Subsequent treatments beyond progression on osimertinib in EGFR-mutated NSCLC and leptomeningeal metastases.

BACKGROUND: Despite the reported efficacy of osimertinib, central nervous system (CNS) progression is still frequent in EGFR-mutated NSCLC. This study aimed to reveal site-specific resistant mechanisms to osimertinib and investigate subsequent treatments for leptomeningeal metastases (LM). METHODS: EGFR-mutated NSCLC with LM who progressed on osimertinib were included. Molecular analysis of cerebrospinal fluid (CSF) at osimertinib progression was performed. Subsequent treatments of LM were collected and analyzed. RESULTS: A total of 246 patients were identified. Only those with LM as a progression site on osimertinib were included (n=81). In 58 CSF-plasma pairs, more alterations were uniquely detected in CSF (77%) than in plasma (7%). These mechanisms led to 22 patients receiving matched targeted therapy. Among them, 16 (72.7%) had a clinical response. The median overall survival was 7.2 months. For non-matched therapy (n=59), the osimertinib combination had a longer median overall survival than the regimen switch in CNS-only progression (15.3 vs. 7 months, p=0.03). Finally, serial monitoring by CSF revealed the potential evolution of LM. CONCLUSIONS: Private resistant mechanisms in CSF might match osimertinib-resistant LM for targeted therapy. Besides, continuing osimertinib with intensification strategy might prolong survival, especially for those with CNS-only progression. Prospective  exploration is needed.

An integrated biomarker of PD-L1 expression and intraepithelial CD8+ T cell infiltration was associated with the prognosis of lung cancer patients after intracranial resection of brain metastases.

BACKGROUND: Brain metastases (BM) are common in lung cancer. However, data on the status of immune biomarkers in BM lesions remain limited. METHODS: We retrospectively analyzed PD-L1 expression and infiltration levels of CD3+ , CD4+ , CD8+ T cells as biomarkers by immunohistochemistry in both BM lesions and primary lung cancer (PL) lesions of 29 lung cancer (LC) patients. In addition, the correlations between these biomarkers and the clinical outcome were analyzed using log-rank test. RESULTS: Intratumoral heterogeneous expression of PD-L1 was observed on tumor cells (TCs) in 11 cases and on immune cells (ICs) in 10 cases with BM samples from multiple regions. There was a disagreement in PD-L1 expression on TCs between paired BM and PL lesions in 15 cases and on ICs in seven cases. Intraepithelial CD3+ and CD8+ T cell infiltration levels in BM samples were lower than those in the paired PL samples. PD-L1 positivity on both TCs and ICs was associated with a better post-BM-surgery prognosis (p = 0.010; p = 0.041). Notably, PD-L1 positivity on TCs and a high level of intraepithelial CD8+ T cell infiltration could serve as an integrated biomarker that indicates longer survival time (p = 0.004) in LC patients. CONCLUSION: The heterogeneity in PD-L1 expression was common in both stromal and intraepithelial regions in BM lesions of LC patients, suggesting the need for multiregional PD-L1 testing in clinical practice. More importantly, a combination of PD-L1 expression on TCs with intraepithelial CD8+ T cell infiltration might predict better post-BM-surgery outcomes.

[Neuroendoscopic treatment for 372 cases of intracranial lesions].

