Recently, the 2015 American Thyroid Association (ATA) risk stratification and the 8^th edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) TNM staging system were released. This study was conducted to assess the clinical value of the lymph node ratio (LNR) as a predictor of recurrence when integrated with these newly released stratification systems, and to compare the predictive accuracy of the modified systems with that of the newly released systems. The optimal LNR threshold value for predicting papillary thyroid cancer (PTC) recurrence was 0.17857 using the Contal and O’Quigley method. The 8^th edition of the AJCC/UICC TNM staging system with the LNR and the 2015 ATA risk stratification system with the LNR were significant predictors of recurrence. Furthermore, calculation of the proportion of variance explained (PVE), the Akaike information criterion (AIC), Harrell’s c index, and the incremental area under the curve (iAUC) revealed that the 8^th edition of the TNM staging system with the LNR, and the 2015 ATA risk stratification system with the LNR, showed the best predictive performance. Integration of the LNR with the TNM staging and the ATA risk stratification systems should improve prediction of recurrence in patients with PTC.

The risk factors for late-onset Pneumocystis jirovecii pneumonia (PCP) after liver transplantation (LT) have not been well studied. We aimed to analyze the clinical features preceding PCP in LT recipients that would guide individualized prophylaxis. Among 742 patients who underwent LT and routine PCP prophylaxis from January 2009 through December 2019 at Severance Hospital, 27 patients developed PCP. We conducted a retrospective case-control study matching each patient with four controls and analyzed the risk factors for late-onset PCP. After 6 months, post-transplant PCP cases increased steadily with an overall incidence of 6.36 cases per 1000 patient-year. The PCP-related mortality was 37.0%. In the multivariate analyses, age at LT ≥65 years (odds ratio [OR], 13.305; 95% confidence interval [CI], 2.507-70.618; P = 0.002), cytomegalovirus infection (OR, 5.390; 95% CI, 1.602-18.132; P = 0.006), steroid pulse therapy (OR, 6.564; 95% CI, 1.984-21.719; P = 0.002), hepatocellular carcinoma recurrence (OR, 18.180; 95% CI, 3.420-96.636; P = 0.001), and lymphocytopenia (OR, 3.758; 95% CI, 1.176-12.013; P = 0.026) were independently associated with PCP. Late-onset PCP after routine prophylaxis after LT remains a lethal infection and is associated with age ≥65 years at LT, cytomegalovirus infection, steroid pulse therapy, hepatocellular carcinoma recurrence, and lymphocytopenia. Targeted prophylaxis considering these risk factors could improve the prevention of this potentially lethal complication.

Locally advanced thyroid cancer exhibits aggressive clinical features requiring extensive neck dissection. Therefore, it is important to identify changes in the tumor biology before local progression. Here, whole exome sequencing (WES) using tissues from locally advanced papillary thyroid cancer (PTC) presented a large number of single nucleotide variants (SNVs) in the metastatic lymph node (MLN), but not in normal tissues and primary tumors. Among those MLN-specific SNVs, a novel HHIP G516R (G1546A) mutation was also observed. Interestingly, in-depth analysis for exome sequencing data from the primary tumor presented altered nucleotide ‘A’ at a very low frequency indicating intra-tumor heterogeneity between the primary tumor and MLN. Computational prediction models such as PROVEAN and Polyphen suggested that HHIP G516R might affect protein function and stability. In vitro, HHIP G516R increased cell proliferation and promoted cell migration in thyroid cancer cells. HHIP G516R, a missense mutation, could be a representative example for the intra-tumor heterogeneity of locally advanced thyroid cancer, which can be a potential future therapeutic target for this disease.

Cytomegalovirus (CMV), a common pathogen, causes infectious complications and affects long-term survival after transplantation. Studies examining living donor liver transplantation (LDLT) are limited. This study analyzed the risk factors for CMV infection and its impact on the survival of LDLT patients. A nested case–control design retrospectively analyzed data from 952 patients who underwent LDLT from 2005–2021. The incidence of CMV infection for the study cohort was 15.2% at 3 months for LDLT patients managed preemptively. Patients with CMV infections were matched with those without the infection at corresponding time points (index postoperative day) in a 1:2 ratio. Graft survival was significantly lower in the CMV infection group than in the control group. CMV infection was an independent risk factor for graft survival in the matched cohort (HR 1.93, p = 0.012). Independent risk factors for CMV infection were female sex (HR 2.4, p = 0.003), pretransplant MELD (HR 1.06, p = 0.004), pretransplant in-hospital stay (HR 1.83, p = 0.030), ABO incompatibility (HR 2.10, p = 0.009), donor macrovesicular steatosis ≥10% (HR 2.01, p = 0.030), and re-operation before index POD (HR 2.51, p = 0.035). CMV infection is an independent survival risk factor, and its risk factors should be included in the surveillance and treatment of CMV infections after LDLT.

Background: The benefits of living-donor liver transplantation (LDLT) in patients with a high Model for End-stage Liver Disease (MELD) score (who have high waitlist mortality) are unclear. Regional availability of deceased-donor organs must be considered when evaluating LDLT benefits. The authors aimed to compare the survival benefit of intended-LDLT to awaiting deceased-donor liver transplantation (DDLT) in patients with a MELD score greater than or equal to 30 in a region with severe organ shortage. Materials and methods: This retrospective review included 649 patients with a MELD score greater than or equal to 30 placed on the liver transplantation waitlist. They were divided into intended-LDLT (n=205) or waiting-DDLT (n=444) groups based on living-donor eligibility and compared for patient survival from the time of waitlisting. Post-transplantation outcomes of transplant recipients and living donors were analyzed. Results: Intended-LDLT patients had higher 1-year survival than waiting-DDLT patients (53.7 vs. 28.8%, P<0.001). LDLT was independently associated with lower mortality [hazard ratio (HR), 0.62; 95% CI, 0.48–0.79; P<0.001]. During follow-up, 25 patients were de-listed, 120 underwent LDLT, 170 underwent DDLT, and 334 remained on the waitlist. Among patients undergoing transplantation, the risk of post-transplantation mortality was similar for LDLT and DDLT after adjusting for pretransplantation MELD score (HR, 1.86; 95% CI, 0.73–4.75; P=0.193), despite increased surgical complications after LDLT (33.1 vs. 19.4%, P=0.013). There was no mortality among living-donors, but 4.2% experienced complications of grade 3 or higher. Conclusions: Compared to awaiting DDLT, LDLT offers survival benefits for patients with a MELD score greater than or equal to 30, while maintaining acceptable donor outcomes. LDLT is a feasible treatment for patients with a MELD score greater than or equal to 30 in regions with severe organ shortages.