Dynamics of viral load and anti-SARS-CoV-2 antibodies in patients with positive RT-PCR results after recovery from COVID-19

Recently, the number of patients with coronavirus disease 2019 (COVID-19) who have tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), via the reverse transcription polymerase chain reaction (RT-PCR) test, after recovery has increased; this has caused a dilemma regarding the medical measures and policies. We evaluated the dynamics of viral load and anti-SARS-CoV-2 antibodies in four patients with positive RT-PCR results after recovery. In all patients, the highest levels of immunoglobulin G (IgG) and IgM antibodies were reached after about a month of the onset of the initial symptoms. Then, the IgG titers plateaued, and the IgM titers decreased, regardless of RT-PCR results. The IgG and IgM levels did not increase after the post-negative positive RT-PCR results in any of the patients. Our results reinforced that the post-negative positive RT-PCR results may be due to the detection of RNA particles rather than reinfection in individuals who have recovered from COVID-19.

N-acetylglucosaminyltransferase II Is Involved in Plant Growth and Development Under Stress Conditions

Alpha-1,6-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase [EC 2.4.1.143, N-acetylglucosaminyltransferase II (GnTII)] catalyzes the transfer of N-acetylglucosamine (GlcNAc) residue from the nucleotide sugar donor UDP-GlcNAc to the α1,6-mannose residue of the di-antennary N-glycan acceptor GlcNAc(Xyl)Man₃(Fuc)GlcNAc₂ in the Golgi apparatus. Although the formation of the GlcNAc₂(Xyl)Man₃(Fuc)GlcNAc₂ N-glycan is known to be associated with GnTII activity in Arabidopsis thaliana, its physiological significance is still not fully understood in plants. To address the physiological importance of the GlcNAc₂(Xyl)Man₃(Fuc)GlcNAc₂ N-glycan, we examined the phenotypic effects of loss-of-function mutations in GnTII in the presence and absence of stress, and responsiveness to phytohormones. Prolonged stress induced by tunicamycin (TM) or sodium chloride (NaCl) treatment increased GnTII expression in wild-type Arabidopsis (ecotype Col-0) but caused severe developmental damage in GnTII loss-of-function mutants (gnt2-1 and gnt2-2). The absence of the 6-arm GlcNAc residue in the N-glycans in gnt2-1 facilitated the TM-induced unfolded protein response, accelerated dark-induced leaf senescence, and reduced cytokinin signaling, as well as susceptibility to cytokinin-induced root growth inhibition. Furthermore, gnt2-1 and gnt2-2 seedlings exhibited enhanced N-1-naphthylphthalamic acid-induced inhibition of tropic growth and development. Thus, GnTII's promotion of the 6-arm GlcNAc addition to N-glycans is important for plant growth and development under stress conditions, possibly via affecting glycoprotein folding and/or distribution.

Developing a predictive model for distinguishing invasive nail unit melanoma from nail unit melanoma in situ

BACKGROUND

Clinical information that distinguishes invasive nail unit melanoma from nail unit melanoma in situ before surgery would aid physicians in the decision-making process and estimating prognosis. However, limited information is available on the detailed demographic and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ for differential diagnosis.

OBJECTIVE

This study aimed to investigate the demographic data and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ and establish a predictive model for differentiating these two forms of nail unit melanoma.

METHODS

A retrospective observational study of ninety-seven patients diagnosed with nail unit melanoma (59 in situ and 38 invasive cases) in four healthcare centres in South Korea (three tertiary referral hospitals and one second referral hospital) from March 2014 to December 2019.

RESULTS

A multivariable analysis revealed that ulcer (odds ratio = 21.6, confidence interval = 2.1-219.8, P = 0.009), total melanonychia (odds ratio = 17.6, confidence interval = 3.0-104.0, P = 0.002), nail plate destruction (odds ratio = 10.9, confidence interval = 2.0-59.4, P = 0.006) and polychromia (odds ratio = 5.3, confidence interval = 1.36-20.57, P = 0.016) were distinctive dermoscopic features of invasive nail unit melanoma. A predictive model with scores ranging from 0 to 6 points demonstrated a reliable diagnostic value (C-statistic = 0.902) in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

CONCLUSIONS

Invasive nail unit melanoma and nail unit melanoma in situ have different dermoscopic features. A predictive model based on morphologic dermoscopic features could aid in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

A Case Study on the Customized Nutrition Intervention for a Patient with Primary Gastrointestinal Non-Hodgkin Lymphoma Underlying Chronic Kidney Disease

