Some cancers in adolescents and young adults may contain unique genetic and biological features. Researchers are working to acquire more about the biology of cancers in young adults so that they can integrate molecularly targeted therapies that may be effective in these cancers. Young adults are mostly kid or an older adults to be identified with definite cancers, such as, thyroid cancer, Hodgkin lymphoma, testicular cancer, melanoma, and sarcomas. Nevertheless, the incidence of specific cancer types differs according to age. Leukaemia, testicular cancer, and thyroid cancer was the most common cancers among 15-24-year-olds. Among 25-39-year-olds, breast cancer and melanoma were the most common cancer diseases.