Impact of extracapsular lymph node involvement on tumor progression in esophageal squamous cell carcinoma after neoadjuvant therapy and effects on lymph nodes induced by chemotherapy and chemoradiotherapy

Background

Neoadjuvant therapy followed by surgery can improve long-term survival and reduce local recurrence in patients with esophageal squamous cell carcinoma (ESCC). Extracapsular lymph node involvement (ECLNI) reflects tumor progression in gastrointestinal malignancies. The aim of this study was to clarify the correlation between ECLNI and clinical outcome in ESCC following neoadjuvant therapy.

Methods

A total of 36 patients with ESCC who underwent neoadjuvant therapy followed by surgery were enrolled in this study (CT: n = 16; CRT: n = 20). The correlation between ECLNI and clinicopathological variables was investigated. In addition, we also evaluated whether differences in pathological response existed between primary tumors and metastatic lymph nodes (LNs), and whether chemotherapy (CT) and chemoradiotherapy (CRT) had different effects on LNs.

Results

Of 36 patients, 22.2 % had detectable ECLNI. ECLNI was significantly correlated with tumor size (>40 mm), LN density (≧20 %), advanced stage, lymphatic invasion, non-R0 resection, and poor pathological response. Patients with ECLNI had a significantly poorer prognosis than those without ECLNI (P = 0.0040). No differences in pathological response were observed between primary tumors and metastatic LNs for each type of therapy. The median number of dissected LNs was 21, 45, and 14 in the surgery alone (n = 22), CT, and CRT groups, respectively (P < 0.05). More severe morphologic changes in LNs appeared to be induced by CRT than by CT.

Conclusion

ECLNI was correlated with poor prognosis in patients with ESCC after neoadjuvant therapy. CT and CRT had different effects on LNs.     

Influence of PD‐L1 cross‐linking on cell death in PD‐L1‐expressing cell lines and bovine lymphocytes

Programmed death‐ligand 1 (PD‐L1) blockade is accepted as a novel strategy for the reactivation of exhausted T cells that express programmed death‐1 (PD‐1). However, the mechanism of PD‐L1‐mediated inhibitory signalling after PD‐L1 cross‐linking by anti‐PD‐L1 monoclonal antibody (mAb) or PD‐1–immunogloblin fusion protein (PD‐1‐Ig) is still unknown, although it may induce cell death of PD‐L1⁺ cells required for regular immune reactions. In this study, PD‐1‐Ig or anti‐PD‐L1 mAb treatment was tested in cell lines that expressed PD‐L1 and bovine lymphocytes to investigate whether the treatment induces immune reactivation or PD‐L1‐mediated cell death. PD‐L1 cross‐linking by PD‐1‐Ig or anti‐PD‐L1 mAb primarily increased the number of dead cells in PD‐L1^high cells, but not in PD‐L1^low cells; these cells were prepared from Cos‐7 cells in which bovine PD‐L1 expression was induced by transfection. The PD‐L1‐mediated cell death also occurred in Cos‐7 and HeLa cells transfected with vectors only encoding the extracellular region of PD‐L1. In bovine lymphocytes, the anti‐PD‐L1 mAb treatment up‐regulated interferon‐γ (IFN‐γ) production, whereas PD‐1‐Ig treatment decreased this cytokine production and cell proliferation. The IFN‐γ production in B‐cell‐depleted peripheral blood mononuclear cells was not reduced by PD‐1‐Ig treatment and the percentages of dead cells in PD‐L1⁺ B cells were increased by PD‐1‐Ig treatment, indicating that PD‐1‐Ig‐induced immunosuppression in bovine lymphocytes could be caused by PD‐L1‐mediated B‐cell death. This study provides novel information for the understanding of signalling through PD‐L1.     

Localization of Hsp27 in the Rat Submandibular Gland Following the Application of Various Surgical Treatments

Salivary glands repair and regenerate following various types of injuries and surgical procedures. However, the tissue responses induced in the contralateral glands have yet to be elucidated in detail. Hsp27, a member of the heat-shock protein (Hsp) family, is strongly expressed in physiological environments, particularly during development. Hsp27 was previously shown to play a role in the regulation of acinar cell proliferation and differentiation in the rat submandibular gland.The present study performed the following surgical treatments on the right submandibular glands of adult rats: 1) duct ligation followed by unligation after one week; 2) partial sialoadenectomy; and 3) total sialoadenectomy. Immunohistochemistry for Hsp27 and Ki67 was performed in the experimental and normal contralateral glands, and localization was histologically and morphometrically analyzed.The results obtained revealed the localization of Hsp27 to the intercalated duct in the submandibular glands of non-treated rats. The expression of Hsp27 was strongly induced in both the uninjured contralateral control glands as well as treated glands of experimental rats regardless of the surgical procedure performed. The number of Hsp27-immunopositive cells increased rapidly following surgery, and subsequently returned to the same level as that in non-treated rats after 4 weeks. However, no marked changes were observed in the number of Ki67-immunopositive proliferating cells. Therefore, the change in the number of Hsp27-immunopositive cells may have contributed to compensatory hypertrophy. The results of the present study indicate that the expression of Hsp27 in the intercalated duct in the submandibular gland may play a role in the differentiation of acinar cells.     

