About one in six survivors of an adolescent and young adult cancer will develop a subsequent primary neoplasm within 30 years of their original diagnosis, according to the results of a population-based study published in the Canadian Medical Association Journal.
“When combined with the relatively high survival rates in this age range, at approximately 86%, there is a growing population of young cancer survivors that will be adversely affected by their cancer diagnosis and its treatment even decades later,” wrote Miranda M. Fidler-Benaoudia, PhD, Clinical and Descriptive Cancer Epidemiologist at the University of Calgary Cumming School of Medicine and Cancer Care Alberta, Calgary, Alberta, with her coauthors.
The study authors suggested that these findings highlight the need for earlier cancer screenings for this population. “Our findings suggest that earlier cancer surveillance in this population may be warranted, which agrees with numerous survivorship guidelines that recommend earlier breast and colorectal cancer surveillance for at-risk cancer survivors,” they wrote.
Background and Study Methods
Rates of adolescent and young adult cancers have increased annually by 1.3% in Canada from 1998 to 2012. Adolescent and young adult cancer survivors are about 1.6 to 4.3 times more likely to develop a subsequent primary neoplasm than the general population, current research suggests, leading to the most common cause of death among this population.
Researchers sought out to quantify the risk of subsequent primary neoplasms that survivors of adolescence and young adult cancers face in Alberta, Canada. The Alberta Adolescent and Young Adult Cancer Survivor Study was a retrospective, population-based study that included patients aged 15 to 39 years who had a neoplasm that was first diagnosed between 1983 and 2017. The researchers looked at overall survival and after 5-year survival as determined by standardized incidence ratios and absolute excess risks per 10,000 person-years, in comparison with the general population's expected rates. There was up to 30 years of follow-up in the study.
Key Findings
The study looked at 24,459 individuals with a cancer diagnosis in their adolescence or young adulthood. Of these patients, 1,442 (6%) had a subsequent primary neoplasm, and 1,129 of these occurred after 5 years of survival from the original cancer.
The overall risk of subsequent primary neoplasm was similar to the after 5-year survival risk, with a standardized incidence ratio of 2.2 (95% confidence interval [CI] = 2.1–2.4) vs 2.0 (95% CI = 1.9–2.2), respectively. The absolute excess risks were 31.7 per 10,000 person-years for overall risk of subsequent neoplasm (95% CI = 28.7–34.6) vs 35.7 per 10,000 person-years for after 5-year survival risk (95% CI = 31.6–39.8).
The most common subsequent primary neoplasms were breast, digestive, hematopoietic, or respiratory cancers.
The 30-year cumulative incidence of a subsequent primary neoplasm was 17.7% (95% CI = 16.5%–18.9%) after the 5-year survival timepoint from the original cancer. The incidence was highest for survivors of adolescent and young adult cancers of the oral cavity, lip, or pharynx (28.9%; 95% CI = 18.9%–39.6%); breast cancer (27.3%; 95% CI = 23.7%–30.9%); colon cancer (23.5%; 95% CI = 14.2%–34.1%); and Hodgkin lymphoma (22.7%; 95% CI = 18.2%–27.6%).
“Although people with nearly all types of adolescent and young adult cancer investigated were at an increased risk of developing a subsequent primary neoplasm, survivors of Hodgkin lymphoma and breast cancer were identified as particularly vulnerable populations, with nearly one-third of subsequent primary neoplasms occurring after 5-year survival diagnosed in these survivor groups,” the authors wrote. “These findings are consistent with previous studies and reflect the established late effects of radiotherapy, chemotherapy, and hormone therapy.”
“Given that subsequent primary neoplasms are major contributors to morbidity and premature mortality, these findings underscore the need for innovative solutions to prevent, detect, and treat subsequent primary neoplasms among survivors of adolescent and young adult cancer,” the authors concluded.
DISCLOSURES: Dr. Fidler-Benaoudia reports funding from the Canadian Institutes of Health Research, Alberta Health, the University of Calgary, the Alberta Children’s Hospital Research Institute, and the Arnie Charbonneau Cancer Institute. Dr. Fidler-Benaoudia is a member of the Cancer in Young People in Canada Management Committee. Dr. Alam was supported by the Cumming School of Medicine Cancer Screening, Detection & Risk Reduction Postdoctoral Fellowship Award. No other competing interests were declared.