Non-Hodgkin lymphoma comprises 2.1% of the total number of cancers in South Korea. Among those, diffuse large B cell lymphoma (DLBCL) comprises the largest percentage. Nutrition interventions have been highlighted because nutritional status in non-Hodgkin's lymphoma patients has a significant impact on treatment and prognosis, but relevant studies are inadequate. Therefore, the aim of this study was to share the case of a nutrition intervention for a patient with primary gastrointestinal non-Hodgkin lymphoma underlying chronic kidney disease who was comorbid with tumor lysis syndrome, which was a complication of a specific chemotherapy. The subject is a 76-year-old patient who was diagnosed with DLBCL. He had abdominal pain, constipation, and anorexia. After chemotherapy, he experienced the tumor lysis syndrome. The patient's condition was continuously monitored, and various nutrition interventions, such as nutrition counseling and education, provision of therapeutic diet, oral nutritional supplement, change of meal plans, and parenteral nutrition support were attempted. As a result of the nutrition intervention, oral intake was increased from 27% of the energy requirement to 70% and from 23% of the protein requirement to 77%. Despite the various nutrition interventions during the hospitalization, there were no improvements in weight and nutrition-related biochemical parameters or malnutrition. However, it was meaningful in that the patient was managed to prevent worsening and the planned third chemotherapy could be performed. These results can be used as the basis for establishing guidelines for nutritional interventions customized to patients under the same conditions.

Search for Sub-eV Sterile Neutrinos at RENO

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (ν[over ¯]_{e}) disappearance taking place between six 2.8 GW_{th} reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ν[over ¯]_{e} oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on sin^{2}2θ_{14} in the 10^{-4}≲|Δm_{41}^{2}|≲0.5  eV^{2} region, free from reactor ν[over ¯]_{e} flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at |Δm_{41}^{2}|≲0.002  eV^{2} using the ν[over ¯]_{e} disappearance channel.

Treatment strategy for papillary renal cell carcinoma type 2: a case series of seven patients treated based on next generation sequencing data

Background

Papillary renal cell carcinoma type 2 (PRCC2) is refractory to systemic treatment and has a dismal prognosis. Previous studies showed that genetic alterations in PRCC2 were heterogeneous regardless of germline or somatic mutations. In this study, we aimed to perform precision treatment of PRCC2 based on genetic information.

Methods

We performed exome and genome sequencing of tumor tissues and matched normal samples. Based on sequencing data, we treated patients with metastatic PRCC2 using precision oncology.

Results

Four patients underwent curative surgery of PRCC2 and three patients had metastatic PRCC2. All PRCC2 heterogeneously harbored own driver mutations. Two out of the three patients with metastatic disease had fumarate hydratase (FH) germline mutations. One patient with a germline FH mutation was diagnosed with hereditary leiomyomatosis RCC. He was treated with bevacizumab and erlotinib combination and showed a durable response. The other metastatic PRCC2 patient harboring a germline FH mutation had an additional somatic FH mutation and was durably controlled with pazopanib. Other metastatic PRCC2 patient with somatic PBRM1 and SETD2 mutations had over 5 years of overall survival with axitinib treatment.

Conclusions

We performed precision systemic treatment based on genetic information. Genome sequencing could help identify candidates for targeted therapy in PRCC2, a genetically heterogeneous disease.

The First Korean Case of Baraitser-Winter Cerebro-Fronto-Facial Syndrome with a Novel Mutation in ACTB Diagnosed Via Targeted Gene Panel Sequencing and Literature Review

Baraitser-Winter Cerebro-fronto-facial syndrome (BWCFF, OMIM #243310, #614583) is caused by a heterozygous gain-of-function mutation of ACTB and ACTG1 that encodes actin. The syndrome is characterized by striking facial features, structural brain abnormalities, ocular coloboma, hearing loss, cardiac defects, intellectual disabilities, short stature, and developmental delay. We report a two-year-old girl who had distinctive facial features, including hypertelorism, arched eyebrows, bilateral ptosis, short broad nose with a flat nasal tip, long philtrum, retrognathia, low-set ears, and a thin upper lip. In addition, she also exhibited short stature, pectus excavatum, developmental delay, brain malformation, and hearing loss. Targeted gene panel sequencing identified a de novo heterozygous missense variant c.826G>A (p.Glu276Lys) in ACTB This is the first Korean case of BWCFF with a novel mutation in ACTB.

Comparison of Dynamic Contrast-Enhancement Parameters between Gadobutrol and Gadoterate Meglumine in Posttreatment Glioma: A Prospective Intraindividual Study

BACKGROUND AND PURPOSE

Differences in molecular properties between one-molar and half-molar gadolinium-based contrast agents are thought to affect parameters obtained from dynamic contrast-enhanced imaging. The aim of our study was to investigate differences in dynamic contrast-enhanced parameters between one-molar nonionic gadobutrol and half-molar ionic gadoterate meglumine in patients with posttreatment glioma.

MATERIALS AND METHODS

This prospective study enrolled 32 patients who underwent 2 20-minute dynamic contrast-enhanced examinations, one with gadobutrol and one with gadoterate meglumine. The model-free parameter of area under the signal intensity curve from 30 to 1100 seconds and the Tofts model-based pharmacokinetic parameters were calculated and compared intraindividually using paired t tests. Patients were further divided into progression (n = 12) and stable (n = 20) groups, which were compared using Student t tests.

