Chiho Obayashi

Pharmacokinetics and Antitumor Efficacy of Chemoembolization Using 40 µm Irinotecan-Loaded Microspheres in a Rabbit Liver Tumor Model

PURPOSE To evaluate the pharmacokinetics and antitumor efficacy of 40 μm irinotecan-loaded drug-eluting microspheres (Embozene TANDEM Microspheres; CeloNova BioSciences, Inc, San Antonio, Texas) (TANDEM-IRI). MATERIALS AND METHODS The following three groups included eight VX2 rabbits each: group 1, full-loaded (50 mg irinotecan/1 mL TANDEM)/high-dose injection (1 mg irinotecan/kg); group 2, full-loaded (50 mg irinotecan/1 mL TANDEM)/low-dose injection (0.5 mg irinotecan/kg); and group 3, half-loaded (25 mg irinotecan/1 mL TANDEM)/low-dose injection (0.5 mg irinotecan/kg). Irinotecan and SN-38 in the plasma and tumors were measured within 72 hours. Histologic examinations were conducted on days 1, 3, and 7. RESULTS Serum irinotecan levels remained near the maximum concentration for 180 minutes after transarterial chemoembolization; in group 1, levels were 351.4 ng/mL at 30 minutes, 329.0 ng/mL at 60 minutes, and 333.5 ng/mL at 180 minutes. The area under the curve for 0-24 hours of irinotecan in group 1 was approximately two times higher than the same value in groups 2 and 3. High irinotecan and SN-38 concentrations in the tumors were measured at 24 hours and 72 hours. After transarterial chemoembolization, levels of liver enzymes aspartate aminotransferase and alkaline phosphatase were significantly higher in group 1 compared with groups 2 and 3. Histologic findings showed microspheres had deeply penetrated into tumors. Significantly higher tumor necrosis ratios were observed in groups 1 (86.6%-90.0%) and 3 (90.0%-100%) compared with group 2 (63.3%-70%) (P = .031 and P = .016). CONCLUSIONS Slow drug release with high drug concentration in tumors can be provided with 40 μm TANDEM-IRI. When complete arterial embolization is performed, the dose of irinotecan loaded on 40 μm TANDEM microspheres can be reduced while maintaining efficacy.

Programmed death ligand 1 (PD-L1) expression and tumor microenvironment: Implications for patients with oral precancerous lesions

OBJECTIVES Cancer immunoediting represents a relatively novel concept attempting to explain the process of tumor escape from the host immune system response. Here, we attempted to elucidate the role of programmed death ligand 1 (PD-L1), the tumor microenvironment, and tumor escape mechanisms that allow malignant transformation of oral precancerous lesions. MATERIALS AND METHODS Patients with oral precancerous lesions managed at the Nara Medical University Hospital, Japan, (n=120) were enrolled in this study. Epithelial dysplasias were graded by experienced pathologists, and subepithelial PD-L1-, CD163-, and CD8-positive cells were counted in the superficial lamina propria of oral mucosa. Epithelial PD-L1 expression was evaluated according to the staining intensity. The association of clinicopathological factors with epithelial dysplasia, malignant-free survival time, and significance of risk factors for malignant transformation were determined. RESULTS Multivariate analysis showed that the subepithelial CD163-positive cell count was the only significant risk factor for high-grade epithelial dysplasia (P<0.001), while subepithelial CD163- and PD-L1-positive cell counts, and epithelial PD-L1 positivity were significantly associated with malignant-free survival (P=0.004, 0.04, and <0.001, respectively). Subepithelial PD-L1-positive cell count and epithelial PD-L1 positivity were significantly associated with malignant transformation (P=0.01 and 0.04, respectively). CONCLUSION Our results indicate that PD-L1-expressing dysplastic epithelial and recruited subepithelial cells in oral precancerous legions may evade the host immune system, and that the inhibition of PD-1/PD-L1 pathway may potentially prevent malignant transformation of oral precancerous legions as well as can treat advanced cancers.

Evaluation of RNA and DNA extraction from liquid-based cytology specimens.

