Incidence and survival trends of cancers diagnosed in young adults (20-39 years): A population-based study.

1567 Background: Cancer in young adults (YAs; 20–39 years) is rare but its incidence is increasing globally. In The Netherlands, care for YA cancer patients is mostly dispersed, in contrast to centralized care for all pediatric cancer patients. Aim of this population-based study was to examine trends in YA cancer incidence and survival. Methods: Data from all YAs diagnosed between 1989-2015 (n = 89,675) were obtained from The Netherlands Cancer Registry. Age-standardized incidence rates with estimated annual percentage of change and five-year relative survival rates were calculated. Results: Cancer incidence in YAs increased significantly from 48 to 67 per 100,000 person years in males (1.7%) and from 78 to 97 per 100,000 person years in females (1.1%). In both males and females, significant rising incidence trends were found for melanoma (2.3%), skin (2.3%) and thyroid cancer (3.2%), CML (7.2%), Hodgkin (1.3%) and Non-Hodgkin lymphoma (0.9%). In females, the incidence of breast cancer increased (1.2%), while it decreased for lung (-1.3%) and ovarian cancer (-4.3%). In males, testicular cancer incidence increased significantly (4.1%). The most common cancers in male YAs were testicular cancer (33%), melanoma (15%), gastrointestinal cancer (8%), Non-Hodgkin and Hodgkin lymphoma (both 7%), whereas in females breast cancer (34%), melanoma (19%), gynecological (14%), thyroid and gastro-intestinal cancer (both 5%) were most frequently diagnosed. Over time, the five-year relative survival increased significantly from 72% to 85%. Survival improved for almost all tumor types, except for pediatric tumors: medulloblastoma (~60%), Ewing sarcoma (~43%) and rhabdomyosarcoma (~41%). A < 80% five-year survival rate was also found for tumors of the lung (36%), gastro-intestinal tract (61%), ALL (60%), AML (65%) and soft tissue sarcomas (77%). Conclusions: Over the last 26 years, a marked increase in the incidence of a diverse spectrum of hematological and solid malignancies, pediatric and adult-type cancers was found for YAs. Survival improved over time, however remains poor for certain tumor types. Our data underpin the importance of knowledge of tumors at YA age to guide centralization of care and clinical research.