Can doping increase risk of cancer? Yes. Testicular cancer? Unknown.
Oprah Winfrey says that during her interview with Lance Armstrong, to be aired in two parts starting Thursday, he admitted to doping during his cycling career. That detail is feeding speculation among the public and the media about whether those doping activities may have contributed to his diagnosis of testicular cancer.
So far, it’s not possible to give a definitive answer to that question. The known connection between testicular cancer and common doping regimens is tenuous at best.
Further, although there’s been plenty of speculation about how Armstrong doped, there hasn’t been confirmation about what substances he used. The amounts and the duration of use – either before or after his cancer diagnosis and treatment – are also unconfirmed.
This is what’s currently known. Armstrong was diagnosed in 1996, at the age of 25, with advanced stage testicular cancer that had metastasized to his lungs, abdomen and brain. Testicular cancer is one of the most curable types of cancer, with a 95 percent survival rate if caught in an early stage when it's confined to a testicle. It has an 80 percent survival rate if caught in more advanced stages, when it has spread to other organs.
The risk factors associated with testicular cancer include:
- Having an undescended testicle that has not dropped fully from the belly cavity into the scrotum
- A family history of testicular cancer
- Infection with the human immunodeficiency virus (This is the only infection associated with testicular cancer.)
- Age. Half of testicular cancer cases are diagnosed in men between the ages of 20 and 34, though men of all ages are diagnosed.
- Ethnicity. White American men are five times more likely to be diagnosed with testicular cancer than black men, and roughly three times more likely than Asian, Native American and Hispanic men.
The common methods of doping for cyclists that have any associated cancer risk include:
- Use of erythropoietin, commonly called EPO. The drug is often used to treat chemotherapy-induced anemia that boosts the production of red blood cells. In cyclists looking for an advantage, the more oxygen that can be delivered to the lungs and muscles, the greater the cyclist’s endurance. The U.S. Food and Drug Administration warns that among the side effect risks of EPO treatment for cancer patients is cancer recurrence or tumor progression among patients with breast, lung, head and neck, lymphoid and cervical cancers.
- Use of testosterone as a steroid. Such use promotes muscle mass, enhances muscle recovery from heavy exercise and increases endurance. Testosterone helps the development and growth of some types of hormone-dependent prostate cancers. And high levels of female testosterone are often a sign of ovarian cancer.
- Use of human growth hormone. Often administered as a treatment for children and adults with growth disorders, some athletes use it to get benefits similar to those from steroids, but without testing positive for steroid use. No links have been established between human growth factor and cancer risk, but some studies have shown ties between high levels of human growth factor and high levels of insulin growth factor, which is linked to diabetes and some cancers. And a number of new cancer drugs target EGFR, another type of growth factor that is highly active in many cancers.
Even if these doping products are not directly tied to testicular cancer, the fact that the products are linked to other cancers should give anyone pause about doping. And, besides, cancer survivors are already at an increased risk for developing a cancer recurrence or an entirely new second cancer.
Doping products may provide a winning edge, but they are a losing gamble when it comes to cancer.