Hirotaka Ishida

c-Met in esophageal squamous cell carcinoma: an independent prognostic factor and potential therapeutic target

Backgroundc-Met is widely known as a poor prognostic factor in various human malignancies. Previous studies have suggested the involvement of c-Met and/or its ligand, hepatocyte growth factor (HGF), in esophageal squamous cell carcinoma (ESCC), but the correlation between c-Met status and clinical outcome remains unclear. Furthermore, the identification of a novel molecular therapeutic target might potentially help improve the clinical outcome of ESCC patients.MethodsThe expression of c-Met and HGF was immunohistochemically assessed in 104 surgically obtained tissue specimens. The correlation between c-Met/HGF expression and patients’ clinicopathological features, including survival, was evaluated. We also investigated changes in cell functions and protein expression of c-Met and its downstream signaling pathway components under treatments with HGF and/or c-Met inhibitor in ESCC cell lines.ResultsElevated expression of c-Met was significantly correlated with tumor depth and pathological stage. Patients with high c-Met expression had significantly worse survival. In addition, multivariate analysis identified the high expression of c-Met as an independent prognostic factor. Treatment with c-Met inhibitor under HGF stimulation significantly inhibited the invasive capacity of an ESCC cell line with elevated c-Met mRNA expression. Moreover, c-Met and its downstream signaling inactivation was also detected after treatment with c-Met inhibitor.ConclusionsThe results of our study identified c-Met expression as an independent prognostic factor in ESCC patients and demonstrated that c-Met could be a potential molecular therapeutic target for the treatment of ESCC with elevated c-Met expression.

Decreased expression of ARID1A contributes to infiltrative growth of esophageal squamous cell carcinoma.

The clinical outcome for esophageal squamous cell carcinoma (ESCC) patients is often poor because of the invasive nature of this tumor type. AT-rich interactive domain 1A (ARID1A) functions as a tumor suppressor, and its gene mutation has been reported in various human malignancies. ARID1A is a non-catalytic subunit of the SWItch/Sucrose Non Fermentable (SWI/SNF) chromatin-remodeling complex that regulates gene transcription. Decreased expression of ARID1A protein has been reported to decrease the expression of E-cadherin, an adhesion protein. However, the correlation between ARID1A and E-cadherin expression status in ESCC remains largely unknown. To address this issue, we examined the expression of ARID1A and E-cadherin in tumor specimens excised from 83 ESCC patients using immunohistochemical analysis. The intensity of the ARID1A immunoreactivity was significantly lower in tumors with a growth pattern characterized by ill-defined borders than that in tumors with an expansive growth pattern having a well-demarcated border or tumors with an intermediate growth pattern. Thus, decreased ARID1A immunoreactivity correlated with infiltrative growth of ESCC. In contrast, E-cadherin status did not correlate with the infiltrative growth pattern of ESCC. Moreover, ARID1A expression status did not significantly correlate with any of other clinicopathological factors, E-cadherin expression levels, or the clinical outcome of the patients. On the other hand, the patients with tumors expressing low levels of E-cadherin exhibited significantly lower survival rates than those with high expression. In conclusion, reduced ARID1A expression in tumor tissues contributes to infiltrative growth of ESCC, irrespective of E-cadherin expression levels.

Residual carcinoma cells after chemoradiotherapy for esophageal squamous cell carcinoma patients: striving toward appropriate judgment of biopsy