RESULTS

Gadobutrol and gadoterate meglumine did not show any significant differences in the area under the signal intensity curve or pharmacokinetic parameters of K ^trans, V_e, V_p, or K_ep (all P > .05). Gadobutrol showed a significantly higher mean wash-in rate (0.83 ± 0.64 versus 0.29 ± 0.63, P = .013) and a significantly lower mean washout rate (0.001 ± 0.0001 versus 0.002 ± 0.002, P = .02) than gadoterate meglumine. Trends toward higher area under the curve, K ^trans, V_e, V_p, wash-in, and washout rates and lower K_ep were observed in the progression group in comparison with the treatment-related-change group, regardless of the contrast agent used.

CONCLUSIONS

Model-free and pharmacokinetic parameters did not show any significant differences between the 2 gadolinium-based contrast agents, except for a higher wash-in rate with gadobutrol and a higher washout rate with gadoterate meglumine, supporting the interchangeable use of gadolinium-based contrast agents for dynamic contrast-enhanced imaging in patients with posttreatment glioma.

Clinical advantage of targeted sequencing for unbiased tumor mutational burden estimation in samples with low tumor purity

Background

Tumor mutational burden (TMB) measurement is limited by low tumor purity of samples, which can influence prediction of the immunotherapy response, particularly when using whole-exome sequencing-based TMB (wTMB). This issue could be overcome by targeted panel sequencing-based TMB (pTMB) with higher depth of coverage, which remains unexplored.

Methods

We comprehensively reanalyzed four public datasets of immune checkpoint inhibitor (ICI)-treated cohorts (adopting pTMB or wTMB) to test each biomarker’s predictive ability for low purity samples (cut-off: 30%). For validation, paired genomic profiling with the same tumor specimens was performed to directly compare wTMB and pTMB in patients with breast cancer (paired-BRCA, n=165) and ICI-treated patients with advanced non-small-cell lung cancer (paired-NSCLC, n=156).

Results

Low tumor purity was common (range 30%–45%) in real-world samples from ICI-treated patients. In the survival analyzes of public cohorts, wTMB could not predict the clinical benefit of immunotherapy when tumor purity was low (log-rank p=0.874), whereas pTMB could effectively stratify the survival outcome (log-rank p=0.020). In the paired-BRCA and paired-NSCLC cohorts, pTMB was less affected by tumor purity, with significantly more somatic variants identified at low allele frequency (p<0.001). We found that wTMB was significantly underestimated in low purity samples with a large proportion of clonal variants undetected by whole-exome sequencing. Interestingly, pTMB more accurately predicted progression-free survival (PFS) after immunotherapy than wTMB owing to its superior performance in the low tumor purity subgroup (p=0.054 vs p=0.358). Multivariate analysis revealed pTMB (p=0.016), but not wTMB (p=0.32), as an independent predictor of PFS even in low-purity samples. The net reclassification index using pTMB was 21.7% in the low-purity subgroup (p=0.016).

Conclusions

Our data suggest that TMB characterization with targeted deep sequencing might have potential strength in predicting ICI responsiveness due to its enhanced sensitivity for hard-to-detect variants at low-allele fraction. Therefore, pTMB could act as an invaluable biomarker in the setting of both clinical trials and practice outside of trials based on its reliable performance in mitigating the purity-related bias.

Unilateral pleuroparenchymal fibroelastosis as a rare form of idiopathic interstitial pneumonia: A case report

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial pneumonia characterized by predominantly upper lobe involvement with pleural fibrosis and subjacent parenchymal fibrosis. Recently, there have been increasing reports of PPFE, and PPFE might coexist with other interstitial lung diseases in the lower lobe and upper lobe. However, cases of unilateral PPFE are scarce.

CASE SUMMARY

A 75-year-old Korean male presented to our hospital with chronic dry cough and exertional dyspnea. The patient’s symptoms started 6 mo previously and had been gradually worsening. At the time of presentation, he felt dyspnea when walking at his own pace. Radiologic findings suggested PPFE, but the lesion was localized in the upper lobe of the right lung. After multidisciplinary discussion, a transbronchial lung biopsy in the right upper lobe revealed collapsed alveoli with parenchymal fibroelastosis, and elastic van Gieson staining demonstrated septal elastosis with intra-alveolar collagenosis, which met the histopathologic criteria of definite PPFE. After multidisciplinary discussion in an experienced interstitial lung disease center, we confirmed the diagnosis of unilateral PPFE. Furthermore, we confirmed the progression of PPFE on radiologic findings during the follow-up period.

CONCLUSION

Clinicians should consider PPFE, even in cases with unilateral, predominantly upper lung involvement in interstitial lung disease patients through multidisciplinary discussion.

Prognostic Factor and Survival Benefit of Adjuvant Chemotherapy in Stage IIA Colon Cancer

Purpose

There is no clear evidence of the benefit of adjuvant chemotherapy (AC) in stage IIA colon cancer. Therefore, we aimed to evaluate the prognostic factors and survival benefit of AC in this disease.

