Purpose: To investigate the clinical characteristics and genetic features of childhood-onset congenital combined pituitary hormone deficiency (cCPHD) in Korean patients. Methods: We retrospectively analyzed 444 patients diagnosed with childhood-onset CPHD at a tertiary center between 1994 and 2021. After excluding acquired case, 43 patients with cCPHD were enrolled. Anthropometric measurements, hormone evaluations, brain magnetic resonance imaging (MRI), extrapituitary phenotypes, and adult outcomes were analyzed. Genetic analyses were performed on 26 patients using a targeted gene panel or whole exome sequencing. Results: Mean age at diagnosis was 3.2 years, and 41.9% were diagnosed at less than 1 year old. Short stature was the most frequent (37.2%) initial presentation, and mean height z-score was -2.4. More than half (n=23, 53.5%) of patients had neonatal features suggestive of hypopituitarism; however, only 15 (65.2%) were diagnosed in infancy. Growth hormone deficiency (GHD) was prevalent in 42 (97.7%), and 33 (76.7%) had 3 or more hormone deficiencies. Extrapituitary phenotypes were identified in 31 (72.1%). Brain MRI abnormalities correlated with a higher number of hormone deficiencies (P for trend 0.049) and were present in 33 patients (80.5%). Adult GHD was diagnosed in all 17 investigated patients, and metabolic disturbances were noted in 10 (58.9%). Pathogenic variants in POU1F1, GLI2, HESX1, TBC1D32, and ROBO1 were found in 5 (19.2%). Conclusion Considering the high proportion of neonatal presentations, identification of the early neonatal features of hypopituitarism to manage pituitary and extrapituitary phenotypes is critical. The genetic etiology of cCPHD warrants further exploration.

Purpose: To investigate the clinical characteristics and genetic features of childhood-onset congenital combined pituitary hormone deficiency (cCPHD) in Korean patients. Methods: We retrospectively analyzed 444 patients diagnosed with childhood-onset CPHD at a tertiary center between 1994 and 2021. After excluding acquired case, 43 patients with cCPHD were enrolled. Anthropometric measurements, hormone evaluations, brain magnetic resonance imaging (MRI), extrapituitary phenotypes, and adult outcomes were analyzed. Genetic analyses were performed on 26 patients using a targeted gene panel or whole exome sequencing. Results: Mean age at diagnosis was 3.2 years, and 41.9% were diagnosed at less than 1 year old. Short stature was the most frequent (37.2%) initial presentation, and mean height z-score was -2.4. More than half (n=23, 53.5%) of patients had neonatal features suggestive of hypopituitarism; however, only 15 (65.2%) were diagnosed in infancy. Growth hormone deficiency (GHD) was prevalent in 42 (97.7%), and 33 (76.7%) had 3 or more hormone deficiencies. Extrapituitary phenotypes were identified in 31 (72.1%). Brain MRI abnormalities correlated with a higher number of hormone deficiencies (P for trend 0.049) and were present in 33 patients (80.5%). Adult GHD was diagnosed in all 17 investigated patients, and metabolic disturbances were noted in 10 (58.9%). Pathogenic variants in POU1F1, GLI2, HESX1, TBC1D32, and ROBO1 were found in 5 (19.2%). Conclusion Considering the high proportion of neonatal presentations, identification of the early neonatal features of hypopituitarism to manage pituitary and extrapituitary phenotypes is critical. The genetic etiology of cCPHD warrants further exploration.

Purpose: To investigate the clinical characteristics and genetic features of childhood-onset congenital combined pituitary hormone deficiency (cCPHD) in Korean patients. Methods: We retrospectively analyzed 444 patients diagnosed with childhood-onset CPHD at a tertiary center between 1994 and 2021. After excluding acquired case, 43 patients with cCPHD were enrolled. Anthropometric measurements, hormone evaluations, brain magnetic resonance imaging (MRI), extrapituitary phenotypes, and adult outcomes were analyzed. Genetic analyses were performed on 26 patients using a targeted gene panel or whole exome sequencing. Results: Mean age at diagnosis was 3.2 years, and 41.9% were diagnosed at less than 1 year old. Short stature was the most frequent (37.2%) initial presentation, and mean height z-score was -2.4. More than half (n=23, 53.5%) of patients had neonatal features suggestive of hypopituitarism; however, only 15 (65.2%) were diagnosed in infancy. Growth hormone deficiency (GHD) was prevalent in 42 (97.7%), and 33 (76.7%) had 3 or more hormone deficiencies. Extrapituitary phenotypes were identified in 31 (72.1%). Brain MRI abnormalities correlated with a higher number of hormone deficiencies (P for trend 0.049) and were present in 33 patients (80.5%). Adult GHD was diagnosed in all 17 investigated patients, and metabolic disturbances were noted in 10 (58.9%). Pathogenic variants in POU1F1, GLI2, HESX1, TBC1D32, and ROBO1 were found in 5 (19.2%). Conclusion Considering the high proportion of neonatal presentations, identification of the early neonatal features of hypopituitarism to manage pituitary and extrapituitary phenotypes is critical. The genetic etiology of cCPHD warrants further exploration.

