Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Few opportunities exist to evaluate the carcinogenic effects of long-term internal exposure to alpha-particle-emitting radionuclides. Patients injected with Thorotrast (thorium-232) during radiographic procedures, beginning in the 1930s, provide one such valuable opportunity. We evaluated site-specific cancer incidence and mortality among an international cohort of 3,042 patients injected during cerebral angiography with either Thorotrast (n = 1,650) or a nonradioactive agent (n = 1,392) and who survived 2 or more years. Standardized incidence ratios (SIR) for Thorotrast and comparison patients (Denmark and Sweden) were estimated and relative risks (RR), adjusted for population, age and sex, were generated with multivariate statistical modeling. For U.S. patients, comparable procedures were used to estimate standardized mortality ratios (SMR) and RR, representing the first evaluation of long-term, site-specific cancer mortality in this group. Compared with nonexposed patients, significantly increased risks in Thorotrast patients were observed for all incident cancers combined (RR = 3.4, 95% CI 2.9-4.1, n = 480, Denmark and Sweden) and for cancer mortality (RR = 4.0, 95% CI 2.5-6.7, n = 114, U.S.). Approximately 335 incident cancers were above expectation, with large excesses seen for cancers of the liver, bile ducts and gallbladder (55% or 185 excess cancers) and leukemias other than CLL (8% or 26 excess cancers). The RR of all incident cancers increased with time since angiography (P < 0.001) and was threefold at 40 or more years; significant excesses (SIR = 4.0) persisted for 50 years. Increasing cumulative dose of radiation was associated with an increasing risk of all incident cancers taken together and with cancers of the liver, gallbladder, and peritoneum and other digestive sites; similar findings were observed for U.S. cancer mortality. A marginally significant dose response was observed for the incidence of pancreas cancer (P = 0.05) but not for lung cancer. Our study confirms the relationship between Thorotrast and increased cancer incidence at sites of Thorotrast deposition and suggests a possible association with pancreas cancer. After injection with >20 ml Thorotrast, the cumulative excess risk of cancer incidence remained elevated for up to 50 years and approached 97%. Caution is needed in interpreting the excess risks observed for site-specific cancers, however, because of the potential bias associated with the selection of cohort participants, noncomparability with respect to the internal or external comparison groups, and confounding by indication. Nonetheless, the substantial risks associated with liver cancer and leukemia indicate that unique and prolonged exposure to alpha-particle-emitting Thorotrast increased carcinogenic risks.
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PMID:Site-specific cancer incidence and mortality after cerebral angiography with radioactive thorotrast. 1464 Jul 94

