Purpose: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. Materials and Methods: From January 2001 to December 2015, data of pediatric patients (0–18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. Results: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). Conclusion The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Despite the availability of direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection in Korea, need remains for pangenotypic regimens that can be used in the presence of hepatic impairment, comorbidities, or prior treatment failure. We investigated the efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for 12 weeks in HCV-infected Korean adults. Methods: This Phase 3b, multicenter, open-label study included 2 cohorts. In Cohort 1, participants with HCV genotype 1 or 2 and who were treatment-naive or treatment-experienced with interferon-based treatments, received sofosbuvir–velpatasvir 400/100 mg/day. In Cohort 2, HCV genotype 1 infected individuals who previously received an NS5A inhibitor-containing regimen ≥ 4 weeks received sofosbuvir–velpatasvir–voxilaprevir 400/100/100 mg/day. Decompensated cirrhosis was an exclusion criterion. The primary endpoint was SVR12, defined as HCV RNA < 15 IU/mL 12 weeks following treatment. Results: Of 53 participants receiving sofosbuvir–velpatasvir, 52 (98.1%) achieved SVR12. The single participant who did not achieve SVR12 experienced an asymptomatic Grade 3 ASL/ALT elevation on day 15 and discontinued treatment. The event resolved without intervention. All 33 participants (100%) treated with sofosbuvir–velpatasvir–voxilaprevir achieved SVR 12. Overall, sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir were safe and well tolerated. Three participants (5.6%) in Cohort 1 and 1 participant (3.0%) in Cohort 2 had serious adverse events, but none were considered treatment-related. No deaths or grade 4 laboratory abnormalities were reported. Conclusions: Treatment with sofosbuvir–velpatasvir or sofosbuvir–velpatasvir–voxilaprevir was safe and resulted in high SVR12 rates in Korean HCV patients.

Background: The optimal level of glycosylated hemoglobin (HbA1c) to prevent adverse clinical outcomes is unknown in patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). Methods: We analyzed 707 patients with CKD G1-G5 without kidney replacement therapy and T2DM from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD), a nationwide prospective cohort study. The main predictor was time-varying HbA1c level at each visit. The primary outcome was a composite of development of major adverse cardiovascular events (MACEs) or all-cause mortality. Secondary outcomes included the individual endpoint of MACEs, all-cause mortality, and CKD progression. CKD progression was defined as a ≥50% decline in the estimated glomerular filtration rate from baseline or the onset of end-stage kidney disease. Results: During a median follow-up of 4.8 years, the primary outcome occurred in 129 (18.2%) patients. In time-varying Cox model, the adjusted hazard ratios (aHRs) for the primary outcome were 1.59 (95% confidence interval [CI], 1.01 to 2.49) and 1.99 (95% CI, 1.24 to 3.19) for HbA1c levels of 7.0%–7.9% and ≥8.0%, respectively, compared with <7.0%. Additional analysis of baseline HbA1c levels yielded a similar graded association. In secondary outcome analyses, the aHRs for the corresponding HbA1c categories were 2.17 (95% CI, 1.20 to 3.95) and 2.26 (95% CI, 1.17 to 4.37) for MACE, and 1.36 (95% CI, 0.68 to 2.72) and 2.08 (95% CI, 1.06 to 4.05) for all-cause mortality. However, the risk of CKD progression did not differ between the three groups. Conclusion This study showed that higher HbA1c levels were associated with an increased risk of MACE and mortality in patients with CKD and T2DM.

Alzheimer disease (AD) and depressive disorder (DD) are prevalent among elderly end-stage kidney disease (ESKD) patients. However, whether preexisting mental health disorders increase the risk of ESKD is not well understood. The risk of incident ESKD in patients with or without underlying AD or DD was evaluated in a nationwide cohort of elderly people in Republic of Korea. Methods: This study used data from the National Health Insurance Service-Senior cohort in Republic of Korea. Among the 558,147 total subjects, 49,634 and 54,231 were diagnosed with AD (AD group) or DD (DD group), respectively, during the follow-up period. Propensity score matching was conducted to create non-AD and non-DD groups of subjects. AD and DD diagnoses were analyzed as time-varying exposures, and the study outcome was development of ESKD. Results: The incidence rates of ESKD were 0.36 and 1.17 per 1,000 person-years in the non-AD and AD groups, respectively. After adjustment for clinical variables and competing risks of death, the risk of incident ESKD was higher in the AD group than in the nonAD group (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.34–2.08). The incidence rates of ESKD in the non-DD and DD groups were 0.36 and 0.91 per 1,000 person-years, respectively. The risk of ESKD development was also higher in the DD group than the non-DD group (HR, 1.44; 95% CI, 1.19–1.76). Conclusion: The risk of ESKD development was higher in subjects diagnosed with AD or DD, suggesting that central nervous system diseases can adversely affect kidney function in elderly people.

