Patti Scialfa, Bruce Springsteen's wife and E Street Band member, has multiple myeloma. What to know about the rare form of blood cancer.

Patti Scialfa, a longtime member of the E Street Band and wife of Bruce Springsteen, just quietly revealed in a new documentary that she was diagnosed with a form of blood cancer six years ago.

The 71-year-old shared in Road Diary: Bruce Springsteen and the E Street Band that she received a diagnosis of multiple myeloma in 2018 — and it’s impacted her performances since. While her band is currently on a world tour, Scialfa has mostly not been onstage.

“This affects my immune system, so I have to be careful what I choose to do and where I choose to go,” she noted in the documentary, per Variety.

“Every once in a while, I come to a show or two and I can sing a few songs onstage, and that’s been a treat,” Scialfa said. “That’s the new normal for me right now, and I’m OK with that.” Scialfa didn’t reveal in the documentary if she’s still undergoing treatment, and hasn’t updated fans on social media.

News of the diagnosis has raised a lot of questions about multiple myeloma. Here’s what you need to know.

What is multiple myeloma?

Multiple myeloma is a cancer of plasma cells, which are found in the bone marrow and are an important part of the immune system, according to the American Cancer Society.

With multiple myeloma, cancerous plasma cells build up in the bone marrow. Instead of making antibodies, like plasma cells are supposed to do, they make proteins that don’t work properly, leading to complications of the cancer, per Mayo Clinic. Most people with multiple myeloma are at least 65 years old, according to the ACS.

How common is multiple myeloma?

“Multiple myeloma is an uncommon disease,” Dr. Henry Fung, chair of the Department of Bone Marrow Transplant and Cellular Therapies at Fox Chase Cancer Center, tells Yahoo Life.

The average lifetime risk of getting multiple myeloma for Americans is less than 1%, per the ACS. However, certain factors can raise your risk of being diagnosed with this form of blood cancer, including getting older, being male, having a family history of the cancer, having excess body weight and being African American, according to the ACS.

Multiple myeloma symptoms

Some people with multiple myeloma have no symptoms. However, those who have symptoms may experience the following, the ACS says:

• Bone pain and weakness

• Low blood counts

• Weakness

• Shortness of breath

• Dizziness

• Serious bleeding, even with minor scrapes

• Extreme thirst

• Peeing a lot

• Dehydration

• Severe constipation

• Abdominal pain

• Loss of appetite

• Muscle weakness

• Pins and needles sensations

• Being susceptible to more infections than most

Recurrent infections — meaning, getting regular infections — can also be a symptom, Fung says. However, he adds, “early myeloma may not have any symptoms.”

Still, there’s a wide range of ways this form of cancer is detected, Dr. Ariel Grajales-Cruz, a hematologist and oncologist at Moffitt Cancer Center, tells Yahoo Life. “Sometimes it can just be caught by the primary care physician running through blood work and finding elevated proteins,” he says. Some people can even end up getting a compression fracture of the spine while doing something as simple as carrying grocery bags, which would raise suspicion for multiple myeloma, Grajales-Cruz says.

“In more advanced presentations, it can also lead to kidney failure and elevated calcium levels in the blood which need to be treated urgently in the hospital,” Dr. Hans Lee, associate professor of lymphoma/myeloma at the University of Texas MD Anderson Cancer Center, tells Yahoo Life.

How is multiple myeloma diagnosed?

Scialfa didn’t share details of her diagnosis. Instead, she said in the documentary that she was diagnosed with “early stage” multiple myeloma when she was doing a play on Broadway alongside her husband, per People.

Typically, people are diagnosed after having symptoms related to anemia, which is a blood disorder that happens when your body doesn’t have enough healthy red blood cells to carry oxygen to your tissues, Fung says. That can cause symptoms like fatigue and shortness of breath, which might cause someone to see a doctor, he explains.

But multiple myeloma is usually diagnosed when someone has an abnormal protein called a paraprotein in the blood — and this is detected via a blood test, Dr. Jack Jacoub, a medical oncologist and medical director of MemorialCare Cancer Institute at Orange Coast Medical Center in Fountain Valley, Calif., tells Yahoo Life. “Scenarios when that would be tested would be if someone developed anemia that can’t be explained from something like an iron deficiency or a sudden calcium deficiency,” he says.

But even having that abnormal protein, which Jacoub notes is “estimated to be present in at least 5% of Americans,” doesn’t mean that you have multiple myeloma. For some people, having a paraprotein may mean that they’re diagnosed with a blood disorder known as monoclonal gammopathy of undetermined significance (MGUS). “That situation is followed over several years, and only a small portion of people develop multiple myeloma,” Jacoub says.

How is multiple myeloma treated?

Multiple myeloma may not need to be treated right away. However, there are a lot of treatment options, including targeted therapy to attack chemicals in the cancer cells, immunotherapy, chemotherapy, radiation therapy, bone marrow transplant and CAR T-cell therapy, which trains your immune system cells to fight multiple myeloma, Fung says.

Doctors will usually start a patient with chemo-immunotherapy, followed by a stem cell transplant and “maintenance therapy,” according to Fung. If a patient’s cancer progresses, they may receive CAR T-cell therapy.

“The goals of treatment are to relieve symptoms, prevent complications, prevent organ failures, prolong life and improve and maintain quality of life,” Fung says. But Grajales-Cruz points out that multiple myeloma is incurable.

Having this form of cancer also means that patients need to be careful about getting infections, Lee says. “Myeloma itself suppresses the normal functioning immune system,” he says. “In addition, the treatment for multiple myeloma can suppress the immune system.”

As with many forms of cancer, the prognosis for multiple myeloma depends a lot on the stage of disease and how well someone responds to treatment, Fung says. However, the five-year survival rate for multiple myeloma that hasn’t spread is nearly 80%.

The prognosis for multiple myeloma has gotten much better over the last few decades and is “among the most dramatic improvements we’ve seen in oncology,” Jacoub says.