Effect of total intravenous versus inhalation anesthesia on long-term oncological outcomes in patients undergoing curative resection for early-stage non-small cell lung cancer: a retrospective cohort study / 대한마취과학회지

Background@#Propofol-based total intravenous anesthesia (TIVA) improves long-term outcomes after cancer surgery compared with inhalation anesthesia. However, its effect on patients undergoing non-small cell lung cancer (NSCLC) surgery remains unclear. We aimed to compare the oncological outcomes of TIVA and inhalation anesthesia after curative resection of early-stage NSCLC. @*Methods@#We analyzed the medical records of patients diagnosed with stage I or II NSCLC who underwent curative resection at a tertiary university hospital between January 2010 and December 2017. The primary outcomes were recurrence-free survival (RFS) and overall survival (OS) according to anesthesia type. @*Results@#We included 1,508 patients with stage I/II NSCLC. The patients were divided into the TIVA (n = 980) and Inhalation (n = 528) groups. The two groups were well-balanced in terms of baseline clinical characteristics. The TIVA group demonstrated significantly improved RFS (7.7 years, 95% CI [7.37, 8.02]) compared with the Inhalation group (6.8 years, 95% CI [6.30, 7.22], P = 0.003). Similarly, TIVA was superior to inhalation agents with respect to OS (median OS; 8.4 years, 95% CI [8.08, 8.69] vs. 7.3 years, 95% CI [6.81, 7.71]; P < 0.001). Multivariable Cox regression analysis revealed that TIVA was an independent prognostic factor related to recurrence (hazard ratio [HR]: 1.24, 95% CI [1.04, 1.47], P = 0.014) and OS (HR: 1.39, 95% CI [1.12, 1.72], P = 0.002). @*Conclusions@#Propofol-based TIVA was associated with better RFS and OS than inhalation anesthesia in patients with stage I/II NSCLC who underwent curative resection.

Clinical Characteristics of Clear Cell Ovarian Cancer: A Retrospective Multicenter Experience of 308 Patients in South Korea / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The purpose of this study was to evaluate clinical characteristics and treatment pattern of ovarian clear cell carcinoma (OCCC) in Korea and the role of adjuvant chemotherapy in earlystage. @*Materials and Methods@#Medical records of 308 cases of from 21 institutions were reviewed and data including age, performance status, endometriosis, thromboembolism, stage, cancer antigen 125, treatment, recurrence, and death were collected. @*Results@#Regarding stage of OCCC, it was stage I in 194 (63.6%), stage II in 34 (11.1%), stage III in 66 (21.6%), and stage IV in 11 (3.6%) patients. All patients underwent surgery. Optimal surgery (residual disease ≤ 1 cm) was achieved in 89.3%. Majority of patients (80.5%) received postoperative chemotherapy. The most common regimen was taxane-platinum combination (96%). Median relapse-free survival (RFS) was 138.5 months for stage I, 33.4 for stage II, 19.3 for stage III, and 9.7 for stage IV. Median overall survival (OS) were not reached, 112.4, 48.7, and 18.3 months for stage I, II, III, and IV, respectively. Early-stage (stage I), endometriosis, and optimal debulking were identified as favorable prognostic factors for RFS. Early-stage and optimal debulking were also favorable prognostic factors for OS. Majority of patients with early-stage received adjuvant chemotherapy. However, additional survival benefit was not found in terms of recurrence. @*Conclusion@#Majority of patients had early-stage and received postoperative chemotherapy regardless of stage. Early-stage and optimal debulking were identified as favorable prognostic factors. In stage IA or IB, adding adjuvant chemotherapy did not show difference in survival. Further study focusing on OCCC is required.

Asian Society of Gynecologic Oncology International Workshop 2018 / 부인종양

The Asian Society of Gynecologic Oncology International Workshop 2018 on gynecologic oncology was held in the Ajou University Hospital, Suwon, Korea on the 24th to 25th August 2018. The workshop was an opportunity for Asian doctors to discuss the latest findings of gynecologic cancer, including cervical, ovarian, and endometrial cancers, as well as the future of fertility-sparing treatments, minimally invasive/radical/debulking surgery, radiotherapy, chemotherapy, targeted therapy, and immunotherapy. Clinical guidelines and position statement of Asian countries were presented by experts. Asian clinical trials for gynecologic cancers were reviewed and experts emphasized the point that original Asian study is beneficial for Asian patients. In Junior session, young gynecologic oncologists presented their latest research on gynecologic cancers.