Purpose: Few data on the clinical course after levothyroxine (L-T4) discontinuation in pediatric patients with Hashimoto thyroiditis (HT) are available. We investigated outcomes and predictors for successful withdrawal from L-T4 among children with HT. Methods: Among 168 patients diagnosed with HT between January 2000 and March 2021 at Seoul National University Children’s Hospital and in whom L-T4 therapy was initiated during childhood, we attempted to discontinue this therapy in 47, 3 boys and 44 girls. L-T4 was restarted when patients developed overt or subclinical hypothyroidism (thyroid-stimulating hormone [TSH] levels≥10 mIU/L) after L-T4 discontinuation. Results: Median age at discontinuation was 15.4 years (12.7–18.4 years) with a median duration of L-T4 therapy of 47 months (20.3–80.3 months). During the median 30 months of follow-up (10.6–61.0 months) after L-T4 discontinuation, 33 (70.2%) developed thyroid dysfunction. Among these patients, 17 were eventually restarted on L-T4. TSH levels over 50 mIU/L at L-T4 initiation (hazard ratio, HR 3.5, P=0.002), age under 12 years at L-T4 discontinuation (HR 11.1, P=0.0001), and TSH levels higher than the upper 50% of normal (above 2.25 mIU/L in the present study) at L-T4 discontinuation (HR 2.7, P=0.014) were significantly predictive for overt hypothyroidism or subclinical hypothyroidism after L-T4 discontinuation. In addition, age under 12 years at L-T4 discontinuation was only predictive factor for restarting L-T4 medication (HR 4.3, P=0.012). Conclusion L-T4 discontinuation in pediatric patients with HT resulted in thyroid dysfunction in 70.2% of cases; 36.2% of patients who attempted discontinuation required resumption of L-T4. Older age and lower TSH levels at L-T4 discontinuation were advantageous for successful withdrawal.

In recent years, next-generation sequencing (NGS)–based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

In recent years, next-generation sequencing (NGS)–based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

Purpose: Hypoparathyroidism (hypoPTH) is the most common complication following thyroidectomy. We investigated the frequency and risk factors of hypoPTH after total thyroidectomy (TT) in pediatric patients with thyroid cancer. Methods: This retrospective study included 98 patients younger than 20 years who were diagnosed with thyroid cancer after T T during 1990–2018 and followed for more than 2 years at Seoul National University Hospital. HypoPTH was defined as receiving active vitamin D (1-hydroxycholecalciferol or 1,25-dihydroxycholecalciferol) after surgery. Results: The study included 27 boys (27.6%) and 71 girls (72.4%). The mean age at diagnosis was 14.9±3.7 years. HypoPTH occurred in 43 patients (43.9%). Twenty-one patients (21.4%) discontinued active vitamin D less than 6 months after surgery, while 14 (14.3%) continued active vitamin D for more than 2 years. Tumor multifocality (odds ratio [OR], 3.7 vs. single tumor; P=0.013) and preoperative calcium level (OR, 0.2; P=0.028) were independent predictors of hypoPTH immediately after TT. In addition, age (OR, 0.8; P=0.011) and preoperative calcium level (OR, 0.04; P=0.014) significantly decreased the risk for persistent hypoPTH requiring active vitamin D for more than 2 years. Conclusion HypoPTH occurred in 43.9% of pediatric thyroid cancer patients after TT in this study. Among them, one-third of patients continued active vitamin D medication for more than 2 years, which was predicted by young age and low preoperative calcium level.

