When You Have Two Separate Cancers

Medically Reviewed by Sabrina Felson, MD on September 24, 2022
7 min read

Jennifer Schmid had just learned she had pancreatic cancer and that she would need surgery to remove part of her pancreas, stomach, and intestines. Schmid’s oncologist recommended she have a CT scan to check for cancer anywhere else in her body.

That’s how doctors found the spot on her lung.

To 61-year-old Schmid, of Newhall, CA, this news sounded about as bad as it could get. The pancreas cancer must have been so advanced that it had already spread to her lungs, she thought. But that wasn’t the case.  



Schmid’s oncologist ordered genetic sequencing of both the lung tumor and the pancreas tumor. That’s a test to read the unique DNA of each tumor. It revealed that the two tumors were completely different from each other. Schmid didn’t have a single advanced cancer that had spread from her pancreas to her lungs. She had two separate early-stage cancers: lung cancer and pancreatic cancer. This made all the difference in Schmid’s treatment and long-term prognosis.

“It was a stroke of luck that they found that spot on my lung and that they figured out it was not a metastasis,” Schmid says.

Two separate primary cancers, as opposed to one that has spread to multiple parts of the body, require different treatment and, in many cases, can come with a far better outlook than a single metastatic cancer. And it happens more often than people might think. 

While it may seem like a rare case of lightning striking twice, it’s not terribly uncommon for a person to get two primary cancers – even at the same time. 

Researchers estimate that about 1 in 20 people with cancer have another separate cancer at the same time. They define “at the same time” as two tumors occurring within less than 6 months of each other. It’s even more common to have two different cancers at separate times – that is, a second cancer more than 6 months after the first. This happens in up to 1 in 5 people who have had cancer. 

Lauren Stevens of Louisville, OH, was one of those 1 in 5. She had lived with a brain tumor from 2004 to 2019. Her doctor monitored it with routine scans and as long as it didn’t grow, they chose not to operate. A scan in 2019, however, showed that it had started to grow – and fast. 

Stevens, now 50, had surgery to remove most of the tumor followed by radiation and chemotherapy. Then she resumed routine scans to monitor the remaining tumor that the surgeon wasn’t able to remove. 

Continuing to live with an inoperable brain tumor, Stevens started seeing blood in her stool. A colonoscopy and biopsy revealed that she had colon cancer. Soon, Stevens was back in chemotherapy and radiation followed by surgery to treat this second cancer while still living with the first. 

Understandably, living with cancer since she was 32 years old has been daunting for Stevens. There were times when she wanted to give up and no longer pursue the recommended care. But 7 years ago, she got a new reason to live.

“I have a grandson now,” she says. “He just turned 7. I didn’t know my grandparents growing up. I want my grandson to remember me. We’re very close. I think the sun just rises and sets on him.”

Anyone who has had any type of cancer could get a second cancer of any type. But research shows that those who’ve had bladder cancer or non-Hodgkin’s lymphoma are at greatest risk for second cancers. Lung cancer appears to be the most common second primary cancer. 

There are a number of reasons why a person might develop two separate primary cancers in their lifetime. 

Chance. Anyone is at risk of developing cancer at any given time. You have a lifetime risk, for example, for lung cancer and a separate risk for, say, colorectal cancer. So while it’s less common than having just one of those cancers, it is possible that you could get both. 

Genetics. You can inherit genes from your parents that raise your risk for specific cancers. Mutations in the BRCA1 and BRCA2 genes, for example, that you inherit from a parent raise your risk for breast cancer (as well as ovarian and pancreatic cancers). You can also inherit a gene that raises your risk for colorectal cancer. This genetic predisposition is called Lynch syndrome. 

“This is why it’s important to have genetic testing to look for one of these syndromes if you have two primary cancers,” says Joleen Hubbard, MD, an oncologist at Mayo Clinic. “There are many that we can test for, but there are also probably many cancer syndromes that we aren’t aware of yet.” 

Common risk factors. Many factors that raise your risk for one cancer raise your risk for others as well. Smoking and tobacco use, for example, cause at least 14 different types of cancer. Obesity, alcohol use, and an unhealthy diet are other risk factors for several different kinds of cancer. Exposure to harmful substances in the environment can raise risk for more than one type of cancer, too. 

Previous cancer treatment. Radiation and chemotherapy for one cancer can raise the risk for another cancer down the line. But doctors don’t typically call these cancers second primary cancers. They are radiation-induced or chemotherapy-induced secondary cancers. 

With many cancers, when you get a diagnosis, the doctor will order imaging of your chest, abdomen, and pelvis to see if the cancer has spread beyond where it started. For cancers that commonly spread to the brain, such as lung cancer, testing might include brain imaging, too. 

If additional tumors show up in these images, they might contain clues as to whether they arose from the same cancer or a different one. 



“If you have a patient that has two separate masses and they look different on a PET scan – one lights up more than the other – that raises our suspicion that they might not be the same malignancy, which would require us to sample both areas,” says Arsen Osipov, MD, the oncologist who managed Schmid’s care at Cedars-Sinai Cancer in Los Angeles. He runs the Pancreatic Cancer Multidisciplinary Clinic.

A biopsy and genetic sequencing of both tumors, like Schmid had, can tell doctors definitively whether they are looking at one cancer or two. 

“Finding out whether a person has two primary cancers versus a single cancer that has metastasized is critically important,” Osipov says. “It could have been assumed that she had metastatic pancreatic cancer, but actually she had two separate cancers that could each be treated definitively with the intention to cure. You take care of one, then the other, and those cancers are not as advanced as a single cancer with metastasis would have been.”

When two different cancers arise at the same time, doctors have to make a judgment call: Which cancer should they treat first? 

In unusual cases, the two cancers may share characteristics that would make them respond to the same targeted drug or chemotherapy regimen. 

“This would be an ideal scenario, but it’s very rare,” Osipov says. 

When two simultaneous primary cancers require two different treatments, Hubbard says, “You’ll either treat the most life-threatening cancer first or sometimes it may be best to treat the one that’s easiest to treat first.” 

Schmid had abdominal surgery first for the pancreatic cancer and then radiation and chemotherapy for her lung cancer. The chemotherapy is still in progress. 

If you get a diagnosis of metastatic cancer, make sure you get a biopsy of the metastases to make sure you don’t have two separate cancers.

“Most centers are already doing this,” Hubbard says, “and this is why your doctor needs to biopsy a metastatic site.”

Osipov recommends that people with two simultaneous primary cancers get care at a cancer center where they can work with a multidisciplinary team that includes oncologists, surgeons, radiologists, and pathologists who can all work together on your case. Keep in mind that oncologists tend to specialize in particular types of cancer, so if you have more than one type of cancer, you’d want a team of oncologists at a cancer center to determine which cancer to treat first.

At the least, Hubbard adds, patients with two cancers should get a second opinion on their diagnosis and care.

“This helps not only the patient but the primary treating oncologist have a better idea of what tumors they are dealing with, what treatment options are available, and the best order in which to treat the cancers.”