Prognostic value of neutrophil-to-lymphocyte ratio in locally advanced non-small cell lung cancer treated with concurrent chemoradiotherapy

PURPOSE: This study aimed to investigate neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as prognostic factors in patients with locally advanced non-small cell lung cancer (NSCLC) who received concurrent chemoradiotherapy (CCRT). MATERIALS AND METHODS: We retrospectively analyzed 66 patients with locally advanced NSCLC treated with definitive CCRT. Among these patients, 95% received paclitaxel/carboplatin or docetaxel/cisplatin. The median radiation dose was 66 Gy in 33 fractions. The NLR and PLR before/after CCRT were evaluated. The maximally selected log-rank test was used to obtain the cutoff values related to the overall survival (OS). RESULTS: Patients with high post-CCRT NLR (>3.12) showed worse OS, locoregional progression-free survival (LRPFS), and distant metastasis-free survival (DMFS) than those with low NLR (2-year OS: 25.8% vs. 68.2%, p 141) showed worse OS and LRPFS than those with low PLR (2-year OS: 37.5% vs. 71.1%, p = 0.004; 2-year LRPFS: 16.5% vs. 40.3%, p = 0.040). Patients with high NLR change (>1.61) showed worse OS and LRPFS than those with low NLR change (2-year OS: 26.0% vs. 59.0%, p < 0.001; 2-year LRPFS: 6.8% vs. 31.8%, p = 0.004). The planning target volume (hazard ration [HR] = 2.05, p = 0.028) and NLR change (HR = 3.17, p = 0.025) were the significant factors for OS in the multivariate analysis. CONCLUSION: NLR change after CCRT was associated with poor prognosis of survival in patients with locally advanced NSCLC. An elevated NLR after CCRT might be an indicator of an increased treatment failure risk.

Clinical Characteristics of False-Positive Lymph Node on Chest CT or PET-CT Confirmed by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Lung Cancer / 결핵및호흡기질환

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a standard procedure to evaluate suspicious lymph node involvement of lung cancer because computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography-CT (PET-CT) have limitations in their sensitivity and specificity. There are a number of benign causes of false positive lymph node such as anthracosis or anthracofibrosis, pneumoconiosis, old or active tuberculosis, interstitial lung disease, and other infectious conditions including pneumonia. The purpose of this study was to evaluate possible causes of false positive lymph node detected in chest CT or PET-CT. METHODS: Two hundred forty-seven patients who were initially diagnosed with lung cancer between May 2009 and December 2012, and underwent EBUS-TBNA to confirm suspicious lymph node involvement by chest CT or PET-CT were analyzed for the study. RESULTS: Of 247 cases, EBUS-TBNA confirmed malignancy in at least one lymph node in 189. The remaining 58 patients whose EBUS-TBNA results were negative were analyzed. Age ≥65, squamous cell carcinoma as the histologic type, and pneumoconiosis were related with false-positive lymph node involvement on imaging studies such as chest CT and PET-CT. CONCLUSION: These findings suggest that lung cancer staging should be done more carefully when a patient has clinically benign lymph node characteristics including older age, squamous cell carcinoma, and benign lung conditions.

The Use of the Bethesda System for Reporting Thyroid Cytopathology in Korea: A Nationwide Multicenter Survey by the Korean Society of Endocrine Pathologists

BACKGROUND: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has standardized the reporting of thyroid cytology specimens. The objective of the current study was to evaluate the nationwide usage of TBSRTC and assess the malignancy rates in each category of TBSRTC in Korea. METHODS: Questionnaire surveys were used for data collection on the fine needle aspiration (FNA) of thyroid nodules at 74 institutes in 2012. The incidences and follow-up malignancy rates of each category diagnosed from January to December, 2011, in each institute were also collected and analyzed. RESULTS: Sixty out of 74 institutes answering the surveys reported the results of thyroid FNA in accordance with TBSRTC. The average malignancy rates for resected cases in 15 institutes were as follows: nondiagnostic, 45.6%; benign, 16.5%; atypical of undetermined significance, 68.8%; suspicious for follicular neoplasm (SFN), 30.2%; suspicious for malignancy, 97.5%; malignancy, 99.7%. CONCLUSIONS: More than 80% of Korean institutes were using TBSRTC as of 2012. All malignancy rates other than the SFN and malignancy categories were higher than those reported by other countries. Therefore, the guidelines for treating patients with thyroid nodules in Korea should be revisited based on the malignancy rates reported in this study.

