A new international analysis reveals an increase in six types of cancer among adults aged 20 to 49 in 42 countries, mainly linked to obesity and sedentarism. Except for colorectal cancer, these tumors are also rising in those over 50. Experts urge investigating causes and enhancing prevention.
A study published in Annals of Internal Medicine, led by researchers including Amy Berrington de Gonzalez and Montserrat García Closas, analyzes data from 42 countries between 2003 and 2017. It confirms annual increases in thyroid cancer (3.6%), kidney (2.21%), endometrium (1.66%), colorectal (1.45%), breast (0.89%), and leukemia (0.78%) incidence among young adults aged 20 to 49. These obesity-related tumors are also rising in those over 50, except colorectal, which increases faster in youth in 30% of countries.
Spain was excluded due to incomplete registries up to 2016, but Josep Tabernero from Vall d'Hebron Institute of Oncology states the trends apply: “For years we've warned of signals in certain tumors diagnosed before 50.” García Closas cautions: “If we talk of a 'global epidemic' affecting young adults exclusively, it would only refer to colorectal cancer.”
Possible causes include childhood obesity, dietary changes, sedentarism, and antibiotic use, per Tabernero. Miguel Martín points to endocrine disruptors in tumors like breast and endometrium. Conversely, incidence is falling for stomach (-1.62% annually), esophagus (-0.92%), mouth (-0.42%), and liver (-0.14%) cancers in youth across over half the countries, possibly due to reduced alcohol consumption.
Experts like Peter A. Fasching stress: “We must avoid all factors leading to needing medical advances.” Berrington suggests lowering screening ages for colorectal: “Detection can prevent it by removing polyps early.” José María Martín Moreno concludes: “These findings should not alarm us, but lead to action,” prioritizing prevention and research for all ages.