Background: Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective treatments for non-small cell lung cancer (NSCLC), but their use can lead to severe pneumonitis. This study aims to evaluate the utility of Krebs von den Lungen-6 (KL-6) for predicting and diagnosing PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. Methods: We conducted a prospective observational study at a university-affiliated tertiary hospital in Korea from February 2022 to June 2023. Baseline KL-6 levels were measured immediately before initiating PD-1/PD-L1 inhibitor therapy. In patients who developed pneumonitis, KL-6 levels were monitored every 1–2 weeks from the onset of pneumonitis. For patients without pneumonitis, KL-6 levels were measured every 6 weeks. We compared clinical characteristics and serial KL-6 levels between the pneumonitis and non-pneumonitis groups. Results: Eighteen patients were enrolled, with 11 developing pneumonitis. Baseline KL-6 levels did not significantly differ between the two groups (261 U/mL in the pneumonitis group vs. 373 U/mL in the non-pneumonitis group, p=0.375). In the pneumonitis group, KL-6 levels generally showed an upward trend, with a median of 412 U/mL at pneumonitis onset. Conversely, KL-6 levels in the non-pneumonitis group showed no clear overall change. Conclusion In this pilot study, baseline KL-6 was not clearly linked to PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. However, increases in KL-6 levels post-baseline were more frequently observed in patients who developed pneumonitis, including cases of all-cause pneumonitis.

Objective: This study aimed to determine the safety and efficacy of the RKP00156 vaginal tablet, a CDK9 inhibitor, in healthy women and patients with cervical intraepithelial neoplasia grade 2 (CIN2). Methods: We conducted a phase 1/2a clinical trial of RKP00156. In step 1, RKP00156 at a dose of 10, 25, or 50 mg or a placebo tablet was administered transvaginally to 24 healthy women.In step 2, RKP00156 at a dose of 10, 25, or 50 mg or a placebo tablet was administered once daily for 4 weeks in 62 patients with CIN2. The primary endpoints of this trial were the safety of RKP00156 and the change in the human papillomavirus (HPV) viral load. Results: A total of 86 patients were enrolled and randomized. RKP00156 administration did not cause serious drug-associated adverse events (AEs). Although no significant difference in the HPV viral load was found between the experimental and placebo groups, a reduction in the HPV viral load was observed in the 25 mg-dose group (−98.61%; 95% confidence interval=−99.83%, 4.52%; p=0.046) after treatment completion in patients with a high HPV viral load, despite a lack of statistical power. No differences in histologic regression and HPV clearance were observed. Conclusion The safety of RKP00156 was proved with no serious AEs. Although the study did not show any significance in histologic regression and HPV clearance, our findings indicate that RKP00156 may have a possibility of short-term inhibitory effect on HPV replication in patients with higher viral loads.

Objective: This study aimed to determine the safety and efficacy of the RKP00156 vaginal tablet, a CDK9 inhibitor, in healthy women and patients with cervical intraepithelial neoplasia grade 2 (CIN2). Methods: We conducted a phase 1/2a clinical trial of RKP00156. In step 1, RKP00156 at a dose of 10, 25, or 50 mg or a placebo tablet was administered transvaginally to 24 healthy women.In step 2, RKP00156 at a dose of 10, 25, or 50 mg or a placebo tablet was administered once daily for 4 weeks in 62 patients with CIN2. The primary endpoints of this trial were the safety of RKP00156 and the change in the human papillomavirus (HPV) viral load. Results: A total of 86 patients were enrolled and randomized. RKP00156 administration did not cause serious drug-associated adverse events (AEs). Although no significant difference in the HPV viral load was found between the experimental and placebo groups, a reduction in the HPV viral load was observed in the 25 mg-dose group (−98.61%; 95% confidence interval=−99.83%, 4.52%; p=0.046) after treatment completion in patients with a high HPV viral load, despite a lack of statistical power. No differences in histologic regression and HPV clearance were observed. Conclusion The safety of RKP00156 was proved with no serious AEs. Although the study did not show any significance in histologic regression and HPV clearance, our findings indicate that RKP00156 may have a possibility of short-term inhibitory effect on HPV replication in patients with higher viral loads.

