Advantage of achieving deep response following frontline daratumumab-VTd compared to VRd in transplant-eligible multiple myeloma: multicenter study

Background@#The goal of induction therapy for multiple myeloma (MM) is to achieve adequate disease control. Current guidelines favor triplet (bortezomib-lenalidomide-dexamethasone;VRd) or quadruplet regimens (daratumumab, bortezomib-thalidomide-dexamethasone;D-VTd). In the absence of a direct comparison between two treatment regimens, we conducted this study to compare the outcomes and safety of VRd and D-VTd. @*Methods@#Newly diagnosed MM patients aged ＞18 years who underwent induction therapy followed by autologous stem cell transplantation (ASCT) between November 2020 and December 2021 were identified. Finally, patients with VRd (N=37) and those with D-VTd (N=43) were enrolled. @*Results@#After induction, 10.8% of the VRd group showed stringent complete remission (sCR), 21.6% showed complete response (CR), 35.1% showed very good partial response (VGPR), and 32.4% showed partial response (PR). Of the D-VTd group, 9.3% showed sCR, 34.9% CR, 48.8% VGPR, and 4.2% PR (VGPR or better: 67.6% in VRd vs. 93% in D-VTd, P =0.004). After ASCT, 68.6% of the VRd group showed CR or sCR, while 90.5% of the D-VTd group showed CR or sCR (P=0.016). VRd was associated with an increased incidence of skin rash (P=0.044). Other than rashes, there were no significant differences in terms of adverse events between the two groups. @*Conclusion@#Our study supports the use of a front-line quadruplet induction regimen containing a CD38 monoclonal antibody for transplant-eligible patients with newly diagnosed MM.

Practical issues in CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy presents a revolutionary advancement in personalized cancer treatment. During the production process, the patient's own T-cells are genetically engineered to express a synthetic receptor that binds to a tumor antigen. CAR T-cells are then expanded for clinical use and infused back into the patient's body to attack cancer cells. Although CAR T-cell therapy is considered a major breakthrough in cancer immunotherapy, it is not without limitations. In this review, we discuss the barriers to effective CAR T-cell therapy in Korea.

Reduced-intensity conditioning versus myeloablative conditioning allogeneic stem cell transplantation for patients with myelofibrosis

Background@#Allogeneic hematopoietic stem cell transplantation (alloSCT) is the sole curative option for myelofibrosis (MF). However, it is unknown as to which of the two, myeloablative conditioning (MAC) or reduced-intensity conditioning (RIC), is a better preconditioning regimen. @*Methods@#Twenty-five patients with MF were treated with alloSCT, 12 of whom underwent RIC.Baseline characteristics, response to alloSCT, adverse events, including graft-versus-host disease (GVHD), and survival outcomes were reviewed. @*Results@#There was no difference in the neutrophil engraftment rate and time to engraftment between MAC vs. RIC. The time to platelet engraftment was significantly longer in the MAC group (median, 112.8 vs. 28.8 days for MAC vs. RIC, respectively, P =0.049). RIC was more advantageous in terms of achieving complete chimerism (38.5% vs. 83.3%, P =0.041). The incidence of acute GVHD was 84.6% (11 of 13) and 58.3% (7 of 12) in the MAC and RIC groups, respectively. The cumulative incidence of grade III‒IV acute GVHD was significantly higher in the MAC group than in the RIC group (P =0.03). No significant differences were observed in progression-free and overall survival. The 17-month probability of progression-free survival was 38.4% [95% confidence interval (CI), 19.3‒76.5] vs. 47.6% (95% CI, 25.7‒88.2) (P =0.21), and that of overall survival was 53.8% (95% CI, 32.5‒89.1) vs. 48.6% (95% CI, 26.8‒88.3) (P =0.85) for MAC vs. RIC, respectively. @*Conclusion@#RIC offers a significant advantage over MAC, even in younger patients with MF undergoing alloSCT, in terms of cell engraftment, rate of complete chimerism achievement, and incidence of acute GVHD.

