Randomized phase II study of gefitinib alone or with simvastatin in previously treated advanced non-small cell lung cancer (NSCLC)

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Background: Statins reduce not only serum cholesterol levels but also mevalonate synthesis by inhibiting HMG-CoA reductase. Mevalonate is a precursor of several cellular major products including dolichol, geranylpyrophosphate (GPP) and farnesyl-pyrophosphate (FPP). Dolichol has a stimulatory effect on DNA synthesis and is linked to several tumor cell proteins. GPP and FPP cause isoprenylation of Ras and Rho those regulate signal transduction of several membrane receptors crucial for cell proliferation, differentiation, and apoptosis, which result in resistance to gefitinib. Thus depletion of mevalonate metabolites may enhance gefitinib activity in NSCLC. This study compared gefitinib alone with gefitinib plus simvastatin in patients with recurrent NSCLC after at least one chemotherapy. Methods: Between May 2006 and September 2008, 107 patients (51% male, 74% adenocarcinoma, 50% never-smoker, 54% more than two prior regimens) were randomly assigned to gefitinib alone (250 mg/d orally, n=53) or gefitinib plus simvastatin (250mg/d and 40 mg/d orally, respectively, n=54). A cycle was considered as 4 weeks of treatment. Therapy was continued until disease progression or intolerable toxicities. The primary end point was to assess response rate. Secondary end points included time to progression and survival. Median follow-up was 10.1 months. Results: Efficacy was similar for gefitinib and gefitinib plus simvastatin groups. Objective tumor response rates (RR) were 31.5% (95% CI, 19.1 to 43.9) and 32.1% (95% CI, 19.5 to 44.7); median PFS were 1.9 and 2.0 months; and median OS were 9.5 and 12.7 months, respectively. In subgroup analysis, gefitinib plus simvastatin showed a trend for higher RR than gefitinib alone in non-adenocarcinoma group (38.5% vs. 7.7%, p=0.08). Adverse events at both arms were generally mild (grade 1 or 2) and consisted mainly of skin reactions. Conclusions: Gefitinib combined with simvastatin did not improved efficacy compared to gefitinib alone in this unselected patient population, but showed a trend for higher efficacy in non-adenocarcinoma patients. Although it is preliminary, gefitinib combined with simvastatin showed slightly increased OS. Updated survival data will be presented.

No significant financial relationships to disclose.

Clinical outcome of sequential chemotherapy in metastatic and/or recurrent gastric cancer

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Background: Little is known about data on subsequent chemotherapy (CTx) following 1st-line CTx in stage IV gastric cancer. The purpose of this study was to analyze the natural history of stage IV gastric cancer with sequential CTx Methods: A total of 532 patients (pts) with unresectable gastric adenocarcinoma were studied. They were managed with a strategy of maximal administration of CTx only if pts’ general conditions were allowed. Response evaluation was performed by RECIST every 2 cycles. Response of unmeasurable lesions was dichotomized only into stable disease or progressive disease. Results: When pts were divided into CTx group (460 of 532, 87%) and best supportive care group (BSC; 72 of 532, 13%) resulting from poor performance/pt's refusal/comorbidity (31/23/18), the former had younger age (p = 0.046), better performance (p < 0.001), and less advanced metastatic sites (p = 0.001) than the latter. Median overall survivals from diagnosis of unresectable cancer were 12.0/13.3/2.5 months for overall/CTx/BSC, respectively. 87%/47%/23% of the whole pts received 1st/2nd/3rd-line CTx, respectively. Median number of regimens delivered was 2. Maximally 5th-line CTx was given to 15 pts (3%). Response and disease control rates were 21.7%/12.5%/11.8% and 79.4%/56.3%/49.4% for 1st/2nd/3rd lines, respectively. Median progression-free and overall survivals from CTx were 5.5/3.4/2.5 months and 12.1/7.9/5.5 months for 1st/2nd/3rd lines, respectively. The most common cause of discontinuation of CTx was disease progression (68%/74%/70%) followed by pt's refusal (22%/13%/12%) for 1st/2nd/3rd lines, respectively. Prognosticators were performance status, histology, metastatic site, and CTx before 1st or 2nd line. Conclusions: When pts with unresectable gastric cancer were managed with a strategy of maximal administration of CTx, a considerable number of pts could receive 2nd or 3rd line CTx, showing modest activity. Performance status and metastatic site were consistent prognosticators even if lines changed. Our data on the natural history of stage IV gastric cancer with sequential CTx may suggest that clinical trials can be performed in a 2nd or 3rd line setting as well.