Rubitecan [Orathecin, 9-nitrocamptothecin, 9NC, RFS 2000] is a topoisomerase I inhibitor extracted from the bark and leaves of the Camptotheca acuminata tree, which is native to China. Rubitecan is an oral compound being developed for the treatment of pancreatic cancer and other solid tumours by SuperGen. One of the major benefits of rubitecan is that it can be administered in an outpatient setting, so patients can be treated in their homes. Rubitecan was isolated by the Stehlin Foundation in the US. SuperGen is currently awaiting regulatory approval in the US and the EU for rubitecan in the treatment of pancreatic cancer. At the BIO-2004 conference, SuperGen announced it is seeking a partner for rubitecan for territories outside the US. SuperGen acquired exclusive worldwide rights to rubitecan from the Stehlin Foundation in 1997 except in Mexico, Canada, Spain, Japan, the UK, France, Italy and Germany. SuperGen has also received approval from the US FDA to use its own manufactured rubitecan in clinical trials. SuperGen and the Stehlin Foundation have an 8-year research agreement that secures global rights to other camptothecins and additional anticancer compounds for the former. In December 1999, SuperGen and Abbott signed a worldwide sales and marketing agreement for rubitecan. Under the terms of the agreement, Abbott had exclusive distribution and promotion rights for rubitecan outside the US, and co-promotion rights with SuperGen within the US. In return, Abbott made an initial equity investment in SuperGen. SuperGen and Abbott Laboratories ended their collaboration agreement in February 2002 by mutual consent with SuperGen stating that the dissolution of the agreement was based on commercial motivation rather than anything to do with rubitecan's safety or efficacy. Abbott no longer has rights or obligations to purchase shares of SuperGen stock or an option to purchase up to 49% of the company. For its part, SuperGen will no longer receive milestone payments worth up to $US57 million. SuperGen has formed a clinical and business alliance with US Oncology (created by the merger between American Oncology Resources and Physician Reliance Network in the US), and will collaborate on clinical trials of rubitecan. SuperGen believes that this relationship will increase the patient population available for trials and enable it to market the drug directly to Oncologists. SuperGen and Capital Research and Management Company have completed a $US16.6 million private placement transaction that will enable future funding for the rubitecan programme as well as other oncology programmes. In July 2004, SuperGen's European subsidiary, EuroGen Pharmaceuticals, submitted a Marketing Authorisation Application for rubitecan in the treatment of pancreatic cancer. The application will be reviewed under the EMEA Centralised Procedure. In June 2003, the EMEA granted SuperGen orphan drug status for rubitecan for the treatment of pancreatic cancer. The US FDA has also granted orphan drug status for rubitecan in the treatment of pancreatic cancer and fast-track status for rubitecan for the treatment of locally advanced or metastatic pancreatic cancer that is resistant or refractory to chemotherapy. SuperGen has conducted three phase III pivotal trials in patients with pancreatic cancer. A phase III randomised trial in chemotherapy-naive patients was conducted at 132 centres throughout the US. The trial enrolled approximately 994 patients who were randomised to receive rubitecan or gemcitabine. Enrollment was completed in October 2001. Another phase III trial has compared rubitecan with the most appropriate chemotherapy in chemotherapy-resistant patients. Enrollment of over 400 patients at 200 medical centres across the US was completed in June 2001. Results from the trial were presented at the 39th Annual Meeting of the American Society of Clinical Oncology (ASCO-2003) [Chicago, US; 31 May - 3 June 2003], after they had been compiled, analysed and submitted to the FDA. The results of the study showed that rubitecan could not help all chemotherapy-resistant patients, but could increase survival in those that do respond. The other phase III pivotal trial was conducted in patients with pancreatic cancer who had failed treatment with gemcitabine. This trial completed enrollment in October 2001, and had enrolled approximately 448 patients. SuperGen is conducting phase II trials of rubitecan in patients with solid tumours in the UK, Italy, France, Germany, the Netherlands and Denmark. Each trial will enroll 100-150 patients with various tumour types, including colorectal, lung, breast, gastric, prostate, cervical and head and neck cancers. Phase I/II trials are underway to investigate rubitecan as a radiosensitiser in patients with lung cancer, and phase II trials in patients with breast cancer are also being conducted. A phase II study in ovarian cancer patients is also being conducted. Results from an ongoing phase II study in cancer patients have shown that rubitecan was effective against chordomas, a rare type of bone cancer. Phase II studies are also underway in haematological malignancies including myelodysplastic syndrome (preleukaemia) and chronic myelomonocytic leukaemia. In February 2000, SuperGen announced that its IND submission for rubitecan had been approved by the Therapeutics Products Programme of Canada. The company stated that it intended to begin clinical trials in Canada in the near future. In February 2004, SuperGen announced an offering of shares of its common stock to finance the commercialisation of rubitecan capsules. In July 2003, SuperGen was granted a US patent covering combination therapies with chemotherapeutic anthracycline agents and structural modifications that may one day lead to next-generation rubitecan compounds. In December 2002, SuperGen was granted US patent No. 6,482,830, covering its polymorphic formulations of rubitecan. The patent also covers a class of polymorphs that are similar to the one at the centre of rubitecan. In addition, SuperGen was also issued US patent No. 6,485,514 in December 2002, covering the local delivery of rubitecan via stents and/or catheters to sites of proliferating cells. Stent- or catheter-delivered rubitecan may be beneficial in certain types of cardiac procedures, such as ablation or angioplasty, as well as for direct injection into a certain number of solid tumours. SuperGen is also developing an inhaled, liposomal formulation of rubitecan. It acquired the worldwide rights to this formulation from the Clayton Foundation in December 1999. Inhaled rubitecan is in clinical trials in the US for the treatment of lung cancer and pulmonary metastatic cancer.
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PMID:Rubitecan: 9-NC, 9-Nitro-20(S)-camptothecin, 9-nitro-camptothecin, 9-nitrocamptothecin, RFS 2000, RFS2000. 1535 30

