By Will Boggs MD
NEW YORK (Reuters Health) - 28/2/2019
A new study breaks down the excess risk of new primary malignancies in survivors of adolescent and young adult (AYA) cancers by the type of the first cancer, helping to inform surveillance efforts.
"Lung cancer accounted for a substantial proportion of the excess number of cancers observed after all AYA cancers investigated in detail," Dr. Michael M. Hawkins from the Center for Childhood Cancer Survivor Studies at the University of Birmingham, U.K., told Reuters Health by email.
Previous studies have estimated that survivors of AYA cancer have a rate of subsequent primary neoplasms as much as 3.1 times higher than that expected for the general population.
Dr. Hawkins's team used data from the Teenage and Young Adult Cancer Survivor Study (TYACSS) to calculate the risks of all and specific subsequent primary neoplasms after each type of AYA cancer and to explore variation in these risks in relation to years from diagnosis, age at diagnosis, decade of diagnosis and sex.
During more than 2.6 million person-years of follow-up (median follow-up, 16.8 years), 6% of survivors had a subsequent primary neoplasm, including 15% of breast-cancer survivors, 14% of cervical-cancer survivors, 13% of Hodgkin-lymphoma survivors and 12% of testicular-cancer survivors.
The most common subsequent primary neoplasms after female breast cancer were lung cancer, ovarian cancer, uterine cancer, other female genital cancers, colorectal cancer and melanoma.
Breast, lung, colorectal and bladder cancers were most common after cervical cancer. Prostate, colorectal, bladder and lung cancer were most common after testicular cancer.
Breast and lung cancer were the most common subsequent primary neoplasms among female Hodgkin-lymphoma survivors, whereas lung cancer was the most common subsequent primary neoplasm among male Hodgkin-lymphoma survivors, the researchers report in The Lancet Oncology, online February 20.
Among patients who survived at least 30 years from diagnosis of cervical cancer, testicular cancer, Hodgkin's lymphoma in women, breast cancer, and Hodgkin lymphoma in men, these few subsequent primary neoplasms accounted for 82%, 61%, 58%, 45%, and 41% of the total excess number of neoplasms, respectively.
The burden of the excess number of neoplasms beyond 30 years from diagnosis accounted for by lung cancer was substantial and apparent across all AYA cancers investigated.
Neither age at diagnosis nor decade of diagnosis was systematically associated with excess subsequent primary neoplasms, except for age at diagnosis for breast cancer after female Hodgkin lymphoma and decade of diagnosis for lung cancer after male Hodgkin lymphoma.
These findings "provide an evidence base to guide surveillance efforts," Dr. Hawkins said.
"Description of risk is only a first step towards the ultimate goal of improving the quantity and quality of life for survivors of AYA cancer," writes Dr. Sumit Gupta from the Hospital for Sick Children, in Toronto, Canada, in an accompanying editorial. "Studies that identify effective interventions for this population, whether in the prevention, screening, or treatment of late effects, are crucial. Determining what health-care delivery models maximize uptake of such interventions in a population known to face substantial barriers to access will also be necessary."
Dr. Theresa H. Keegan from UC Davis Comprehensive Cancer Center, in Sacramento, California, who was not involved in the research, told Reuters Health by email, "This study identifies the excess risk of specific subsequent cancers by types of first cancer in 5-year survivors, informing tailored surveillance for subsequent cancers in this population."
Dr. Yasushi Ishida from Ehime Prefectural Central Hospital, in Japan, has studied secondary cancers after a childhood cancer diagnosis. He told Reuters Health by email, "I'm surprised that lung cancer accounted for a high proportion of subsequent primary neoplasms across all AYA-cancer survivors."
"The prognosis of lung cancer is not good," said Dr. Ishida, who was not involved in the new work. "We should identify the population at high-risk of lung cancer more specifically in the future and make surveillance to find it at an early stage."
Lancet Oncol 2019.