No significant financial relationships to disclose.

Characterization of cytochrome P450s mediating ipriflavone metabolism in human liver microsomes

Ipriflavone, a synthetic flavonoid for the prevention and treatment of osteoporosis, has been reported to be extensively metabolized in man to seven metabolites (M1-M7). This study was performed to characterize the human liver cytochrome P450s (CYP) responsible for the metabolism of ipriflavone. Hydroxylation at the beta-ring to M3, O-dealkylation to M1 and oxidation at isopropyl group to M4 and M5 are major pathways for ipriflavone metabolism in three different human liver microsome preparations. The specific CYPs responsible for ipriflavone oxidation to the active metabolites, M1, M3, M4 and M5 were identified using a combination of correlation analysis, immuno-inhibition, chemical inhibition in human liver microsomes and metabolism by expressed recombinant CYP enzymes. The inhibitory potencies of ipriflavone and its five metabolites, M1-M5 on seven clinically important CYPs were investigated in human liver microsomes. Our results demonstrate that CYP3A4 plays the major role in O-dealkylation of ipriflavone to M1 and CYP1A2 plays a dominant role in the formation of M3, M4 and M5. Ipriflavone and/or its five metabolites were found to inhibit potently the metabolism of CYPs 1A2, 2C8, 2C9 and 2C19 substrates.

Cellular and molecular mechanisms for immune modulation by deoxynivalenol and other trichothecenes: unraveling a paradox

Macrophages, T cells, and B cells of the immune system are central targets of deoxynivalenol (DON) and other trichothecenes-mycotoxins that can be immunostimulatory or immunosuppressive depending on dose, exposure frequency and timing of functional immune assay. Notably, low dose trichothecene exposure transcriptionally and post-transcriptionally upregulates expression of cytokines, chemokines and inflammatory genes with concurrent immune stimulation, whereas high dose exposure promotes leukocyte apoptosis with concomitant immune suppression. DON and other trichothecenes, via a mechanism known as the ribotoxic stress response, bind to ribosomes and rapidly activate mitogen-activated protein kinases (MAPKs). The latter are important transducers of downstream signaling events related to immune response and apoptosis. Using cloned macrophages, our laboratory has identified two critical upstream transducers of DON-induced MAPK activation. One transducer is double-stranded RNA-(dsRNA)-activated protein kinase (PKR), a widely-expressed serine/theonine protein kinase that can be activated by dsRNA, interferon, and other agents. The second transducer is hematopoetic cell kinase (Hck), a non-receptor associated Src family kinase. Inhibitors and gene silencing studies have revealed that Hck and PKR play roles in DON induced gene expression and apoptosis. Future studies should focus on the molecular linkages between these kinases and trichothecene toxicity.

Purulent pericarditis caused by group G streptococcus as an initial presentation of colon cancer

Bacterial pericarditis has been recognized as a rare disease since the development of antibiotics. Usually, the disease is associated with underlying conditions or a seeding of infection elsewhere to the pericardium. Here we describe a case of group G streptococcal pericarditis as an initial presentation of colon cancer. A 52-yr-old man was admitted because of dyspnea. An electrocardiogram showed a diffuse ST-segment elevation and a two-dimensional echocardiogram showed a large amount of pericardial effusion. A pericardiocentesis was done and purulent fluid was drained. Group G streptococci was cultured in pericardial fluid. The patient was treated with antibiotics and pericardiostomy with saline irrigation. A colonoscopy revealed a small mass with moderately differentiated adenocarcinoma in rectosigmoid colon. He underwent a mucosectomy and was recovered without any complication.

[Chemoradiotherapy and salvage surgery in a patient with advanced esophageal cancer]

We report a case of advanced esophageal cancer, which was treated by chemoradiotherapy combined with surgical treatment. Moreover, 14 advanced esophageal cancer patients treated by chemoradiotherapy are discussed. The chemoradiotherapy showed beneficial control of the tumor; however, it sometimes leads to esophageal stenosis and ulcer. We conclude that additional salvage surgery is needed for such complications.