The relation between self-reported physician-diagnosed asthma and/or hay fever and cancer mortality was explored in a prospective cohort study of 1,102,247 US men and women who were cancer-free at baseline. During 18 years of follow-up, from 1982 to 2000, there were 81,114 cancer deaths. Cox proportional hazards models were used to obtain adjusted relative risks for all cancer mortality and for cancer mortality at 12 sites associated with allergy indicators. There were significant inverse associations between a history of both asthma and hay fever and overall cancer mortality (relative risk (RR) = 0.88, 95% confidence interval (CI): 0.83, 0.93) and colorectal cancer mortality (RR = 0.76, 95% CI: 0.64, 0.91) in comparison with persons with neither of these allergic conditions. A history of hay fever only was associated with a significantly lowered risk of pancreatic cancer mortality, and a history of asthma only was associated with a significantly lowered risk of leukemia mortality. In never smokers, these associations persisted but were no longer significant. Results for mortality from cancer at other sites were less consistent. Collectively, these results suggest an inverse association between a history of allergy and cancer mortality; however, the strength of evidence for this association is limited.
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PMID:Cancer mortality among US men and women with asthma and hay fever. 1637 13

Nitric-oxide-donating aspirin (NO-ASA), consisting of ASA (aspirin) plus an -ONO2 moiety linked to it via a molecular spacer, is a new drug for cancer prevention. NO-ASA seems to overcome the low potency and toxicity of traditional ASA. The -ONO2 moiety is responsible for releasing NO, and it appears to be required for biological activity. In studies in vitro, NO-ASA inhibits the growth of colon, pancreatic, prostate, lung, skin, leukaemia and breast cancer cells, and is up to 6000-fold more potent than traditional ASA. This effect is owing to cell kinetics [inhibition of proliferation, induction of apoptosis (multiple criteria) and blocking the G1 to S cell-cycle transition] and cell signalling [inhibition of Wnt signalling (IC50=0.2 microM), inhibition of NF-kappaB (nuclear factor kappaB) activation (IC50=7.5 microM), inhibition of nitric oxide synthase-2 expression (IC50=48 microM), inhibition of MAPK (mitogen-activated protein kinase) signalling (IC50=10 microM) and induction of cyclo-oxygenase-2 at approx. 10 microM]. In studies in vivo, NO-ASA inhibits intestinal carcinogenesis in Min mice (tumour multiplicity was reduced by 59% after 3 weeks, with no effect in control animals and no side effects) and in the N-nitrosobis(2-oxopropyl)amine model of pancreatic cancer, where there was an 89% reduction in NO-ASA (3000 p.p.m. in the diet)-treated animals (P<0.001). There was no statistically significant effect by traditional ASA at equimolar doses. Our data indicate that NO-ASA is a highly promising agent for the prevention and/or treatment of cancer.
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PMID:Molecular targets of nitric-oxide-donating aspirin in cancer. 1604 78

