Development and internal validation of the ABC score for overall survival prediction in cancer patients aged 80 years and older
- 1Department of Academic Studies and Research in Hematology and Oncology (DEPAHOn), Centro Universitário FMABC, São Paulo, Brazil
Abstract
Background: Individuals aged over 80 years (the “oldest-old”) represent the fastest-growing demographic in clinical oncology. While the Age-Adjusted Charlson Comorbidity Index (ACCI) is a traditional benchmark for multimorbidity, its predictive accuracy in the ultra-elderly may be limited by competing risks of death and the physiological burden of active malignancy.
Objective: To evaluate the prognostic utility of the ACCI and to develop and internally validate a streamlined stratification tool, the ABC Score, for octogenarian cancer patients.
Methods: We conducted a retrospective cohort study of 203 patients aged ≥ 80 years, first evaluated between 2022 and 2024 at a Brazilian public institution. Overall survival (OS) was analysed using Cox proportional-hazards models. Variables significant at p < 0.20 in univariate screening were entered into a multivariable model with backward elimination to derive a points-based score from the β coefficients. Discrimination was assessed by Harrell’s C-index and internally validated by bootstrap resampling with optimism correction; calibration was assessed at 6, 12, and 24 months.
Results: Over a median follow-up of 30.5 months, 80 deaths (39.4%) occurred among 203 patients. The ACCI was significant in univariate analysis (HR = 1.28, p < 0.001) but lost independent prognostic value after adjustment (p = 0.30). Independent predictors were ECOG performance status, clinical stage, and chronic pulmonary disease. The ABC Score had an apparent C-index of 0.778 and an optimism-corrected C-index of 0.771 (95% CI 0.721–0.825) after bootstrap validation, with excellent calibration at 6, 12, and 24 months. Three risk tiers stratified survival (log-rank p < 0.001).
Conclusion: The ABC Score is a promising, pragmatic exploratory tool that prioritises functional and respiratory reserve over aggregate comorbidity counts; it requires external, multicentre validation before clinical use.
Related
- Development and internal validation of a pretreatment magnetic resonance imaging-based radiomics prediction model for 1-year overall survival in treatment-naïve patients with hepatocellular carcinoma receiving transarterial chemoembolization combined with targeted therapy and immune checkpoint inhibitors.
- Development and internal validation of a prognostic model for cancer-specific survival in elderly patients with metastatic non-small cell lung cancer: a SEER-based study
- Development and internal validation of a nomogram for predicting short- and long-term overall survival in patients with breast cancer liver metastasis: a SEER-based prognostic study
- Development and internal validation of a clinical prediction model for postoperative venous thromboembolism after neurosurgical intervention in patients with traumatic brain injury
- Development and Internal Validation of a Preintubation Prediction Model for Postintubation Hypotension in Trauma Patients Undergoing Emergency Endotracheal Intubation: A Retrospective Cohort Study
BibTeX
@article{nascimento2026development,
title = {{Development and internal validation of the ABC score for overall survival prediction in cancer patients aged 80 years and older}},
author = {Gustavo Henrique Barboza Nascimento and Luiz Vinicius de Alcantara Sousa and Daniel Iracema Gomes Cubero and Daniele Evaristo Vieira Alves and Janine Capobiango Martins and Auro Del Giglio},
journal = {BMC Cancer},
year = {2026},
month = aug,
doi = {10.1186/s12885-026-16627-6},
url = {https://doi.org/10.1186/s12885-026-16627-6},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Development and internal validation of the ABC score for overall survival prediction in cancer patients aged 80 years and older
AU - Gustavo Henrique Barboza Nascimento
AU - Luiz Vinicius de Alcantara Sousa
AU - Daniel Iracema Gomes Cubero
AU - Daniele Evaristo Vieira Alves
AU - Janine Capobiango Martins
AU - Auro Del Giglio
PY - 2026
DA - 2026/08/07
JO - BMC Cancer
DO - 10.1186/s12885-026-16627-6
UR - https://doi.org/10.1186/s12885-026-16627-6
AB - Background: Individuals aged over 80 years (the “oldest-old”) represent the fastest-growing demographic in clinical oncology. While the Age-Adjusted Charlson Comorbidity Index (ACCI) is a traditional benchmark for multimorbidity, its predictive accuracy in the ultra-elderly may be limited by competing risks of death and the physiological burden of active malignancy. Objective: To evaluate the prognostic utility of the ACCI and to develop and internally validate a streamlined stratification tool, the ABC Score, for octogenarian cancer patients. Methods: We conducted a retrospective cohort study of 203 patients aged ≥ 80 years, first evaluated between 2022 and 2024 at a Brazilian public institution. Overall survival (OS) was analysed using Cox proportional-hazards models. Variables significant at p < 0.20 in univariate screening were entered into a multivariable model with backward elimination to derive a points-based score from the β coefficients. Discrimination was assessed by Harrell’s C-index and internally validated by bootstrap resampling with optimism correction; calibration was assessed at 6, 12, and 24 months. Results: Over a median follow-up of 30.5 months, 80 deaths (39.4%) occurred among 203 patients. The ACCI was significant in univariate analysis (HR = 1.28, p < 0.001) but lost independent prognostic value after adjustment (p = 0.30). Independent predictors were ECOG performance status, clinical stage, and chronic pulmonary disease. The ABC Score had an apparent C-index of 0.778 and an optimism-corrected C-index of 0.771 (95% CI 0.721–0.825) after bootstrap validation, with excellent calibration at 6, 12, and 24 months. Three risk tiers stratified survival (log-rank p < 0.001). Conclusion: The ABC Score is a promising, pragmatic exploratory tool that prioritises functional and respiratory reserve over aggregate comorbidity counts; it requires external, multicentre validation before clinical use.
SN - 1471-2407
ER -