Enhanced radiation killing by 5-fluorouracil of biliary tract cancer cell lines

Despite the frequent clinical use of 5-fluorouracil (5-FU) in combination with radiotherapy for patients with biliary tract cancers, data remain scarce concerning specifically the influence of 5-FU on the sensitivity of these cancer cells to radiation. The present study was carried out to evaluate the effects of concomitant treatment with 5-FU on radiation-induced cell killing in two established human biliary tract cancer cell lines (Mz-ChA-2 and SK-ChA-1 cells). These lines were chosen as we have previously shown that SK-ChA-1 cells are significantly more resistant to both radiation and 5-FU than Mz-ChA-2 cells. Clonogenic survival was employed as the end-point for cell killing. Administration of 5-FU at LD50 doses to each cell line significantly enhanced radiation-induced cell killing. The enhancement ratio (ER) was obtained by dividing the radiation dose required to decrease the cell survival fraction to 37% (D0) by the dose to decrease cell survival to the same level when the cells were also treated with 5-FU. The ER in each of the cell lines was greater when they were incubated with 5-FU after radiation rather than prior to radiation. Longer exposure times with 5-FU resulted in enhanced radiation killing. The ER was significantly higher in the radioresistant cell line than in the radiosensitive line. These findings suggest that therapy with radiation and 5-FU may be of value as components of multidisciplinary treatment for biliary tract cancer. Protracted low dose exposure to 5-FU may prove to be most efficacious in enhancing the effects of radiation therapy.

Regulation of the fatty acid synthase promoter by insulin

Expression of critical enzymes in fatty acid and fat biosynthesis is tightly controlled by nutritional and hormonal stimuli. The expression of fatty acid synthase, which catalyzes all reactions for synthesis of palmitate from acetyl-CoA and malonyl-CoA, and of mitochondrial glycerol-3-phosphate acyltransferase, which catalyzes the first acylation step in glycerophospholipid synthesis, is decreased to an undetectable level during fasting. Food intake, especially a high carbohydrate, fat-free diet after fasting, causes a dramatic increase in the transcription of these genes. Insulin secretion is increased during feeding and has a positive effect on expression. By using adipocytes in culture and transgenic mice that express the reporter gene driven by the fatty acid synthase promoter, the cis-acting sequence that mediates insulin regulation of the fatty acid synthase promoter was defined. Upstream stimulatory factors (USF) that bind to the -65 E-box are required for insulin-mediated transcriptional activation of the fatty acid symthase gene. Sterol regulatory element binding protein (SREBP)-1 may be also involved in induction of these genes during feeding. Using specific inhibitors and expressing various signaling molecules, we found that insulin regulation of the fatty acid synthase promoter is mediated by the phosphatidylinositol (PI)3-kinase signaling pathway and that protein kinase B/akt is a downstream effector.

Increase in signal intensities on T1-weighted magnetic resonance images in asymptomatic manganese-exposed workers

OBJECTIVES

To clarify the clinical significance of increased signal intensities on T1 weighted magnetic resonance imaging (MRI) we performed a large-scale epidemiological study on asymptomatic manganese (Mn)-exposed workers with its focus on MRI.

METHODS

We randomly selected 121 male workers out of a total of 750 workers including Mn-exposed, non-exposed manual, and non-exposed clerical workers in the factories. We studied environmental and biological monitoring, neurological examination, and MRI.

RESULTS

The proportion of workers with increased signal intensities among the exposed, the non-exposed manual workers, and the non-exposed clerical workers was 46.1%, 18.8%, and 0%, respectively. Especially, 73.5% of the welders showed increased signal intensities. In no subject, were clinical signs of manganism observed. The pallidal index correlated with blood Mn concentration.

CONCLUSION

Increase in signal intensities on the T1-weighted image reflect recent exposure to Mn, but not necessarily manganism. At which increase of signal intensity, the progression of manganism from Mn exposure occurs, remains to be solved.

Hematopoietic and reproductive toxicity of 2-bromopropane, a recently introduced substitute for chlorofluorocarbons

2-Bromopropane and hydrochlorofluorocarbons (HCFCs), whose toxicity has scarcely been known, have recently been introduced as main substitutes for chlorofluorocarbons (CFCs). A major corporation in Korea replaced CFCs with 2-bromopropane and this actually led 23 Korean workers to be the world's first 2-bromopropane intoxication victims. Out of 25 female workers in the tactile switch assembling section, 17 (68%) were diagnosed as having ovarian failure. Two affected female workers showed marked pancytopenia with markedly hypoplastic marrow. In the same section, two out of eight male workers showed azoospermia and four some degree of oligospermia. The above toxicity of 2-bromopropane was reproduced in experimental animal studies. Recently, health effects of HCFC 123, including toxic hepatitis, have been reported by several authors. The principle of replacement of toxic substances with non-toxic or less toxic chemicals is important in risk management, but substances still poorly known should not be confused with non-toxic or less toxic substances. Measures aimed at reducing exposure to chemicals with known toxicity rather than using new unknown alternatives may be a rational and effective approach to risk management.