Molecular diagnosis using DNA and RNA derived from malignant tumors and molecular biological tools such as the quantitative polymerase‐chain‐reaction (qPCR) is a commonly used technique in clinical pathology. In this report, we compared the qualitative extraction of RNA and DNA from cancer cells fixed using several liquid‐based cytology (LBC) kits. Ten to 1,000 cells from the T24 urinary bladder cancer cell line and SKG‐II cervical cancer cell line were fixed with 55% methanol and three different methanol‐based LBC solutions. The mRNA levels of CD44 in T24 cells and E7 in SKG‐II cells and DNA levels of p53 in T24 cells and E7 in SKG‐II cells were analyzed by qPCR. mRNA and DNA extracted from T24 and/or SKG‐II cells fixed with methanol‐based LBC solutions were efficiently detected, but to differing degrees, by qPCR. mRNA, and DNA from cells fixed with a formaldehyde‐containing fixative liquid were detected at significantly low copy numbers by qPCR. Our results demonstrate that LBC systems are powerful tools for cytopathology and immunocytochemistry applications. However, the appropriate fixative must be selected for cell preservation when a small number of LBC samples is used for molecular testing, particularly in RNA‐based molecular analyses. Diagn. Cytopathol. 2016;44:833–840.

Multivariate analyses of Ki-67, cytokeratin 13 and cytokeratin 17 in diagnosis and prognosis of oral precancerous lesions

BACKGROUND Ki-67, cytokeratin 13, and/or cytokeratin 17 detection by immunohistochemistry has been reported to be useful for the diagnosis of oral precancerous lesions. However, the use of these markers remains controversial because of the lack of appropriately designed statistical studies. We assessed the hypothesis that Ki-67, cytokeratin 13, or cytokeratin 17 immunohistochemistry could facilitate the diagnosis of oral precancerous lesions and/or predict prognosis. METHODS Epithelial dysplasia was classified as low grade (none or mild dysplasia) or high grade (moderate dysplasia, severe dysplasia, or carcinoma in situ). This study included 58 low-grade and 36 high-grade dysplasia cases. We used logistic regression to assess the diagnostic values of Ki-67, cytokeratin 13, and cytokeratin 17 for high-grade dysplasia. Correlations between these markers and the prognosis of oral atypical epithelium were assessed using the Cox proportional hazards model. RESULTS Ki-67 overexpression and cytokeratin 13 loss were independent diagnostic markers for high-grade dysplasia (odds ratios, 1.92 and 2.53; 95% confidence intervals, 1.03-3.58, and 1.19-5.38, respectively). The area under the curve of Ki-67 was 0.73 and that of cytokeratin 13 was 0.72. However, the combination of Ki-67 and cytokeratin 13 yielded the area under the curve of 0.78. Ki-67 overexpression was significantly associated with recurrence and/or malignant transformation of oral atypical epithelium (hazard ratio, 7.25; 95% confidence interval, 1.07-48.92). CONCLUSIONS Ki-67 overexpression and cytokeratin 13 loss may be useful for distinguishing oral precancerous lesions from reactive atypical epithelium. Moreover, Ki-67 overexpression may be a risk factor for recurrence and/or malignant transformation of oral atypical epithelium.

Treatment of long-segment Barrett’s adenocarcinoma by complete circular endoscopic submucosal dissection: a case report

BackgroundWe present the first description of en bloc endoscopic submucosal dissection (ESD) for total circumferential Barrett’s adenocarcinoma, predominantly of the long-segment Barrett’s esophagus (LSBE), with a 2-year follow-up and management strategies for esophageal stricture prevention.Case presentationA 59-year-old man was diagnosed with LSBE and Barrett’s adenocarcinoma by esophagogastroduodenoscopy (EGD). A 55-mm-long circumferential tumor was completely resected by ESD. Histopathology revealed a well-differentiated adenocarcinoma within the LSBE superficial muscularis mucosa. For post-ESD stricture prevention, the patient underwent an endoscopic triamcinolone injection administration, oral prednisolone administration, and preemptive endoscopic balloon dilatation. Two years later, there is no evidence of esophageal stricture or recurrence.ConclusionsESD appears to be a safe, effective option for total circumferential Barrett’s adenocarcinoma in LSBE.

