to our cohorts. Multivariate analysis showed that advanced age, multifocal lesions, and high cerebrospinal fluid (CSF) protein concentrations were correlated significantly. A novel model for predicting prognosis was then developed based on these variables. Each variable was assigned 1 point; patients with a total score of 0, 1, 2, and 3 were categorized into the low- (N=17), moderate- (N=26), high- (N=14), and very high-risk groups (N=4), respectively. Sixty-one patients were eligible considering our model; the median OS was 58.2, 34.8, 9.0, and 1.8 months in the low-, moderate-, high-, and very high-risk groups, respectively (P<0.01). CONCLUSION: Advanced age, multifocal lesions, and high CSF protein concentration were adversely related with prognosis. Our model can be helpful in pre-treatment risk stratification for patients with primary CNS lymphoma with diffuse large B-cell histology.

Clinical Features and Survival of Patients With Follicular Lymphoma in Korea.

BACKGROUND: The incidence of follicular lymphoma (FL) varies according to geographic location. It is the second most common non-Hodgkin lymphoma in Western countries but has a very low incidence in Asia. Thus, no representative data are available for FL. Therefore, we gathered our own data to build a foundation for FL research. PATIENTS AND METHODS: We collected a total of 343 patient records. The median age was 53 years, and the ratio of male to female patients was 1.4:1. Most patients received chemotherapy with or without rituximab. RESULTS: The incidence of grade 1 and 2 FL was 64.9% (n = 205) and of stage III and IV was 51.2% (n = 171). The grade tended to be higher and the stage to be lower compared with Western data. In the chemotherapy group, the complete response rate was 76.0%, and the partial response rate was 17.1%. The median follow-up duration was 38.1 months. The estimated 5- and 10-year progression-free survival and overall survival rates were 68.3% and 84.9% and 63.0% and 71.3%, respectively. CONCLUSION: We could not find definitive differences between our Korean data and the Western data, although we found some trends in the baseline characteristics. Therefore, we hope to develop an understanding of FL and perform more qualitative studies in the future.

Paraneoplastic Guillain-Barré Syndrome in Small Cell Lung Cancer.

Guillain-Barré syndrome (GBS) is defined as an acute, autoimmune polyradiculoneuropathy. It is a rare disease that occurs at a rate of 1.11 cases per 100,000 person-years. However, once infected, up to 20%percnt; of patients develop severe disability, and approximately 5%percnt; die. There have been reports of GBS in different cancers. Among them, there are 6 previous reports of GBS in small cell lung cancer. Here, we report a case of a 52-year-old man who was diagnosed with GBS in the setting of small cell lung cancer with chemotherapy.

Prognostic Implications of Primary Tumor Resection in Stage IVB Colorectal Cancer in Elderly Patients.

PURPOSE: The aim of this study was to identify prognostic factors in stage IVB colorectal cancer in elderly patients, focusing on the influence of treatment modalities, including palliative chemotherapy and primary tumor resection. METHODS: A cohort of 64 patients aged over 65 years who presented with stage IVB colorectal cancer at the Gangneung Asan Hospital between July 1, 2001, and December 31, 2009, was analyzed. Demographics, tumor location, tumor grade, performance status, levels of carcinoembryonic antigen (CEA), level of aspartate aminotransferase (AST), and distant metastatic site at diagnosis were analyzed. Using the treatment histories, we analyzed the prognostic implications of palliative chemotherapy and surgical resection of the primary tumor retrospectively. RESULTS: The cohort consisted of 30 male (46.9%) and 34 female patients (53.1%); the median age was 76.5 years. Primary tumor resection was done on 28 patients (43.8%); 36 patients (56.2%) were categorized in the nonresection group. The median survival times were 12.43 months in the resection group and 3.58 months in the nonresection group (P < 0.001). Gender, level of CEA, level of AST, Eastern Cooperative Oncology Group performance status, tumor location, and presence of liver metastasis also showed significant differences in overall survival. On multivariate analysis, male gender, higher level of CEA, higher AST level, and no primary tumor resection were independent poor prognostic factors. In particular, nonresection of the primary tumor was the most potent/poor prognostic factor in the elderly-patient study group (P = 0.001; 95% confidence interval, 2.33 to 21.99; hazard ratio, 7.16). CONCLUSION: In stage IVB colorectal cancer in elderly patients, resection of the primary tumor may enhance survival.

Primary mediastinal large B-cell lymphoma: a single-center experience in Korea.

