Adolescent patients with cancer reside in a "no-man's land" between the world of pediatric oncology and that of "adult" medical oncology. As compared to younger and older patients, adolescents and young adults are under-represented on clinical trials. This relative lack of participation in clinical protocols has been associated to a lack of progress in survival improvement over the last years. One of the main reasons for the deficit in protocol enrolment and the worse outcome of adolescents (when compared in particular to children) is the lack of awareness by the public, community and healthcare systems that cancer may occur in this age group. However, physicians--inadequately trained or reluctant to care for adolescents--have important responsibilities. Most 15- to 19-year-olds diagnosed with cancer are treated at adult facilities, although two-thirds to three-fourths of their cancers are typical of those that occur in the pediatric age range. The best choice may be to treat them according to their type of tumor, not according to their age: "pediatric" tumors treated by pediatric oncologists, "adult" tumors by adult medical oncologists, regardless of the patient's age. This solution, however, is probably appropriate for the tumor, but not necessarily for the patient. Adolescents are neither old children nor young adults, and are very complicated individuals, with unique socio-psychological problems and needs, that may be addressed only by dedicated professionals, adequately trained and supported. The ultimate challenge is the development of a new discipline, adolescent/teenage and young adult oncology, devoted to the care of these patients.