Objective: This study aimed to determine the safety and efficacy of the RKP00156 vaginal tablet, a CDK9 inhibitor, in healthy women and patients with cervical intraepithelial neoplasia grade 2 (CIN2). Methods: We conducted a phase 1/2a clinical trial of RKP00156. In step 1, RKP00156 at a dose of 10, 25, or 50 mg or a placebo tablet was administered transvaginally to 24 healthy women.In step 2, RKP00156 at a dose of 10, 25, or 50 mg or a placebo tablet was administered once daily for 4 weeks in 62 patients with CIN2. The primary endpoints of this trial were the safety of RKP00156 and the change in the human papillomavirus (HPV) viral load. Results: A total of 86 patients were enrolled and randomized. RKP00156 administration did not cause serious drug-associated adverse events (AEs). Although no significant difference in the HPV viral load was found between the experimental and placebo groups, a reduction in the HPV viral load was observed in the 25 mg-dose group (−98.61%; 95% confidence interval=−99.83%, 4.52%; p=0.046) after treatment completion in patients with a high HPV viral load, despite a lack of statistical power. No differences in histologic regression and HPV clearance were observed. Conclusion The safety of RKP00156 was proved with no serious AEs. Although the study did not show any significance in histologic regression and HPV clearance, our findings indicate that RKP00156 may have a possibility of short-term inhibitory effect on HPV replication in patients with higher viral loads.

Purpose: Visible scars on the neck caused by thyroid surgery give rise to significant aesthetic, functional, and psychosocial problems. The objective of this study is to comparatively investigate the public perception of neck scar cosmesis in Turkish and South Korean populations. Methods: This survey was prepared to collect participants’ demographic and socioeconomic data and determine their perception of scar cosmesis on the neck and consisted of 15 questions. One thousand thirty-nine individuals who did not undergo thyroid surgery completed the survey. The P-values of <0.05 were deemed to indicate statistical significance. Results: There were 1,039 respondents, of whom 525 (50.5%) were Turkish and 514 (49.5%) were South Korean. South Korean respondents stated that they would be significantly more uncomfortable with the thought of having a scar due to thyroid surgery, compared to the Turkish respondents (P < 0.001). The South Korean respondents stated that they would be significantly more concerned about the scar’s length, thickness, and darkening color, compared to the Turkish respondents (P < 0.001 for all cases). Conclusion Patients’ expectations, which are affected by various sociodemographic factors and cultural characteristics, are as important as the medical condition when deciding on the type of thyroid surgery. The study findings clearly indicated that the South Korean population would be significantly more uncomfortable with having a scar on the neck, compared to the Turkish population. Therefore, in selected cases, a scarless thyroidectomy approach, such as transoral endoscopic thyroidectomy, vestibular approach may be preferable for societies like South Korea.

Background and Objectives: The aim of this study was to demonstrate the efficacy and safety of treatment with drug-coated balloon (DCB) in a large real-world population. Methods: Patients treated with DCBs were included in a multicenter observational registry that enrolled patients from 18 hospitals in Korea between January 2009 and December 2017. The primary outcome was target lesion failure (TLF) defined as a composite of cardiovascular death, target vessel myocardial infarction, and clinically indicated target lesion revascularization at 12 months. Results: The study included 2,509 patients with 2,666 DCB-treated coronary artery lesions (1,688 [63.3%] with in-stent restenosis [ISR] lesions vs. 978 [36.7%] with de novo lesions).The mean age with standard deviation was 65.7±11.3 years; 65.7% of the patients were men.At 12 months, the primary outcome, TLF, occurred in 179 (6.7%), 151 (8.9%), 28 (2.9%) patients among the total, ISR, and de novo lesion populations, respectively. A history of hypertension, diabetes, acute coronary syndrome, previous coronary artery bypass graft, reduced left ventricular ejection fraction, B2C lesion and ISR lesion were independent predictors of 12 months TLF in the overall study population. Conclusions This large multicenter DCB registry study revealed the favorable clinical outcome of DCB treatment in real-world practice in patient with ISR lesion as well as small de novo coronary lesion.

Background/Aims: Recurrent acute myocardial infarction (AMI) is an adverse cardiac event in patients with a first AMI. The predictors of recurrent AMI after the first AMI in patients who underwent successful percutaneous coronary intervention (PCI) have not been elucidated. Methods: We analyzed the data collected from 9,869 patients (63.2 ± 12.4 years, men:women = 7,446:2,423) who were enrolled in the Korea Acute Myocardial Infarction Registry-National Institute of Health between November 2011 and October 2015, had suffered their first AMI and had received successful PCI during the index hospitalization. Multivariable logistic regression analysis was performed to identify the independent predictors of recurrent AMI following the first AMI. Results: The cumulative incidence of recurrent AMI after successful PCI was 3.6% (359/9,869). According to the multivariable logistic regression analysis, the significant predictive factors for recurrent AMI were diabetes mellitus, renal dysfunction, atypical chest pain, and multivessel disease. Conclusions In this Korean prospective cohort study, the independent predictors of recurrent AMI after successful PCI for the first AMI were diabetes mellitus, renal dysfunction, atypical chest pain, and multivessel disease.

