Cancer Profiles, Times to Treatment, and Survival for Adolescents and Young Adults: Comparisons with Children and Older Adults in New South Wales, Australia.

Purpose: To compare cancer types, stages, times to treatment, and survival for adolescent and young adults (AYAs) 15-24 years of age with other cancer patients <40 years. Methods: New South Wales Cancer Registry and treatment data were linked to explore differences in cancer type, stage, time to treatment, and survival between AYAs, children, and adults. Multivariable logistic regression and competing-risk regression were adjusted for sociodemographic, diagnostic period, and clinical characteristics. Results: Most common cancers in AYAs and adults were carcinomas compared with leukemias in children. Advanced (regional and distant) stage applied to 33% of AYA solid cancers, which was similar to adult stages, but lower than the 40% for children (adjusted odds ratio 1.21, 95% confidence interval [CI] 1.01-1.47). Proportions starting treatment ≤60 days from diagnosis were 93% for AYAs and children, and 94% for adults, with higher adjusted odds of starting ≤60 days of 1.39 (95% CI 1.11-1.73) for children and 1.23 (95% CI 1.06-1.44) for adults. Five-year disease-specific survival was 90% for AYAs and adults, and 87% for children. The adjusted subhazard ratio for children compared with AYAs was 0.67 (95% CI 0.52-0.88). Age differences in cancer stage, treatment start, and cancer survival varied by cancer type. Conclusions: After adjusting for cancer type, diagnostic period, and sociodemographic characteristics, AYAs had less advanced solid tumors than children; fewer AYAs were treated within 60 days than children and adults; and AYA survival was lower than for children. The potential for residual confounding from leukemia type and other confounders needs further analysis with larger Australia-wide cohorts.