In esophageal squamous cell carcinoma (ESCC) patients who are treated with chemoradiotherapy (CRT), identification of the presence or absence of residual or recurrent carcinoma is usually pivotal in their clinical management. In addition, the extent of carcinoma invasion into the esophageal wall could determine the clinical outcome of these patients following CRT. Therefore, in this study, we evaluated the response to CRT both macroscopically and histologically in a consecutive series of 42 ESCC patients receiving neoadjuvant chemoradiotherapy following curative esophageal resection at Tohoku University Hospital between August 2011 and December 2012. The histological grading of tumor regression was as follows: grade 3, markedly effective (no viable residual tumor cells); grade 2, moderately effective (residual tumor cells in less than one-third of the tumor); grade 1, slightly effective (1b, residual tumor cells in one-third to two-thirds of the tumor; 1a, residual tumor cells in more than two-thirds of the tumor); and grade 0, ineffective. In this study, we selected grade 2 and 1b cases because they might show a complete response with definitive CRT. We evaluated the presence of any residual in situ lesions and tumor depth in detail. The grading of tumor regression in primary sites was as follows: grade 3 (7 cases), grade 2 (16 cases), grade 1b (13 cases), and grade 1a (6 cases). The concordance rate between macroscopic and histopathological evaluation on the depth of the tumor was 40% (17/42). Among 29 cases (grade 2 and grade 1b), intraepithelial lesions were not detected in 17 cases, and tumor nests were not detected in the lamina propria mucosae in 9 cases. The results of this study highlight the difficulties of detecting residual carcinoma cells using conventional endoscopic biopsy in patients who have received CRT. Therefore, when residual cancer is clinically suspected in patients who have received CRT, the biopsy specimen should be obtained from the deep layer of the esophagus whenever possible. Additionally, close follow-up is required using positron emission tomography/computed tomography, endoscopy, and other radiological evaluations.

Inflammation and PD-L1 expression in pulmonary neuroendocrine tumors

In the light of novel cancer immune therapies, the status of antitumor inflammatory response and its regulation has gained much attention in patients with lung cancer. Ample datasets exist for non-small-cell lung cancer, but those for pulmonary neuroendocrine tumors are scarce and controversial. Here, tumor-associated inflammation, CD8+ cell infiltration and PD-L1 status were evaluated in a cohort of 57 resected carcinoids and 185 resected neuroendocrine carcinomas of the lung (58 large cell carcinomas and 127 small cell carcinomas). Data were correlated with clinicopathological factors and survival. Moderate or high tumor-associated inflammation was detected in 4 carcinoids (7%) and in 37 neuroendocrine carcinomas (20%). PD-L1 immunoreactivity was seen in immune cells of 73 (39%) neuroendocrine carcinomas, while tumor cells were labeled in 21 (11%) cases. Inflammatory cells and tumor cells in carcinoids lacked any PD-L1 expression. In neuroendocrine carcinomas, PD-L1 positivity in immune cells, but not in tumor cells, was associated with intratumoral CD8+ cell infiltration (P < 0.001), as well as with the severity of tumor-associated inflammation (P < 0.001). In neuroendocrine carcinomas, tumor-associated inflammation and PD-L1 positivity in immune cells correlated with prolonged survival and the latter factor was also an independent prognosticator (P < 0.01, hazard ratio 0.4 for overall survival, P < 0.001 hazard ratio 0.4 for disease-free survival). Taken together, in neuroendocrine tumors, antitumor inflammatory response and PD-L1 expression are largely restricted to neuroendocrine carcinomas, and in this tumor entity, PD-L1 expression in inflammatory cells is positively correlated to patient survival.

Estrogen receptor β in Merkel cell carcinoma: its possible roles in pathogenesis

Sex steroids have been postulated to influence skin development and functions as well as its pathogenesis. MCC occurs in both sexes; however, the specific differences in pathogenesis among sexes have yet to be conclusively defined. The detailed status of sex steroid receptors (AR, PRA and PRB, and ERα, ERβ) are also unknown in MCC patients. We first immunolocalized sex steroid receptors and compared the results with immunolocalization of relevant transcription factors including SOX2, FOXA1, and Bcl-2 and Ki-67 in 18 cases of MCCs. AR, PRA, PRB, ERα, ERβ, Bcl-2, SOX2, and FOXA1 immunoreactivity was evaluated by using the modified H score method, and Ki-67 was quantified using labeling index. ERβ immunoreactivity was markedly present in all the cases of MCC examined, with relatively weak immunoreactivity of ERα, AR, PRA, and PRB. The status of ERβ immunoreactivity was also significantly correlated with Ki-67 labeling index and Bcl-2 score. These results demonstrated that ERβ could be associated with regulation of both cell proliferation and apoptosis in MCCs.

