Sorafenib in Japanese Patients with Locally Advanced or Metastatic Medullary Thyroid Carcinoma and Anaplastic Thyroid Carcinoma.

BACKGROUND: Therapeutic options for treating advanced or metastatic medullary thyroid carcinoma (MTC) and anaplastic thyroid carcinoma (ATC) are still limited in Japan, even though vandetanib for MTC and lenvatinib for MTC and ATC have been approved. Sorafenib is an oral multikinase inhibitor approved for the treatment of patients with radioactive iodine-refractory differentiated thyroid cancer (DTC). An uncontrolled, open-label, multicenter, single-arm, Phase 2 clinical study was conducted to evaluate the safety and efficacy of sorafenib in Japanese patients with MTC and ATC. METHODS: Japanese patients with histologically confirmed ATC and locally advanced or metastatic MTC were enrolled from April to September 2014. The primary endpoint was to evaluate the safety of sorafenib. Treatment efficacy variables including progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and maximum reduction in tumor size were evaluated as secondary endpoints. Patients received sorafenib 400 mg orally twice daily on a continuous basis and then continued treatment until the occurrence of disease progression, unacceptable toxicity, or withdrawal of consent. RESULTS: A total of 20 patients were screened, and 18 (8 with MTC and 10 with ATC) were enrolled. The most common drug-related adverse events were palmar-plantar erythrodysesthesia (72%), alopecia (56%), hypertension (56%), and diarrhea (44%). In the ATC patients, median PFS was 2.8 months [confidence interval 0.7-5.6], and median OS was 5.0 months [confidence interval 0.7-5.7]; ORR and DCR were 0% and 40%, respectively. In the MTC population, neither median PFS nor OS had been reached at the time of this analysis; ORR was 25% and DCR was 75%. CONCLUSIONS: The toxicities reported in this study were consistent with the known safety profile of sorafenib. Sorafenib seems to be effective in the treatment of advanced MTC but not ATC, and could be a new treatment option for locally advanced or metastatic MTC and radioactive iodine-refractory DTC.

Antibody αPEP13h reacts with lymphangioleiomyomatosis cells in lung nodules.

BACKGROUND: Lymphangioleiomyomatosis (LAM) is characterized by the proliferation in the lung, axial lymphatics (eg, lymphangioleiomyomas), and kidney (eg, angiomyolipomas) of abnormal smooth muscle-like LAM cells, which express melanoma antigens such as Pmel17/gp100 and have dysfunctional tumor suppressor tuberous sclerosis complex (TSC) genes TSC2 or TSC1. Histopathologic diagnosis of LAM in lung specimens is based on identification of the Pmel17 protein with the monoclonal antibody HMB-45. METHODS: We compared the sensitivity of HMB-45 to that of antipeptide antibody αPEP13h, which reacts with a C-terminal peptide of Pmel17. LAM lung nodules were laser-capture microdissected to identify proteins by Western blotting. RESULTS: HMB-45 recognized approximately 25% of LAM cells within the LAM lung nodules, whereas αPEP13h identified > 82% of LAM cells within these structures in approximately 90% of patients. Whereas HMB-45 reacted with epithelioid but not with spindle-shaped LAM cells, αPEP13h identified both spindle-shaped and epithelioid LAM cells, providing greater sensitivity for detection of all types of LAM cells. HMB-45 recognized Pmel17 in premelanosomal organelles; αPEP13h recognized proteins in the cytoplasm as well as in premelanosomal organelles. Both antibodies recognized a Pmel17 variant of approximately 50 kDa. CONCLUSIONS: Based on its sensitivity and specificity, αPEP13h may be useful in the diagnosis of LAM and more sensitive than HMB-45.

Involvement of lymphatics in lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM), a rare multisystem disease, occurs primarily in women, with cystic destruction of the lungs, abdominal tumors, and involvement of the axial lymphatics in the thorax and abdomen. To understand the pathogenesis of LAM, we initiated a longitudinal study of patients with LAM; over 500 patients have been enrolled. LAM results from the proliferation of a neoplastic cell (LAM cell), which has mutations in the tuberous sclerosis complex (TSC) genes, TSC1 or TSC2. Consistent with their metastatic behavior, LAM cells were isolated from blood, urine, and chylous effusions. Surface proteins on LAM cells include those found on metastatic cells and those involved in cell migration. In the lung, LAM cells are found clustered in nodules, which appear in the walls of the cysts, and in the interstitium. LAM lung nodules are traversed by slit-like vascular structures, with lining cells showing reactivity with antibodies against components of lymphatic endothelial cells. The axial lymphatics appear to be infiltrated by LAM cells, which may result in obstruction and formation of chyle-filled lymphangioleiomyomas. LAM cell clusters have been isolated from chylous pleural effusions, and it is hypothesized that these clusters may be responsible for metastatic spread of LAM cells via lymphatic vessels. Consistent with a lymphangiogenic process, levels of VEGF-D, a lymphangiogenic factor, were higher in sera of patients with LAM and lymphatic involvement (i.e., lymphangioleiomyoma, adenopathy) than in healthy volunteers or LAM patients with cystic disease limited to the lung. These findings are consistent with an important function for lymphangiogenesis in LAM.

Helicobacter pylori infection-negative gastric cancer in Japanese hospital patients: incidence and pathological characteristics.

We used Helicobacter pylori sero-positivity and mucosal atrophy as detected by the serum pepsinogen method to identify H. pylori infection-negative gastric cancer patients with or without atrophy. One hundred and six of 748 (14.2%) primary gastric cancer patients were infection-negative by a serum antibody detection system. Further, 121 (16.2%) of the 748 were negative for gastric mucosal atrophy by the pepsinogen method, of whom 15/748 (2.0%) were H. pylori-negative by pepsinogen I level (>70 ng/mL) and pepsinogen I/II ratio (>3.0). Twenty-seven of 782 (3.6%) gastric cancer patients were H. pylori-negative by antibodies and severe atrophy as determined by pepsinogen I level (<30 ng/mL) and pepsinogen I/II ratio (<2.0). H. pylori-negative gastric cancer patients with severe atrophy likely had a previous infection. These results indicate that the actual number of H. pylori-negative patients is 2.0% at minimum and 10.6% (14.2% minus 3.6%) at maximum in the general Japanese population. Five of 15 (33%) cases displaying neither anti-H. pylori antibodies nor atrophy were intestinal-type and 10 (67%) were diffuse-type adenocarcinomas. Thirteen surgical patients with primary gastric cancer displaying neither antibodies nor mucosal atrophy were further analyzed for pathological and phenotypic characteristics. The mucin phenotype was divided into four gastric, five gastric and intestinal, two intestinal and two null types, independent of histological classification. Intestinal phenotype elements were detected by Cdx2 immunohistochemical methods in nine of 13 (70%) cases examined. We conclude that a small fraction of gastric cancer patients displayed multifactorial carcinogenesis without H. pylori infection, indicating that gastric cancer risk still exists in the absence of H. pylori infection, at an incidence of 2.0% at minimum and 10.6% at maximum in the general Japanese population.