The increasing toll of adolescent cancer incidence in the US

Abstract

Cancer incidence is rising among adolescents ("teens"). The causes of the increase are unknown but studying incidence patterns and trends may produce insights into etiology. Using data from the US National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program we described trends of cancer incidence among teens (15-19 year olds). We reviewed and summarized incidence patterns for histologic cancer groups and the most frequently diagnosed sites of cancer among teens during 2008-2012 reported by the SEER Cancer Statistics Review. We calculated annual incidence rates for the years 1975-2012 and used linear regression analysis to evaluate trends and calculate rates of change. Incidence for all sites combined increased annually by 0.67% for males and 0.62% for females during the period 1975 through 2012 -resulting in more than a 25% increase over 38 years. The biggest annual incidence increases occurred in non-Hodgkin lymphoma (NHL) (2.16% females; 1.38% males), thyroid cancer (2.12% females; 1.59% males), acute myeloid leukemia (AML) (1.73% females) and testicular cancer (1.55% males). Incidence rates for most histologic groups and sites showed steady long term increases over the 38 years of data. Despite improvements in survival, rising incidence trends mean growing numbers of young adults are undergoing painful and costly cancer treatments. A concerted research program is vital to investigate causes of steadily rising teen cancer rates.

Fig 1. Age-specific incidence rates per 100,000, all sites combined, <1–24 years, 2008-2012^a.

^aAdapted from Howlader et al. 2015, Table 2.7.

Fig 2. Histologic cancer group incidence rates, 2008–2012.

Male incidence rates are shown with blue bars and female rates are shown by red bars^a. ^aAdapted from Howlader et al. 2015, Table 32.4.

Fig 3. Annual incidence trends for all sites combined, acute lymphoid leukemia, and Non-Hodgkin lymphoma, 1975–2012, SEER 9 registries.

Annual rates are shown by connected points and the least squares regression line is shown as a straight line. Regression equations and p-values for trend are also shown. SEER 9 registries include Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, Seattle-Puget Sound, and Utah.

Fig 4. Annual incidence trends for Hodgkin lymphoma, astrocytoma, and osteosarcoma, 1975–2012, SEER 9 registries.

Annual rates are shown by connected points and the least squares regression line is shown as a straight line. Regression equations and p-values for trend are also shown. SEER 9 registries include Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, Seattle-Puget Sound, and Utah.

Fig 5. Annual incidence trends for testicular cancer, melanoma, and thyroid cancer, 1975–2012, SEER 9 registries.

Annual rates are shown by connected points and the least squares regression line is shown as a straight line. Regression equations and p-values for trend are also shown. SEER 9 registries include Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, Seattle-Puget Sound, and Utah.

Fig 6. Annual percent change for all sites combined, histologic cancer groups, and nine sites, 1975–2012.

Graphs showing annual percent change for all sites combined (large circles, labeled in all capital letters), histologic cancer groups (medium circles, labeled in all capital letters), and nine cancer sites (small circles). The 95% confidence intervals are shown as error bars extending from the markers.