Keratin 19 as a key molecule in progression of human hepatocellular carcinomas through invasion and angiogenesis

BackgroundKeratin (K) 19-positive hepatocellular carcinoma (HCC) is well known to have a higher malignant potential than K19-negative HCC: However, the molecular mechanisms involved in K19-mediated progression of HCC remain unclear. We attempted to clarify whether K19 directly affects cell survival and invasiveness in association with cellular senescence or epithelial-mesenchymal transition (EMT) in K19-positive HCC.MethodsK19 expression was analysed in 136 HCC surgical specimens. The relationship of K19 with clinicopathological factors and survival was analysed. Further, the effect of K19 on cell proliferation, invasion, and angiogenesis was examined by silencing K19 in the human HCC cell lines, HepG2, HuH-7, and PLC/PRF/5. Finally, we investigated HCC invasion, proliferation, and angiogenesis using K19-positive HCC specimens.ResultsAnalysis of HCC surgical specimens revealed that K19-positive HCC exhibited higher invasiveness, metastatic potential, and poorer prognosis. In vitro experiments using the human HCC cell lines revealed that K19 silencing suppressed cell growth by inducting apoptosis or upregulating p16 and p27, resulting in cellular senescence. In addition, transfection with K19 siRNA upregulated E-cadherin gene expression, significantly inhibited the invasive capacity of the cells, downregulated angiogenesis-related molecules such as vasohibin-1 (VASH1) and fibroblast growth factor 1 (FGFR1), and upregulated vasohibin-2 (VASH2). K19-positive HCC specimens exhibited a high MIB-1 labelling index, decreased E-cadherin expression, and high microvessel density around cancer foci.ConclusionK19 directly promotes cancer cell survival, invasion, and angiogenesis, resulting in HCC progression and poor clinical outcome. K19 may therefore be a novel drug target for the treatment of K19-positive HCC.

Cytological features in eight patients with ALK-rearranged lung cancer

ALK‐rearranged lung cancer has been recently identified. Although signet‐ring cell morphology and mucinous cribriform pattern are considered to be characteristic of ALK‐rearranged lung cancer. Some studies have also suggested cytological features.

Usefulness of computed tomography density of a tumor in predicting the response of advanced esophageal cancer to preoperative chemotherapy

Background. In Japan, preoperative chemotherapy is considered essential for resectable stage II or III esophageal cancers. It is important to identify nonresponders for preoperative chemotherapy because continuing ineffective chemotherapy is not beneficial for them. We investigated the correlation between the computed tomography number of tumor and the effect of preoperative chemotherapy in patients with esophageal cancer. Methods. This retrospective study included 50 patients receiving preoperative chemotherapy with docetaxel, cisplatin, and 5‐fluorouracil for stage II or III esophageal cancer. The computed tomography number of tumor was measured as the mean of Hounsfield Units of the primary lesion on a plain computed tomography measured within a freehand region of interest drawn around the tumor border. For analysis, the patients were classified into responders and nonresponders to chemotherapy, with the pathologic response evaluated using the Japanese and Mandard classification. We analyzed the associations between the computed tomography number of tumor and clinical factors; histopathologic features, including the tumor size, depth of tumor invasion, capillary invasion, Ki‐67, p53, and CK5/6 expression; the pathologic response to chemotherapy and prognosis. Results. There was a significant association between the computed tomography number of tumor and the response to chemotherapy. The cut‐off value of the computed tomography number of tumor in predicting responders to chemotherapy was 40 Hounsfield Units (area under the receiver operating characteristic curve = 0.73, P = .009); patients with computed tomography number of tumor greater than this value significantly responded to chemotherapy (P = .02 in the Japanese and P = .009 in the Mandard classification) with good postoperative prognosis (P = .04). Only Ki‐67 expression among the histopathogic features were associated with the computed tomography number of tumor in histopathologic features (P = .01). Conclusion. The computed tomography number of tumor may be useful to predict the efficacy of preoperative chemotherapy and subsequent prognosis for patients with advanced esophageal cancer.

Barrett’s Esophageal Adenocarcinoma with CREST Syndrome

Scleroderma is a systemic and connective tissue disease. Gastrointestinal manifestations including esophageal dysmotility are common in scleroderma patients. The relationship between esophageal reflux and scleroderma has been well described; however, the complication of Barrett’s esophagus and adenocarcinoma due to chronic esophagitis is rare. In addition, there are no detailed reports on the treatment of esophageal adenocarcinoma or the pathological findings in patients with scleroderma. We report the case of a 55-year-old woman who presented with chronic cough and a dilated esophagus. The patient was diagnosed with Barrett’s adenocarcinoma and CREST syndrome, which is a form of scleroderma. Subtotal esophagectomy was performed, and the patient’s chronic cough was relieved. A surgical specimen revealed histological changes at the dilated parts of the esophagus that showed the thinning of the muscular layer with fibrotic changes.