Photo by Rhoda Baer
Doctor consults with cancer patient and her father
Second cancers take a greater toll on patients under the age of 40, according to research published in JAMA Oncology.
Researchers studied 14 types of cancer occurring in more than 1 million patients.
For nearly all of the cancers studied, 5-year survival rates were much higher if the cancer occurred as a first malignancy rather than a second cancer.
These survival differences were more pronounced in pediatric patients and adolescents and young adults (AYAs) than they were in patients age 40 and older.
Researchers hope these findings will help guide clinicians in providing age-specific recommendations on cancer prevention, screening, treatment, and survivorship, especially among the AYA population.
“Although the increased incidence of second cancers is well known among cancer survivors, less is known about outcomes of these cancers or the influence of age,” said Theresa Keegan, PhD, of the UC Davis Comprehensive Cancer Center in Sacramento, California.
With this in mind, Dr Keegan and her colleagues analyzed data on patients diagnosed with either a single cancer or a first and second malignancy during 1992 through 2008. The researchers used Surveillance, Epidemiology and End Results program data collected from 13 cancer registries.
The team collected data on the 14 most common cancer types that affect AYAs: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), soft tissue sarcoma, and bone sarcoma, as well as female breast, thyroid, testicular, colorectal, central nervous system, cervical, and ovarian cancers.
There were a total of 15,954 pediatric patients (younger than 15 years at diagnosis), 125,750 AYAs (ages 15 to 39), and 878,370 older adult patients (age 40 and older).
Survival rates
For pediatric patients, the 5-year relative survival was 80% for a first cancer and 47% for a second primary malignancy.
For AYAs, the 5-year relative survival was 81% for a first cancer and 60% for a second primary malignancy.
For older adults, the 5-year relative survival was 70% for a first cancer and 61% for a second primary malignancy.
When the researchers looked at 5-year survival by age and individual cancer types, they found striking differences depending on whether it was a first or second malignancy in all but 2 of the 14 cancer types, testicular cancer and melanoma.
“For almost every type of cancer, the AYA population did worse with a secondary cancer,” said study author Melanie Goldfarb, MD, of John Wayne Cancer Institute at Providence Saint John’s Health Center in Santa Monica, California.
“What struck us was that the second cancer caused such an increased risk of death.”
Lymphomas
For pediatric patients with HL, the 5-year relative survival was 95% when patients had HL as a first cancer. There were no data on HL as a second primary malignancy.
For AYAs, the 5-year relative survival was 93% when patients had HL as a first cancer and 72% when they had HL as a second primary malignancy.
For older adults, the 5-year relative survival was 69% when patients had HL as a first cancer and 54% when they had HL as a second primary malignancy.
For pediatric patients with NHL, the 5-year relative survival was 84% when patients had NHL as a first cancer and 63% when they had NHL as a second primary malignancy.
For AYAs, the 5-year relative survival was 64% when patients had NHL as a first cancer and 22% when they had NHL as a second primary malignancy.
For older adults, the 5-year relative survival was 57% when patients had NHL as a first cancer and 54% when they had NHL as a second primary malignancy.
Leukemias
For pediatric patients with ALL, the 5-year relative survival was 87% when patients had ALL as a first cancer and 63% when they had ALL as a second primary malignancy.
For AYAs, the 5-year relative survival was 48% when patients had ALL as a first cancer and 26% when they had ALL as a second primary malignancy.
For older adults, the 5-year relative survival was 17% when patients had ALL as a first cancer and 11% when they had ALL as a second primary malignancy.
For pediatric patients with AML, the 5-year relative survival was 57% when patients had AML as a first cancer and 29% when they had AML as a second primary malignancy.
For AYAs, the 5-year relative survival was 46% when patients had AML as a first cancer and 23% when they had AML as a second primary malignancy.
For older adults, the 5-year relative survival was 12% when patients had AML as a first cancer and 10% when they had AML as a second primary malignancy.
Why younger patients tend to fare worse after a second cancer than older patients is not fully understood or specifically addressed in the current study, the researchers noted.
Now, the team plans to examine how the time between getting a first and second cancer affects survival and whether the type of treatment for the first cancer influences the outcome of a second cancer.