Clinical Characteristics and Continued Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Administration in EGFR-mutated Non-Small Cell Lung Cancer with Skeletal Metastasis / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The aim of this study was to analyze clinical characteristics of skeletal metastasis in epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) and treatment outcomes of continued EGFR tyrosine kinase inhibitor (TKI) therapy in patients presenting with skeletal metastasis progression. MATERIALS AND METHODS: Of the 216 patients treated with EGFR-TKI for management of stage III-IV NSCLC between 2006 and 2012 in Seoul St. Mary's Hospital, 76 patients with confirmed EGFR-mutated NSCLC with skeletal metastases during therapy were analyzed retrospectively. RESULTS: Of 76 patients with EGFR mutant lung cancer with skeletal metastasis, 37 patients developed first progressive disease (PD) in skeletal regions. EGFR-TKI was continued in these 37 patients after first PD in skeletal regions. Median time to first PD of skeletal regions was 8.9 months (95% confidence interval [CI], 4.8 to 13.0). Median time of continued EGFR-TKI after first PD of skeletal regions was 8.0 months (95% CI, 2.9 to 13.0) in patients with disease progression of preexisting regions, 5.6 months (95% CI, 4.5 to 6.7) in patients showing new localized regions, and 3.3 months (95% CI, 1.1 to 5.5) in patients with multiple new metastatic regions (p=0.006). Median time of postskeletal metastasis progression survival was 23.0 months (95% CI, 13.5 to 32.5), 15.0 months (95% CI, 3 to 34.7), and 7.0 months (95% CI, 6.0 to 8.0) (p=0.004) in the above described patient groups, respectively. Overall, seven patients (18.9%) had more than one episode of skeletal progression of disease without extraskeletal PD. CONCLUSION: Continued EGFR-TKI treatment with adequate local treatment after progression of skeletal metastasis may be considered for patients who show disease progression in preexisting regions or local progression.

Hepatocellular Carcinoma with Cervical Spine and Pelvic Bone Metastases Presenting as Unknown Primary Neoplasm / 대한소화기학회지

The occurrence of hepatocellular carcinoma (HCC) is closely associated with viral hepatitis or alcoholic hepatitis. Although active surveillance is ongoing in Korea, advanced or metastatic HCC is found at initial presentation in many patients. Metastatic HCC presents with a hypervascular intrahepatic tumor and extrahepatic lesions such as lung or lymph node metastases. Cases of HCC presenting as carcinoma of unknown primary have been rarely reported. The authors experienced a case of metastatic HCC in a patient who presented with a metastatic bone lesion but no primary intrahepatic tumor. This case suggests that HCC should be considered as a differential diagnosis when evaluating the primary origin of metastatic carcinoma.

A Case of Adenosquamous Carcinoma Arising from the Base of Tongue / 대한이비인후과학회지

Adenosquamous carcinoma (ASC) of the head and neck is a rare malignancy. This entity was first described in 1968 by Gerughty, et al. Nowadays, ASC is defined in the World Health Organization classification of tumors of the upper respiratory tract and ear as a malignant tumor with histological features of both adenocarcinoma and squamous cell carcinoma. We report a case of adenosquamous carcinoma arising from the base of tongue salvaged by transoral robotic surgery with review of literature.

A Case of IgG4-Related Pancreas and Kidney Disease Mimicking a Renal Pelvic Malignancy / 대한내과학회지

IgG4-related sclerosing disease is a disease entity that has recently attracted attention, manifesting as a multiorgan disease characterized by high serum IgG4 levels, extensive IgG4-positive plasma cells and lymphocyte infiltration of the affected organs, with the pancreas (autoimmune pancreatitis) and kidney as representative targets. In cases of renal involvement, parenchymal lesions are predominant, such as renal cortical lesions or diffuse renal enlargement. However, mass-like lesions involving the renal pelvis are very rare, and mass forming or pelvic involvement types should be distinguished from lymphomas, metastatic cancers and other genitourinary malignancies to avoid unnecessary surgery. Herein, we report a case of IgG4-related sclerosing disease involving the kidney as an unusual involvement pattern presenting as a mass-like lesion with pelvic and perirenal involvement.