Eltrombopag for Post-Transplant Poor Graft Function in East Asian Patients

Poor graft function (PGF) is a serious, potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation. Eltrombopag has shown multilineage responses in patients with refractory severe aplastic anemia, supporting the idea that it may improve cytopenia in patients with PGF. This retrospective, single center analysis included 8 Korean patients receiving eltrombopag for PGF. Median interval between transplant and eltrombopag treatment was 73 days, and the median duration treatment was 3.5 weeks.With median maximum daily dose of 50 mg, the time to best response was 93 days. Median hemoglobin increased from 8.2 g/dL to 10.9 g/dL, platelet from 18.5 × 109 /L to 54 × 109 /L, and absolute neutrophil count from 1.25 × 109 /L to 3.32 × 109 /L. In conclusion, eltrombopag is a good option for PGF in Korean patients, even at a lower dose compared to western patients.

Chimeric Antigen Receptor-T Cell Therapy / 대한내과학회지

Chimeric antigen receptor (CAR) T-cell therapy constitutes a revolutionary advancement in personalized cancer treatment. During this treatment, a patient's own T cells are genetically engineered to express a synthetic receptor that binds a tumor antigen. CAR-T cells are then expanded for clinical use and infused back into the patient's body to attack cancer. CAR-T cells have produced remarkable clinical responses with B-cell malignancies. However, CAR-T cells therapy is not without problems. Barriers to effective CAR-T cells therapy include severe life-threatening toxicities and modest anti-tumor activity. In this review, we introduce the concept of CAR-T cells therapy, currently available CAR-T cells therapy options, and how to deal with adverse events.

How myeloproliferative neoplasms patients’ experience and expectations differ from physicians’: the international MPN Landmark survey

Background/Aims@#Recent advances in the understanding of the pathophysiology of myeloproliferative neoplasms (MPN) were not paralleled with advances in treatment options; thus many questions regarding optimal MPN management remain unanswered. Here, we report the results of descriptive survey study of Korean MPN patients and their attending physicians. @*Methods@#A total of 105 Korean patients (myelofibrosis [MF], 39; polycythemia vera [PV], 25; essential thrombocythemia [ET], 41) and 30 physicians completed the Landmark Health Survey, then data from the survey were analyzed. @*Results@#Among the MPN-Symptom Assessment Form symptoms, the most severe symptom reported was ‘fatigue or tiredness’ in MF and ET patients and ‘itching’ in PV patients. The majority of the patients agreed that MPN reduced their quality of life (QoL). Interestingly, physicians gave higher scores regarding the impact of MPN on patient’s daily and social life compared to patients themselves. For patients, the most important treatment goal was symptom improvement regardless of MPN subtype, while for physicians the highest priority for treatment was better QoL regardless of MPN subtype. Generally, both patients and physicians were satisfied with the overall treatment/management of MPN and communications. However, many patients felt there was not enough time during the appointment for discussion, while many physicians felt they lacked effective drugs to offer to their patients. @*Conclusions@#Our study suggests there are room for better-standardized monitoring of symptoms and treatment options and those continuous efforts to bridge the gap between patients and physicians are necessary for better care of MPN patients.

IDH1/2 mutations in acute myeloid leukemia

The mutational and epigenetic landscape of acute myeloid leukemia (AML) has become increasingly well understood in recent years, informing on biological targets for precision medicine. Among the most notable findings was the recognition of mutational hot-spots in the isocitrate dehydrogenase (IDH) genes. In this review, we provide an overview on the IDH1/2 mutation landscape in Korean AML patients, and compare it with available public data. We also discuss the role of IDH1/2 mutations as biomarkers and drug targets.Taken together, occurrence of IDH1/2 mutations is becoming increasingly important in AML treatment, thus requiring thorough examination and follow-up throughout the clinical course of the disease.

Multicenter retrospective analysis of patients with chronic lymphocytic leukemia in Korea

Background@#Chronic lymphocytic leukemia (CLL) is the most common type of adult leukemia in Western countries but is rare in the East Asian countries. Due to its rarity and the lack of feasible novel agents and laboratory prognostic tools, there are limited data on the clinical outcomes of this disease in Asia. To clarify the current treatment status, we performed a multicenter retrospective analysis of patients with CLL in Korea. @*Methods@#The medical records of 192 eligible patients between 2008 and 2019 were reviewed for clinical characteristics, treatment courses, and outcomes. The first-line treatment regimens of the patients included in this analysis were as follows: fludarabine/cyclophosphamide/rituximab (FCR) (N=117, 52.7%), obinutuzumab plus chlorambucil (GC) (N=30, 13.5%), and chlorambucil monotherapy (N=24, 10.8%). @*Results@#The median progression-free survival (PFS) was 55.6 months, and the average 2-year PFS rate was 80.3%. PFS was not significantly different between the patients receiving FCR and those receiving GC; however, chlorambucil treatment was associated with significantly inferior PFS (P ＜0.001). The median overall survival was 136.3 months, and the average 5- and 10-year OS rates were 82.0% and 57.4%, respectively. @*Conclusion@#This is one of the largest studies involving Korean patients with CLL. Although the patients had been treated with less favored treatment regimens, the outcomes were not different from those reported in Western studies.

