From frailty to decision: impact of comprehensive geriatric assessment on surgical planning and outcomes in older adults with gastrointestinal malignancies

Background: Frailty is a major determinant of postoperative morbidity, functional decline, and survival in older adults with cancer, yet it is not consistently integrated into oncologic surgical decision-making. Comprehensive geriatric assessment (CGA) provides a multidimensional evaluation of physiological reserve, functional status, and patient priorities; but, its influence on treatment planning and survival in surgical oncology remains incompletely defined. Methods: We conducted a retrospective cohort study of adults aged ≥65 years referred for preoperative CGA between 2020 and 2023 at a dedicated geriatric surgery clinic within a large academic center. Patients were stratified by frailty status and CGA-derived clinical recommendation: Fit for Treatment, Prehabilitation & Surgery, or Other Intervention. Primary outcomes were modification of the initial treatment plan and overall survival. Associations were evaluated using multivariable logistic regression and Cox proportional hazards models. Results: Among 273 patients (median age 82 years; 42% female), treatment plans were modified in 21%, with modification rates increasing by frailty severity (non-frail 10%, mild-moderate 31%, severe 65%; p<0.001). Both frailty status and CGA recommendation independently predicted treatment-plan modification. Overall, 64% of patients underwent surgery, with marked variation by recommendation (Fit for Treatment 78%, Prehabilitation & Surgery 70%, Other Intervention 18%; p<0.001). Survival differed by frailty status (p=0.012) and CGA recommendation (p=0.008). In multivariable analysis, CGA recommendation was the strongest independent predictor of mortality, whereas frailty category was not independently associated with survival. Conclusion: CGA-derived recommendations substantially influenced surgical oncology treatment selection and were independently associated with survival, providing prognostic information beyond frailty status alone. Integrating CGA into preoperative surgical oncology workflows may support individualized, goal-concordant decision-making and help avoid potentially non-beneficial surgery in older adults with cancer.