Lymphomas account for approximately 20-25% of annual cancer diagnoses in the adolescent and young adult (AYA) population, defined as ages 15–39 years. Despite continued improvements in lymphoma outcomes, AYAs have not exhibited survival gains to the same extent as other age groups. At present, this survival gap is a manifestation of many compounding factors including a lack of sufficient understanding of the tumor biology or the optimal therapeutic approaches, as well as delays in diagnosis, the supportive care needs, long‐term toxicity risk, developmental stage of the AYA, and socioeconomic factors. There is no established standard of care for AYA lymphomas, and there is significant divergence in treatment approaches between medical and pediatric oncology.
Data on the heterogeneity of lymphoid malignancies in the AYA population as compared with younger pediatric and older adult groups will be reviewed. The highest proportion (35-70%) of lymphoid malignancies are due to Hodgkin lymphoma and lymphoblastic leukemia/lymphoma, followed by diffuse large B-cell lymphoma (10%-20%). Sex, race, and ethnic differences in the AYA lymphomas are also observed. These findings suggest that AYA lymphomas are biologically distinct from those present in the pediatric and adult populations. Factors that may contribute to the observed age-based variation in disease include evolution of the immune system with age, changes in the impact of genetic susceptibility, and viral and/or environmental exposures.
There is a marked difference between the pediatric and adult approaches for AYA lymphomas. The example of AYA Hodgkin lymphoma will be reviewed. The pediatric backbone chemotherapy regimen has been doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide (ABVE-PC), whereas the adult regimen has been doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). Radiation therapy is incorporated more often in pediatric high-risk regimens and adult low-risk approaches. Because disease biology does not conform to an 18-year-old cutoff, which of these approaches is most appropriate for AYAs has not been established. Treatment approach is not standard and is often driven by the experience of the physician. Recent progress in developing collaborative clinical trials through the North American National Clinical Trials Network will be reviewed.
Citation Format: Kara Kelly. AYA lymphomas: Bridging the divide [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr IA11.