A Case-Control Study to Identify Risk Factors for Totally Implantable Central Venous Port-Related Bloodstream Infection / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To date, the risk factors for central venous port-related bloodstream infection (CVP-BSI) in solid cancer patients have not been fully elucidated. We conducted this study in order to determine the risk factors for CVP-BSI in patients with solid cancer. MATERIALS AND METHODS: A total of 1,642 patients with solid cancer received an implantable central venous port for delivery of chemotherapy between October 2008 and December 2011 in a single center. CVP-BSI was diagnosed in 66 patients (4%). We selected a control group of 130 patients, who were individually matched with respect to age, sex, and catheter insertion time. RESULTS: CVP-BSI occurred most frequently between September and November (37.9%). The most common pathogen was gram-positive cocci (n=35, 53.0%), followed by fungus (n=14, 21.2%). Multivariate analysis identified monthly catheter-stay as a risk factor for CVP-BSI (p=0.000), however, its risk was lower in primary gastrointestinal cancer than in other cancer (p=0.002). Initial metastatic disease and long catheter-stay were statistically significant factors affecting catheter life span (p=0.005 and p=0.000). Results of multivariate analysis showed that recent transfusion was a risk factor for mortality in patients with CVP-BSI (p=0.047). CONCLUSION: In analysis of the results with respect to risk factors, prolonged catheter-stay should be avoided as much as possible. It is necessary to be cautious of CVP-BSI in metastatic solid cancer, especially non-gastrointestinal cancer. In addition, avoidance of unnecessary transfusion is essential in order to reduce the mortality of CVP-BSI. Finally, considering the fact that confounding factors may have affected the results, conduct of a well-designed prospective controlled study is warranted.

High-Dose-Rate Brachytherapy for the Treatment of Vaginal Intraepithelial Neoplasia / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Vaginal intraepithelial neoplasia (VAIN), a rare premalignant condition, is difficult to eradicate. We assess the effectiveness of high-dose rate intracavitary brachytherapy (HDR-ICR) in patients with VAIN or carcinoma in situ (CIS) of the vagina after hysterectomy. MATERIALS AND METHODS: We reviewed 34 patients treated for posthysterectomy VAIN or CIS of the vagina by brachytherapy as the sole treatment. All patients underwent a coloposcopic-directed punch biopsy or had abnormal cytology, at least 3 consecutive times. All patients were treated with a vaginal cylinder applicator. The total radiation dose was mainly 40 Gy in 8 fractions during the periods of 4 weeks at a prescription point of the median 0.2 cm (range, 0 to 0.5 cm) depth from the surface of the vaginal mucosa. RESULTS: Acute toxicity was minimal. Seven patients had grade 1/2 acute urinary and rectal complications. There were 15 cases of late toxicity, predominantly vaginal mucosal reaction in 12 patients. Of these patients, two patients suffered from grade 3 vaginal stricture and dyspareunia continuously. After a median follow-up time of 48 months (range, 4 to 122 months), there were 2 recurrences and 2 persistent diseases, in which a second-line therapy was needed. The success rate was 88.2%. The average prescription point in failure patients was 1.1 mm from the surface of the vagina compared to an average of 2.6 mm in non-recurrent patients (p=0.097). CONCLUSION: HDR-ICR is an effective treatment method in VAIN patients. In spite of high cure rates, we should consider issues regarding vaginal toxicity and radiation techniques to reduce the occurrence of failure and toxicity.

