G8 geriatric score as a determinant of survival and treatment in metastatic breast cancer.

Abstract

e24121 Background: Metastatic breast cancer in elderly women remains a major therapeutic challenge, with frequent undertreatment driven by concerns about frailty and toxicity. The G8 geriatric screening score has demonstrated prognostic value in older cancer populations, but its impact on treatment strategy and survival in metastatic breast cancer is poorly defined. This study aimed to evaluate the association between baseline G8 score, treatment patterns, and survival outcomes in a real-world cohort. Methods: We conducted a retrospective descriptive and analytic cohort study including 93 women aged ≥70 years with metastatic breast cancer treated between 2018 and 2024. All patients had baseline G8 assessment and were classified as impaired (≤14) or non-impaired ( > 14). Clinical, pathological, and therapeutic data were collected. Results: A total of 93 elderly women with metastatic breast cancer were included. The median age was 76.2 years (range 70–89). Fifty-eight patients (62.4%) had a G8 score ≤14. After a median follow-up of 26 months, median PFS was 14.6 months (95% CI: 12.8–16.4) in the G8 non-impaired group compared with 7.2 months (95% CI: 6.1–8.3) in the impaired group (HR 1.89; 95% CI: 1.21–2.95; p = 0.002). Median OS was 38.5 months (95% CI: 34.1–42.9) in patients with G8 > 14 versus 18.7 months (95% CI: 16.3–21.1) in those with G8 ≤14 (HR 2.31; 95% CI: 1.42–3.75; p < 0.001). In univariate analysis, G8 impairment, ECOG performance status ≥2, triple-negative subtype, presence of visceral metastases, and non-chemotherapy first-line treatment were significantly associated with worse OS. In multivariate Cox regression, G8 impairment remained independently associated with poorer OS (HR 2.08; 95% CI: 1.27–3.41; p = 0.004), after adjustment for performance status, tumor subtype, and treatment strategy. Conclusions: The G8 geriatric screening score is an independent prognostic factor for survival and treatment tolerance in elderly women with metastatic breast cancer. Its routine use could improve risk stratification and guide personalized therapeutic strategies in this vulnerable population.