Leukemic stem cell phenotype is associated with mutational profile in acute myeloid leukemia

Background/Aims@#Understanding leukemic stem cell (LSC) is important for acute myeloid leukemia (AML) treatment. However, association of LSC with patient prognosis and genetic information in AML patients is unclear. @*Methods@#Here we investigated the associations between genetic information and the various LSC phenotypes, namely multipotent progenitor (MPP)-like, lymphoid primed multipotent progenitor (LMPP)-like and granulocyte-macrophage progenitors (GMP)-like LSC in 52 AML patients. @*Results@#In secondary AML patients, MPP-like LSC was significantly higher than de novo AML (p = 0.0037). The proportion of MPP-like LSC was especially high in post-myeloproliferative neoplasm AML (p = 0.0485). There was no correlation between age and LSC phenotype. Mutations of KRAS and NRAS were observed in MPP-like LSC dominant patients, TP53 and ASXL1 mutations in LMPP-like LSC dominant patients, and CEBPA, DNMT3A and IDH1 mutations in GMP-like LSC dominant patients. Furthermore, KRAS mutation was significantly associated with MPP-like LSC expression (p = 0.0540), and TP53 mutation with LMPP-like LSC expression (p = 0.0276). When the patients were separated according to the combined risk including next generation sequencing data, the poorer the prognosis, the higher the LMPP-like LSC expression (p = 0.0052). This suggests that the dominant phenotype of LSC is one of the important factors in predicting the prognosis and treatment of AML. @*Conclusions@#LSC phenotype in AML is closely associated with the recurrent mutations which has prognostic implication. Further research to confirm the meaning of LSC phenotype in the context of genetic aberration is warranted.

Pilot study for the Psychometric Validation of the Sheffield Profile for Assessment and Referral to Care (SPARC) in Korean Cancer Patients / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#This study aimed to validate the Sheffield Profile for Assessment and Referral to Care (SPARC) as an effective tool for screening palliative care needs among Korean cancer patients. @*Materials and Methods@#The English version of the SPARC was translated by four Korean oncologists and reconciled by a Korean language specialist and a medical oncologist fluent in English. After the first version of the Korean SPARC (K-SPARC) was developed, back-translation into English was performed by a professional translator and bilingual oncologist. The back-translated version was reviewed by the original author (S.H.A.), and modifications were made (ver. 2). The second version of the K-SPARC was tested against other questionnaires, including the Functional Assessment of Cancer Therapy-General (FACT-G) and the Edmonton Symptom Assessment System (ESAS). @*Results@#Thirty patients were enrolled in the pilot trial. Fifteen were male, and the median age was 64.5 years. Six patients had an Eastern Cooperative Oncology Group performance status of 2 or more. All patients except one were receiving chemotherapy. Regarding internal consistency, the Cronbach’s α scores for physical symptoms, psychological issues, religious and spiritual issues, independency and activity, family and social issues, and treatment issues were 0.812, 0.804, 0.589, 0.843, 0.754, and 0.822, respectively. The correlation coefficients between the SPARC and FACT-G were 0.479 (p=0.007) for the physical domain and –0.130 (p=0.493) for the social domain. @*Conclusion@#This pilot study indicates that the K-SPARC could be a reliable tool to screen for palliative care needs among Korean cancer patients. A further study to validate our findings is ongoing.

High Cell-Free DNA Levels in Cerebrospinal Fluid Predict Leptomeningeal Seeding of Hematologic Malignancy

Background@#and Purpose: The main difficulty when diagnosing leptomeningeal metastases (LMSs) is the low sensitivity of cytology. Cancer cells release cell-free DNA (cfDNA) during proliferation and apoptosis, and so we analyzed the cfDNA level as a biomarker for LMSs in hematologic malignancy. @*Methods@#This study prospectively enrolled 20 patients with hematologic malignancy who underwent cerebrospinal fluid (CSF) analysis. LMS was diagnosed based on both CSF cytology and clinical findings. @*Results@#The CSF level of cfDNA was higher in patients with LMSs (108.17±84.84 ng/mL, mean±standard deviation) than in non-LMS patients (14.23±2.78 ng/mL). The sensitivity of cfDNA was higher than that of cytology (100% vs. 87%). @*Conclusions@#The cfDNA level in the CSF can be used as a supplemental marker for diagnosing LMS in hematologic malignancy patients.