High-Dose-Rate Brachytherapy for the Treatment of Vaginal Intraepithelial Neoplasia / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Vaginal intraepithelial neoplasia (VAIN), a rare premalignant condition, is difficult to eradicate. We assess the effectiveness of high-dose rate intracavitary brachytherapy (HDR-ICR) in patients with VAIN or carcinoma in situ (CIS) of the vagina after hysterectomy. MATERIALS AND METHODS: We reviewed 34 patients treated for posthysterectomy VAIN or CIS of the vagina by brachytherapy as the sole treatment. All patients underwent a coloposcopic-directed punch biopsy or had abnormal cytology, at least 3 consecutive times. All patients were treated with a vaginal cylinder applicator. The total radiation dose was mainly 40 Gy in 8 fractions during the periods of 4 weeks at a prescription point of the median 0.2 cm (range, 0 to 0.5 cm) depth from the surface of the vaginal mucosa. RESULTS: Acute toxicity was minimal. Seven patients had grade 1/2 acute urinary and rectal complications. There were 15 cases of late toxicity, predominantly vaginal mucosal reaction in 12 patients. Of these patients, two patients suffered from grade 3 vaginal stricture and dyspareunia continuously. After a median follow-up time of 48 months (range, 4 to 122 months), there were 2 recurrences and 2 persistent diseases, in which a second-line therapy was needed. The success rate was 88.2%. The average prescription point in failure patients was 1.1 mm from the surface of the vagina compared to an average of 2.6 mm in non-recurrent patients (p=0.097). CONCLUSION: HDR-ICR is an effective treatment method in VAIN patients. In spite of high cure rates, we should consider issues regarding vaginal toxicity and radiation techniques to reduce the occurrence of failure and toxicity.

Clinical Features and Treatment of Collecting Duct Carcinoma of the Kidney from the Korean Cancer Study Group Genitourinary and Gynecology Cancer Committee / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Collecting duct carcinoma (CDC) of the kidney is an aggressive disease with a poor prognosis, accountings for less than 1% of all renal cancers. To date, no standard therapy for CDC has been established. The aim of this study is an investigation of clinicopathologic findings of CDC and correlation of the disease status with a prognosis. MATERIALS AND METHODS: From 1996 to 2009, 35 patients with CDC were treated at eight medical centers. The diagnosis of CDC was made based on nephrectomy in 27 cases and renal biopsy in eight cases. RESULTS: Median PFS and OS for all patients were 5.8 months (95% CI 3.5 to 9.2) and 54.4 months (95% CI 0 to 109.2), respectively. The OS of patients with Stages I-III was 69.9 months (95% CI 54.0 to 85.8), while that of patients with Stage IV was 8.6 months (95% CI 0 to 23.3), which showed a statistically significant difference (p=0.01). In addition, among patients with Stage IV, the OS of patients who received a palliative treatment (immunotherapy, chemotherapy, or targeted therapy) was 18.4 months, which was higher than the OS of patients without treatment of 4.5 months. CONCLUSION: CDC is a highly aggressive form of renal cell carcinoma. Despite most of the treatments, PFS and OS were short, however, there were some long-term survivors, therefore, conduct of additional research on the predictive markers of the several clinical, pathological differences and their treatments will be necessary.

A Case of Ancient Schwannoma in Retromaxillary Area Removed with Le Fort I Osteotomy Approach

Schwannoma, which manifests as a smooth and solitary, encapsulated lesion, originates from the nerve sheaths of Schwann cells. Ancient schwannoma, a rare histologic variant of schwannoma, characterized by its distinctive degenerative changes. Basically, treatment entails complete removal of the mass, with maximal safeguarding of the nerve. However, depending on tumor size and extent, complete removal can be problematic. Le Fort I osteotomy in orthognathic surgery is widely utilized and can be effective to remove the skull base tumors. A 25-year-old woman presented with stabbing pain of 1-2 seconds duration occurring every two hours in the interior of the right face, which condition had persisted for one year. Magnetic resonance imaging showed mass lesion in the right retromaxillary area. Mass in retromaxillary area was removed by Le Fort I osteotomy. Pathologic examination confirmed the diagnosis of ancient schwannoma. In the course of a six-month follow-up, neither recurrence nor malocclusion was observed.

A Case of Right Sinus of Valsalva Rupture with Dissection into Interventricular Septum Causing Left Ventricular Outflow Tract Obstruction

Sinus of Valsalva aneurysm (SVA) is an uncommon anomaly of the aorta. Rupture of SVA often precipitates dramatic clinical complications, including heart failures. Right SVAs are the most common type, and when they rupture, they usually rupture into the right ventricle or right atrium. Rupture into left ventricle or interventricular septum is rare. Herein, we report a case of right SVA rupture with dissection into interventricular septum, which produced significant left ventricular outflow tract obstruction and aortic regurgitation. The case was successfully treated by surgical operation.

