["Psycho-Oncology, Volume 35, Issue 6, June 2026. ", "\nABSTRACT\n\nBackground\nMiddle‐aged and older cancer survivors experience frailty related to both age and cancer. While studies have explored the associations between risk factors and frailty in this population, there is still a gap in understanding the long‐term associations and mechanisms linking adverse childhood experiences (ACEs) to frailty in later life.\n\n\nObjective\nThis study examines the long‐term association between a social connectedness‐oriented dimension of ACEs—adverse childhood friendships—and frailty in later life among cancer survivors. Additionally, this study seeks to elucidate the mediating mechanisms by investigating the roles of social isolation in later life, as well as its offline (physical inactivity) and online (digital exclusion) components.\n\n\nMethods\nThis study analyzed a sample of 419 middle‐aged and older cancer survivors, with a mean age of 63.41 years (SD = 9.64), drawn from the 2014 and 2020 waves of the China Health and Retirement Longitudinal Study. Structural equation modeling was employed to test the proposed model. Additional multigroup analyses were conducted to examine whether the proposed associations differed by gender.\n\n\nResults\nAdverse childhood friendships exhibit a significant long‐term association with increased frailty in later life among cancer survivors. Furthermore, overall social isolation, along with its offline (physical inactivity) and online (digital exclusion) components, serves as mediating factors in this long‐term relationship. Multigroup analyses revealed no significant gender differences in the structural pathways.\n\n\nConclusions\nThe observed long‐term association underscores the importance of integrating a life‐course perspective on ACEs into intervention and care strategies for middle‐aged and older cancer survivors. Besides, addressing social isolation—both offline and online—may be considered as a potential component of comprehensive care programs.\n\n"]