Several studies have evaluated cancer risk associated with occupational and environmental exposure to dichlorodiphenyltrichloroethane (DDT). Results are mixed. To further inquire into human carcinogenicity of DDT, we conducted a mortality follow-up study of 4,552 male workers, exposed to DDT during antimalarial operations in Sardinia, Italy, conducted in 1946 to 1950. Detailed information on DDT use during the operations provided the opportunity to develop individual estimates of average and cumulative exposure. Mortality of the cohort was first compared with that of the Sardinian population. Overall mortality in the cohort was about as expected, but there was a deficit for death from cardiovascular disease and a slight excess for nonmalignant respiratory diseases and lymphatic cancer among the unexposed subcohort. For internal comparisons, we used Poisson regression analysis to calculate relative risks of selected malignant and nonmalignant diseases with the unexposed subcohort as the reference. Cancer mortality was decreased among DDT-exposed workers, mainly due to a reduction in lung cancer deaths. Birth outside from the study area was a strong predictor of mortality from leukemia. Mortality from stomach cancer increased up to 2-fold in the highest quartile of cumulative exposure (relative risk, 2.0; 95% confidence interval, 0.9-4.4), but no exposure-response trend was observed. Risks of liver cancer, pancreatic cancer, and leukemia were not elevated among DDT-exposed workers. No effect of latency on risk estimates was observed over the 45 years of follow-up and within selected time windows. Adjusting risks by possible exposure to chlordane in the second part of the antimalarial operations did not change the results. In conclusion, we found little evidence for a link between occupational exposure to DDT and mortality from any of the cancers previously suggested to be associated.
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PMID:Cancer mortality among men occupationally exposed to dichlorodiphenyltrichloroethane. 1623 Apr 25

The Notch signalling cascade influences several key aspects of normal development by regulating differentiation, proliferation and apoptosis. Its association to human cancer is firmly established in T-cell leukaemia where point mutations or chromosomal translocations lead to constitutive signalling. Accumulating data indicate that deregulated Notch activity is involved also in the genesis of other human cancers, such as pancreatic cancer, medulloblastoma and mucoepidermoid carcinoma. In these tumours, the oncogenic effect of Notch signalling reflects an aberrant recapitulation of the highly tissue-specific function of the cascade during normal development and in tissue homeostasis.
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PMID:The Notch pathway in cancer: differentiation gone awry. 1623 5

Psorospermin is a natural product that has been shown to have activity against drug-resistant leukemia lines and AIDS-related lymphoma. It has also been shown to alkylate DNA through an epoxide-mediated electrophilic attack, and this alkylation is greatly enhanced at specific sites by topoisomerase II. In this article, we describe the synthesis of the two diastereomers of O5-methyl psorospermin and their in vitro activity against a range of solid and hematopoietic tumors. The diastereomeric pair (+/-)-(2'R,3'R) having the naturally occurring enantiomer (2'R,3'R) is the most active across all the cell lines and shows approximately equal activity in both drug-sensitive and drug-resistant cell lines. In subsequent studies using all four enantiomers of O5-methyl psorospermin, the order of biological potency is (2'R,3'R) > (2'R,3'S) = (2'S,3'R) > (2'S,3'S). This order of potency is also found in the topoisomerase II-induced alkylation of O5-methyl psorospermin and can be rationalized by molecular modeling of the psorospermin-duplex binding complex. Therefore, this study defines the optimum stereochemical requirements for both the topoisomerase II-induced alkylation of DNA and the biological activity by psorospermin and its O5-methyl derivatives. Finally, (2'R,3'R) psorospermin was found to be as effective as gemcitabine in slowing tumor growth in vivo in a MiaPaCa pancreatic cancer model. In addition, (2'R,3'R) psorospermin in combination with gemcitabine was found to show an at least additive effect in slowing tumor growth of MiaPaCa.
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PMID:Determination of the importance of the stereochemistry of psorospermin in topoisomerase II-induced alkylation of DNA and in vitro and in vivo biological activity. 1627 94

CXCR4 is the receptor of the chemokine CXCL12, which is involved in progression and metastasis of several types of cancer cells, HIV infection and rheumatoid arthritis. The authors developed selective CXCR4 antagonists, T22 and T140, initially as anti-HIV agents, which inhibit T cell line-tropic (X4-) HIV-1 infection through their specific binding to CXCR4. Recently, T140 analogues have also been shown to inhibit CXCL12-induced migration of breast cancer cells, leukaemia T cells, pancreatic cancer cells, small cell lung cancer cells, chronic lymphocytic leukaemia B cells, pre-B acute lymphoblastic leukaemia cells and so on in vitro. Biostable T140 analogues significantly suppressed pulmonary metastasis of breast cancer cells and melanoma cells in mice. Furthermore, these compounds significantly suppressed the delayed-type hypersensitivity response induced by sheep red blood cells and collagen-induced arthritis, which represent in vivo mouse models of arthritis. Thus, T140 analogues proved to be attractive lead compounds for chemotherapy of these problematic diseases. This article reviews recent research on T140 analogues, referring to several other CXCR4 antagonists.
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PMID:The therapeutic potential of CXCR4 antagonists in the treatment of HIV infection, cancer metastasis and rheumatoid arthritis. 1630 Apr 75