A Case of Right Sinus of Valsalva Rupture with Dissection into Interventricular Septum Causing Left Ventricular Outflow Tract Obstruction

Sinus of Valsalva aneurysm (SVA) is an uncommon anomaly of the aorta. Rupture of SVA often precipitates dramatic clinical complications, including heart failures. Right SVAs are the most common type, and when they rupture, they usually rupture into the right ventricle or right atrium. Rupture into left ventricle or interventricular septum is rare. Herein, we report a case of right SVA rupture with dissection into interventricular septum, which produced significant left ventricular outflow tract obstruction and aortic regurgitation. The case was successfully treated by surgical operation.

Detection of BRAF(V600E) Mutation using Peptide Nucleic Acid-Mediated PCR Clamping Method in Fine Needle Aspiration Cytology / 대한내분비외과학회지

PURPOSE: The aim of this study was to evaluate the diagnostic value of a peptide nucleic acid (PNA)-mediated PCR clamping method for the detection of BRAFV600E mutations in fine needle aspiration cytology (FNAC). METHODS: One hundred sixty four patients underwent FNAC to evaluate BRAFV600E mutations between April 2011 and November 2011. Among them, forty-two patients were diagnosed with papillary thyroid carcinoma in a permanent pathologic specimen. A PNA-mediated PCR clamping method and a Dual-Priming Oligonucleotide (DPO)-based Real-time PCR method were used to detect the BRAFV600E mutation. We compared the result of mutation between the two methods. RESULTS: A BRAF mutation was found in 31 samples created by the PNA-mediated PCR clamping method, and in 28 samples in the DPO-based Real-time PCR method. The rate of BRAF mutation was 73.8% in association with the PNA-mediated PCR clamping method, and 66.7% in association with the DPO-based Real-time PCR method. There was no statistical differences between the two methods (P>0.05). CONCLUSION: The PNA-mediated PCR clamping method may be an alternative to the DPO-based Real-Time PCR method for detection of BRAF mutations in thyroid nodules.

Papillary Fibroelastoma Mimicking Vegetation of the Mitral Valve

Although cardiac papillary fibroelastoma is rare, it is the most common primary tumor of cardiac valves. The clinical presentation of these tumors varies from asymptomatic to embolic complications. We report an asymptomatic case of papillary fibroelastoma of mitral valve which was diagnosed by transthoracic echocardiography. The tumor was successfully resected by surgery.

WHO Classification of Malignant Lymphomas in Korea: Report of the Third Nationwide Study

BACKGROUND: The aim of study was to determine the relative frequency of malignant lymphoma according to World Health Organization (WHO) classification in Korea. METHODS: A total of 3,998 cases diagnosed at 31 institutes between 2005 and 2006 were enrolled. Information including age, gender, pathologic diagnosis, site of involvement and immunophenotypes were obtained. RESULTS: The relative frequency of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) was 95.4% and 4.6%, respectively. B-cell lymphomas accounted for 77.6% of all NHL, while T/natural killer (T/NK)-cell lymphomas accounted for 22.4%. The most frequent subtypes of NHL were diffuse large B-cell lymphoma (42.7%), extranodal marginal zone B-cell lymphoma (MZBCL) of mucosa-associated lymphoid tissue (19.0%), NK/T-cell lymphoma (6.3%) and peripheral T-cell lymphoma (PTCL), unspecified (6.3%), in decreasing order. The relative frequency of HL was nodular sclerosis (47.4%), mixed cellularity (30.6%), and nodular lymphocyte predominant (12.1%) subtypes. Compared with a previous study in 1998, increase in gastric MZBCL and nodular sclerosis HL, and slight decrease of follicular lymphoma, PTCL, and NK/T-cell lymphoma were observed. CONCLUSIONS: Korea had lower rates of HL and follicular lymphoma, and higher rates of extranodal NHL, extranodal MZBCL, and NK/T-cell lymphoma of nasal type compared with Western countries. Changes in the relative frequency of lymphoma subtypes are likely ascribed to refined diagnostic criteria and a change in national health care policy.