Background

With prior reports indicating a lack of progress in survival improvement in older adolescents and young adults (AYAs) aged 15 to 39 years with cancer compared with both younger and older patients with cancer, the current analysis provides an update of survival trends of cancers among AYAs, children, and older adults.

Methods

Data from the National Cancer Institute Surveillance, Epidemiology, and End Results database for 13 regions were used to ascertain survival trends of the 34 most frequent cancers diagnosed in AYAs compared with children and older adults.

Results

As of 2002 through 2006, the 5-year relative survival rate for all invasive cancers in AYAs was 82.5% (standard error, 0.2%). In AYAs, 14 cancers demonstrated evidence of a statistically significant improvement in their 5-year relative survival since 1992. Survival improved less in AYAs than in children for acute myeloid leukemia and medulloblastoma. Fourteen cancers had survival improvements that were found to be less in AYAs compared with older adults, including hepatic carcinoma, acute myeloid leukemia, high-grade astrocytoma, acute lymphocytic leukemia, pancreatic carcinoma, low-grade astrocytoma, gastric carcinoma, renal carcinoma, cancer of the oral cavity and pharynx, Hodgkin lymphoma, ovarian cancer, fibromatous sarcoma, other soft tissue sarcoma, and thyroid carcinoma.

Conclusions

Improvements in the survival of several cancer types that occur frequently in AYAs are encouraging. However, survival does not appear to be improving to the same extent in AYAs as in children or older adults for several cancers. Further investment in exploring the distinct biology of tumors in this age group, and of their hosts, must be a priority in AYA oncology.

Background

In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults.

Methods

Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults.

Findings

There were 1·19 million (95% UI 1·11-1·28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59·6 [54·5-65·7] per 100 000 person-years) and high-middle SDI countries (53·2 [48·8-57·9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14·2 [12·9-15·6] per 100 000 person-years) and middle SDI (13·6 [12·6-14·8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23·5 million (21·9-25·2) DALYs to the global burden of disease, of which 2·7% (1·9-3·6) came from YLDs and 97·3% (96·4-98·1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally.

Interpretation

Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts.

Funding

Bill & Melinda Gates Foundation, American Lebanese Syrian Associated Charities, St Baldrick's Foundation, and the National Cancer Institute.