BACKGROUND: Primary mediastinal large B-cell lymphoma (PMBL) is a distinct subtype of non-Hodgkin lymphoma, which has no consensus for its ideal treatment or prognosis. METHODS: We reviewed the clinicopathologic features and clinical outcomes of 25 PMBL cases diagnosed at a single institution between 1993 and 2009 and compared them with 588 cases of non-mediastinal, diffuse large B-cell lymphoma (DLBCL, control group) diagnosed during the same period. RESULTS: Thirteen (52.0%) PMBL patients had Ann Arbor stage III or IV disease, and 10 (40.0%) had B symptoms. Thirteen (52%) PMBL patients were classified as high-intermediate/high-risk according to the International Prognostic Index. There was a significant prevalence of young (median: 31 years; range, 15-78 years; P<0.001), female (68%; P=0.014) patients in the PMBL group compared to the control group (median: 56 years; range, 15-85 years; 43.2% female). Bulky disease and elevated levels of lactate dehydrogenase (LDH) were more frequent in the PMBL group (P<0.001 and P=0.003, respectively). Nineteen (76%) PBML patients achieved complete remission, and 18 were alive at the last follow-up (median: 43 months; range, 1-92 months). There was no difference in the 3-year, overall survival rate (72%, 95% confidence interval [CI]: 54.0-83.0 versus 70.1%, 95% CI, 109.0-126.0; P=0.686) between PMBL and control patients, respectively. CONCLUSION: Compared to patients with non-mediastinal DLBCL, Korean patients with PMBL are predominantly young women with bulky disease and high LDH levels but with no significant difference in survival.

Prognostic implications of EGFR and HER-2 alteration assessed by immunohistochemistry and silver in situ hybridization in gastric cancer patients following curative resection.

BACKGROUND: The aim of this study was to use immunohistochemistry (IHC) and silver in situ hybridization (SISH) to evaluate alterations in EGFR and HER2 in gastric cancer in order to determine the relationship with prognosis in gastric cancer patients following curative resection. PATIENTS AND METHODS: In this study, we analyzed EGFR and HER-2 status by IHC and SISH in 254 stage I-III gastric cancer patients who underwent curative surgery. RESULTS: Thirteen cases (2.48 %) showed EGFR alteration by IHC or SISH. EGFR alteration was associated with older age (P = 0.021), intestinal type (P = 0.040) and higher stage disease (P < 0.001). The patients with operable state gastric cancer who had EGFR alteration had an unfavorable prognosis, and multivariate analysis confirmed that EGFR alteration was an independent unfavorable prognostic factor. Twenty-seven cases (10.6 %) showed HER-2 alteration by IHC or SISH. HER-2 alteration was associated with older age (P = 0.006), well or moderately differentiated histology (P < 0.001) and intestinal type (P = 0.002). CONCLUSION: HER-2 alteration is not an independent prognostic factor for curatively resectable gastric cancer. We observed EGFR alteration in a subset of cases with operable state gastric cancer and determined that it was associated with an unfavorable prognosis.

Advanced Gastric Cancer Associated with Disseminated Intravascular Coagulation Successfully Treated with 5-fluorouracil and Oxaliplatin.

Gastric cancer patients with acute disseminated intravascular coagulation experiences a rare but severe complication resulting in a dismal prognosis. We report a case of advanced gastric cancer complicated with disseminated intravascular coagulation with intractable tumor bleeding which was successfully treated with chemotherapy consisting of 5-fluorouracil and oxaliplatin. The patient was a 63-year-old man who complained of abdominal pain, melena, and dyspnea on 24 November 2010. We diagnosed stage IV gastric cancer complicated by disseminated intravascular coagulation. Gastric tumor bleeding was not controlled after procedures were repeated three times using gastrofiberscopy. With the patient's consent, we selected the 5-fluorouracil and oxaliplatin combination chemotherapy for treatment. After one cycle of 5-fluorouracil and oxaliplatin therapy, symptoms of bleeding improved and the disseminated intravascular coagulation process was successfully controlled. The primary tumor and multiple metastatic bone lesions were remarkably shrunken and metabolically remitted after eight cycles of chemotherapy. In spite of progression, systemic chemotherapy is effective in disease control; further, the patient gained the longest survival time among cases of gastric cancer with disseminated intravascular coagulation.

Colorectal micropapillary carcinomas are associated with poor prognosis and enriched in markers of stem cells.

