Cancer burden in adolescents and young adults (AYAs) is expressed through a large proportion of the quality of life lost on individual level and also causes losses to the society in terms of a decreased productivity and social structure. A specific cancer spectrum and distinctive needs of AYA patients require targeted studies and cancer control measures. Incidence is intermediate between that for children and for older adults, and two-thirds of the AYA cancers affect women. Cancers of the breast and cervix uteri, representing a large portion of the burden, are amenable to prevention. Survival is relatively high, but it is lower in AYA patients with certain cancers that are common in childhood or older adulthood. Tailored cancer care with centralized multidisciplinary provision improves the outcome, as demonstrated by survival of leukemia patients. Mortality is decreasing in high-income countries for the cancers that contribute to the burden most, but lack of progress is seen for some rarer subtypes, such as brain tumors and sarcomas of the bone and soft tissue. There is unacceptable lack of information on cancer burden in low-income countries in which the outcomes for AYA patients are likely dreadful. Investment is required to establish cancer registration system and appropriate cancer care delivery in these settings.