Treatment of spontaneous esophageal rupture (Boerhaave syndrome) using thoracoscopic surgery and sivelestat sodium hydrate

Background The mortality rate of spontaneous esophageal rupture remains 20% to 40% due to severe respiratory failure. We have performed thoracoscopic surgery for esophageal disease at our department since 1994. Sivelestat sodium hydrate reportedly improves the pulmonary outcome in the patients with acute lung injury (ALI). Methods We retrospectively evaluated the usefulness of thoracoscopic surgery and perioperative administration of sivelestat sodium hydrate for spontaneous esophageal rupture in 12 patients who underwent thoracoscopy at our department between 2002 and 2014. Results The patient cohort included 11 males and one female (median age, 61 years). The lower left esophageal wall was perforated in all patients. Surgical procedures consisted of thoracoscopic suture and thoracic drainage in six patients, transhiatal suture and thoracoscopic thoracic drainage in five, and thoracoscopic esophagectomy and thoracic drainage in one. The median time from onset to surgery was 8 hours with a surgical duration of 210 minutes, blood loss 260 mL, postoperative ventilator management 1 day, intensive care unit (ICU) stay 5 days, and interval to restoration of oral ingestion 13 days. Postoperative complications included respiratory failure in four patients, pyothorax in three, and leakage in one. There was no instance of perioperative mortality. Regarding perioperative administration of sivelestat sodium hydrate, the postoperative arterial oxygen partial pressure-to-fractional inspired oxygen ratio (P/F) and C-reactive protein (CRP) levels in the administration group were significantly better than those in the non-administration group on postoperative days 4 (P=0.035) and 5 (P=0.037), respectively. In contrast, there was no significant difference between the groups in median time of ventilator management, ICU stay, oral ingestion following surgery, or hospital stay. Conclusions Thoracoscopic surgery obtained acceptable results in all patients, including two with a significant time elapse from onset to treatment. Furthermore, sivelestat sodium hydrate was suggested to help improve postoperative respiration and inflammatory response.

Different strategy of salvage esophagectomy between residual and recurrent esophageal cancer after definitive chemoradiotherapy

Background Clinical outcomes appear to differ between patients with residual or recurrent esophageal cancer after definitive chemoradiotherapy. We aimed to identify the patients most likely to benefit from this high-risk surgery, divided by the patients whose cancer was residual and recurrent groups, respectively. Methods We retrospectively examined 100 cases of patients who failed to respond to definitive chemoradiotherapy for thoracic esophageal squamous cell carcinoma and subsequently underwent salvage transthoracic esophagectomy. Results In-hospital morbidity was similar in both groups. T status prior to administration of chemoradiotherapy correlated with survival in the group with residual cancer (P=0.010), but this relationship was not significant in the group with recurrent cancer (P=0.635). On the other hand, pathological T status showed a significant correlation with survival in both the residual (P<0.001) and recurrent groups (P=0.001). Patients with T3 disease in the recurrent group showed better survival, similar to T0-2 patients, while worse survival was demonstrated in the residual group. In the recurrent group, N status before chemoradiotherapy did not correlate with survival (P=0.895). Conclusions Patients with residual cancer would have good prognosis by salvage esophagectomy in cases in which the cancer had not invaded to the adventitia at the time of chemoradiotherapy and surgery. Conversely, patients whose cancer was recurrent might benefit from salvage surgery if the cancer appears to be resectable. T and N status before chemoradiotherapy are not important factors in consideration of salvage esophagectomy in cases of recurrent cancer.

