池田 純一郎

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been used to diagnose and stage lung cancer. Acquire™ Pulmonary and Expect™ Pulmonary dedicated EBUS-TBNA needles were introduced as the Franseen and Lancet needles, respectively. It is still unclear whether the Franseen or Lancet needles yield a higher quality specimen especially focusing on next-generation sequencing-based molecular testing. METHODS: A single-center, prospective study performed at the Chiba University Hospital randomly assigned patients to two groups: Group A, wherein the first and second EBUS-TBNA were performed using Lancet and Franseen needles, respectively, and Group B, wherein the first and second EBUS-TBNA were performed using Franseen and Lancet needles, respectively. Each specimen was compared and analyzed pathologically. The primary outcome was the histological tissue area except blood clot and the cellularity of each sample. We also examined the success rate of molecular testing. RESULTS: Twelve patients who underwent EBUS-TBNA between November 2022 and February 2023 were enrolled in this study. The tissue area of the specimens obtained by the Franseen and Lancet needles was 13.3 ± 6.4 mm2 and 10.6 ± 6.3 mm2, respectively (P = .355). The tumor cellularity in the specimens obtained using the Franseen and Lancet needles was 54.0 ± 30.3 and 46.2 ± 36.3%, respectively (P = .608). The success rate of molecular testing using the single-pass sample by Franseen needle was 85.7 and 57.1% by Lancet needle. No serious complications were reported. CONCLUSIONS: The Franseen needle tended to show a greater amount of specimen with higher tumor cellularity than the Lancet needle which may contribute higher success rate of molecular testing. Further studies must be conducted to validate the results of this study. KEY FINDINGS: What is known and what is new?  What is the implication, and what should change now?

BACKGROUND: This study aimed to investigate the utility of intensive triamcinolone acetonide (TA) injections after extensive esophageal endoscopic submucosal dissection (ESD). METHODS: This retrospective study included 27 lesions in 27 consecutive patients who underwent ESD (ulcers encompassing ≥3/4 of the esophageal circumference) and received TA injections without oral steroid administration. Groups A and B included patients undergoing ESD with and without complete circumferential resection, respectively. All patients received TA injections (100 mg/session) immediately after ESD. In Group A, weekly based TA injections were performed until near-complete ulcer epithelialization. In Group B, patients did not receive additional injections or received weekly or biweekly TA injections. The primary outcome was stricture rate, and the secondary outcomes were the proportion of patients requiring endoscopic balloon dilation (EBD) and the number of TA injections. RESULTS: Group A included 7 lesions, and Group B included 20 lesions. The median (range) tumor lengths were 40 (30-90) and 45 (30-110) mm in Groups A and B, respectively. In Group A, the median circumferential resection diameter was 40 (20-80) mm. The stricture rate and the proportion of patients requiring EBD were 0 (0%) in Group A and 1 (5.0%) in Group B. The number of TA injection sessions was significantly higher in Group A than in Group B (8 [5-25] vs 1.5 [1-3]; p < 0.001). CONCLUSIONS: Intensive weekly or biweekly based TA injections might aid in preventing post-ESD stricture and the need for EBD in patients undergoing extensive resection involving the entire esophageal circumference.

Keratins are intermediate filament proteins in epithelial cells, and they are important for cytoskeletal organization. Keratin 6A (KRT6A), classified as a type II keratin, is normally expressed in stratified squamous epithelium and squamous cell carcinomas. Little is known about the expression and role of KRT6A in adenocarcinomas. We investigated the clinicopathological and molecular biological significance of KRT6A in colorectal adenocarcinoma. Immunostaining of our institution's colorectal adenocarcinoma cases demonstrated that KRT6A showed significantly stronger expression at the invasive front than the tumor center (p < 0.0001). The high-KRT6A-expression cases (n = 47) tended to have a high budding grade associated with significantly worse prognoses. A multivariate analysis revealed that the KRT6A expression status was an independent prognostic factor for overall survival (p = 0.0004), disease-specific survival (p = 0.0097) and progression-free survival (p = 0.0033). The correlation between KRT6A and patient prognoses was also validated in an external cohort from a published dataset. To determine the function of KRT6A in vitro, KRT6A was over-expressed in three colon cancer cell lines, DLD-1, SW620, and HCT 116. KRT6A overexpression increased migration and invasion in DLD-1, but did not in SW620 and HCT116. In three-dimensional sphere-forming culture, KRT6A expression enhanced the irregular protrusion around the spheroid in DLD-1. Our findings in the present study indicated that KRT6A expression is a valuable prognostic marker of colorectal cancer and KRT6A may be involved the molecular mechanism in the progression of invasive areas of colorectal cancer.

Pancreatic ductal adenocarcinoma (PDAC) has a very poor prognosis. Neoadjuvant chemotherapy is an effective PDAC treatment option, but chemotherapy causes unfavorable side effects. Glucocorticoids (e.g., dexamethasone [DEX]) are administered to reduce side effects of chemotherapy for solid tumors, including pancreatic cancer. Glucocorticoids have both beneficial and detrimental effects, however. We investigated the functional changes and gene-expression profile alterations induced by DEX in PDAC cells. PDAC cells were treated with DEX, and the cell proliferation, migration, invasion, and chemosensitivity to gemcitabine (GEM) were evaluated. The results demonstrated decreased cell proliferative capacity, increased cell migration and invasion, and decreased sensitivity to GEM. A comprehensive genetic analysis revealed marked increases in ECM1 and KRT6A in DEX-treated PDAC cells. We evaluated the effects of ECM1 and KRT6A expression by using PDAC cells transfected with those genes. Neither ECM1 nor KRT6A changed the cells' proliferation, but each enhanced cell migration and invasion. ECM1 decreased sensitivity to GEM. We also assessed the clinicopathological significance of the expressions of ECM1 and KRT6A in 130 cases of PDAC. An immunohistochemical analysis showed that KRT6A expression dominated the poorly differentiated areas. High expressions of these two proteins in PDAC were associated with a poorer prognosis. Our results thus demonstrated that DEX treatment changed PDAC cells' functions, resulting in decreased cell proliferation, increased cell migration and invasion, and decreased sensitivity to GEM. The molecular mechanisms of these changes involve ECM1 and KRT6A, whose expressions are induced by DEX.