Colorectal micropapillary carcinoma has recently been reported as an aggressive variant of adenocarcinoma with a high incidence of lymph node metastasis, but has not been well investigated in terms of survival analysis. This study analyzed the clinicopathological characteristics, including survival data, of the patients with micropapillary carcinoma. We hypothesized that the aggressive features of micropapillary carcinoma might be related to the presence of more tumor cells with stem cell phenotype in colorectal cancer. Fifty-five (10%) micropapillary carcinoma cases were identified among 561 cases of colorectal cancer. We compared the clinicopathological characteristics, including survival data and immunohistochemical profiles of stem cell markers (SOX2, NOTCH3, CD44v6, CD166, ALDH1) of micropapillary carcinomas with those of randomly selected 112 conventional adenocarcinomas lacking micropapillary carcinoma components (non-micropapillary carcinoma) in the colorectum. To exclude the possibility of dilution of control group by patients with microsatellite instability-high carcinomas, we divided non-micropapillary carcinomas into microsatellite instability-high carcinoma and microsatellite stable tumors. Micropapillary carcinomas were characterized by more frequent lymphovascular invasion (P<0.0001) and lymph node metastasis (P<0.0001), higher pathological T and tumor node metastasis stages (P=0.047 and P=0.001), and more frequent SOX2 (P=0.038) and NOTCH3 expressions (P=0.005). Overall 5-year survival rate for patients with micropapillary carcinoma (37%) was significantly lower than for microsatellite instability-high carcinoma and microsatellite stable carcinoma patients (92 and 72%, P<0.0001). The presence of the micropapillary carcinoma component was shown to be associated with a significantly worse survival rate in univariate (P<0.0001) and multivariate (P=0.003, Cox hazard ratio 2.402) analyses. In conclusion, recognition of the micropapillary carcinoma component in colonic adenocarcinoma is very important, because the micropapillary carcinoma has been associated with a significantly worse prognosis. We also found a higher expression rate of cancer stem cell markers in micropapillary carcinomas, suggesting their potential contribution to the survival disadvantage of micropapillary carcinoma.

Male breast adenoid cystic carcinoma.

INTRODUCTION: Adenoid cystic carcinoma (ACC) of the breast is a rare condition, and cases in male patients are even less common. CASE: We describe a case of ACC of the breast with axillary lymph node metastasis, disseminated osteolytic bone metastasis and bone marrow involvement in a 41-year-old man. CONCLUSION: Male breast ACC is an extremely rare malignancy; there can be difficulty in obtaining a final diagnosis. We report this case because of its rarity.

Impact of triple-negative breast cancer phenotype on prognosis in patients with stage I breast cancer.

PURPOSE: Although most patients with stage I breast cancer have a good prognosis, their clinical outcomes may vary significantly. We assessed clinical outcomes and prognostic factors in stage I breast cancer patients with and without triple-negative breast cancer (TNBC) phenotype. METHODS: Of 2,489 patients undergoing breast cancer surgery between January 1998 and December 2002, 554 (22.3%) had stage I breast cancer (tumor size ≤2 cm, and lymph node-negative). TNBC was defined as a primary tumor negative for estrogen and progesterone receptors (Allred scores <3/8) and for HER2/neu (0-1+ by immunohistochemistry). RESULTS: Of the 554 patients with stage I breast cancer, 78 (14.1%) had TNBC. A significant proportion of TNBC patients had histologic grade 3 tumors (47.4% vs. 34.5%, p=0.031) and tumors >1 cm (87.2% vs. 75.8%, p=0.028) and received adjuvant chemotherapy (79.5% vs. 44.7%, p<0.001). During a median follow-up time of 8.7 years, 72 patients experienced tumor recurrences; 18 (23.1%) in the TNBC group and 54 (11.3%) in the non-TNBC group (p=0.010), with cumulative 3-year rate of recurrence of 12.8% and 5.3%, respectively (p=0.010). Ten-year relapse-free survival (RFS; 75.6% vs. 87.5%, p=0.004) and overall survival (OS; 83.0% vs. 91.4%, p=0.002) rates were significantly lower in the TNBC group. Multivariate analysis showed that triple negativity and histologic grade were independent predictors of shorter RFS and OS. CONCLUSION: TNBC had more aggressive clinicopathologic characteristics and was associated with poorer survival in patients with stage I breast cancer. More intensive adjuvant chemotherapy or a different therapeutic strategy targeting this population is warranted.

Role of adjuvant chemotherapy in malignant mucosal melanoma of the head and neck.