Curative resection of advanced esophageal cancer with metachronous stage IV breast cancer: A case report

Highlights • Our literature search revealed no curative surgery cases for esophageal cancer in patients with multiple primary cancers with distant metastasis.• We report a case of esophageal cancer with metachronous breast cancer involving liver and mediastinal lymph node metastasis and cancerous peritonitis.• Curative resection of esophageal cancer can be considered when the prognosis of the additional cancer is not poor.

Myosin 5a regulates tumor migration and epithelial-mesenchymal transition in esophageal squamous cell carcinoma: utility as a prognostic factor

Esophageal squamous cell carcinoma (ESCC) is highly malignant. Recently, the expression of myosin 5a, a member of the myosin superfamily, was reported to be associated with increased invasiveness and metastasis in many tumor types. Moreover, myosin 5a is upregulated by Snail and activated by Akt2, both of which are epithelial-mesenchymal transition (EMT) markers. In this study, we confirmed the expression of myosin 5a in ESCC surgical specimens and cell lines, revealing its correlation with tumor invasion, migration, patient prognosis, and expression of EMT-related proteins. The expression of myosin 5a, vimentin, and E-cadherin was immunohistochemically evaluated in 118 patients with ESCC who underwent esophagectomy without chemotherapy or irradiation therapy prior to surgery. We also investigated ESCC cell migration under myosin 5a silencing by siRNA induction. The high expression of myosin 5a was correlated with tumor depth, lymph node metastasis, pathological stage, high vimentin expression, and low E-cadherin expression. Patients with high expression of myosin 5a, including those with pT1 cancer, exhibited significantly worse survival. Moreover, the expression level of vimentin mRNA and the number of migrated ESCC cells decreased significantly following myosin 5a silencing. Our findings demonstrate that high expression of myosin 5a may be an independent prognostic factor in patients with ESCC, even in early invasive carcinoma, and indicate myosin 5a has a role in both cell migration and EMT.

SOX2 and Rb1 in esophageal small-cell carcinoma: their possible involvement in pathogenesis

Clinicopathological features and pathogenesis of esophageal small-cell carcinoma remain unclear. We hypothesized common cellular origin and pathogenesis in small-cell carcinoma of esophagus and lung associated with SOX2 overexpression and loss of Rb1. Expression of squamous-basal markers (CK5/6 and p40), glandular markers (CK18 and CEA), SOX2, and Rb1 were evaluated in 15 esophageal small-cell carcinomas, 46 poorly differentiated squamous cell carcinomas, and 88 small-cell lung carcinoma, as well as 16 embryonic esophagus. Esophageal small-cell carcinoma expressed higher levels of glandular markers and lower levels of squamous-basal markers than poorly differentiated squamous cell carcinoma. No significant differences were observed in immunohistochemistry profiles between small-cell carcinoma of the esophagus and the lung. SOX2 expression was high in esophageal small-cell carcinoma (70%±33% of nuclei), small-cell lung carcinoma (70%±26%), and the embryonic esophagus (75%±4%), and it was significantly lower in poorly differentiated squamous cell carcinoma (29%±28%). Rb1 expression was significantly lower in esophageal small-cell carcinoma (0.3%±1%), small-cell lung carcinoma (2%±6%), and the embryonic esophagus (7%±5%), and it was significantly higher in poorly differentiated squamous cell carcinoma (51%±24%). The immunohistochemistry profiles of small-cell carcinoma of the esophagus and the lung are highly similar. The loss of Rb1 function is a key contributor to the pathogenesis of both neoplasms. In addition, SOX2 overexpression observed in esophageal and lung small-cell carcinoma as well as in the embryonic esophagus indicated that esophageal small-cell carcinoma may arise from embryonic-like stem cells in the esophageal epithelium. The two distinct differentiation patterns (neuroendocrine and glandular) of esophageal small-cell carcinoma further support the fact that SOX2 has a pivotal role in the differentiation of pluripotent stem cells into esophageal small-cell carcinoma cells.