Methods

A retrospective data collection for patients who underwent radical surgery for colon cancer between January 2008 and December 2015 was undertaken. The cohort was divided into the no-AC and AC groups.

Results

We included 227 patients with stage IIA colon cancer in our study cohort, including 67 and 160 patients in the no-AC and AC groups, respectively. The number of retrieved lymph nodes and the presence of tumor complications as obstruction or perforation were independent risk factors for survival. In the no-AC group, there was a significant difference in survival according to the number of retrieved lymph nodes. In the AC group, there were significant differences in survival according to sidedness and preoperative carcinoembryonic antigen (CEA). There was no significant difference in survival between the no-AC and the AC groups.

Conclusion

The number of retrieved lymph nodes and the presence of tumor complications were prognostic factors for stage IIA colon cancer but lymphovascular and perineural invasion were not. Sidedness and preoperative CEA could be used as factors to predict the benefit of adjuvant chemotherapy. Currently, it is believed that there is no benefit of AC for stage IIA colon cancer. Further studies are needed to determine the survival benefit of adjuvant chemotherapy in stage IIA colon cancer.

The First Korean Family with Aarskog-Scott Syndrome Harboring a Novel Mutation in FGD1 Diagnosed via Targeted Gene Panel Sequencing

Aarskog-Scott syndrome (AAS), also known as faciogenital dysplasia (FGD, OMIM # 305400), is an X-linked recessive inheritance, characterized by short stature, facial dysmorphism, and skeletal abnormalities. We report the clinical and molecular analysis of a family with ASS. A 31-month-old boy and his cousin were initially mistaken for having Noonan syndrome owing to short stature and facial dysmorphism. Considering the family history, we suspected the possibility of an X-linked genetic disease and performed targeted gene panel sequencing; a novel hemizygous variant c.1192-1 G>A in FGD1 was identified in both the proband and his cousin. This is the first report of ASS in Korea. Targeted gene panel sequencing can be an effective tool for diagnosing rare complex syndromes, including ASS.

Effects of anti-resorptive drugs on implant survival and peri-implantitis in patients with existing osseointegrated dental implants: a retrospective cohort study

The effect of anti-resorptive drug (ARD) usage among patients with successful dental implant osseointegration is controversial. This study showed an increased risk of implant failure in ARD users. Risk factors included pre-existing marginal bone loss, overdenture, diabetes, and a short interval between implant placement and ARD administration.

INTRODUCTION

This retrospective study aimed to determine whether anti-resorptive drug (ARD) usage increased risk of implant failure among patients with successful implant osseointegration. Additionally, the study investigated risk factors that affected implant survival rate in ARD users.

METHODS

Eighty ARD users with 344 implants who had more than 12 months of follow-up from the initiation of ARD treatment during the period between 2008 and 2017 were included, along with 80 non-ARD users from the same period. The primary outcome was dental implant survival. Kaplan-Meier survival curves and Cox proportional hazard models were used for survival analysis.

RESULTS

Average follow-up was 85.3 months. Implant survival rates were 89.83% in ARD users and 96.03% in non-ARD users. In the univariate Cox proportional hazard model, risk of implant failure was significantly higher in patients with pre-existing marginal bone loss (MBL), diabetes, and concurrent bone augmentation. However, risk of implant failure was significantly lower when the interval between implant placement and ARD administration was < 36 months. Compared with overdenture, single crown and fixed splinted users had lower risk of implant failure. In multivariate analysis, variables including pre-existing MBL, diabetes, < 36-month interval between implant placement and ARD treatment, and usage of fixed splinted prosthesis were significantly associated with increased risk of implant failure.

CONCLUSIONS

ARD administration after implant osseointegration was correlated with a reduced implant survival rate. Pre-existing MBL, diabetes, type of final prosthesis, and the interval between implant placement and initiation of ARD administration influenced risk of implant failure.

Clinical implications of HER2 mRNA expression and intrinsic subtype in refractory HER2-positive metastatic breast cancer treated with pan-HER inhibitor, poziotinib

INTRODUCTION

We explored clinical implication of intrinsic molecular subtype in human epidermal growth factor receptor 2 (HER2) + metastatic breast cancer (BC) with pan-HER inhibitor from a phase II clinical trial of poziotinib in refractory HER2+BC patients.

METHODS

For this translational research correlated with phase II clinical trial, we performed an nCounter expression assay, using gene panel including 50 genes for PAM50 prediction and targeted deep sequencing.

