Frequency and features of myasthenia gravis developing after thymectomy

BACKGROUND AND PURPOSE

Thymectomy is an effective treatment for myasthenia gravis (MG) with anti-acetylcholine receptor (AChR) antibodies. We rarely encounter patients who develop MG after surgery for thymic tumors. This study aimed to investigate the characteristics and frequency of post-thymectomy onset (PostTx) MG.

METHODS

We reviewed the clinical information of thymoma-associated MG in 158 patients. Of these, 18 (11%) patients with PostTx MG were identified.

RESULTS

The presence of anti-AChR antibodies (82%) and electrophysiological abnormalities (50%) was confirmed before thymectomy in patients with PostTx MG. The clinical characteristics of PostTx MG were similar to those of pre-thymectomy onset (PreTx) MG. In PostTx MG, the duration between thymectomy and MG onset were distributed as < 6 months (early-onset PostTx MG) and ≥ 6 months (late-onset PostTx MG). Notably, some patients with late-onset PostTx MG were associated with thymoma relapse.

CONCLUSION

Our results suggest that approximately 11% of patients with thymoma-associated MG were PostTx MG and pre-surgical assessment of anti-AChR antibody titer or electrophysiological testing may predict PostTx MG development. However, no difference in clinical manifestation and prognosis was observed between PreTx MG and PostTx MG.

Feasibility of cytological diagnosis of sarcoidosis with endobronchial US-guided transbronchial aspiration

BACKGROUND

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has a high diagnostic value in sarcoidosis if the obtained histological specimen is indicative of a non-caseating epithelioid-cell granuloma. However, EBUS-TBNA in sacoidosis sometimes affords solely cytological specimens.

OBJECTIVE

To investigate the relevance of EBUS-TBNA cytology specimens in diagnosing sarcoidosis.

DESIGN

The study population comprised 72 patients with sarcoidosis and 116 patients who had thoracic malignancies and intrathoracic lymphadenopathy but were eventually proven to be metastasis-free (controls). The EBUS-TBNA samples obtained for these subjects were blindly evaluated for the presence of epithelioid cell clusters by 2 independent cytoscreeners and a pathologist.

RESULTS

Interobserver variability in the specimen grading was minimal. The sensitivity and specificity were 65.3% and 94.0%, respectively. The sensitivity was high, at 87.5%, for the combined cytological and histological examinations. Of 7 controls whose cytological specimens showed epithelioid cell clusters, 3 were also deemed positive for sarcoidosis on histological examination, which indicated that they had sarcoid reaction to cancer.

CONCLUSIONS

Cytological evaluation of the EBUS-TBNA specimens had higher sensitivity than histological evaluation alone for intrathoracic lymphadenopathy due to sarcoidosis. It should be recognized, however, that up to 6% of patients with thoracic malignancy may have sarcoid reaction in non-metastatic lymph nodes.

Nuclear survivin in pN2 nonsmall cell lung cancer: prognostic and clinical implications

Patients with N2 nonsmall cell lung cancer (N2-NSCLC) represent heterogeneous groups. Survivin is a member of the inhibitor of apoptosis family. If N2-NSCLC patients could be stratified, based on survivin expression and/or its relation to cell cycle proteins, into homogeneous subgroups, certain therapies could be selected for those patients. Survivin expression in 78 surgically resected primary pathological N2-NSCLC tumours was evaluated using immunohistochemistry. Relationships of survivin expression to overall survival, clinical features and expression of six cell cycle-related proteins (pRb, cyclin D1, p16(INK4A), p53, p21(Waf1) and Ki-67) were analysed. Nuclear survivin and the number of mediastinal lymph node (LN) stations were independent prognostic factors. The patient group with combined negative survivin/single mediastinal LN station were the most favourable prognostic group, and was related to the clinical nodal factor. Indeed, patients with negative survivin/low Ki-67 labelling indices had the best survival, especially in nonsquamous histopathology. The current authors conclude that nuclear survivin is strongly related to lymph node metastasis and proliferative potentials in pathological N2 nonsmall cell lung cancer patients. Pre-operative N2 nonsmall cell lung cancer patients with combined negative nuclear survivin and a single mediastinal lymph node station, or low proliferative indices, particularly in clinical N0-1 disease and nonsquamous histopathology, respectively, are expected to have a favourable post-operative prognosis and may be candidates for primary resection.

