A Strike Against You
If your family has a history of cancer, are you doomed? Even though many of his relatives succumbed to the disease—including his famous father—Mickey Mantle, Jr., didn’t think so. Then he got sick.
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HE SHOULD HAVE BEEN—THOUGH IN truth, the odds are just as good that Mickey Junior’s tumor was a so-called sporadic cancer, the result of lifestyle and environment.
All cancer is genetic in that it involves damage to and dysfunction of certain genes responsible for regulating cellular replication. But these damaged genes are truly inherited—that is, passed from parent to child at conception—in only 5 to 10 percent of the most prevalent cancers: breast, ovary, colon, prostate, and melanoma. The remaining 90 to 95 percent is due to genetic damage incurred after birth: simple wear and tear on the body over time, poor diet, and smoking and other long-term exposures to cancer-instigating substances.
“We forget that cancer is very prevalent,” says Dr. Gail Tomlinson, an assistant professor of pediatrics at the University of Texas Southwestern Medical Center at Dallas and an expert in cancer genetics. “If you remember that one in three of us will develop some form of cancer during our lives, then you realize that a person could have a lot of instances of cancer in his extended family and none of it would necessarily be hereditary.” Indeed, while cancer can tend to “cluster” in certain families, Tomlinson notes that the answer isn’t always pure heredity. A multigenerational chain of it, could just as easily be the result of shared geography or diet (a lifestyle factor said to be responsible for 35 percent of all cancers). In the Mantles’ case, many of the men afflicted with Hodgkin’s disease spent most of their life in the lead and zinc mines that were once the primary industry in northeastern Oklahoma—and such exposures have been known to instigate various cancers.
Then there is the issue of “syndromes.” A syndrome is a clearly hereditary run of cancer in a family and may involve malignancies at different anatomical sites—breast, ovaries, prostate—as well as non-tumorous symptoms through several generations, all results of similar genetic damage. When such cancers follow a clear pattern of genetic inheritance—dominant or recessive—they’re called hereditary; those that do not follow an identifiable pattern of inheritance but appear in multiple family members are called familial clusters. Outside of the well-defined syndromes, it is not conclusively known whether a long line of, say, Hodgkin’s disease can be responsible for a later incidence of, say, squamous cell skin cancer. In Mantle’s case, this suggests that while he’s probably always had a predisposition to Hodgkin’s, he may be out of the woods, since the tendency in his family has been for early onset. As for the skin cancer, Steckler states flatly, “Mickey got it because he’s fair-skinned and fair-haired. That’s the prototype for acquiring skin cancer.”
And even a diagnosed genetic predisposition still doesn’t come close to being a death sentence, says Dr. Gordon Mills, the chairman of the Department of Molecular Oncology at the University of Texas M. D. Anderson Cancer Center in Houston. For one thing, heredity only predisposes the individual to affliction. It still takes seven to nine genetic mutations to form a cancer, Mills explains, and the inherited gene is but one of them. “And the changes have to take place in the same cell,” he adds. “All it really means is that you have a head start on development of the disease.” Mills cites the newest figures on breast cancer as proof that even when members of a family are prone to cancer, it is far from certain that a descendant will actually develop it, let alone die of it: Among women with strong histories of breast cancer in their families, only 30 percent tested positive for one of the two main breast cancer genes—and of those, only 50 to 60 percent will actually develop the disease during their lifetime.
Not that heredity means nothing. Both Mills and Tomlinson are quick to point out that someone like Mickey Mantle, Jr., has every reason to be more sensitive to cancer’s warning signs than does someone with absolutely no cancer in his family history. With the more common and well-researched malignancies like breast cancer, there are established odds for developing the disease based on its history in your family: For example, if your mother had breast cancer at any age, your relative risk is 1.7 times to 4 times that of a person with no family history; with more first-degree relatives involved—say, a mother and a sister—and premenopausal onset, your relative risk runs many times that of the control group. And as genetic science uncovers and marks more genes related to specific cancers, the percentage of heredity cancers may rise. One recent study has even suggested that the most “lifestyle-acquired” cancer, lung cancer, may have a slight hereditary component: The offspring of smokers who died of the disease seemed more prone to it, even if they themselves didn’t smoke.
But in general, Tomlinson says, the fear of inherited cancer tends to be out of proportion with the actual threat. A person should be concerned if he can establish the following about his family’s history with the disease: Two or more confirmed cancers of the same kind in two or more first-degree relatives; early age of onset, generally meaning at least ten years earlier than is normal for the disease (with breast and colon cancers, the average age of onset is between 50 and 60; with lung cancer, it is 65 or so); and the presence of rare cancers at an early age in the family history.
If some or all of those factors are present, you may be a candidate for genetic-risk counseling and DNA testing. Counseling involves working up a family pedigree detailing your ancestors’ experience with cancer and your odds of inheritance. Testing, which is generally available for major hereditary cancers like those of the breast, ovaries, prostate, and colon, can locate a cancer gene if it has been passed on. Such counseling and testing are useful for (1) getting a better fix on your cancer risk, (2) determining the seriousness of a tumor if you already have cancer, and (3) determining the reproductive risks if you’ve undergone radiation or chemotherapy. Mills and Tomlinson both stress that counseling and testing are not for the mildy curious: The processes can be expensive—several hundred dollars for the former, several thousand for the latter—and are designed primarily to help members of families who have a documented cancer history. If your risk of cancer is nothing out of the ordinary, Mills says, you should simply observe the standard risk-reducing behaviors: don’t smoke, drink in moderation, and watch your diet. Beyond that, it’s all left to chance. “One other thing that heredity-cancer findings have confirmed for us,” he says, “is that a lot of cancer is still just plain bad luck.”
MICKEY MANTLE, JR., HAD NEITHER the time nor the inclination to ponder such matters before Steckler had him on the operating table. In August the oncologist performed a radical neck dissection, an operation in which the lymph nodes on one side of the neck are removed along with the nerve that serves the trapezius muscle. “This was a case where you had prior skin cancers,” Steckler says, “and you had this one going all the way to one lymph node. You didn’t want to take any chances.” Because of that, Mickey Junior underwent a lengthy round of forty radiation treatments to make certain every last bit of the squamous cell carcinoma was terminated.
Five months later the area on his neck behind and below his left ear is still noticeably distended with thick scar tissue. His neck and face are a deep, almost purplish red. But his checkups, he says, have been “so far, so good.” The only real damage has been to his golf swing, a consequence of his stiffer-than-normal posture—and that will improve.
Mickey Junior’s brush with cancer has left him chastened about how much time he spends unprotected in the sun, but he’s unwilling to let it run his life. “I think it’s a waste of time worrying,” he says, again sounding more than a bit like his father. “You should take care, but I really think you can make things worse by sitting around thinking about it.”
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