Clinical and epidemiological profile and overall survival by age-adjusted Charlson Comorbidity Index in patients aged 80 years or older receiving cancer care in São Paulo, Brazil.

Abstract

e13766 Background: In daily oncology practice, caring for people aged ≥ 80 years often means balancing tumor control with comorbidity, functional reserve, and supportive needs. Because treatment decisions are frequently made under time pressure and with incomplete geriatric information, simple bedside tools can be helpful. We assessed whether the age-adjusted Charlson Comorbidity Index (ACCI) helps identify patients with different overall survival (OS). Methods: Retrospective cohort at a tertiary cancer center in São Bernardo do Campo (São Paulo, Brazil). We included patients diagnosed with cancer at age ≥ 80 years from Jan 2022 to Jan 2024. Data included demographics, tumor site, clinical stage and metastatic status at diagnosis, ECOG performance status, polypharmacy (≥ 5 chronic medications), palliative care follow-up, and ACCI. Patients were grouped as ACCI < 11 versus ≥ 11. OS was estimated by Kaplan–Meier, compared with log-rank, and assessed with Cox proportional hazards regression. Results: We analyzed 203 patients (mean age 84.2±3.2 years; 53.7% male). The most frequent tumors were prostate (17.7%), breast (16.3%), colon (12.8%), rectum (11.3%), and lung (5.9%). Stage distribution was I 10.3%, II 42.9%, III 23.2%, and IV 23.6%; metastases at diagnosis were present in 19.7%. Polypharmacy occurred in 38.4% and palliative care follow-up in 26.1%. ACCI ≥ 11 was present in 47 patients (23.2%). Male sex was more frequent in ACCI ≥ 11 (63.8% vs 50.6%), while tumor-site distribution was similar across ACCI groups (p > 0.05). Compared with ACCI < 11 (n = 156), ACCI ≥ 11 was associated with ECOG 3–4 (27.7% vs 11.5%; p = 0.011), stage IV disease (78.7% vs 7.1%; p < 0.001), metastatic presentation (68.1% vs 5.1%; p < 0.001), and palliative care follow-up (44.7% vs 20.5%; p = 0.002). Polypharmacy was higher in ACCI ≥ 11 (48.9% vs 35.3%) without statistical significance (p = 0.129). During follow-up, 80 deaths occurred (39.4%). Median OS was 94.8 months for ACCI < 11 and 18.0 months for ACCI ≥ 11 (log-rank p < 0.001). In Cox models, ACCI ≥11 increased mortality (HR 2.81, 95%CI 1.80–4.40), and each 1-point increase in ACCI increased mortality risk (HR 1.28, 95%CI 1.16–1.41). Conclusions: Among patients aged ≥ 80 years, higher ACCI marked a clinically vulnerable subgroup with worse performance status, more advanced disease, and substantially shorter OS. Beyond prognosis, this profile can guide conversations about goals of care, intensity of anticancer therapy, and follow-up planning. As a quick score derived from routine history, ACCI may complement geriatric assessment and support earlier supportive and palliative care when appropriate.