Cancer trade-offs

An article in Tech Central Station discusses why cancer guidelines should be crafted by cancer epidemiologists, not toxicologists. Epidemiologists study real populations of real people, toxicologists don't.

In addition, list of cancer causes doesn't attempt to evaluate the risks and benefits of any given chemical.

the NTP list is one-dimensional. It makes no attempt to separate out any possible benefits of the listed chemicals, only their purported cancer risk -- and shockingly, the list makes no reference to dose of exposure as it relates to risk. For example, the NTP lists tamoxifen as a "known carcinogen" because it increases the risk of uterine cancer, but that label may distract people from another fact NTP notes about the drug: it can reduce the rate of new and recurrent breast cancers in high-risk women. Similarly, the NTP is proposing putting steroidal estrogen on its cancer-causing list because hormone replacement and birth control preparations containing the hormone have been associated with endometrial cancer and, to a lesser extent, breast cancer. "Consumption of alcoholic beverages" makes the "known cause of cancer" list -- but NTP never mentions what dose. How much alcohol is "known" to cause cancer? One glass of wine a day? It is known that moderate alcohol consumption, in the absence of smoking cigarettes, has never been shown to be a risk factor for cancer.

So do you avoid tamoxifen and risk breast cancer, or use it and risk uterine cancer? Do you avoid alcohol altogether, including the daily glass of red wine that's been shown to reduce heart disease?

You could go crazy calculating risks, even if you had the numbers in hand. When you don't have numbers, or only half of the numbers, you can go crazy without calculating.

That's only useful if you're truly math-phobic.