Wise Young
08-18-2005, 12:23 AM
This is a very interesting way to do a population based study. Using cancer registry to identify a particular population, they looked for ALS deaths amongst the cancer survivors. In a population of 1.9 million cancer survivors, they are able to state definitively that there is a modest significant association between melanoma and both ALS and Parkinson's disease. However, there was no relationshipo between other cancers and ALS.
They found in this study something that is well-known: there is an inverse relationship between Parkinson's disease and smoking-related cancers. The reason is not that smoking protects against Parkinson's. Rather, people who have Parkinson's disease compensate for the disease by increasing acetylcholinergic innervation of their basal ganglia. They are consequently sensitive to nicotine and do not smoke.
Wise.
Freedman DM, Travis LB, Gridley G and Kuncl RW (2005). Amyotrophic Lateral Sclerosis Mortality in 1.9 Million US Cancer Survivors. Neuroepidemiology 25: 176-180. Background: Large cancer registries offer the opportunity to explore and generate hypotheses about the pathogenesis of cancer and other diseases, including neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). Methods: Using data from nine population-based cancer registries of the Surveillance, Epidemiology, and End Results (SEER) Program of the US National Cancer Institute (NCI) and death certificates, we followed 1.9 million cancer survivors who were diagnosed between 1973 and 2000 and who survived at least 1 year, through the year 2000. The outcome of interest was the standardized mortality ratio (SMR) of observed to expected ALS deaths among cancer survivors. To assess the validity of the study design, we also examined associations with Parkinson's disease mortality, which we expected to be inversely associated with smoking-related cancers. Results: There was no significantly increased risk or deficit of ALS mortality for all cancer sites combined (SMR = 1.0). Parkinson's disease mortality was, as expected, significantly and inversely associated with smoking-related cancers. Both ALS and Parkinson's disease mortality were significantly elevated following melanoma (SMR = 1.6; 95% CI = 1.1-2.2; SMR = 1.5; 1.2-1.8, respectively). Contrary to previous hypotheses, ALS was unrelated to lymphomas or lymphoproliferative malignancies and was not associated with smoking-related cancers. Conclusions: In this exploratory study, we observed a modest, significant association between melanoma and both ALS and Parkinson's disease mortality. It would be useful to explore these findings in other large national databases that are able to link cancer and ALS and Parkinson's disease. Copyright (c) 2005 S. Karger AG, Basel. National Cancer Institute, Division of Epidemiology and Genetics, NIH, DHHS, Bethesda, Md., USA. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16103728
They found in this study something that is well-known: there is an inverse relationship between Parkinson's disease and smoking-related cancers. The reason is not that smoking protects against Parkinson's. Rather, people who have Parkinson's disease compensate for the disease by increasing acetylcholinergic innervation of their basal ganglia. They are consequently sensitive to nicotine and do not smoke.
Wise.
Freedman DM, Travis LB, Gridley G and Kuncl RW (2005). Amyotrophic Lateral Sclerosis Mortality in 1.9 Million US Cancer Survivors. Neuroepidemiology 25: 176-180. Background: Large cancer registries offer the opportunity to explore and generate hypotheses about the pathogenesis of cancer and other diseases, including neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). Methods: Using data from nine population-based cancer registries of the Surveillance, Epidemiology, and End Results (SEER) Program of the US National Cancer Institute (NCI) and death certificates, we followed 1.9 million cancer survivors who were diagnosed between 1973 and 2000 and who survived at least 1 year, through the year 2000. The outcome of interest was the standardized mortality ratio (SMR) of observed to expected ALS deaths among cancer survivors. To assess the validity of the study design, we also examined associations with Parkinson's disease mortality, which we expected to be inversely associated with smoking-related cancers. Results: There was no significantly increased risk or deficit of ALS mortality for all cancer sites combined (SMR = 1.0). Parkinson's disease mortality was, as expected, significantly and inversely associated with smoking-related cancers. Both ALS and Parkinson's disease mortality were significantly elevated following melanoma (SMR = 1.6; 95% CI = 1.1-2.2; SMR = 1.5; 1.2-1.8, respectively). Contrary to previous hypotheses, ALS was unrelated to lymphomas or lymphoproliferative malignancies and was not associated with smoking-related cancers. Conclusions: In this exploratory study, we observed a modest, significant association between melanoma and both ALS and Parkinson's disease mortality. It would be useful to explore these findings in other large national databases that are able to link cancer and ALS and Parkinson's disease. Copyright (c) 2005 S. Karger AG, Basel. National Cancer Institute, Division of Epidemiology and Genetics, NIH, DHHS, Bethesda, Md., USA. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16103728