The naturally occurring compound 3beta,16beta,17alpha-trihydroxycholest-5-en-22-one 16-O-(2-O-4-methoxybenzoyl-beta-D-xylopyranosyl)-(1-->3)-(2-O-acetyl-alpha-L-arabinopyranoside) (OSW-1) is found in the bulbs of Ornithogalum saudersiae and is highly cytotoxic against tumor cell lines. Using various human cancer and nonmalignant cell lines, we investigated the anticancer activity and selectivity of OSW-1 and its underlying mechanisms of action. OSW-1 exhibited extremely potent cytotoxic activity against cancer cells in vitro. Nonmalignant cells were statistically significantly less sensitive to OSW-1 than cancer cells, with concentrations that cause a 50% loss of cell viability 40-150-fold greater than those observed in malignant cells. Electron microscopy and biochemical analyses revealed that OSW-1 damaged the mitochondrial membrane and cristae in both human leukemia and pancreatic cancer cells, leading to the loss of transmembrane potential, increase of cytosolic calcium, and activation of calcium-dependent apoptosis. Clones of leukemia cells with mitochondrial DNA defects and respiration deficiency that had adapted the ability to survive in culture without mitochondrial respiration also were resistant to OSW-1. In vitro analysis revealed that OSW-1 effectively killed primary leukemia cells from chronic lymphocytic leukemia patients with disease refractory to fludarabine. The promising anticancer activity of OSW-1 and its unique mechanism of action make this compound worthy of further investigation for its potential to overcome drug resistance.
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PMID:OSW-1: a natural compound with potent anticancer activity and a novel mechanism of action. 1633 34

We studied 5555 seminoma patients and 3733 patients with nonseminomatous testicular cancers diagnosed in Southeast England between 1960 and 2004. For both groups survival improved over time: 10-year relative survival increased from 78% in 1960-1969 to 99% in 1990-2004 for seminomas, and from 55 to 95% for nonseminomas. In the early period mortality was still significantly increased more than 15 years after diagnosis in both groups, whereas in more recent periods the excess deaths mainly occurred in the first 5 years after diagnosis. For seminomas, there was a significant excess of cancers of the colon (standardised incidence ratio (SIR) 2.36; 95% confidence interval (CI) 1.13-4.35), soft tissue (SIR 13.64; CI 1.65-49.28) and bladder (SIR 4.28; CI 2.28-7.31) in the long term (20+ years after diagnosis), of pancreatic cancer in both the medium (10-19 years) (SIR 2.91; CI 1.26-5.73) and long term (SIR 5.48; CI 2.37-10.80), of leukaemia in both the short (0-9 years) (SIR 3.01; CI 1.44-5.54) and long term (SIR 4.48; CI 1.64-9.75), and of testis cancer in both the short (SIR 6.69; CI 4.28-9.95) and medium term (SIR 3.96; CI 1.08-10.14). For nonseminomas, significant excesses were found in the long term for cancers of the stomach (SIR 5.13; CI 1.40-13.13), rectum (SIR 4.49; CI 1.22-11.51) and pancreas (SIR 10.17: CI 3.73-22.13), and for testis cancer in the medium term (SIR 5.94; CI 2.18-12.93). Leukaemia was significantly increased in the short term (SIR 6.78; CI 2.93-13.36). The better survival observed is largely attributable to improved treatment, and the trend in reducing the toxicity of therapy should continue to reduce future health risks in testicular cancer survivors.
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PMID:Mortality and incidence of second cancers following treatment for testicular cancer. 1726 80


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