(Reuters Health) - Cancer survivors diagnosed as teens or young adults are living longer now than young people diagnosed decades ago, largely because of advances in treatment, a U.S. study suggests.
Overall, among people diagnosed between ages 15 and 39, deaths from all causes from five through 10 years after diagnosis dropped to 5.4% among those diagnosed with cancer in 2005-2011, from 8.3% among young people diagnosed in 1975-1984.
The patterns were similar for survival up to 15 years after diagnosis, researchers report in the Journal of the National Cancer Institute.
“As more and more patients are surviving beyond that five-year timepoint, and because adolescents and young adults have many potential years of life remaining after cancer, they are an important population in which to study long-term outcomes,” said study coauthor Chelsea Anderson, a postdoctoral fellow at the American Cancer Society at Atlanta.
Anderson’s team analyzed data from a U.S. population-based cancer registry, focusing on 282,969 people diagnosed with cancer at ages 15 to 39 between 1975 and 2011, who survived at least five years after diagnosis.
The authors followed patients from five years after cancer diagnosis until death or the end of 2016.
Most survivors in the sample were white women, 30 to 39 years old when diagnosed with cancer. The most common cancer was breast cancer, for which mortality rates dropped from 15.9% of patients diagnosed in 1975-1984 to 10.1% in 2005-2011.
The most significant drops in death rates between the earliest and most recent diagnosis periods was seen in patients with leukemia (28.6% to 6.6%), non-Hodgkin lymphoma (13.0% to 3.6%), central nervous system tumors (25.0% to 17.2%) and kidney cancer (10.7% to 4.4%).
This was driven mainly by fewer deaths caused by the primary cancer between these periods - down to 4.2% from 6.8%.
Not all cancers have seen the same level of improvement, however. There was little improvement in mortality over the same period for patients with colorectal, bone, cervical/uterine, bladder cancers and sarcomas.
The cancers that showed little improvement were ones that typically affected adults, said Dr. Kara Kelly, chief of Roswell Park Oishei Children’s Cancer and Blood Disorders program and professor of pediatrics at the University at Buffalo Jacobs School of Medicine and Biomedical Sciences in New York.
“This may, in part, be related to how there aren’t as many clinical trials for these cancers,” Kelly, who was not involved in the study, told Reuters Health by phone.
“The greatest improvements were seen in patients with cancers that are also more prevalent in children - and these improvements in childhood cancer have resulted from clinical trials,” she said.
While the study affirms improvements in preventing deaths from primary cancers, Kelly said it didn’t provide details about how other races and ethnicities fared.
The data set the researchers used also doesn’t detail types of treatments or how well patients were managed if they relapsed, she said.
As young adult patients are transitioning to independence and many are uninsured or under-insured, it is critical to understand the access they have to treatment, Kelly said.
Kelly also pointed out the need for less toxic treatments to reduce mortality rates.
Overall, the findings demonstrate the progress made over the past few decades in improving outcomes among long-term survivors of adolescent and young adult cancers, Anderson said by email.
“Some cancer types have not shared in these improvements, and these survivors may be priority groups for efforts to improve long-term surveillance and reduce late mortality from cancer among adolescents and young adults,” she said.
SOURCE: bit.ly/2wQGcsR Journal of the National Cancer Institute, online March 3, 2020.
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