RESULTS

From 106 participants, we obtained 97 tumor tissues and analyzed gene expression in 91 of these samples. Of 91 HER2+BCs, 40 (44.0%) were HER2-enriched (E) intrinsic molecular subtype, 17 (18.7%) of Luminal A, 16 (17.6%) of Basal-like, 14 (15.4%) of Luminal B and 4 (4.4%) of Normal-like. HER2-E subtype was associated with hormone receptor negativity (odds ratio [OR] 2.93; p = 0.019), 3 + of HER2 immunohistochemistry(IHC) (OR 5.64; p = 0.001), high mRNA expression of HER2 (OR 14.43; p = 0.001) and copy number(CN) amplification of HER2 (OR 12.80; p = 0.005). In genetic alterations, alteration was more frequently observed in HER2-E subtype (OR 3.84; p = 0.022) but there was no association between PIK3CA alteration and HER2-E subtype (p = 0.655). In terms of drug efficacy, high mRNA expression of HER2 was the most powerful predictor of poziotinib response (median progression-free survival [PFS): 4.63 months [high] vs. 2.56 [low]; p < .001). In a combination prediction model, median PFS of intrinsic subtypes except Her2-E with high HER2 mRNA expression without PIK3CA genetic alteration was 6.83 months and that of the remaining group was 1.74 months (p < .001).

CONCLUSION

HER2-E subtype was associated with hormone receptor status, HER2 IHC, CN and mRNA expression and TP53 mutation. In survival analysis, the information of level of HER2 mRNA expression, intrinsic molecular subtype and PI3K pathway alteration would be independent predictors to poziotinib treatment. ClinicalTrials.gov identifier: NCT02418689.

Cytokine profiling in serum-derived exosomes isolated by different methods

Exosomes in blood play an important role in cell-to-cell signaling and are a novel source of biomarkers for the diagnosis and prognosis of diseases. Recently, evidence has accumulated that cytokines are released from encapsulated exosomes and are capable of eliciting biological effects upon contact with sensitive cells. However, there is currently limited information on exosome isolation methods for cytokine research. In this study, we evaluated three exosome isolation methods for their usability, yield, purity, and effectiveness in subsequent cytokine profiling. We found that ultracentrifugation (UC) and Exoquick (EQ), but not exoEasy, yielded appropriate exosome sizes, and EQ had higher exosome extraction efficiency than the other two methods. Although UC generated markedly fewer particles than EQ, it yielded a relatively high purity. Next, we performed a multiplex assay with the ProcartaPlex Immune Monitoring 65-Plex Panel to determine the feasibility of these methods for cytokine profiling. The results indicated significant differences among isolation methods when analyzing exosomal cytokine profiles. We further investigated the changes of exosomal cytokines according to breast cancer progression in triple-negative breast cancer. We found significantly decreased concentrations of MIP-3 alpha, IL-23, M-CSF, Eotaxin-3, BLC, SDF-1 alpha, IL-2R, MDC, FGF-2, IL-22, and IL-31 in exosomes from metastatic breast cancer (MBC) patients.

Clinical features of subungual melanoma according to the extent of Hutchinson's nail sign: a retrospective single-centre study

BACKGROUND

Hutchinson's nail sign (HS) is among the diagnostic criteria for subungual melanoma (SUM). However, there is minimal evidence supporting the overall clinical significance of HS in SUM.

OBJECTIVES

To identify clinicopathological features of SUM according to the extent of HS.

METHODS

Retrospective cohort study was performed with consecutive SUM patients at a single centre from January 2006 to December 2017. The extent of HS was defined by the number of affected nail folds (range 0-4). Comparison groups were organized as follows: patients with HS (affecting ≥1 nail folds) vs. without HS; patients with HS affecting ≥2 nail folds vs. HS affecting <2 nail folds; patients with HS affecting ≥3 nail folds vs. HS affecting <3 nail folds. Clinicopathological characteristics of SUM were compared between the groups.

RESULTS

Sixty-one SUM patients were included. Forty-six (75.4%) exhibited HS; 22 (47.8%) on a toe and 24 (52.2%) on a finger. In multivariate analysis, nail destruction [hazard ratio (HR), 10.00; 95% confidence interval (CI), 2.61-38.30; P = 0.001] was significantly associated with the presence of HS and amputation was significantly associated with HS affecting ≥2 nail folds (HR, 4.75; 95% CI, 1.36-16.61; P = 0.015). High T stage (HR, 1.85; 95% CI, 1.20-2.85; P = 0.005, Fig. 2) was significantly associated with HS appearing in ≥3 nail folds.

CONCLUSION

Besides its value of detecting SUM, HS provides useful clinical information. The number of nail folds exhibiting HS could be a useful clinical clue for planning therapeutic strategies for SUM.

Clinical Characteristics and Exploratory Genomic Analyses of Germline BRCA1 or BRCA2 Mutations in Breast Cancer

