A: It seems unlikely. Aluminum, a sweat-stopping ingredient in antiperspirants, has caused cell mutations in test-tube and animal studies. And parabens, chemicals in antiperspirants, deodorants, and many other personal-care products, may mimic the hormone estrogen, which fuels breast-cancer growth. One small study found parabens in some human breast cancer tumors. Another study found that breast-cancer survivors who had used antiperspirants or deodorants more often or earlier in life tended to develop the malignancy at an earlier age.

But both of those human studies had major flaws. And a larger study of healthy women found no increased risk of developing the cancer in heavy users of underarm products. Research has similarly failed to link underarm shaving, which theoretically might increase the absorption of the suspect chemicals, with any elevated risk. So while the available research doesn’t provide definitive answers, there’s probably not enough evidence to warrant concern.

If you suspect you have or are at risk for breast cancer, make an appointment with your doctor soon. Prompt, proper treatment can help limit the spread of breast cancer and restore your quality of life. With many surgical and therapeutic options available, having up-to-date, unbiased information is crucial.