Overview
- Stanford-led research in Nature Aging found older mice developed substantially fewer, smaller, and less-aggressive lung tumors than young mice.
- Fifteen weeks after tumor induction, younger mice had about three times the overall lung cancer burden and roughly triple the tumor count compared with older mice.
- Using genetically engineered, KRAS-driven lung cancers triggered by an inhaled gene-delivery system, researchers compared 4–6 month-old mice with 20–22 month-old animals.
- Inactivation of the tumor suppressor PTEN promoted tumors far more strongly in young mice, indicating mutation effects can depend on host age.
- The findings align with epidemiology showing cancer incidence plateaus or declines after about 85 years, though the authors caution that clinical relevance for humans remains uncertain and call for wider use of aged animal models.