Epidemiology of Congenital Bleeding Disorders: a Nationwide Populationbased Korean Study

Background@#Except for data in the Korea Hemophilia Foundation Registry, little is known of the epidemiology of congenital bleeding disorders in Korea. @*Methods@#Data were obtained from the Korean Health Insurance Review and Assessment Service (HIRA) database. @*Results@#From 2010 to 2015, there were 2,029 patients with congenital bleeding disorders in the Korean HIRA database: 38% (n = 775) of these patients had hemophilia A (HA), 25% (n = 517) had von Willebrand disease (vWD), 7% (n = 132) had hemophilia B (HB), and 25% (n = 513) had less common factor deficiencies. The estimated age-standardized incidence rate (ASR) of HA and HB was 1.78–3.15/100,000 and 0.31–0.51/100,000, respectively. That of vWD was 1.38–1.95/100,000. The estimated ASR of HA showed increase over time though the number of new patients did not increase. Most patients with congenital bleeding disorders were younger than 19 years old (47.8%), and most were registered in Gyeonggi (22.1%) and Seoul (19.2%). @*Conclusion@#This is the first nationwide population-based study of congenital bleeding disorders in Korea. This study provides data that will enable more accurate estimations of patients with vWD. This information will help advance the comprehensive care of congenital bleeding disorders. We need to continue to obtain more detailed information on patients to improve the management of these diseases.

A case of immune thrombocytopenia associated with invasive thymoma successfully treated with eltrombopag

No abstract available.

Costs and clinical outcomes of patients with diffuse large B-cell lymphoma in first remission: role of PET/CT surveillance

BACKGROUND/AIMS@#The role of [18F]-f luorodeoxyglucose positron emission tomography-computed tomography (PET/CT) in patients with diffuse large B-cell lymphoma (DLBCL) in first remission is unclear.@*METHODS@#Medical costs within the first 3 years of treatment completion and clinical outcomes of 118 patients with DLBCL in first remission with and without surveillance PET/CT (PET/CT [+] group [n = 76] and PET/CT [−] group [n = 42], respectively) were retrospectively analyzed.@*RESULTS@#In a propensity matched cohort with adjustment for International Prognostic Index risk and relapse, the PET/CT (+) group was shown to have similar medical costs as the PET/CT (−) group. Relapse-free survival (RFS) and overall survival (OS) were comparable between the two groups (median RFS not reached [NR] for both groups, p = 0.133; median OS NR, p = 0.542). Among 76 patients with surveillance PET/CT, 31 (40.8%) had findings suggestive of recurrence and 16 of these (51.6%) were later confirmed to have recurrent disease. Fifteen patients (48.4%) were confirmed to not have recurrence after follow-up CT or PET/CT evaluation (n = 10) and biopsy (n = 4). None of the patients with negative PET/CT findings had disease recurrence. Sensitivity, specificity, positive predictive value, and negative predictive value of PET/CT for detection of recurrence were 1, 0.75, 0.52, and 1, respectively.@*CONCLUSIONS@#Surveillance PET/CT resulted in similar clinical outcomes and medical costs compared to no surveillance PET/CT. Approximately half of patients with PET/CT findings of recurrence had no recurrence after follow-up imaging and biopsy, which would not have been carried out if PET/CT had not been performed in the first place.

Busulfan plus melphalan versus high-dose melphalan as conditioning regimens in autologous stem cell transplantation for newly diagnosed multiple myeloma