The objective of this study was to analyze the role of adjuvant chemotherapy and prognostic factors in malignant mucosal melanoma of the head and neck (HNMM). Thirty-two patients with mucosal melanoma of the head and neck who received local treatment with or without adjuvant chemotherapy were reviewed. Clinicopathologic parameters including anatomic sites, gender, age (60 vs.>60years), stage, level of invasion, p53 and MDM2 [murine double minute 2] expressions, performance status, and adjuvant chemotherapy were evaluated. The patients' median age was 62years, and 16 (50%) received adjuvant chemotherapy. Expressions of p53 and MDM2 were demonstrated in six of 24 and three of 26 cases, respectively. Predictors of poor survival according to univariate analysis were level of invasion and anatomic location of the primary tumor. Patients who received adjuvant chemotherapy had prolonged survival (p=0.002), which was also shown in the multivariate Cox regression model (HR, 0.24; p=0.014). Our analysis suggests a significant role of adjuvant chemotherapy and different patterns of p53 and MDM2 expression in HNMM relative to cutaneous melanomas. However, since this study is retrospective and observational, with a small sample size, further studies are needed to confirm the definitive role of adjuvant chemotherapy in the treatment of malignant mucosal melanoma of the head and neck.

Ki-67 expression as a prognostic factor in diffuse large B-cell lymphoma patients treated with rituximab plus CHOP.

BACKGROUND: Assessment of tumor cell proliferation based on Ki-67 expression yielded conflicting prognostic predictions of patients with diffuse large B-cell lymphoma (DLBCL). The introduction of rituximab to the DLBCL treatment regime has led to alterations in the significance of previous prognostic factors. METHODS: We analyzed Ki-67 expression and its correlation with prognosis in 144 patients with DLBCL treated with rituximab plus CHOP (R-CHOP) between July 2003 and January 2008. RESULTS: The complete response (CR) rates following R-CHOP administration were not significantly different, based on Ki-67 expression status (P = 0.104). However, higher rates of relapse were observed in the high Ki-67 expression group (Ki-67 >or= 85%, n = 46) with 25.0%, compared to 10.0% in the low Ki-67 expression group (Ki-67 < 85%, n = 88) (P = 0.040). The 2-yr event-free survival (EFS) rates were 44.3% and 74.1% in the high and low Ki-67 expression groups, respectively (P = 0.011). The 2-yr overall survival (OS) rate was 66.4% in the high Ki-67 expression group and 82.2% in the low Ki-67 expression group (P = 0.016). In multivariate analysis, Ki-67 expression was a significant prognostic factor for EFS [hazard ratio (HR) = 2.909; 95% confidence interval (CI) 1.261-6.708; P = 0.012]. Ki-67 was associated with OS but with borderline significance (HR = 2.876; 95% CI, 0.972-8.508; P = 0.056). CONCLUSION: Elevated Ki-67 expression seems to be associated with higher relapse after CR and inferior EFS in patients with DLBCL treated with R-CHOP.

Detection of Plasmodium vivax infection in the Republic of Korea by loop-mediated isothermal amplification (LAMP).

Loop-mediated isothermal amplification (LAMP) is a novel technique that rapidly amplifies target DNA in isothermal conditions. In a previous study, the sensitivities and specificities of LAMP, microscopy, and nested PCR were compared in the context of rapid malaria detection. In the present study, LAMP detected vivax malaria parasites in 115 of 117 microscopically positive samples (sensitivity, 98.3%; 95% CI, 97.4-100%), which agreed well with the nested PCR results (sensitivity, 99.1%; 95% CI: 96.0-100%). No positive cases of malaria were detected by LAMP or nested PCR in 50 consecutive feverish patients other than malaria from malaria endemic areas. LAMP performed on DNA extracted from heat-treated blood had a sensitivity of 93.3% (28/30, 95% CI: 84.4-100%) and specificity of 100% (30/30, 95% CI: 100%). The present study shows that LAMP based assays have high sensitivity, specificity, and amplification efficiencies for Plasmodium vivax detection. The authors recommend that LAMP can be considered as a rapid nucleic acid amplification assay for the molecular diagnosis of P. vivax in both clinical laboratories and malaria clinics in areas where vivax malaria is endemic.

Prognostic value of immunohistochemical staining of p53, bcl-2, and Ki-67 in small cell lung cancer.

