How Common Is Martina Navratilova's Double Cancer Diagnosis?

This month, tennis legend Martina Navratilova, 66, announced that she has been diagnosed with stage one throat cancer and breast cancer.

Navratilova—who won 59 Grand Slam titles during her career—said that she noticed an enlarged lymph node in her neck back in November 2022 during the WTA finals in Fort Worth, Texas.

When the lymph node didn’t go down, Navratilova said that she underwent testing and a biopsy. That is when her providers determined that she had stage one throat cancer, which is caused by the human papillomavirus (HPV). Her providers then discovered a suspicious lump in her breast, which was found to be stage one breast cancer that was unrelated to the throat cancer.

“This double whammy is serious but fixable,” Navratilova said in a statement. “I’m hoping for a favorable outcome. It’s going to stink for a while, but I’ll fight with all have I got.” 

This isn’t Navratilova’s first cancer diagnosis. In 2010, she announced on Good Morning America that she was diagnosed with breast cancer a routine mammogram identified a tumor. She had the tumor surgically removed and underwent six weeks of radiation, as reported by ABC News.

According to a statement on her website, Navratilova will begin treatment later this month. A representative for Navratilova added that “both these cancers are in their early stages with great outcomes.” 

Navratilova’s announcement has made a lot of people aware of the possibility of having more than one cancer at the same time. Here’s what experts say about how common secondary primary cancer is and how the cancers are treated.

What Are Second Primary Cancers? 

William Dahut, MD, chief scientific officer at the American Cancer Society (ACS), told Verywell that a second primary cancer is when a new cancer occurs in an organ that is not related to a previous cancer diagnosis. While they can occur at the same time, as in Navratilova’s case, it’s more likely that one cancer will develop some time after the other.

According to Dahut, a second primary cancer can either be in the same organ as the first or in a different organ; however, the new cancer has no genomic relationship to the initial tumor.

“A woman could actually have unique but independent tumors in each breast—or like in the case of Martina Navratilova, they could originate in different locations,” Dahut said. “They can also occur at the same time or be temporally different.”

Providers use microscopes and genetic testing to determine where different cancers start in the body.

“Cancers from different organs will look different under the microscope and express divergent molecular markers,” Dahut said.

Who Is At Risk For Second Primary Cancers? 

Otis Brawley, MD, professor of oncology at the Johns Hopkins University School of Medicine, told Verywell that it’s not clear what causes second cancer to develop. Researchers are also still trying to figure out what makes a person more at risk for getting a second cancer.

“Part of the reason that people get these cancers is that people just get cancer,” Brawley said. “Why people end up with two cancers is simply bad luck.” 

However, the risk of developing a second primary cancer can be higher for people who had certain types of cancers, received specific cancer treatments, or people with genes that raise their risk. 

“There are certain people who have genetic mutations or treatments that increase their chances of getting a second primary or third primary cancer,” Brawley said. “For example, men and women who have specific mutations like BRCA1 or BRCA2 can’t fix DNA damage as well, so they’re at higher risk of that DNA damage leading to cancer.” 

Dahut said that other factors can put people at risk of developing a second primary cancer, including lifestyle, family history, environment, genetics, use of tobacco products, and alcohol consumption. 

“Each organ has an independent risk for cancer, but certain risk factors such as genetics, tobacco, and alcohol can increase the risk in different organs,” Dahut said.

How Common Are Second Primary Cancers? 

Linda Duska, MD, MPH, a gynecologic oncologist at the University of Virginia (UVA) Health System, told Verywell that it’s not common for patients to be diagnosed with more than one unrelated type of cancer at once.

Research suggests that the overall reported frequency of multiple primary cancers varies between 2% to 17%.

Brawley said that nearly 40% of Americans will be diagnosed with cancer at some point in their lives. With such a high percentage of people getting cancer, some people will get two or even three cancers.

“It’s a little less normal to be diagnosed with two cancers at the very same time, but it’s not unheard of,” said Brawley. “Fifteen percent of all cancer survivors are ultimately at some point in their life diagnosed with a second cancer and it’s about 7% of all cancer patients who at some point in their life are diagnosed with a third cancer.”

While cancer patients have about a 2% to 17% increased risk of getting a second cancer, Dahut said that it’s important to keep in mind that the risk “varies significantly by tumor type.”

Which Cancers Are Most Likely to Occur at the Same Time? 

According to Duska, some people have specific genetic syndromes that make them more susceptible to having multiple primary cancers. For example, the BRCA gene makes people more at risk for both ovarian and breast cancer, which are two different primary tumors.

Duska said another example would be HPV-related cancers, as “women who have HPV-related cervical cancer are also at risk for other HPV-related cancers such as anal and vulvar.”

Beyond inherited mutations or genetics, Dahut said that alcohol, tobacco, and other environmental factors can also cause dual primary tumors to occur.

“Cancers that are secondary to tobacco such as head and neck cancer, lung cancer, and bladder cancer or from inherited mutations are likely to present with multiple cancers either at initial diagnosis or over time,” he said.

Brawley added that other common cancers that can occur at the same time are pancreatic and prostate cancer, pancreatic and breast cancer, and breast and ovarian cancer.

How Are Second Primary Cancers Treated? 

If someone is diagnosed with two different types of cancers at once, as in Navratilova’s case, experts say that the two cancers must be treated individually.

“You treat each cancer as if it were in a person who only had one cancer,” Brawley said. “For instance, you may very well decide to treat throat cancer first then breast cancer, or vice versa.”

However, Brawley noted that in most cases, the more aggressive cancer that’s causing the most harm or poses the most risk is usually treated first.

Depending on the type of cancer, Dahut said treatment may include surgery, radiation, and/or chemotherapy. Occasionally, the treatments overlap.

If radiation is needed, Dahut said planning needs to be carefully done to effectively treat both cancers safely. If chemotherapy is needed, then therapy is targeted at the most lethal cancer with potentially a local therapy for the other.

“In general, you hope to give the best possible treatment for each cancer,” said Dahut. “It is also important to know that radiation and/or chemotherapy for one cancer can lead to a second primary tumor later.”