Evaluation of exposure to ethylene glycol monoethyl ether acetates and their possible haematological effects on shipyard painters

OBJECTIVES

To evaluate exposure to mixed solvents containing ethylene glycol monoethyl ether acetate (EGEEA) in shipyard painters, to determine if EGEEA is toxic to the bone marrow.

METHODS

An industrial hygiene survey was performed to identify exposure to EGEEA of two groups of shipyard painters, a low exposure group (n = 30) and a high exposure group (n = 27). Urinary ethoxyacetic acid and methyl hippuric acid as well as haemoglobin, packed cell volume, red cell indices, total and differential white blood cell counts (WBCs), and platelet count for the shipyard painters and the control subjects were measured.

RESULTS

The mean (range) exposure concentration (ppm) to EGEEA in the high and low exposure groups were 3.03 (not detectable to 18.27), 1.76 (not detectable to 8.12), respectively. The concentrations of methyl hippuric acid and ethoxyacetic acid in the high exposure group were significantly higher than those in the control group. The mean WBCs in the high exposure group were significantly lower than in the control group, and a significant proportion, six (11%) of the 57 painters, were leucopenic; none of the controls were affected.

CONCLUSION

The high rate of possible haematological effects among shipyard painters and a hygienic evaluation of their working environment in the present study suggests that EGEEA might be toxic to bone marrow.

Idiopathic parkinsonism with superimposed manganese exposure: utility of positron emission tomography

It is difficult to distinguish manganism from idiopathic parkinsonism by clinical signs only. Case history and examination: A 48-year-old welder for over 10 years complained of masked face, right side (arm and leg) resting tremor, and bradykinesia for over one year. Magnetic resonance imaging (MRI) findings showed symmetrical high signal intensities in the globus pallidus on T1 weighted image. These intensities disappeared almost completely six months after cessation of exposure. 18F-6-fluorodopa (18F-dopa) positron emission tomography (PET) findings showed reduced 18F-dopa uptake in the left putamen, findings which appear in idiopathic parkinsonism. A PET study is necessary to distinguish manganism from idiopathic parkinsonism, especially in a working environment with elevated Mn concentrations, such as welding.

Killing effects of 5-fluorouracil on human biliary tract cancer cell lines

Data concerning the cellular sensitivity of human biliary tract cancer cell lines to 5-FU are scarce. The purpose of the present study was to evaluate the cellular sensitivity of Mz-ChA-2 (derived from gall bladder cancer) and SK-ChA-1 (derived from bile duct cancer) to 5-FU. The clonogenic capacity of these lines after pulse (1 h) or continuous (168 h) administration of various 5-FU concentrations (0.1-100 microg/ml) was evaluated in exponentially growing cells as well as in those that had reached the plateau phase. In both cell lines, exponentially growing cells were 1.8-times more susceptible to 5-FU than those in plateau phase. However, when cells in the same growth phase were compared, Mz-ChA-2 cells were 10 times more sensitive to the drug than SK-ChA-1 cells. Regardless of the growth phase or cell line, increasing the duration of exposure to 5-FU decreased the proportion of surviving cells. Even at a non-cytocidal dosage, exposing the cells for three doubling times markedly decreased the number of viable cells remaining after treatment.

Special medical examination program reform proposal in Korea

We are at a time when reform in the special medical examination program in keeping with the changing times is desperately needed because the common perception of workers, employers, and medical examination facilities is "special medical examination is merely ritualistic and unproductive." Therefore, we have tried to set forth the basic structure for reforming the special medical examination program by taking a close look at the management status of the current program and analyzing its problems. The specifics of the special medical examination program reform proposal consist of three parts such as the types, health evaluation based on occupational medicine, and the interval, subject selection, items and procedure. Pre-placement medical examination and non-periodic medical examinations-as-necessary are introduced newly. Health evaluation based on occupational medicine consists of classification of health status, evaluation of work suitability, and post-examination measure. Details regarding the medical examination interval, subject selection, items and procedure were changed.