BACKGROUND: High-dose melphalan (HDMEL) represents the standard conditioning regimen before autologous stem cell transplant (ASCT) in multiple myeloma (MM), but recent updates have suggested combination of melphalan with bulsulfan (BUMEL) is also associated with favorable outcomes. We performed the current study to address the lack of comparative studies between the two conditioning regimens in Asian populations. METHODS: Using the Korean National Health Insurance and Korean Health Insurance Review and Assessment Service databases, 1,304 patients newly diagnosed with MM undergoing ASCT between January 2010 and December 2014 were identified. Patients were divided according to conditioning regimen (HDMEL vs. BUMEL), and after case matching, 428 patients undergoing HDMEL conditioning were compared to 107 patients undergoing BUMEL conditioning with respect to clinical course and treatment outcomes. RESULTS: The 3-year progression-free survival (PFS) was 52.5% for the HDMEL conditioning group versus 70.3% for the BUMEL conditioning group (P=0.043). The 3-year overall survival (OS) was 82.0% versus 83.5% (P=0.525), respectively. Although not statistically significant, BUMEL conditioning was associated with more platelet transfusion, while HDMEL was associated with more granulocyte colony stimulating factor support. In multivariate analysis, BUMEL conditioning was not inferior to HDMEL conditioning in regard to both PFS and OS. CONCLUSION: Our study confirmed that BUMEL is an effective and well-tolerated alternative to HDMEL conditioning, with better PFS.

Cyclophosphamide, Methotrexate, and 5-Fluorouracil as Palliative Treatment for Heavily Pretreated Patients with Metastatic Breast Cancer: A Multicenter Retrospective Analysis / 한국유방암학회지

PURPOSE: This study aimed to evaluate the efficacy and safety of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) chemotherapy beyond standard treatment for anthracycline- and taxane-pretreated metastatic breast cancer (MBC). METHODS: We consecutively enrolled 158 MBC patients who underwent CMF chemotherapy in a palliative setting at two academic hospitals in Korea between 2002 and 2016. RESULTS: The median age of the 158 enrolled patients was 51 years (range, 30–77 years). The enrolled patients were treated with a median of 5 lines of systemic treatment (range, 2–11) before CMF therapy, and the median time from diagnosis of MBC to CMF administration was 36.0 months (range, 7.1–146.7 months). The median number of cycles of CMF treatment was 3 (range, 1–19), and the relative dose intensity was 90.4%. The toxicity profile was mild, with an observed 3.1% of grade 2 and 5.0% of grade 3/4 neutropenia. Among 147 patients (93.0%) whose response to CMF was evaluated, the response rate was 10.9% (16/147), with complete response (CR) in one and partial response (PR) in 15. In addition, the disease control rate (calculated as CR+PR+stable disease) was 44.2% (65/147). The median progression-free survival and overall survival were 3.1 months (95% confidence interval [CI], 2.7–3.6) and 9.4 months (95% CI, 7.1–11.6), respectively. CONCLUSION: CMF therapy is effective and tolerable as salvage treatment for heavily pretreated MBC.

The Association between End-of-Life Care and the Time Interval between Provision of a Do-Not-Resuscitate Consent and Death in Cancer Patients in Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We explored the relationship between the use of each medical intervention and the length of time between do-not-resuscitate (DNR) consent and death in Korea. MATERIALS AND METHODS: A total of 295 terminal cancer patients participated in this retrospective study. Invasive interventions (e.g., cardiopulmonary resuscitation, intubation, and hemodialysis), less invasive interventions (e.g., transfusion, antibiotic use, inotropic use, and laboratory tests), and the time interval between the DNR order and death were evaluated. The subjects were divided into three groups based on the amount of time between DNR consent and death (G1, time interval ≤ 1 day; G2, time interval > 1 day to ≤ 3 days; and G3, time interval > 3 days). RESULTS: In general, there were fewer transfusions and laboratory tests near death. Invasive interventions tended to be implemented only in the G1 group. There was also less inotrope use and fewer laboratory tests in the G3 group than G1 and G2. Moreover, the G3 group received fewer less invasive interventions than those in G1 (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.03 to 0.84; 3 days before death, and OR, 0.16; 95% CI, 0.04 to 0.59; the day before death). The frequency of less invasive interventions both 1 and 3 days before death was significantly lower for the G3 group than the G1 (p ≤ 0.001) and G2 group compared to G1 (p=0.001). CONCLUSION: Earlier attainment of DNR permission was associated with reduced use of medical intervention. Thus, physicians should discuss death with terminal cancer patients at the earliest practical time to prevent unnecessary and uncomfortable procedures and reduce health care costs.

