Adolescent and Young Adult Oncology: An Emerging Field
Authors: David M. Thomas, Karen H. Albritton, Andrea Ferrari
Journal: Journal of Clinical Oncology (2010)

The emergence of adolescent and young adult oncology (AYAO) illustrates many features of new fields of endeavor. What are these features? The most important is a clear clinical need. Cancer is the leading disease-related cause of death in young adults in the United States and affects eight times as many individuals between the ages of 15 and 40 as those younger than 15 years of age. These dry figures are given a human voice from patients themselves, expressed through grass-roots advocacy organizations, Web sites, philanthropic efforts, blogs, books, and conferences. A new field should appeal to practitioners and researchers from many existing fields. AYAO has relevance to many aspects of oncology, from basic biology through health services and treatment to psycho-oncology. This special edition of Journal of Clinical Oncology indicates how far AYAO has come during the past few years. In this issue, we sought in the main to review overarching topics of clinical care of AYA cancer, rather than focus on specific diseases. There is much of relevance to many readers: pediatric and medical oncologists, psychologists, radiation oncologists, reproductive endocrinologists, nurses, and palliative care specialists—all who work closely with AYAs with cancer. Many of the themes addressed have broad relevance to AYA health and we hope will contribute to improvements for AYAs with chronic or severe endocrine, gastrointestinal, and respiratory illnesses. It is clear that some cancers that affect young people have worse outcomes than others: leukemias, brain tumors, epithelial cancers and sarcomas. Furthermore, various findings suggest that tumor biology and clinical outcome for a given tumor vary in different age groups, thus suggesting tailored approaches according to patient’s age. In this issue, Kieran et al draw attention to the complex range of brain tumors seen in a population bridging childhood to adulthood. A recurrent theme is the fact that “childhood” tumors (medulloblastoma, for example) may be seen in adults, even as “adult” tumors may still affect adolescents. This raises an important question: is it reasonable to extrapolate from treatment paradigms used in noncognate populations to older or younger patients? Oncology treatments— chemotherapy as well as surgery and radiotherapy—are far from innocuous. In an excellent review, Veal et al point out the surprising gap in pharmacologic data on cytotoxics in adolescence and young adulthood. This is partly a result of the artificial divide between pediatric and adult medicine into which young patients often fall, to their detriment. Differences in anthropometric measures, body composition, size, and maturity of organs, as well as hormonal status, may directly influence the disposition and clearance of drugs, the susceptibility to treatment morbidity, even the relationship between the tumor cells and the host. A child is not a “small adult” and does not become an adult on a given birthday or at a given weight. It is unclear to what extent one can apply drug dosing or treatment regimens between pediatric and adult populations, although this is frequent in practice. Another problem is that young people may be less compliant with recommended treatments than other age groups, for the many reasons discussed by Butow et al. Reviewing the literature, they find that 27% to 60% of young people may be poorly adherent to cancer treatment, which obviously may affect cancer survival rates in this population. This problem may only become more significant as the number of orally available treatments increase. Fortunately, the great majority of childhood, adolescent, and young adult patients with cancer will survive their cancer diagnosis and will constitute a sizeable fraction of the community. The quality of survivorship is critical to any assessment of the quality of treatment. Although there are few data on young adult cancer survivorship, the landmark Children’s Cancer Survivorship Study has revealed an unexpected burden of morbid sequelae for young adult survivors of childhood cancer. Again, the health care delivery system has not determined how best to care for this population. Freyer argues that systematic health care transition constitutes the standard of care for young adult survivors of childhood cancer, and discusses current research on their medical needs, current models, and innovative approaches for follow-up care. Unfortunately, not all young people will survive a cancer diagnosis. Palliative care is a particularly challenging area of young adult oncology, on the basis of the gathering experience of those who work with young people dying from cancer and their families. The unique features of palliative care in this age group, where death is incongruous and tragic, are introduced by Wein et al in this issue. An example is communication among the dying person, the family, and the treating team. By comparing experiences in Israel and Australia in young adult palliative care, Wein et al reflect on how cultural taboos influence discussions about death and dying and are accentuated for young patients. Sexuality, fertility, drug use, and the Internet are important subjects for young people, with or without cancer. The cultural context of youth changes faster than any other age group, and clinicians who care JOURNAL OF CLINICAL ONCOLOGY O V E R V I E W VOLUME 28 NUMBER 32 NOVEMBER 1