A range of public health leaders, who should know better, have rushed to repeat and, with their stature, endorse the apparently unfounded claim by baseball great Curt Schilling that his mouth cancer was caused by smokeless tobacco.
Claims about cancer causation can significantly influence national health policy; when made by recognized authorities, they should be based on scientific and medical facts.
While I fully sympathize with Mr. Shilling, his claim of causation has no on-the-record support from his medical team. That has not stopped the anti-tobacco establishment from rushing to the media.
In remarks trashing smokeless tobacco, Schilling’s oncologist, Dr. Robert Haddad of the Dana-Farber Cancer Institute, made no comments specifically connecting his patient’s cancer to use of smokeless products.
Regardless, in short order, the FDA Center for Tobacco Products repeated Schilling’s causation claim on Twitter (here), and the presidents of the Massachusetts Medical and Dental Societies (here) and the director of the Arizona Department of Health Services (here) gave it further credence.
I don’t question Schilling’s belief that smokeless tobacco caused his cancer. However, before endorsing his statements, public health officials should address several points:
1. Where, specifically, was the “mouth cancer”? According to this National Cancer Institute monograph (here), almost all cases of mouth cancer attributable to smokeless tobacco occur in the location where it is used. That is also my experience in 30 years as an oral pathologist. In addition, the cases of mouth cancer that I have seen are almost always in users of dry powdered snuff, and they occur in the gum-cheek area. Schilling hasn’t disclosed the location of his cancer, which he blames on moist snuff. Users of that product are not protected from mouth cancer, but epidemiologic studies show that they are not at higher risk than nonusers.
2. Other risk behaviors. It can be uncomfortable, but doctors need to know about all risk factors for oral cancer. Those at higher risk are individuals who smoke and drink, a combination that tends to be associated with cancers in the throat as well as the mouth. Human papillomavirus infection is an emerging risk factor, especially for throat cancer. Schilling disclosed that his cancer was discovered as a “lump” in his neck; this presentation is more common with a throat cancer than a mouth cancer. Schilling hasn’t disclosed information on his other risk factors.
It is inappropriate for the FDA, presidents of medical societies and other public health authorities to blindly endorse unvalidated medical claims. Hundreds of thousands of former smokers in the U.S. use smokeless tobacco. Dreading the prospect of getting mouth cancer, they might be motivated by these authorities’ pronouncements to start smoking again, not knowing that the latter significantly increases their mouth, throat and lung cancer risks. Public health advocates should stick to the facts, not engage in scaremongering.