Altering Food and Light Schedules Affects Cancer Genes in Mice
A new study has found that altering food schedules and light/dark exposure in mice modified the expression of circadian clock genes and genes involved in carcinogenesis and tumor progression.
The circadian clock regulates the approximate 24-hour cycles of many animals, including mammals. It has been reported that tumors grow faster in animals with a disrupted circadian clock--which happens, for example, in chronic jet lag--but the molecular mechanism is unclear.
Francis Lévi, M.D., Ph.D., of the French National Institute of Health and Medical Research (INSERM) and University Paris XI at Paul Brousse Hospital in Villejuif, France, and colleagues compared the expression patterns of circadian clock and cell cycle genes in the livers and tumors of mice synchronized by normal light and dark schedules (normal circadian clock) or with schedules designed to simulate chronic jet lag in humans (disrupted circadian clock). They found that meal timing reversed the disrupted circadian clock gene expression patterns and slowed tumor growth in chronic jet lagged mice. The authors conclude that the altered light/dark or feeding schedules modified the expression of circadian clock genes and genes involved in carcinogenesis and tumor progression.
Contact: Monique Lévi, French National Institute of Health and Medical Research, 33 1 45 59 38 55, email@example.com
Adding Chemotherapy to Radiation May Improve Survival in Nasopharyngeal Cancer Patients
The addition of cisplatin chemotherapy to radiotherapy was associated with better survival rates compared with radiotherapy alone in patients with nasopharyngeal cancer, according to a new study.
Nasopharyngeal cancer patients are usually treated with radiotherapy. Despite some encouraging early results, randomized trials in which chemotherapy was added before or after radiotherapy have not shown improvements in survival.
Anthony T. C. Chan, M.D., of the Prince of Wales Hospital in Hong Kong, and colleagues conducted a randomized trial in which 350 patients with locoregionally advanced nasopharyngeal carcinoma were treated with either radiotherapy alone or concurrently with cisplatin.
Overall 5-year survival was higher among patients treated with radiotherapy and cisplatin compared with radiotherapy alone (70.3% versus 58.6%, respectively). The authors conclude that these results confirm that the combination therapy has promise as a standard treatment in locoregionally advanced nasopharyngeal cancer.
Contact: Janet Chow, Chinese University of Hong Kong, (852) 2632 2846, firstname.lastname@example.org
Dietary Patterns Not Associated With Pancreatic Cancer Risk
A new study that examined dietary patterns in two large cohorts of men and women found no association between pattern of diet and pancreatic cancer risk.
Diabetes appears to be a risk factor for pancreatic cancer, and several large studies have found an association between obesity and pancreatic cancer risk. However, it is not known if dietary patterns, and particularly western types of diet, also affect the risk of pancreatic cancer.
To determine whether dietary patterns are associated with the risk of pancreatic cancer, Dominique S. Michaud, Sc.D., of the Harvard School of Public Health in Boston, and colleagues analyzed data from two large prospective cohort studies. They identified two major dietary patterns, "prudent" (characterized by high fruit and vegetable intake) and "western" (characterized by high meat and high fat intake). The authors found no association between either dietary pattern and the risk of pancreatic cancer.
Contact: Kevin Myron, Office of Communications, Harvard School of Public Health, 617-432-3952, email@example.com
Maintenance Chemotherapy for Advanced Lung Cancer Does Not Improve Survival, Study Finds
Maintenance chemotherapy using vinorelbine does not improve survival in patients with advanced non–small-cell lung cancer (NSCLC), according to a new study.
Survival rates for patients with advanced NSCLC treated with standard cisplatin-based chemotherapy are low--30% to 40% after 1 year and 15% after 2 years. Maintenance chemotherapy, which prolongs the duration of chemotherapy either with the original regimen or with other regimens, increases the total dose of chemotherapy and could conceivably improve survival.
Virginie Westeel, M.D., Ph.D., of Jean Minjoz University Hospital in Besançon, France, and colleagues conducted a randomized trial in which 181 patients with advanced NSCLC, who responded to induction treatment, were randomly assigned to receive either maintenance vinorelbine therapy or to receive no further treatment. There were no differences between the two groups in either overall or progression-free survival. However, the authors suggest that other agents should be evaluated before the concept of maintenance chemotherapy for NSCLC is abandoned.
Contact: Virginie Westeel, Jean Minjoz University Hospital, (33) 3 81 66 88 02, firstname.lastname@example.org
Also in the April 6 JNCI:
Sequence Variants in Toll-Like Receptor Gene Cluster (TLR6-TLR1-TLR10) and Prostate Cancer Risk Antioxidant May Have Adverse Effects in Head and Neck Cancer Patients: http://www.eurekalert.org/emb_releases/2005-04/jotn-amh033105.php Studies Examine Menopausal Hormone Therapy and Risk of Breast Cancer Recurrence: http://www.eurekalert.org/emb_releases/2005-04/jotn-sem033105.php Study Examines Effectiveness of Anti-Anemia Drug in Treatment of Cancer Patients: http://www.eurekalert.org/emb_releases/2005-04/jotn-see033105.php
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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The important thing is not to stop questioning. Curiosity has its own reason for existing. Never lose a holy curiosity.
~ Albert Einstein