Pop star Selena Gomez revealed to Billboard magazine that she has the autoimmune disease lupus. Rumors swirled when the she checked into an Arizona rehab facility in January 2014. “I was diagnosed with lupus, and I’ve been through chemotherapy,” Gomez told the magazine. “That’s what my break was really about.”
Lupus is an autoimmune disease that affects mostly women, and onset is typically from age 15 through 44. In lupus, the body’s immune system starts to attack its own tissues and organs, leading to pain and inflammation, and damage to joints, kidneys, lungs, heart and other systems. About 1.5 million Americans live with the disease, and between 3 and 20 percent of people with lupus have a stroke as a complication.
Lupus is sometimes treated with chemotherapy drugs that, when given in a very low dose, are known as disease-modifying antirheumatic drugs, or DMARDs. Undergoing chemotherapy is not the same as taking a DMARD, however.
“I don’t think they [cancer and lupus] should be talked about as similar diseases,” says rheumatologist Paula Rackoff, MD, associate professor of clinical medicine at NYU. “Some of the treatments overlap but the dosage [for lupus] is much lower.”
Chemotherapy for cancer is also given more frequently. “We don’t generally see the same effects that oncologists do,” says Rackoff. Side effects, which include oral sores, mild hair loss and gastrointestinal discomfort, “are more pronounced and more frequent” in cancer treatment, according to Rackoff.
The drugs used in both cancer and lupus treatment target rapidly dividing cells, according to Sharecare’s chief medical officer, Keith Roach, MD. “Cancer cells divide rapidly, so they’re more likely to pull up the medication and be killed by it. Some of the cells in autoimmune diseases are of the same type,” Dr. Roach says.
Roach adds that as far as Gomez calling her treatment chemotherapy, she’s technically right. “But the doses in cancer are much, much higher. It’s not quite really the same thing,” he says.