Eun-Jae Chung

Pattern of lymph node metastasis in hypopharyngeal squamous cell carcinoma and indications for level VI lymph node dissection

The purpose of this study was to determine the incidence, risk factors, and prognostic significance of level VI lymph node metastases from hypopharyngeal squamous cell carcinoma (SCC).

Prevention of polydimethylsiloxane microsphere migration using a mussel-inspired polydopamine coating for potential application in injection therapy

The use of injectable bulking agents is a feasible alternative procedure for conventional surgical therapy. In this study, poly(dimethylsiloxane) (PDMS) microspheres coated with polydopamine (PDA) were developed as a potential injection agent to prevent migration in vocal fold. Uniform PDMS microspheres are fabricated using a simple fluidic device and then coated with PDA. Cell attachment test reveals that the PDA-coated PDMS (PDA-PDMS) substrate favors cell adhesion and attachment. The injected PDA-PDMS microspheres persist without migration on reconstructed axial CT images, whereas, pristine PDMS locally migrates over a period of 12 weeks. The gross appearance of the implants retrieved at 4, 8, 12 and 34 weeks indicates that the PDA-PDMS group maintained their original position without significant migration until 34 weeks after injection. By contrast, there is diffuse local migration of the pristine PDMS group from 4 weeks after injection. The PDA-coated PDMS microspheres can potentially be used as easily injectable, non-absorbable filler without migration.

Changes in programmed death-ligand 1 expression during cisplatin treatment in patients with head and neck squamous cell carcinoma

Programmed death-ligand 1 (PD-L1) expression is regarded as a predictive marker for anti-PD-1/PD-L1 therapy. The purpose of study was to explore the changes in PD-L1 expression in head and neck squamous cell carcinoma (HNSCC) during treatment. Paired HNSCC tissues prior to and after cisplatin-based treatment were evaluated to determine PD-L1 protein expression by immunohistochemistry. Among the 35 HNSCC patient samples, PD-L1 expression status changed after treatment in 37.1% (13/35) of samples. Among the 13 patients whose baseline PD-L1 was negative, PD-L1 expression was increased in 9 cases (69.2%) and remained negative in 4 cases (30.8%, P = 0.003). Patients exposed to cisplatin generally showed PD-L1 up-regulation (83.3%, P = 0.037) compared to those not exposed to cisplatin (57.1%, P = 0.072). To validate these findings in vitro, changes in PD-L1 expression in HNSCC cell lines (Detroit-562, PCI-13, SNU-1041, SNU-1066, SNU-1076, and FaDu) were analyzed by western blotting and flow cytometry after treatment with cisplatin and interferon-gamma. In HNSCC cell lines, PD-L1 expression was significantly up-regulated after cisplatin, along with phosphor-MAPK/ERK kinase up-regulation. In conclusion, PD-L1 expression in HNSCC may be altered during cisplatin treatment, activating the MAPK/ERK kinase pathway.Programmed death-ligand 1 (PD-L1) expression is regarded as a predictive marker for anti-PD-1/PD-L1 therapy. The purpose of study was to explore the changes in PD-L1 expression in head and neck squamous cell carcinoma (HNSCC) during treatment. Paired HNSCC tissues prior to and after cisplatin-based treatment were evaluated to determine PD-L1 protein expression by immunohistochemistry. Among the 35 HNSCC patient samples, PD-L1 expression status changed after treatment in 37.1% (13/35) of samples. Among the 13 patients whose baseline PD-L1 was negative, PD-L1 expression was increased in 9 cases (69.2%) and remained negative in 4 cases (30.8%, P = 0.003). Patients exposed to cisplatin generally showed PD-L1 up-regulation (83.3%, P = 0.037) compared to those not exposed to cisplatin (57.1%, P = 0.072). To validate these findings in vitro, changes in PD-L1 expression in HNSCC cell lines (Detroit-562, PCI-13, SNU-1041, SNU-1066, SNU-1076, and FaDu) were analyzed by western blotting and flow cytometry after treatment with cisplatin and interferon-gamma. In HNSCC cell lines, PD-L1 expression was significantly up-regulated after cisplatin, along with phosphor-MAPK/ERK kinase up-regulation. In conclusion, PD-L1 expression in HNSCC may be altered during cisplatin treatment, activating the MAPK/ERK kinase pathway.

Clinical outcome analysis of 47 patients with advanced head and neck cancer with preoperative suspicion of carotid artery invasion

The purpose of this study was to retrospectively analyze the feasibility of the surgical management of the carotid artery in advanced head and neck cancer with preoperative suspicion of carotid artery invasion.