Purpose: High incidence of osteoporosis has been reported in breast cancer patients due to early menopause triggered by adjuvant treatment and temporary ovarian function suppression. In this study, we sought to determine whether long-term breast cancer survivors had an elevated risk of low bone density compared to the general population. Methods: Long-term breast cancer survivors who had been treated for more than 5 years were selected for this study. Data were obtained from medical records and using a questionnaire from the Korea National Health and Nutrition Examination Survey (KNHANES). An agematched non-cancer control group was selected from the KNHANES records. Incidence of fracture and bone mineral density (BMD) were compared between the two groups. Results: In total, 74 long-term breast cancer survivors and 296 non-cancer controls were evaluated. The incidence of fracture did not differ between the two groups (P=0.130). No differences were detected in lumbar BMD (P=0.051) following adjustment for body mass index, while hip BMD was significantly lower in breast cancer survivors (P=0.028). Chemotherapy and endocrine treatment were not related to low BMD in breast cancer survivors. In more than half of the survivors, the 10-year risk of osteoporotic fracture was less than 1%. Conclusion Long-term breast cancer survivors had low bone density but a comparable risk of fracture compared to non-cancer agematched controls. Further studies on the factors related to low bone density in long-term breast cancer survivors are required.

Purpose: Mutation of the Kirsten Ras (KRAS) oncogene is present in 30%-40% of colorectal cancers and has prognostic significance in rectal cancer. In this study, we examined the ability of radiomics features extracted from T2-weighted magnetic resonance (MR) images to differentiate between tumors with mutant KRAS and wild-type KRAS. Materials and Methods: Sixty patients with primary rectal cancer (25 with mutant KRAS, 35 with wild-type KRAS) were retrospectively enrolled. Texture analysis was performed in all regions of interest on MR images, which were manually segmented by two independent radiologists. We identified potentially useful imaging features using the two-tailed t test and used them to build a discriminant model with a decision tree to estimate whether KRAS mutation had occurred. Results: Three radiomic features were significantly associated with KRASmutational status (p < 0.05). The mean (and standard deviation) skewness with gradient filter value was significantly higher in the mutant KRAS group than in the wild-type group (2.04±0.94 vs. 1.59±0.69). Higher standard deviations for medium texture (SSF3 and SSF4) were able to differentiate mutant KRAS (139.81±44.19 and 267.12±89.75, respectively) and wild-type KRAS (114.55±29.30 and 224.78±62.20). The final decision tree comprised three decision nodes and four terminal nodes, two of which designated KRAS mutation. The sensitivity, specificity, and accuracy of the decision tree was 84%, 80%, and 81.7%, respectively. Conclusion Using MR-based texture analysis, we identified three imaging features that could differentiate mutant from wild-type KRAS. T2-weighted images could be used to predict KRAS mutation status preoperatively in patients with rectal cancer.

The optimal dose of beta blockers after acute myocardial infarction (MI) remains uncertain. We evaluated the effectiveness of low-dose nebivolol, a beta1 blocker and a vasodilator, in patients with acute MI. A total of 625 patients with acute MI from 14 teaching hospitals in Korea were divided into 2 groups according to the dose of nebivolol (nebistol®, Elyson Pharmaceutical Co., Ltd., Seoul, Korea): low-dose group (1.25 mg daily, n=219) and usual- to high-dose group (≥2.5 mg daily, n=406). The primary endpoints were major adverse cardiac and cerebrovascular events (MACCE, composite of death from any cause, non-fatal MI, stroke, repeat revascularization, rehospitalization for unstable angina or heart failure) at 12 months. After adjustment using inverse probability of treatment weighting, the rates of MACCE were not different between the low-dose and the usual- to high-dose groups (2.8% and 3.1%, respectively; hazard ratio: 0.92, 95% confidence interval: 0.38 to 2.24, p=0.860). The low-dose nebivolol group showed higher rates of MI than the usual- to high-dose group (1.2% and 0%, p=0.008). The 2 groups had similar rates of death from any cause (1.1% and 0.3%, p=0.273), stroke (0.4% and 1.1%, p=0.384), repeat PCI (1.2% and 0.8%, p=0.428), rehospitalization for unstable angina (1.2% and 1.0%, p=0.743) and for heart failure (0.6% and 0.7%, p=0.832). In patients with acute MI, the rates of MACCE for low-dose and usual- to high-dose nebivolol were not significantly different at 12-month follow-up.