Regenerative responses after mild heart injuries for cardiomyocyte proliferation in zebrafish

Background: The zebrafish heart regenerates after various severe injuries. Common processes of heart regeneration are cardiomyocyte proliferation, activation of epicardial tissue, and neovascularization. In order to further characterize heart regeneration processes, we introduced milder injuries and compared responses to those induced by ventricular apex resection, a widely used injury method. We used scratching of the ventricular surface and puncturing of the ventricle with a fine tungsten needle as injury‐inducing techniques. Results: Scratching the ventricular surface induced subtle cardiomyocyte proliferation and responses of the epicardium. Endothelial cell accumulation was limited to the surface of the heart. Ventricular puncture induced cardiomyocyte proliferation, endocardial and epicardial activation, and neo‐vascularization, similar to the resection method. However, the degree of the responses was milder, correlating with milder injury. Sham operation induced epicardial aldh1a2 expression but not tbx18 and WT1. Conclusions: Puncturing the ventricle induces responses equivalent to resection at milder degrees in a shorter time frame and can be used as a simple injury model. Scratching the ventricle did not induce heart regeneration and can be used for studying wound responses to epicardium. Developmental Dynamics 243:1477–1486, 2014. © 2014 Wiley Periodicals, Inc.     

Impacts of Recombinant Human Erythropoietin Treatment During Predialysis Periods on the Progression of Chronic Kidney Disease in a Large‐Scale Cohort Study (Co‐JET study)

The effect of recombinant human erythropoietin (rHuEPO) treatment on the progression of chronic kidney disease (CKD) has not been fully evaluated in Japan. We therefore retrospectively evaluated this in a sub‐cohort of a prospective multicenter study to investigate optimal hemoglobin (Hb) level of CKD patients on hemodialysis (HD) treated with rHuEPO; Japan Erythropoietin Treatment Study for Target Hb and Survival (JET study). Effect of rHuEPO treatment during predialysis period to delay initiation of HD was retrospectively assessed in 2434 patients from the JET study comparing groups with and without rHuEPO treatment. The assessment was done by Cox proportional hazards regression analysis and inverse probability‐weighted (IPW) analysis to adjust for time‐dependent confounders. The weights used in the IPW analysis were calculated using a logistic model that included baseline confounders and time‐dependent variables. During the predialysis period, 71.7% (1746 patients) were treated with rHuEPO (mean Hb level of 8.7 g/dL at initiation of rHuEPO treatment). Covariates significantly associated with initiation of rHuEPO treatment were Hb level, serum creatinine level, age, diabetes, cardiac insufficiency, and hypertension. The adjusted hazard ratio for time until HD initiation under rHuEPO treatment was 0.272 (95% CI, 0.223–0.331; P < 0.001) in the Cox analysis and 0.63 (95% CI, 0.53–0.76; P < 0.0001) in the IPW analysis. This retrospective study suggests that rHuEPO treatment during the predialysis period has preventive effects on the progression of CKD although further prospective investigation on the efficacy is needed.     

Pathological complete response of synchronous multiple liver metastases associated with advanced gastric cancer to gastrectomy and prompt S-1 treatment in combination with fractional cisplatin: report of a case

Systemic chemotherapy is the treatment recommended for prolonged survival in cases of metastatic gastric cancer. There have been a number of clinical reports of surgical resection of liver metastasis in selected patients with gastric cancer. Here, we report on a case of treatment of far advanced gastric cancer with synchronous multiple liver metastases with prompt S-1 in combination with fractional cisplatin sandwiched between twostage surgery. Metastases including peritoneal dissemination and extensive lymph node involvement were absent so it was feasible to completely remove all of the macroscopic liver metastases. Each step of the chemotherapy progressed satisfactorily and histological examination after the hepatectomy yielded a pathologically complete response of liver metastases from the gastric cancer. This strategy provides a promising treatment for far advanced gastric cancer with a limited number of synchronous liver metastases. The referral to surgical oncology is a crucial step for the documentation of pathological complete response.