Clinicopathologic and immunohistochemical features of surgically resected small cell carcinoma of the esophagus

Esophageal small cell carcinoma (SmC) is considered an aggressive cancer carrying a poor prognosis, although the rarity of this tumor has impeded statistical evaluation. We reviewed records of 457 esophageal cancer patients treated in our department from 1986 to 2000, comparing clinicopathologic factors and post-treatment outcomes, for 9 patients with SmC, most undergoing esophagectomy including lymphadenectomy, with data from 128 patients with esophageal squamous cell carcinoma (SqC) invading to the muscular layer or beyond. Immunohistochemical features were compared between the SmC and 12 consecutive SqC. All patients studied had localized disease according to preoperative staging. SmC showed more ulcerative and infiltrative growth, and more aggressive lymphatic spread, than SqC. All SmC patients had lymph node metastasis (thoracic nodes, 9 patients: abdominal 6; cervical 1). All SmC specimens but no SqC were immunoreactive for neuron-specific enolase. Two and three SmC specimens were reactive for epithelial membrane antigen and keratin, respectively. Survival of SmC patients after esophagectomy (median, 11 months) was worse than for SqC patients (p=0.013). However, 1 SmC patient remains alive at 76 months. Survival was not related to any clinicopathologic or immunohistochemical features. While SmC shows aggressive behavior and worse outcomes than SqC, combining esophagectomy with chemotherapy or radiotherapy may prolong survival.     

Tracking cell invasion of human glioma cells and suppression by anti-matrix metalloproteinase agent in rodent brain-slice model

Persistent expression of green fluorescent protein (GFP) in human malignant glioma cell clones (U87MG, U251MG, and U373MG) was established using the pEGFP-C1 vector. Tumor spheroid was implanted into the caudate nucleus-putamen of a severely compromised immunodeficient (SCID) mouse brain slice. To allow quantitative assessment of tumor cell invasion, the invasion area index was measured on days 1, 3, 5, and 7 by a fluorescence stereomicroscope and an image analyzer in the presence of varying concentrations of SI-27. In the control group (0μg/ml), all glioma cell lines invaded in a fingerlike fashion, reaching the contralateral hemisphere via the corpus callosum. SI-27 at concentrations of 10, 50, or 100 μg/ml significantly suppressed the index on days 5 and 7 in a dose-dependent manner, whereas 1 μg/ml had no effect. Laser confocal microscopy indicated that the tumor cells penetrated through the brain slice. This model enabled unequivocal periodic tracking of individual invading tumor cells in the normal brain. The significant suppression of glioma cell invasion by SI-27 indicates that anti-matrix metalloproteinase (MMP) treatment may represent an important future therapeutic strategy for malignant cerebral neoplasms.     

Histone deacetylase inhibitors such as sodium butyrate and trichostatin A inhibit vascular endothelial growth factor (VEGF) secretion from human glioblastoma cells

We investigated the effects of histone deacetylase (HDAC) inhibitors such as sodium butyrate (SB) and trichostatin A (TSA) on the expression of vascular endothelial growth factor (VEGF) by human glioblastoma T98G, U251MG, and U87MG cells. The glioblastoma cells secreted three VEGF isoforms, VEGF (189), (165), and (121), although the expression levels of VEGF differed between the cell types. Treatment with either 5mM SB or 100ng/ml TSA reduced VEGF secretion in conditioned media and reduced VEGF mRNA expression. We also studied the expression of VEGF-B,-C, and-D mRNA in human glioblastoma cells and their modulation by HDAC inhibitors. The PCR products of VEGF-B (357 bp), VEGF-C (501 bp), and VEGF-D (484 bp) were amplified in all glioblastoma cells examined. Treatment with SB reduced the expression of VEGF-D mRNA in U251MG cells and the expression of VEGF-B mRNA in U87MG cells. TSA treatment reduced the expression of VEGF-D in U251MG cells. These results suggest that HDAC inhibitors reduce VEGF secretion and modulate the expression of the other VEGF family members, and therefore may inhibit angiogenesis in glioblastoma tissues.     

