4 ms·
I not only mean to say that, it is what I said. Yes it is possible for some specific rare cancers to have some single specific cause (mesothelioma and asbestos
by danieltillett 8y ago
I not only mean to say that, it is what I said.
Yes it is possible for some specific rare cancers to have some single specific cause (mesothelioma and asbestos are probably the best known example), but this is not what is seen with nearly all other carcinogens.
The reason is two fold:
1) Almost all carcinogens are not localised to a precise body location (asbestos is a rare example). Once inside a person the carcinogen is distributed everywhere. This is why exposure to tobacco smoke for example gives rise to cancers in distant locations to the lung.
2) Carcinogenic pollutants are almost never just a single chemical, but a wide range of compounds.
Cancer is not like infectious disease where you have one causative agent that gives rise to a distinct set of symptoms. The nature by which cancer arise (loss of cellular replication control), by its very nature rarely proceeds down the same path - expose one person to a specific carcinogen and they might get liver cancer and lung cancer in a different person.
- nkurz 8y agoThanks. So you think that apart from very special cases like asbestos, any chemical cause would cause other cancers as well, and there is no reasonable chance that a particular chemical could cause only rhabdomyosarcoma. I'll defer to your expertise here. I was partly confused by one of the links from the article[1], which says "These cancers are derived from similar cellular lineage; therefore, these sarcomas are closely related in cellular composition. It is biologically plausible that a common exposure exists." Is there a way in which this might make sense? Are they suggesting that it might be biologically contagious rather than chemically induced? And the second question? When you conclude that the prevalence of this particular must be a statistical artifact rather than a reproducible effect, do you have reason to believe that there are not elevated levels of other cancers in the area? Or is this not actually necessary to show? [1] https://www.facebook.com/notes/jason-c-spencer/response-to-waycross-journal-herald-opinion-piece-tv-news-report-wrong/10153989158988685/ https://www.facebook.com/notes/jason-c-spencer/response-to-w...
- danieltillett 8y agoI don't think it is biologically plausible at all that a common chemical exposure exists. It is possible, just unlikely. It also doesn't match up with what we know about pollutant chemicals being a wide range of compounds, nor the broad range of cancers seen with other known pollutant chemicals. I would be far more likely to believe that a large number of unrelated cancers in an area were caused by pollutant carcinogens, than a small number of rare cancers. I don't know if there is an elevated rate of cancer in this area, but I assume not since it would be the first thing that anyone looking at this rare cancer cluster would look for.