OBJECTIVE: To explore the application of neuroendoscopic treatment for intracranial lesions. METHODS: The clinic data of 372 patients with intracranial lesions, who underwent neuroendoscopic treatment at our department from May 1998 to May 2010, were reviewed retrospectively. Representative endoscopic treatments included endoscopic third ventriculostomy (ETV) (n = 198), ETV & endoscopic biopsy (n = 69), neuroendoscopic ostomy for septum pellucidum fenestration (n = 55) (for septum pellucidum cysts, n = 37) and endoscopic cystoventriculostomy for ventricular cysts (n = 50). Their surgical indications and clinical outcomes were summarized for analysis. RESULTS: ETV was performed successfully in 369 cases. Among them, 2 failed cases underwent other operations and endoscopic biopsy failed in 1 case. Within a short post-operative period, the symptoms were resolved in 347 cases (93.3%), showed no improvement in 23 cases (6.2%) and 2 died (0.5%). At Month 6 post-operation, a failure of ETV was detected in 22 cases (9.5%), a failure of neuroendoscopic ostomy for septum pellucidum cysts in 23 (69.7%) and for ventricular cysts in 12 cases (26.7%). CONCLUSION: ETV is effective in the treatment of obstructive hydrocephalus, but its indication should be strictly controlled for children. Effective rate of neuroendoscopic treatment for intracranial septum pellucidum cysts remains unsatisfactory so that its operative indication should be strictly controlled.

Genetic analysis of interleukin-1A C(-889)T polymorphism with Alzheimer disease.

Neuroinflammation has been implicated in the etiology of Alzheimer's disease (AD). Many studies have suggested that C(-889) T promoter polymorphism in one of the proinflammatory cytokine interleukin-1 (IL-1) encoding gene IL-1A may be associated with AD pathogenesis. To determine whether the polymorphism contributes to the risk for late-onset AD (LOAD) in Chinese, we carried out our investigation in 344 sporadic LOAD patients and 224 healthy controls. No statistical significant association was obtained between IL-1A C(-889) T polymorphism and LOAD and no statistical difference was found between cases and controls after stratification for apolipoprotein E allele 4 (APOE epsilon4) status. The results reveal that it is not likely that the IL-1A C(-889) T polymorphism is involved in AD pathogenesis in the Chinese population. Further studies of the associations between other IL-1A genetic polymorphisms and AD should be performed in a larger population and biologic functional analysis of IL-1A gene is required to verify the underlying roles of IL-IA in LOAD.

Adenoviral-mediated interleukin-18 expression in mesenchymal stem cells effectively suppresses the growth of glioma in rats.

Glioma is the most common primary intracranial malignant tumor. Despite advances in surgical techniques and adjuvant radio- and chemotherapies, the prognosis for patients with glioma remains poor. We have explored the effects of using genetically modified mesenchymal stem cells (MSCs) to treat malignant glioma in rats. Mesenchymal stem cells isolated from Sprague-Dawley rats can directly suppress the growth of C6 cells in vitro. MSCs transplanted intratumorally can also significantly inhibit the growth of glioma and prolong survival in C6 glioma-bearing models. MSCs producing Interleukin-18 infected by adenoviral vector inhibited glioma growth and prolonged the survival of glioma-bearing rats. Transplantation of IL-18 secreting MSCs was associated with enhanced T cell infiltration and long-term anti-tumor immunity. Thus, IL-18 may be an effective adoptive immunotherapy for malignant glioma. When used in conjunction with MSCs as targeting vehicles in vivo, IL-18 may offer a promising new treatment option for malignant glioma.

[Culture and identification of neural stem cells derived from the subventricular zone of adult mice].

OBJECTIVE: To establish a method for culturing and identifying neural stem cells (NSCs) derived from the subventricular zone (SVZ) in adult mice. METHODS: NSCs were isolated from the SVZ of adult mouse brain and cultured in serum-free medium. Cell cloning and BrdU incorporation were performed to identify the self-renewal and proliferative capacity of the NSCs. Fluorescence immunocytochemistry was used to examine the expressions of the NSC markers nestin and SOX2, neuronal marker Tuj1, astrocyte marker GFAP and oligodendrocyte marker NG2. The expressions of nestin and SOX2 were further examined by Western blotting and RT-PCR. RESULTS: NSCs with self-renewal and proliferative capacity were obtained from the SVZ of adult mice and grown as floating neurospheres. The NSCs expressed nestin and SOX2 and could differentiated into Tuj1-positive neurons, GFAP-positive astrocytes and NG2-positive oligodendrocytes. CONCLUSION: This method allows simple and stable culture of NSCs from the SVZ of adult mice.