gBRCA1/2 mutations increase the incidence of breast cancer by interrupting the homologous recombination repair (HRR) pathway. Although gBRCA1 and gBRCA2 breast cancer have similar clinical profiles, different molecular characteristics have been observed. In this study, we conducted comprehensive genomic analyses and compared gBRCA1/2 breast cancer. Sanger sequencing to identify gBRCA1/2 mutations was conducted in 2,720 patients, and gBRCA1 (n = 128) and gBRCA2 (n = 126) mutations were analyzed. Within this population, deep target sequencing and matched whole-transcriptome sequencing (WTS) results were available for 46 and 34 patients, respectively. An internal database of patients with breast cancer with wild-type gBRCA was used to compile a target sequencing (n = 195) and WTS (n = 137) reference dataset. Three specific mutation sites, p.Y130X (n = 14) and p.1210Afs (n = 13) in gBRCA1 and p.R294X (n = 22) in gBRCA2, were comparably frequent. IHC subtyping determined that the incidence of triple-negative breast cancer was higher among those with a gBRCA1 mutation (71.9%), and estrogen receptor-positive breast cancer was dominant in those with a gBRCA2 mutation (76.2%). gBRCA1/2 mutations were mutually exclusive with PIK3CA somatic mutations (P < 0.05), and gBRCA1 frequently cooccurred with TP53 somatic mutations (P < 0.05). The median tumor mutation burden was 6.53 per megabase (MB) in gBRCA1 and 6.44 per MB in gBRCA2. The expression of AR, ESR1, and PGR was significantly upregulated with gBRCA2 mutation compared with gBRCA1 mutation. gBRCA1 and gBRCA2 breast cancer have similar clinical characteristics, but they have different molecular subtypes, coaltered somatic mutations, and gene expression patterns. IMPLICATIONS: Even though gBRCA1 and gBRCA2 mutations both alter HRR pathways, our results suggest that they generate different molecular characteristics and different mechanisms of carcinogenesis.

Prediction of Successful Ovarian Protection Using Gonadotropin-Releasing Hormone Agonists During Chemotherapy in Young Estrogen Receptor-Negative Breast Cancer Patients

Background: It is important to identify factors predicting successful ovarian protection using gonadotropin-releasing hormone (GnRH) agonists during chemotherapy. However, only a few studies have prospectively assessed this issue in young breast cancer patients.

Objective: This study evaluated the predictive factors for successful ovarian protection with GnRH agonists during chemotherapy in young estrogen receptor-negative breast cancer patients.

Materials and Methods: This prospective study analyzed 67 estrogen receptor-negative breast cancer patients ≤40 years of age who were longitudinally assessed after receiving GnRH agonists during cyclophosphamide-based chemotherapy for ovarian protection. Associations between clinical characteristics or pretreatment hormones and successful ovarian protection [resumption of menstruation and anti-Müllerian hormone (AMH) ≥1 ng/ml].

Results: The mean age and pretreatment serum level of AMH were 33.2 years and 4.57 ng/ml, respectively. At 12 months after the completion of chemotherapy, most women (97%) experienced the resumption of menstruation. However, the proportion of patients with AMH ≥1 ng/ml at 12 months was 70.1%. In multivariate analyses, only the pretreatment serum AMH level (P < 0.001) was predictive for AMH ≥1 ng/ml at 12 months. Receiver operating characteristic curve analyses of pretreatment AMH exhibited an area under the curve of 0.866 (95% CI = 0.777–0.955) for AMH ≥1 ng/ml at 12 months. The cutoff value for the prediction of AMH concentration ≥1 ng/ml at 12 months was 2.87 ng/ml of pretreatment AMH with a sensitivity of 0.87 and a specificity of 0.75.

Conclusions: Pretreatment AMH (2.87 ng/ml) is a useful predictor for AMH ≥1 ng/ml at 12 months after receiving GnRH agonists in young estrogen receptor-negative breast cancer patients. This finding can help improve decision-making regarding fertility preservation.

Clinical Characteristics of Korean Breast Cancer Patients Who Carry Pathogenic Germline Mutations in Both BRCA1 and BRCA2: A Single-Center Experience

There are few reports of breast cancer patients who carry germline mutations in both germline breast cancer susceptibility genes 1 (gBRCA1) and 2 (gBRCA2). In this study, we analyzed the clinical, pathological, and genomic characteristics of Korean breast cancer patients with both gBRCA1 and gBRCA2 mutations. Medical records of patients who received gBRCA1 and gBRCA2 testing at Samsung Medical Center between January 2007 to October 2018 were retrospectively reviewed. Genomic DNA was isolated from peripheral blood leukocytes. Among a total of 2720 patients, four patients with both gBRCA1 and gBRCA2 mutations were identified (4/2720; 0.14%). Seven patients who had a gBRCA1 mutation and gBRCA2 variants of uncertain significance (VUS) were also identified. In those patients with both gBRCA1 and gBRCA2 mutations, the mean age at diagnosis for breast cancer was 36 years (range, 31–43 years). All four tumors were infiltrating ductal carcinomas and three of the tumors were estrogen receptor-negative, progesterone receptor-negative, and human epidermal growth factor receptor 2-negative (triple-negative). All four patients who carried germline mutations in both BRCA1 and BRCA2 had a family history of breast/ovarian cancer. Pathologic stage was II in three patients and I in one patient. Breast cancer patients with both gBRCA1 and gBRCA2 mutations were rare, young at diagnosis, and all but one tumor was triple-negative based on our single-center experience.

