Survivors of childhood cancer are twice as likely as the general population be diagnosed with cancer after age 40. Even more distressing, the researchers discovered that if childhood survivors were diagnosed with a second cancer before age 40, they were even more likely to develop a third.

A second (or third) primary cancer diagnosis — that is, a new cancer unrelated to the first — is common among childhood cancer survivors. A new study by Dr. Lucie Turcotte from the University of Minnesota and Fred Hutch researchers Dr. Wendy Leisenring and John Whitton sheds light on just how common.

“Once I was ten years out, they felt that I was cured so the lung cancer thing took us completely by surprise,” Tomalia said. “I couldn’t believe it, especially being a nonsmoker.”

Tori Tomalia also got hit with a cancer “double whammy.” At 14, she was diagnosed with osteogenic sarcoma , a form of bone cancer. Two years ago at age 37, the mother of three was diagnosed with stage 4 lung cancer.

“In 1976, I was diagnosed with Hodgkin’s disease,” said Gillespie, now 51. “They took out my spleen and gave me strong doses of radiation from the chest up. In 1986, I was diagnosed with thyroid cancer from all the radiation to my chest, so they took out my thyroid. [Then] in 2006, they found breast cancer.”

Pam Gillespie didn’t just beat cancer as a 12-year-old. She did it again at age 22. And yet again at age 42.

Childhood cancer survivor Tori Tomalia was diagnosed with stage 4 lung cancer two years ago. While her doctors believe the two cancers are unrelated, many childhood cancer survivors are diagnosed with second cancers brought on by treatments like radiation.

Double-edged sword

Dianne Mackay, a marketing manager from Burnaby, British Columbia, also beat cancer twice: first a Wilms tumor, a type of kidney cancer, when she was 14, and later breast cancer in her early 40s.

“In some ways the fact that I had been through it all those years earlier meant that I knew what to expect, and that’s a double-edged sword,” she said. “Knowing what to expect, you don’t have a lot of surprises, but I knew that it was going to be a really long haul.”

Mackay and Gillespie’s later diagnoses match Turcotte’s findings: Former childhood cancer patients were five times more likely to have breast cancer than the general population at the same age. Other common second primary cancers include renal cancer, soft-tissue sarcoma and thyroid cancer. A history of radiation treatments was one of the greatest risk factors associated with developing a second primary cancer.

“Breast cancer among female Hodgkin lymphoma survivors was a major outcome,” Leisenring said. “A lot of that is due to (the amount of) chest radiation in these patients, which probably saved their life originally but what it means is that people need to be a lot more vigilant about screening.”

Better treatment has led to more people surviving childhood cancers, Turcotte explained. But this treatment can also have consequences, which is what prompted the researchers to explore the long-term effects of therapies like radiation.

“The calculations show that a lot of it is not necessarily something intrinsic about the cancer they had, it’s the treatments that they received that are putting them at risk of other things happening to them, in this case second cancers,” said Leisenring, one of the study’s statisticians.

While Tomalia’s doctors believe her two cancers are unrelated, both Mackay and Gillespie’s doctors believe their second cancers were caused by treatment. Both had radiation.

“When I was diagnosed with breast cancer in the fall of 2012, (my doctors) believed that it was a result of the treatment I had 30 years earlier,” Mackay said.

Screening for second cancers

Researchers used data from the Childhood Cancer Survivor Study, based at St. Jude Children’s Research Hospital and statistically analyzed at Fred Hutch, which included a cohort of over 14,000 U.S. childhood cancer survivors diagnosed between 1976 and 1986. They focused specifically on the approximately 3,000 survivors who’d reached the age of 40 to see if those individuals were at a higher risk.

“The crux of the message is that for (survivors) even after they reach the age of 40 when the rest of the population is starting to have some cancers, they’re still at higher risk,” Leisenring said.

Turcotte says these results mean patients should get regular screenings not just for their primary cancer, but also for subsequent cancers. She advised survivors to stay in close contact with their physicians and start screening early.

“No one ever told me I would be at risk for other things,” Gillespie said. “I went in for blood work every six months but they were always looking for the Hodgkin’s to come back. They weren’t worried about other things.”

Seattle Cancer Care Alliance offers a number of resources for childhood cancer survivors through their Cancer Survivor Program, including education, consultation with a child’s primary care physician, and the opportunity to address social or educational issues or any potential late effects of treatment.

While some patients may be concerned about receiving additional radiation through constant screening, Turcotte doesn’t see this as a major risk factor and recommends screenings such as breast MRIs which have no radiation.

A dwindling statistic?

And there is cause for hope. The researchers said the high rate of secondary cancers may dwindle, thanks to new therapies and a “less-is-more” philosophy regarding radiation that’s emerged in recent years.

The Childhood Cancer Survivor Study has recently expanded to include survivors who were treated between 1987 and 1999. Fred Hutch’s Leisenring hopes future studies will show the next generation of childhood cancer survivors experience fewer treatment-driven cancers later in life.

“The thing that’s surprised me the most is how much cancer care has changed in 20 years,” said Tomalia. “When I was first diagnosed with my second cancer I assumed it would be exactly like the first. But even the comfort care measures now are so different … Right now I’m not even on chemo; I take a pill twice per day that controls the mutation. The research gives me hope.”

Mackay expressed similar sentiments.

“The actual chemotherapy was a much better experience for me the second time around,” she said. “I think you have to treat each experience as a new journey rather than be looking back at what happened before. Things change, technologies change, you change.”

Gillespie said she hasn’t let her three bouts with cancer stop her from living a full life. She currently resides on the North Shore of Oahu, Hawaii, with her husband and enjoys spending time with her son and daughter, both in their twenties.

As for feeling resentment about her two treatment-related cancers, Gillespie said she prefers to stay focused on the positive.

“I believe in wanting to live,” she said. “Let’s just get it done and move on.”

Megan Herndon is a freelance writer for the Fred Hutch news team. She is a senior at University of Washington, where she is majoring in journalism, minoring in French and pursuing a Certificate of Sales. Reach her at mherndon@fredhutch.org.