Cancer survivors who are diagnosed during adolescence or early adulthood (age 15-20 years) are at increased risk of premature death compared to the general population, a study* published in The Lancet Oncology shows.
Childhood cancer survivors are known to have a higher risk of early death and long-term health problems related to their treatment, including heart conditions and circulatory problems, but little is known about the long-term consequences of cancer treatment on adolescents and young adults. To address this the researchers examined data from the Childhood Cancer Survivor Study, which has been tracking health outcomes from more than 24,000 people who were diagnosed between 1970 and 1999 in the USA and survived for five or more years after diagnosis.
They tracked the death rates and causes of death for three groups of patients: those who were aged between 15 and 21 years at the time of their initial cancer diagnosis (5,804 people); childhood cancer survivors diagnosed with the same cancers before age 15 (5,804 people), and a group of siblings of similar ages recruited for comparison (5,059 people). They also examined medical records for occurrences of cancer, severe health problems associated with the heart, lungs, and musculoskeletal systems, as well as metabolic and neurological conditions.
Based on their analysis, the authors estimate that the likelihood of a young adult cancer survivor developing a severe health condition by age 45 was 39% (one in 2.6), compared with 12% for siblings of the same age (one in eight). The risks for people diagnosed as adolescents were lower than those of childhood cancer survivors diagnosed before age 15, where the likelihood of developing a severe condition by age 45 was 56% (more than one in two).
The risk of mortality from any cause among young adult survivors was almost six times higher than would be expected in those of same age and sex in the general population (standardised mortality ratio [SMR] 5.9, 1357 deaths compared with an expected 231.9). The standardised mortality ratio for childhood cancer survivors was similarly elevated over the general population (SMR 6.2, 963 deaths compared with an expected 155.7).
Early adolescent and young adult survivors were 1.6 times as likely to die from recurrence or progression of their primary cancer compared with childhood cancer survivors (492 deaths of adolescent survivors compared with 325 deaths of childhood survivors).
The differences in health outcomes between childhood survivors and young adults were most notable 20 years after diagnosis. The researchers say this underlines the importance of long-term health screening for both groups of cancer survivors.
Dr Tara Henderson, associate professor at the University of Chicago, USA, said: “Focused efforts are needed to ensure young adult cancer survivors receive long-term health monitoring, with a focus on cancer screening, to reduce their risk of health problems and early death. Studies have shown that adherence to such programmes is poor, so we need to do more to highlight the importance of lifelong care to survivors and their families, as well as primary health care providers. We also need further research to understand how best to deliver risk-based care for survivors that incorporates both cancer specialists and primary care providers in the community.”
The researchers caution that their findings may not be generalisable to patients treated today, who are likely to receive different treatment regimens than in previous decades. Also, the cohort of survivors included in the study did not include the full range of cancers typically seen in this age group, notably gonadal tumours, melanomas and thyroid cancers were not included but account for almost 40% of cancers diagnosed between the ages of 15 and 20 years.
*Suh E, Stratton KL, Leisenring WM, et al. Late mortality and chronic health conditions in long-term survivors of early-adolescent and young adult cancers: a retrospective cohort analysis from the Childhood Cancer Survivor Study. The Lancet Oncology. Published: February 14, 2020. DOI:10.1016/S1470-2045(19)30800-9