First-in-human phase I study of ALT-P7, a HER2-targeting antibody-drug conjugate in patients with HER2-positive advanced breast cancer

3551

Background: ALT-P7 is an antibody-drug conjugate, in which two molecules of monomethyl auristatin E (MMAE) are site-specifically conjugated to a cysteine-containing peptide motif of trastuzumab variant. This is the first-in-human study evaluating safety and pharmacokinetics of ALT-P7 in patients with HER2-positive advanced breast cancer. Methods: This was an open label, 3+3 dose-escalation phase 1 trial. Eligible patients were with HER2-positive advanced breast cancer progressive to at least two kinds of prior anti-HER2 treatment. ALT-P7 at doses from 0.3mg/kg to 4.8mg/kg were intravenously administered once every 3 weeks. Dose limiting toxicities were evaluated over the first cycle of 21 days. Primary objective was to define the maximum tolerated dose. Results: ALT-P7 were administered in 27 patients (n=4 at 0.3mg/kg, n=3 at each of 0.6, 1.2, 2.4, 3.6, 4.2, 4.5 mg/kg, n=5 at 4.8mg/kg) between Jan 2018 and Feb 2020. The median number of previous line of systemic therapy was six, including median four prior anti-HER2 agents. The most common grade (G) 3/4 adverse event (AE) was neutropenia (n=4). The other common drug-related AEs of all grade were myalgia (n=9), fatigue (n=7), sensory neuropathy (n=6), alopecia (n=6), pruritus (n=6), and neutropenia (n=6). Dose limiting toxicities(DLTs) were observed in three patients at 4.8mg/kg (G4 febrile neutropenia, G4 thrombocytopenia, G4 hyperbilirubinemia, G3 myalgia, G4 hyponatremia). No DLTs have been observed up to 4.2mg/kg, and safety evaluation at 4.5mg/kg is currently ongoing. Toxicokinetic analysis for total antibody, drug-conjugated antibody, and free payload suggested that there were no accumulation of ALT-P7 upon repeated injection. In 22 patients with response evaluation, disease control rate at 6 weeks of ALT-P7 treatment was 77.3%(17/22) and partial response was achieved in two out of fifteen patients with measurable lesion. The median PFS at doses from 2.4 to 4.8mg/kg was 6.2 months (95% CI 2.5-9.9 months). Conclusions: ALT-P7 was well tolerated to a dose of 4.2mg/kg in heavily pretreated HER2-positive advanced breast cancer. DLTs were observed at 4.8mg/kg, and 4.5mg/kg is under evaluation. The observed clinical activity warrants further evaluation in a phase 2 trial. Clinical trial information: NCT03281824. Clinical trial information: NCT03281824 .

Characteristics of a "rebound" in smoking after a tobacco price increase

SETTING: In Korea, the price of a pack of cigarettes increased 80% from US$2.2 to US$4 in 2015. The smoking rate decreased in 2015. However, it rebounded in the following year.OBJECTIVE: To evaluate the characteristics associated with this rebound in smoking rate following the price increase.DESIGN: We analysed the KNHANES (Korean National Health and Nutrition Examination Survey) data of 44 015 participants to evaluate current smoking rate and the proportion of smokers planning to quit within 6 months from 2010 to 2016. We also performed focused analysis of 18 303 participants between 2014 and 2016 KNHANES to determine the current smoking rate according to their demographic and socio-economic characteristics.RESULTS: Individuals who were older, female, unemployed, had a low household income or a shorter total smoking period, or smoked less per day were more likely to stop or reduce smoking after the price increase. The current smoking rate increased to 18.8% in 2016 from 17.7% in 2015; this difference was significant in men, those in the lower-middle quartile of household income, those with a middle-school or college education, and those who were employed.CONCLUSION: The rebound in smoking after the price increase was significantly related to the individual's sex, income, education and employment status.

Evaluation of Quality Control Methods for Foot-And-Mouth Disease Vaccines by High-Performance Liquid Chromatography

Foot-and-mouth disease (FMD) is considered one of the highly contagious viral infections affecting livestock. In Korea, an FMD vaccination policy has been implemented nationwide since 2010 for the prevention and control of FMD. Since the vaccines are imported from various countries, standardized quality control measures are critical. In this study, we aimed to validate a high-performance liquid chromatography (HPLC) device in the Animal and Plant Quarantine Agency lab and identify an appropriate FMD vaccine pretreatment method for HPLC-a simple, reliable, and practical method to measure antigen content. Based on the analyses of specificity, linearity, accuracy, repeatability, intermediate precision, limits of detection, and limits of quantification using FMD standard samples, we validated the method using a standard material. Overall, we confirmed that the HPLC technique is effective for the quantitative assessment of the FMD virus 146S antigen in Korea. Using commercial FMD vaccines, we evaluated three separation methods and identified the method using n-pentanol and trichloroethylene as optimal for HPLC analysis. Our HPLC method was effective for the analytical detection of the antigen content in FMD vaccine, and it may be useful as a reference method for national lot-release testing.