Persistent/Recurrent Differentiated Thyroid Cancer: Clinical and Radiological Characteristics of Persistent Disease and Clinical Recurrence Based on Computed Tomography Analysis

BACKGROUND The natural course of persistent/recurrent differentiated thyroid cancer (DTC) has not been fully elucidated. The purpose of this study was to assess the relative incidence and clinico-radiological characteristics of persistent disease and clinical recurrence based on computed tomography (CT) analysis in patients with persistent/recurrent DTC. METHODS From January 2005 to December 2016, this retrospective study included 107 patients (M:F = 28:79; Mage = 53.5 years) with surgically proven cervical locoregional recurrence of DTC. Two neck CT examinations (median interval 1.92 years; range 0.17-7.58 years) before the last thyroid cancer surgery within the study period were reevaluated. Based on the presence of the lesion on the first CT and its progression on the second CT, the locoregional recurrence was classified into the following categories: stable persistence (decrease, no change, or increase by <2 mm in short dimension on the second CT), progressive persistence (increase by ≥2 mm), and clinical recurrence (newly appeared on the second CT). Clinical and radiological characteristics of the three groups were compared using univariate and multivariate logistic regression analyses. RESULTS The relative incidences of stable persistence, progressive persistence, and clinical recurrence were 56.1% (60/107), 15.0% (16/107), and 29.0% (31/107), respectively. Multivariate analysis between the clinical recurrence (29.0%) and persistence (71.0%) groups revealed various independent factors for prediction of clinical recurrence. These included longer interval between the two CT examinations (median 2.67 vs. 1.79 years; p = 0.021), a smaller number of thyroid surgeries (1.16 ± 0.45 vs. 1.55 ± 0.81; p = 0.002), and a history of neck dissection at the location of the largest locoregional recurrence (70.0% vs. 31.4%; p < 0.001). There was no significant independent factor for differentiation between the stable persistence (78.9%; 60/76) and progressive persistence (21.1%; 16/76) groups. The results may have been influenced by selection bias because this study included only surgically proven cases. CONCLUSIONS With regard to cervical locoregional recurrence of DTC, active surveillance may be favored because more than a half of the cases are structurally persistent and stable. However, meticulous evaluation is necessary to detect progressive persistence and clinical recurrence, considering various clinical factors.

Optimal timing for salvage surgery after definitive radiotherapy in hypopharyngeal cancer

Purpose Use of radiotherapy combined with chemotherapy is increasing in hypopharyngeal cancer. However, many show residual tumor after radiotherapy. Timing for treatment evaluation and salvage therapy is essential. However, optimal timing for salvage surgery has not been suggested. In this study, we tried to evaluate optimal timing for salvage surgery. Methods and Materials Patients who were diagnosed with hypopharyngeal squamous cell carcinoma between 2006 and 2015 were retrospectively analyzed. All patients received definitive radiotherapy with or without chemotherapy. Response of all treated patients were analyzed at 1, 3, and 6 months after radiotherapy. Any patients with progression before 6 months were excluded. Results A total of 54 patients were analyzed. Complete remission (CR) rates at 1 month (CR1), 3 months (CR3) and 6 months (CR6) were 66.7%, 81.5%, and 90.7%, respectively. Non-CR at 1 month (NCR1), 3 months (NCR3), and 6 months (NCR6) showed poor locoregional recurrence-free survival rates (1-year rates of 63.7%, 66.7%, and 0.0%, respectively) compared to CR1, CR3, and CR6 (1-year rates 94.3%, 88.0%, and 91.5%, respectively). Particularly significant differences were seen between CR6 and NCR6 (p < 0.001). Of 10 patients with NCR3, 5 showed CR at 6 months (NCR3/CR6). There was no statistical difference in locoregional recurrence-free survival between CR3 and NCR3/CR6 group (p = 0.990). Conclusion Our data suggest half of patients who did not show CR at 3 months eventually achieved CR at 6 months. Waiting until 6 months after radiotherapy may be appropriate for avoiding additional salvage therapy.

Study design and early result of a phase I study of SABR for early-stage glottic cancer: SABR for Early Glottic Cancer

Avoidance of organs at risk has become possible with advances in image‐guided volumetric‐modulated arc therapy (VMAT) techniques. This study was designed to evaluate the safety and feasibility of stereotactic ablative radiotherapy (SABR) for early stage glottic cancer. This report presents the preliminary result of the first and second dose level.