Combined evaluation of Rad51 and ERCC1 expressions for sensitivity to platinum agents in non-small cell lung cancer (NSCLC)

18085

Background: DNA repair enzyme expression in tumor cells possibly affects sensitivity to anti-cancer agents. The aim of this study was to determine the relationship between expression status of DNA repair proteins and chemosensitivity in patients with NSCLC. Rad51 and ERCC1 play important roles in repair of double and single strand breaks of DNA, respectively, and may protect cells from cytotoxic effect of platinum agents. Methods: NSCLC tissues prepared from the surgical specimens of 41 patients were subjected to an immunohistochemical analysis for Rad51 and ERCC1 proteins and to a chemosensitivity test using the MTT assay. The relationships between the expression status of the DNA repair enzymes and ex vivo chemosensitivity to various agents were evaluated. Results: A positive expression for Rad51 and ERCC1 was observed in 17 cases (41%) and 20 cases (49%), respectively. The positivity of Rad51 was closely related to a certain histologic type of squamous cell carcinoma and poor differentiation, and the positivity of ERCC1 tended to be related to squamous cell carcinoma. In chemosensitivity tests, sensitivities to CDDP and CBDCA were significantly lower when both two enzymes were positive (p = 0.012 and 0.04 in CDDP, 0.014 and 0.03 in CBDCA), but not when either or neither of them was positive. Both Rad51 and ERCC1 expressions showed no significant relationship with sensitivities to paclitaxel, etoposide, vinorelbine, gemcitabine, 5-FU, or irinotecan. Conclusions: Combined expression of Rad51 and ERCC1 is associated with resistance to platinum agents in the ex vivo study of clinical NSCLC, and evaluation of expression status of both DNA repair enzymes would be a predictor for clinical response to platinum-based chemotherapies.

No significant financial relationships to disclose.

A case of an inflammatory myofibroblastic tumor in the lung which expressed TPM3-ALK gene fusion

We herein describe a 4-year-old boy who after being treated for pneumonia showed an abnormal shadow at the hilus of the right lung on chest X-rays with continued inflammatory findings in his laboratory data. CT and MR investigations suggested the existence of a neoplasm at that site. An open biopsy was thus performed for a definite diagnosis. The histological findings and the expression of TPM3-ALK fusion gene confirmed a diagnosis of an inflammatory myofibroblastic tumor. A right upper and middle lobectomy including the tumor was thus performed for a complete resection. In addition to the histological diagnosis, the detection of the tumor specific fusion gene provided objective evidence in making a diagnosis.

The characteristics and failure pattern of gefitinib responders with postoperative recurrence of pulmonary adenocarcinoma

AIMS

Gefitinib shows prominent anti-tumor activity against advanced or recurrent non-small cell lung cancer (NSCLC). However, most gefitinib-responsive patients ultimately relapse. We reviewed postoperatively recurrent NSCLC patients who received gefitinib treatment, and analyzed both the clinical features and manifestations of treatment failure in patients who initially responded to gefitinib.

METHODS

From 2002 to 2006, gefitinib was administered to in 34 postoperative recurrent lung adenocarcinoma patients. There were 13 men and 21 women with a mean age of 65 years. Twenty patients had never smoked while 14 were former smokers. Epidermal growth factor receptor (EGFR) gene mutation was measured using surgical specimens of the primary tumor.

RESULTS

The study group showed 1 complete response, 16 partial responses, 7 stable diseases and 8 progressive diseases. Mutations of EGFR gene were detected in 20 of 34 patients. Only the presence of EGFR gene mutations was significantly associated with the clinical response of gefitinib in our limited study (p=0.036). In 9 of 12 responders, gefitinib treatment failed due to the appearance of new lesions.

CONCLUSIONS

Gefitinib was significantly effective for patients with mutations of the EGFR gene and most responders failed due to the appearance of new lesions without progression of the pre-existent target lesions.

Clinical characterization of node-negative non-small cell lung cancer: Results of a prospective investigation

