TUESDAY, Oct. 6, 2015 (HealthDay News) -- Teen and young adult cancer survivors are at increased risk for other cancers later in life, a new study reveals.
Researchers analyzed U.S. National Cancer Institute data on people who survived cancers before age 40. They had the most common types of cancers in that age group: leukemia, lymphoma, testicular, ovarian, thyroid, breast, soft tissue and bone cancers.
"This is a patient demographic that has been largely overlooked," said senior study author Dr. Robert Goldsby, a professor of pediatrics at the University of California, San Francisco Benioff Children's Hospital.
Over 30 years, nearly 14 percent of the survivors were diagnosed with another, different type of cancer. On average, the second cancer occurred within 15 years.
Compared to people in the general population, patients successfully treated for cancer between ages 15 and 39 were nearly 60 percent more likely to develop cancer. In contrast, people successfully treated for cancer after age 40 were 10 percent more likely to develop another cancer.
The most common second cancers were breast, gastrointestinal and genital cancers, and melanoma skin cancer, the study found. Over 30 years, those who received radiation therapy for their first cancer were more likely to have a second cancer than those who did not have radiation therapy -- about 17 percent compared to 12 percent.
Of the 7,384 patients who developed second cancers, 1,195 also developed a third cancer, according to the study published Oct. 6 in the journal Cancer.
Cancer patients used to be told that after five years of remission, they no longer had special health care needs, Goldsby said in a university news release. "But our study demonstrates that adolescent and younger adult survivors require lifelong follow-up with regular medical screening," he added.
In older adults, cancer frequently stems from age and the cumulative effects of long-term exposures or habits, such as smoking or unhealthy diet, he said. "But younger patients may harbor genetic changes that influence the risk of cancer. They may need counseling if their lifestyle choices increase their existing risk," he explained.
The American Cancer Society has more about cancer survivorship.