Background/Aims: Recent data indicate the presence of liver enzyme abnormalities in patients with coronavirus disease 2019 (COVID-19). We aimed to evaluate the clinical features and treatment outcomes of COVID-19 patients with abnormal liver enzymes. Methods: We performed a retrospective, multicenter study of 874 COVID-19 patients admitted to five tertiary hospitals from February 20 to April 14, 2020. Data on clinical features, laboratory parameters, medications, and treatment outcomes were collected until April 30, 2020, and compared between patients with normal and abnormal aminotransferases. Results: Abnormal aminotransferase levels were observed in 362 patients (41.1%), of which 94 out of 130 (72.3%) and 268 out of 744 (36.0%) belonged to the severe and non-severe COVID-19 categories, respectively. The odds ratios (95% confidence interval) for male patients, patients with a higher body mass index, patients with severe COVID-19 status, and patients with lower platelet counts were 1.500 (1.029 to 2.184, p=0.035), 1.097 (1.012 to 1.189, p=0.024), 2.377 (1.458 to 3.875, p=0.001), and 0.995 (0.993 to 0.998, p>0.001), respectively, indicating an independent association of these variables with elevated aminotransferase levels. Lopinavir/ ritonavir and antibiotic use increased the odds ratio of abnormal aminotransferase levels after admission (1.832 and 2.646, respectively, both p<0.05). The median time to release from quarantine was longer (22 days vs 26 days, p=0.001) and the mortality rate was higher (13.0% vs 2.9%, p<0.001) in patients with abnormal aminotransferase levels. Conclusions Abnormal aminotransferase levels are common in COVID-19 patients and are associated with poor clinical outcomes. Multivariate analysis of patients with normal aminotransferase levels on admission showed that the use of lopinavir/ritonavir and antibiotics was associated with abnormal aminotransferase levels; thus, careful monitoring is needed.

At the end of 2019, the cause of pneumonia outbreaks in Wuhan, China, was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In February 2020, the World Health Organization named the disease cause by SARS-CoV-2 as coronavirus disease 2019 (COVID-19). In response to the pandemic, the Korean Cancer Association formed the COVID-19 task force to develop practice guidelines. This special article introduces the clinical practice guidelines for cancer patients which will help oncologists best manage cancer patients during the COVID-19 pandemic.

At the end of 2019, the cause of pneumonia outbreaks in Wuhan, China, was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In February 2020, the World Health Organization named the disease cause by SARS-CoV-2 as coronavirus disease 2019 (COVID-19). In response to the pandemic, the Korean Cancer Association formed the COVID-19 task force to develop practice guidelines. This special article introduces the clinical practice guidelines for cancer patients which will help oncologists best manage cancer patients during the COVID-19 pandemic.

Background/Aims: Recent data indicate the presence of liver enzyme abnormalities in patients with coronavirus disease 2019 (COVID-19). We aimed to evaluate the clinical features and treatment outcomes of COVID-19 patients with abnormal liver enzymes. Methods: We performed a retrospective, multicenter study of 874 COVID-19 patients admitted to five tertiary hospitals from February 20 to April 14, 2020. Data on clinical features, laboratory parameters, medications, and treatment outcomes were collected until April 30, 2020, and compared between patients with normal and abnormal aminotransferases. Results: Abnormal aminotransferase levels were observed in 362 patients (41.1%), of which 94 out of 130 (72.3%) and 268 out of 744 (36.0%) belonged to the severe and non-severe COVID-19 categories, respectively. The odds ratios (95% confidence interval) for male patients, patients with a higher body mass index, patients with severe COVID-19 status, and patients with lower platelet counts were 1.500 (1.029 to 2.184, p=0.035), 1.097 (1.012 to 1.189, p=0.024), 2.377 (1.458 to 3.875, p=0.001), and 0.995 (0.993 to 0.998, p>0.001), respectively, indicating an independent association of these variables with elevated aminotransferase levels. Lopinavir/ ritonavir and antibiotic use increased the odds ratio of abnormal aminotransferase levels after admission (1.832 and 2.646, respectively, both p<0.05). The median time to release from quarantine was longer (22 days vs 26 days, p=0.001) and the mortality rate was higher (13.0% vs 2.9%, p<0.001) in patients with abnormal aminotransferase levels. Conclusions Abnormal aminotransferase levels are common in COVID-19 patients and are associated with poor clinical outcomes. Multivariate analysis of patients with normal aminotransferase levels on admission showed that the use of lopinavir/ritonavir and antibiotics was associated with abnormal aminotransferase levels; thus, careful monitoring is needed.

Background: Hodgkin's lymphoma (HL) constitutes 10%–20% of all malignant lymphomas and has a high cure rate (5-year survival, around 90%). Recently, interest has increased concerning preventing secondary complications (secondary cancer, endocrine disorders) in long-term survivors. We aimed to study the epidemiologic features and therapeutic outcomes of HL in children, adolescents, and young adults in Korea. Methods: We performed a multicenter, retrospective study of 224 patients aged < 25 years diagnosed with HL at 22 participating institutes in Korea from January 2007 to August 2016. Results: A higher percentage of males was diagnosed at a younger age. Nodular sclerosis histopathological HL subtype was most common, followed by mixed cellularity subtype.Eighty-one (36.2%), 101 (45.1%), and 42 (18.8%) patients were classified into low, intermediate, and high-risk groups, respectively. Doxorubicin, bleomycin, vinblastine, dacarbazine was the most common protocol (n = 102, 45.5%). Event-free survival rate was 86.0% ± 2.4%, while five-year overall survival (OS) rate was 96.1% ± 1.4%: 98.7% ± 1.3%, 97.7% ± 1.6%, and 86.5% ± 5.6% in the low, intermediate, and high-risk groups, respectively (P = 0.021). Five-year OS was worse in patients with B-symptoms, stage IV disease, highrisk, splenic involvement, extra-nodal lymphoma, and elevated lactate dehydrogenase level.In multivariate analysis, B-symptoms and extra-nodal involvement were prognostic factors for poor OS. Late complications of endocrine disorders and secondary malignancy were observed in 17 and 6 patients, respectively. Conclusion This is the first study on the epidemiology and treatment outcomes of HL in children, adolescents, and young adults in Korea. Future prospective studies are indicated to develop therapies that minimize treatment toxicity while maximizing cure rates in children, adolescents, and young adults with HL.