Poor nutritional intake is a dominant factor for weight loss in chronic obstructive pulmonary disease

<sec id="st1"> <title>SETTING</title> Increase in energy expenditure and/or decrease in nutritional intake leads to low body mass index (BMI). The balance between energy expenditure and nutritional intake has rarely been evaluated in a large population of patients with chronic obstructive pulmonary disease (COPD). </sec> <sec id="st2"> <title>OBJECTIVE</title> To evaluate BMI, nutritional intake and physical activity and the association of these factors with the severity of airflow obstruction in COPD patients. </sec> <sec id="st3"> <title>DESIGN</title> We analysed the Korean National Health and Nutrition Examination Survey (KNHANES) data set from 2012 to 2015. </sec> <sec id="st4"> <title>RESULTS</title> Among the 9682 individuals (1601 with COPD and 8081 without COPD) recruited, BMI was lower in COPD patients than in non-COPD participants (males, 23.86 ± 2.76 vs. 24.28 ± 2.80, P < 0.001; females, 23.63 ± 2.94 vs. 23.98 ± 3.10, P < 0.05). As the stage of COPD advanced, BMI, intake of nutrients (food, water and carbohydrates) and total energy levels declined in COPD patients. Total time spent walking in the preceding week decreased with advancing COPD stage in male patients with COPD. COPD severity was an important risk factor for the limitation of physical activity due to respiratory problems (OR 3.92, 95%CI 2.77∼5.34, P < 0.001). </sec> <sec id="st5"> <title>CONCLUSION</title> Patients with COPD had a low nutritional intake with little physical activity, which worsened with advancing COPD stage. In late-stage COPD, impaired nutritional intake outweighed the decrease in physical activity, resulting in weight loss. </sec>.

Abstract P2-09-05: Low estrogen receptor positive (1-10%) breast cancer prevalence, treatment patterns and prognosis: A single institution’s experience in Korea

Background: Estrogen receptor (ER) expression is a predictive and prognostic factor in breast cancer. While the clinical benefit of endocrine therapy is indisputable, evidence suggests patients with low-ER expression (immunohistochemistry (IHC) 1-10%) may be less likely to respond to endocrine therapy and have a prognosis similar to those with hormone receptor negative breast cancer, particularly in the setting of human epidermal growth factor receptor 2 (HER2) negative disease. The objective of this analysis was to estimate the proportion of low-ER expression among female breast cancer patients, and the clinicopathological characteristics, treatment patterns and clinical outcomes using real world data.

Methods: A retrospective analysis was conducted using data from female breast cancer patients that underwent surgery with curative intent for invasive ductal or lobular breast cancer at Samsung Medical Center (Seoul, Korea) between January 2003 and December 2012. IHC was previously performed using standard procedures for determining ER, progesterone receptor (PR) and HER2 levels. PR expression was only used in determining triple-negative breast cancer (TNBC) status. ER-positive patients were further classified as ER expression low (1-10%) and high (&gt;10%) using their Allred Proportion Score (score=2) and Intensity Score (score of 1, 2 or 3). Disease-free survival (DFS) was analyzed using Kaplan-Meier method.

Results: The analysis included 5,930 patients with a median follow-up of 81 months. Overall, approximately 47% were stage 1, 41% stage 2, and 12% stage 3. Seventy-three percent of patients were ER+/HER2-, 13% TNBC, 8% ER+/HER2+ and 6% ER-/HER2+. The proportion of the cohort with low-ER expression was 2.0% (n=117); 63 (53.8%) and 54 (46.2%) with HER2- and HER2+ status, respectively. Among all ER+ women, 2.4% were classified as low-ER. The proportion of women with Ki-67 of ≥14 was greater in the low-ER/HER2- (90.0%) than the high-ER/HER2- cohort (43.3%) and similar to the TNBC cohort (92.2%). Low-ER/HER2- women were more likely to receive adjuvant chemotherapy (93.7%) than those with high-ER/HER2- (58%), which was comparable to women with TNBC (92.2%). Among those with HER2- status, low-ER patients were slightly less likely than their high-ER counterparts to have received adjuvant hormone therapy (92.1% vs 98.9%). Five-year DFS for the overall cohort was 91.7%; highest in the high-ER/HER2- cohort (94.0%), lowest in the TNBC cohort (81.3%) and 85.7% among low-ER/HER2- women.

Conclusion: Women with low-ER/HER2- breast cancer had similar clinicopathological characteristics, treatment patterns, and prognosis compared with those with TNBC. Clinical implication of this low-ER subgroup needs to be elucidated in terms of intrinsic subtyping based on biology to enable optimal treatment. Further research is needed to understand predictive and prognostic factors associated with low-ER/HER2- disease.

Citation Format: Yeon Hee Park, Vassiliki Karantza, Shawna R. Calhoun, Seri Park, Sohee Lee, Ji-Yeon Kim, Jong Han Yu, Seok Won Kim, Jeong Eon Lee, Seok Jin Nam, Gursel Aktan, Mark Marsico. Low estrogen receptor positive (1-10%) breast cancer prevalence, treatment patterns and prognosis: A single institution’s experience in Korea [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-09-05.