The Risk of Tuberculosis in Korean Patients with Inflammatory Bowel Disease Receiving Tumor Necrosis Factor-alpha Blockers

The aims of this study were to assess the risk of tuberculosis (TB) and the status of latent tuberculosis infection (LTBI) in Korean patients with inflammatory bowel disease (IBD) receiving tumor necrosis factor (TNF)-alpha blockers. We reviewed medical records of 525 Korean IBD patients (365 TNF-alpha blocker naive and 160 TNF-alpha blocker exposed) between January 2001 and December 2013. The crude incidence of TB was significantly higher in IBD patients receiving TNF-alpha blockers compared to TNF-alpha-blocker-naive patients (3.1% vs. 0.3%, P=0.011). The mean incidence of TB per 1,000 patient-years was 1.84 for the overall IBD population, 4.89 for TNF-alpha blocker users, and 0.45 for TNF-alpha-blocker-naive patients. The adjusted risk ratio of TB in IBD patients receiving TNF-alpha blocker was 11.7 (95% confidence interval, 1.36-101.3). Pulmonary TB was prevalent in patients treated with TNF-alpha blockers (80.0%, 4/5). LTBI was diagnosed in 17 (10.6%) patients, and none of the 17 LTBI patients experienced reactivation of TB during treatment with TNF-alpha blockers. Treatment with TNF-alpha blockers significantly increased the risk of TB in IBD patients in Korea. De novo pulmonary TB infection was more prevalent than reactivation of LTBI, suggesting an urgent need for specific recommendations regarding TB monitoring during TNF-alpha blocker therapy.

The Risk of Tuberculosis in Korean Patients with Inflammatory Bowel Disease Receiving Tumor Necrosis Factor-alpha Blockers

The aims of this study were to assess the risk of tuberculosis (TB) and the status of latent tuberculosis infection (LTBI) in Korean patients with inflammatory bowel disease (IBD) receiving tumor necrosis factor (TNF)-alpha blockers. We reviewed medical records of 525 Korean IBD patients (365 TNF-alpha blocker naive and 160 TNF-alpha blocker exposed) between January 2001 and December 2013. The crude incidence of TB was significantly higher in IBD patients receiving TNF-alpha blockers compared to TNF-alpha-blocker-naive patients (3.1% vs. 0.3%, P=0.011). The mean incidence of TB per 1,000 patient-years was 1.84 for the overall IBD population, 4.89 for TNF-alpha blocker users, and 0.45 for TNF-alpha-blocker-naive patients. The adjusted risk ratio of TB in IBD patients receiving TNF-alpha blocker was 11.7 (95% confidence interval, 1.36-101.3). Pulmonary TB was prevalent in patients treated with TNF-alpha blockers (80.0%, 4/5). LTBI was diagnosed in 17 (10.6%) patients, and none of the 17 LTBI patients experienced reactivation of TB during treatment with TNF-alpha blockers. Treatment with TNF-alpha blockers significantly increased the risk of TB in IBD patients in Korea. De novo pulmonary TB infection was more prevalent than reactivation of LTBI, suggesting an urgent need for specific recommendations regarding TB monitoring during TNF-alpha blocker therapy.

Insufficient Experience in Thyroid Fine-Needle Aspiration Leads to Misdiagnosis of Thyroid Cancer

BACKGROUND: Fine-needle aspiration (FNA) of the thyroid is a widely accepted confirmatory test for thyroid cancer with high sensitivity and specificity. FNA is a simple procedure that is learned by many clinicians to enable accurate diagnosis of thyroid cancer. However, it is assumed that because the FNA test is a relatively simple procedure, its cytologic results are reliable regardless of the operator's experience. The aim of this study was to evaluate the differences in the diagnostic indices of FNA between operators with different levels of experience. METHODS: A total of 694 thyroid FNA specimens from 469 patients were reviewed, and were separated based on the experience of the clinicians who performed the procedure. One hundred and ninety were categorized in the experienced group, and 504 in the inexperienced group. All FNA results were then compared with histological data from surgically resected specimens, and the sample adequacy and diagnostic accuracy of the groups were compared. RESULTS: The age, gender, and nodule size and characteristics were similar in both groups. The sample adequacy rate was not significantly different between the experienced and nonexperienced groups (96.3% vs. 95.4%, P=0.682). However, the non-experienced group had a higher false-negative rate than the experienced group (6.4% vs. 17.2%, P=0.038), and the sensitivity of the FNA test also tended to be lower in the nonexperienced group (95.6% vs. 88.9%, P=0.065). CONCLUSION: These results suggest that FNA operators who have less experience may miss cases of thyroid cancer by performing the procedure incorrectly. As such, the experience of the FNA operator should be considered when diagnosing thyroid cancer. When clinicians are being trained in FNA, more effort should be made to increase the accuracy of the procedure; therefore, enhanced teaching programs and/or a more detailed feedback system are recommended.