7218

Background: 20 to 30% of clinical stage IA non-small cell lung cancer cases were revealed to be node-positive by pathologic examination of resected specimens. In this prospective study, the clinical features of a truly node-negative population were prospectively investigated to search for candidates of a lesser resection or of a stereotactic radiotherapy. Methods: The clinical data and radiographic features of high-resolution computed tomography (HR-CT) were registered before operation in 169 clinical stage IA lung cancer patients, who were scheduled to undergo a standard lobectomy and systemic mediastinal node dissection. The nodal metastasis was pathologically defined, while the clinical factors associated with the presence of the nodal metastasis were evaluated. Results: In 130 evaluable cases, 16 of 114 adenocarcinoma and 3 of 16 other NSCLC were node-positive. Among all parameters, positivity of the serum carcinoembryonic antigen (CEA) was the only factor significantly associated with nodal metastasis (p = 0.0074). When we focused on adenocarcinomas, the serum CEA, retraction sign and intratumoral air-space on HR-CT were suggested to be predictive factors for lymph node metastasis with hazard ratios of 12.44 (p = 0.0003), 6.53 (p = 0.0533) and 0.17 (0.0073), respectively. In combination with the radiologic features of HR-CT imaging, none of 18 CEA-negative/retraction-negative cases and 3 of 65 CEA-negative/air-space positive cases showed nodal metastasis, in which the incidence of nodal metastasis was significantly lower than the counterparts with respective p-values of 0.0015 and 0.037. The tumor size and the proportion of ground glass attenuation were not associated with the incidence of nodal metastasis. Conclusions: The serum CEA and HR-CT features thus allowed us to identify node-negative lung adenocarcinomas. In clinical stage IA adenocarcinoma cases, a standard operation should be considered when positive serum CEA and/or retraction sign on HRCT is noticed.

No significant financial relationships to disclose.

Essential role of Shp2-binding sites on FRS2alpha for corticogenesis and for FGF2-dependent proliferation of neural progenitor cells

Mammalian corticogenesis occurs through a complex process that includes neurogenesis, in which neural progenitor cells proliferate, differentiate, and migrate. It has been reported recently that neurogenesis occurs in the subventricular zone (SVZ), a region previously thought to be the primary site of gliogenesis. It has been recognized that in the SVZ, intermediate progenitor cells, derived from radial glial cells that are multipotent neural stem cells, produce only neurons. However, the molecular mechanisms underlying the regulation of neural stem cells and intermediate progenitor cells as well as their contribution to overall corticogenesis remain unknown. The docking protein FRS2alpha is a major mediator of signaling by means of FGFs and neurotrophins. FRS2alpha mediates many of its pleiotropic cellular responses by recruiting the adaptor protein Grb2 and the protein tyrosine phosphatase Shp2 upon ligand stimulation. Here, we report that targeted disruption of Shp2-binding sites in FRS2alpha leads to severe impairment in cerebral cortex development in mutant mice. The defect in corticogenesis appears to be due at least in part to abnormalities in intermediate progenitor cells. Genetic evidence is provided that FRS2alpha plays critical roles in the maintenance of intermediate progenitor cells and in neurogenesis in the cerebral cortex. Moreover, FGF2-responsive neurospheres, which are cell aggregates derived from neural stem/progenitor cells (NSPCs), from FRS2alpha mutant mice were smaller than those of WT mice. However, mutant NSPCs were able to self-renew, demonstrating that Shp2-binding sites on FRS2alpha play an important role in NSPC proliferation but are dispensable for NSPC self-renewing capacity after FGF2 stimulation.

Tyrosine phosphorylation sites on FRS2alpha responsible for Shp2 recruitment are critical for induction of lens and retina

Early development of the lens and retina depends upon reciprocal inductive interactions between the embryonic surface ectoderm and the underlying neuroepithelium of the optic vesicle. FGF signaling has been implicated in this signal exchange. The docking protein FRS2alpha is a major mediator of FGF signaling by providing a link between FGF receptors (FGFRs) and a variety of intracellular signaling pathways. After FGF stimulation, tyrosine-phosphorylated FRS2alpha recruits four molecules of the adaptor protein Grb2 and two molecules of the protein tyrosine phosphatase Shp2, resulting in activation of the Ras/extracellular signal-regulated kinase (ERK) and phosphatidylinositol-3 kinase/Akt signaling pathways. In this report, we explore the role of signaling pathways downstream of FRS2alpha in eye development by analyzing the phenotypes of mice that carry point mutations in either the Grb2-(Frs2alpha(4F)) or the Shp2-binding sites (Frs2alpha(2F)) of FRS2alpha. Although Frs2alpha(4F/4F) mice exhibited normal early eye development, all Frs2alpha(2F/2F) embryos were defective in eye development and showed anophthalmia or microphthalmia. Consistent with the critical role of FRS2alpha in FGF signaling, the level of activated extracellular signal-regulated kinase in Frs2alpha(2F/2F) embryos was significantly lower than that observed in wild-type embryos. Furthermore, expression of Pax6 and Six3, molecular markers for lens induction, were decreased in the Frs2alpha(2F/2F) presumptive lens ectoderm. Similarly, the expression of Chx10 and Bmp4, genes required for retinal precursor proliferation and for lens development, respectively, was also decreased in the optic vesicles of Frs2alpha(2F/2F) mice. These experiments demonstrate that intracellular signals that depend on specific tyrosine residues in FRS2alpha lie upstream of gene products critical for induction of lens and retina.