Small cell lung cancer (SCLC) is one of the most fatal cancers in humans and many factors are known to be related to its poor prognosis. Immunohistochemical (IHC) stainings were done on SCLC specimens in order to investigate the prognostic value of the apoptosis-related gene expression and the tumor proliferative maker, and the relationships among these IHC results and patients clinical characteristics, chemoresponsiveness, and survival were analyzed. The medical records of 107 patients were reviewed retrospectively. IHC stainings for p53, bcl-2 and Ki-67 expressions were performed in the 66 paraffin-embedded biopsy samples. Sixty-six out of the 107 patients were evaluable for response rate and survival. The overall response rate was 75% (95% Confidence Interval=74-76%) and the median survival time was 14 months. The median survival time of limited stage was 16 months and that of extensive stage was 10 months. The prevalence of p53, bcl-2 and Ki-67 expression was 62%, 70%, and 49%, respectively. There were no correlations among the immunoreactivities of p53, bcl-2 and Ki-67 with clinical stage, chemoresponsiveness or overall survival. The clinical stage was the only prognostic factor influencing survival. The expression rates of p53, bcl-2, and Ki-67 were relatively high in SCLC without any prognostic significance. The exact clinical role of these markers should be defined through further investigations.

A case of uterine cervical cancer presenting with granulocytosis.

Granulocytosis occurs in 40% of patients with lung and gastrointestinal cancers, 20% of patients with breast cancer, 30% of patients with brain tumor and ovarian cancer and 10% of patients with renal cell carcinoma. Granulocytosis occurs because of production of G-CSF, GM-CSF and IL-6. Uterine cervical carcinoma with granulocytosis as a paraneoplastic syndrome, however, has been rarely reported. We recently witnessed a case of invasive squamous cell carcinoma of the uterine cervix with granulocytosis. Leukocytosis developed up to 69,000/microL, and then normalized after chemo-radiotherapy. There was no evidence of infection, tumor necrosis, glucocorticoid administration, or myeloproliferative disease by examination of a bone marrow aspirate when granulocytosis appeared. This phenomenon was probably associated with the secretion of hematopoietic growth factors such as G-CSF, GM-CSF and IL-6 by the tumor. We suggest that, like some other solid tumors, cervical cancer can present with granulocytosis as a paraneoplastic syndrome.

Secondary hematological malignancies after breast cancer chemotherapy.

According to several reports, the 10 year incidence of secondary acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) after systemic chemotherapy is approximately 1.5%. The cumulative risk increases by 0.25--1% for the first 8 years after treatment. We have reported only 6 cases of hematological malignancies (0.3%) after breast cancer chemotherapy in our institute. We detected 2 cases of secondary AML and 1 case of MDS, 19, 52 and 12 months, respectively, after systemic chemotherapy for breast cancer. Published data on the occurrence of secondary hematological malignancies other than AML or MDS in this setting are scarce. We encountered diffuse large B-cell lymphoma, angioimmunoblastic lymphoma and mantle cell lymphoma as secondary hematological malignancies after systemic chemotherapy for breast cancer.

[The prevalence and clinical characteristics of hepatitis-delta infection in Korea].

BACKGROUND/AIMS: The prevalence of hepatitis delta virus (HDV) infection has been estimated as being approximately 5% among global HBsAg carriers. The anti-delta positive rate in Koreans had been reported as being 0.85% in 1985. While the prevalence of HBV has been decreased from nearly 10% to 5% during the past twenty years, there have been no more studies on the anti-delta prevalence in Koreans. The aim of this study was to estimate the anti-delta prevalence in Koreans and to study the clinical characteristics of anti-delta positive patients in a single center. METHODS: Serum anti-delta was measured in one hundred ninety four HBsAg-positive patients who were admitted to our hospital from February 2003 to August 2003. We checked the genotypes of the HBV in the anti-delta positive patients. The clinical features of the anti-delta positive patients were compared to those clinical features of the anti-delta negative patients from the aspect of age, gender, mode of transmission, the positivity of HBeAg and serum HBV DNA. RESULTS: Serum anti-delta was positive in seven patients among the 194 subjects, giving a 3.6% positive rate. Among these seven patients, six had hepatocellular carcinoma (HCC) and the other one had cholangiocarcinoma. All of the anti-delta positive patients had the C genotype of HBV. The anti-delta positive patients showed significantly suppressed HBV DNA replication compared to the anti-delta negative patients. CONCLUSIONS: In Koreans, anti-delta was positive mainly in HCC patients with an approximate prevalence of 4%, and this rate has not changed much for the past twenty years. HBV DNA replication was suppressed by HDV infection.