The impact of the number of harvested central lymph nodes on the lymph node ratio

OBJECTIVE The purpose of this study was to analyze the impact of lymph node harvest on the lymph node ratio (LNR). METHODS We retrospectively reviewed 106 patients diagnosed preoperatively with PTMC (papillary thyroid microcarcinoma), no evidence of central or lateral neck nodal metastasis, and who underwent a total thyroidectomy and bilateral central lymph node neck dissection (CND). RESULTS The median number of retrieved lymph nodes in the central compartments was 7±6.59 (range: 1-42). The mean number of metastatic lymph nodes in the central compartments on pathology was 1.1±1.79 (range: 0-7). The high node volume group (>7) had a significantly higher rate of central lymph node (CLN) metastasis than the low node volume group (≤7) in the final pathologic report (p<0.001). With the linear regression method, the number of CLN metastasis increased as the number of retrieved lymph nodes increased (correlation coefficient=0.286, p=0.003). The multivariate analysis confirmed the number of retrieved lymph nodes in the central compartments was a risk factor for high LNR (p=0.008, odds ratio 3.737). The rates of vocal fold palsy and hypoparathyroidism did not differ according to the number of retrieved lymph nodes. CONCLUSION The lymph node ratio in the final pathologic report is larger when a greater number of lymph nodes are retrieved during the central compartment neck dissection.

Development of an omentum-cultured oesophageal scaffold reinforced by a 3D-printed ring: feasibility of an in vivo bioreactor

Abstract Current treatments of oesophageal diseases, such as carcinoma, congenital abnormality or trauma, require surgical intervention and oesophageal reconstruction with the stomach, jejunum or colon. However, serious side effects are possible with each treatment option. Despite tissue engineering promising to be an effective regenerative strategy, no functional solution currently exists for oesophageal reconstruction. Here, we developed an omentum-cultured oesophageal scaffold reinforced by a 3D-printed ring. The nano-structured scaffolds were wrapped into the omentum of rats and orthotopically transplanted for the repair of circumferential oesophageal defects two weeks later. The artificial oesophagus exhibited complete healing of the surgically created circumferential defects by the second week. The integration of the omentum-cultured oesophageal scaffold and the regenerative tissue remained intact. Macroscopically, there was no evidence of a fistula, perforation, abscess formation or surrounding soft-tissue necrosis. The omentum-cultured nano-structure scaffold reinforced by a 3D-printed ring is a more practical model with better vascularization for artificial neo-oesophagus reconstruction in a rat model.

Human Laryngeal Infection by Clinostomum complanatum

5A previously healthy 20-year-old man presented with foreign body sensation in the throat that had started 2 days before. Laryngoscopic examination revealed a motile worm on the surface of the cuneiform tubercle of the left arytenoid (Figure 1A and Supplemental video 1). Laboratory investigations revealed awhite blood cell count of 5,100 cells/mm with 1% eosinophils, and all other blood cell counts, serum chemistry, electrolytes, liver function studies, and coagulation studies were normal. The worm in the larynx was removed with forceps during which the worm was partially torn. Thewormwas a linguiform trematodewith two suckers on the ventral side (Figure 1B and Supplemental video 2). Further evaluation after fixation and staining clearly demonstrated ovary and anterior/posterior testis (Figure 1C). Based on the history of consumption of raw mullet 1 day before the symptom and morphology, the worm was identified as Clinostomum complanatum. The symptom was completely relieved after removal, and the patient did not report any recurrence. Clinostomum complanatum is a digenetic trematode that resides and reproduces in the throat of definitive hosts, piscivorous birds such as herons. When the hosts thrust their beaks into the water, eggs are released into the water and hatch, and released miracidia invade the first intermediate hosts, snails. The cercariae exit snails and encyst and develop intometacercariae in the flesh of second intermediate hosts, freshwater fish. The consumption of raw freshwater fish containing metacercariae rarely infects humans where theparasites excyst in the stomachandmigrate and !attach to the throat causing pharyngitis or laryngitis. Althoughmost of the human infection cases have been reported in Korea and Japan, the wide distribution of freshwater fish infection has been reported in North America. Furthermore, along with a few human infection cases after consumption of raw brackish fish, this case suggests that brackish fish is also not completely safe to eat raw in terms of C. complanatum infection. A patient presenting with a globus sensation after consumption of raw fish should be appropriately evaluated including laryngoscopy.