Background: This study investigated the relationship between fibroblast growth factor 21 (FGF21) levels and growth in children with growth hormone deficiency (GHD) and idiopathic short stature (ISS), and the effects of the FGF21 level on response to growth hormone (GH) treatment. Methods: We included 171 pre-pubertal children with a GHD (n = 54), ISS (n = 46), and normal height (n = 71). Fasting FGF21 levels were measured at baseline and every 6 months during GH treatment. Factors associated with growth velocity (GV) after GH therapy were investigated. Results: The FGF21 level was higher in short children than in the controls without significant difference between the GHD and ISS groups. In the GHD group, the FGF21 level was inversely associated with the free fatty acid (FFA) level at baseline (r = −0.28, P = 0.039), however, was positively correlated with the FFA level at 12 months (r = 0.62, P = 0.016). The GV over 12 months of GH therapy was positively associated with the delta insulin-like growth factor 1 level (β = 0.003, P = 0.020). The baseline log-transformed FGF21 level was inversely associated with GV with marginal significance (β = −0.64, P = 0.070). Conclusion The FGF21 level was higher in children of short stature, both those with GHD and the ISS, than in children with normal growth. The pretreatment FGF21 level negatively affected the GV of children with GH-treated GHD. These results suggest the existence of a GH/FFA/FGF21 axis in children.

Purpose: For precision medicine, exploration and monitoring of molecular biomarkers are essential. However, in advanced gastric cancer (GC) with visceral lesions, an invasive procedure cannot be performed repeatedly for the follow-up of molecular biomarkers. Materials and Methods: To verify the clinical implication of serial liquid biopsies targeting circulating tumor DNA (ctDNA) on treatment response, we conducted targeted deep sequencing for serially collected ctDNA of 15 HER2-positive metastatic GC patients treated with anti-PD-1 inhibitor in combination with standard systemic treatment. Results: In the baseline ctDNAs, 14 patients (93%) harbored more than one genetic alteration. A number of mutations in wellknown cancer-related genes, such as KRAS and PIK3CA, were identified. Copy number alterations were identified in eight GCs (53.3%), and amplification of the ERBB2 gene (6/15, 40.0%) was the most recurrent. When we calculated the mean variant allele frequency (VAF) of mutations in each ctDNA as the molecular tumor burden index (mTBI), the mTBI trend was largely consistent with the VAF profiles in both responder and non-responder groups. Notably, in the longitudinal analysis of ctDNA, mTBI provided 2–42 weeks (mean 13.4 weeks) lead time in the detection of disease progression compared to conventional follow-up with CT imaging. Conclusion Our data indicate that the serial genetic alteration profiling of ctDNA is feasible to predict treatment response in HER2-positive GC patients in a minimally invasive manner. Practically, ctDNA profiles are useful not only for the molecular diagnosis of GC but also for the selection of GC patients with poor prognosis for systemic treatment (ClinicalTrials.gov identifier:NCT02901301).

Purpose: Hypothalamic damage may increase the risk of adulthood obesity and cardiovascular disease in patients with craniopharyngioma. We evaluated the effects of hypothalamic involvement (HI) and growth hormone (GH) discontinuation on cardiovascular risk factors during the transition period in patients with childhood-onset craniopharyngioma. Methods: Thirty-three patients (17 males, 16 females) underwent retesting for adult GH deficiency (GHD) between 2005 and 2020 at Seoul National University Children's Hospital. Postoperative HI was graded by Puget's criteria and data regarding GH replacement were collected. At retesting, body mass index (BMI), fasting blood glucose, insulin, high-density lipoprotein cholesterol (HDL-C), triglycerides, and blood pressure were assessed. Results: The mean age of commencement and discontinuation of GH replacement for childhood GHD was 10.0±3.6 and 15.3±3.1 years, respectively. The mean age at retesting for adult GHD was 17.7±2.5 years. When patients were categorized by post-GH discontinuation duration, those with durations >6 months (n=27) showed lower HDL-C levels than those with <6 months (P=0.037). Patients with extensive HI (n=16) had higher BMI z-scores than did those with no HI or mild HI (P=0.020). Both the extent of HI and longer post-GH discontinuation duration were significantly predictive for decreased HDL-C levels (P<0.05, for both). Conclusion The extent of HI and GH discontinuation duration during the transition period can increase cardiovascular risks in patients with childhood-onset craniopharyngioma.