Antitumor effect of TAT-oxygen-dependent degradation-caspase-3 fusion protein specifically stabilized and activated in hypoxic tumor cells

Human solid tumors contain hypoxic regions that have considerably lower oxygen tension than normal tissues. These impart resistance to radiotherapy and anticancer chemotherapy, as well as predisposing to increased tumor metastases. To develop a potentially therapeutic protein drug highly specific for solid tumors, we constructed fusion proteins selectively stabilized in hypoxic tumor cells. A model fusion protein, oxygen-dependent degradation (ODD)-beta-galactosidase (beta-Gal), composed of a part of the ODD domain of hypoxia-inducible factor-1alpha fused to beta-Gal, showed increased stability in cultured cells under a hypoxia-mimic condition. When ODD-beta-Gal was further fused to the HIV-TAT protein transduction domain (TAT(47-57)) and i.p. injected to a tumor-bearing mouse, the biologically active fusion protein was specifically stabilized in solid tumors but was hardly detected in the normal tissue. Furthermore, when wild-type (WT) caspase-3 (Casp3(WT)) or its catalytically inactive mutant was fused to TAT-ODD and i.p. injected to a tumor-bearing mouse, the size of tumors was reduced by the administration of TAT-ODD-Casp3(WT) but not by TAT-ODD-mutant Casp3. TAT-ODD-Casp3(WT) did not cause any obvious side effects on tumor-bearing mice, suggesting specific stabilization and activation of the fusion protein in the hypoxic tumor cells. These results suggest that the combination of protein therapy using a cytotoxic TAT-ODD fusion protein with radiotherapy and chemotherapy may provide a new strategy for annihilating solid tumors.     

Breast cancer

Adjuvant chemo-endocrine therapy for breast cancer (ACETBC) trial has been the first large scaled clinical trial performed in Japan. Several prospective randomized trials have been performed in Japan since ACETBC-1 trial started in 1985. The effect of oral 5-FU agents had been tested in prospective randomized trials and the statistically marginal effect of oral 5-FU agents in adjuvant settings has been reported. Several trials having CMF as a control arm started in 1996 when CMF combination chemotherapy was approved by the government. The results of these trials have not been published. To perform good clinical trials, it is imperative to construct infrastructures including clinical research coordinator, and abolish governmental regulation of the dose of anticancer agents.     

Current status of the chemotherapy for lung cancer

In the treatment of limited-stage small cell lung cancer (LD-SCLC) and unresectable locally-advanced non-small cell lung cancer, several phase III trials and meta-analysis have demonstrated the following: 1) combining chemotherapy and thoracic irradiation is better than chemotherapy alone or radiotherapy alone, 2) the concurrent use of chemoradiotherapy has been expected a better survival than the sequential use, 3) the improvement in outcome seen with a concurrent chemoradiotherapy approach may be because of spatial cooperation, enhanced radiosensitization, and/or enhanced cytotoxicity, and 4) the chemoradiotherapy is tolerable without significant morbidities, such as pneumonitis and esophagitis. However, the chemoradiotherapy is still an investigational strategy because of the absence of a definite schedule and dose on radiotherapy. Newer, more tolerable chemotherapeutic agents, molecular biologic novel approaches and newer irradiated procedures are now being investigated.     

Combination chemotherapy with carboplatin and etoposide for elderly patients aged 76 years or older with small cell lung cancer

Eighteen elderly patients aged 76 years or older with small cell lung cancer were treated with carboplatin (AUC = 4 mg/ml.min, i.v. day 1) and etoposide (70 mg/m2 i.v. day 1-3) and 17 patients were evaluable. The median age of the study population was 77 years (range: 76-81). Eight patients had limited disease (LD) and nine did extensive disease (ED). The overall response rate was 88% for LD patients and 67% for ED patients. Median survival time was 219 days for LD patients and 158 days for ED patients. Grade 3 and 4 leukopenia, neutropenia, thrombocytopenia and anemia occurred in 41%, 76%, 24% and 6% of patients, respectively. There was one treatment-related death due to pneumonitis.