{
  "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.\n\nObjective: 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.\n\nMethods: 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.\n\nResults: 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).\n\nConclusion: 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.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Academic Studies and Research in Hematology and Oncology (DEPAHOn), Centro Universitário FMABC, São Paulo, Brazil"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Gustavo Henrique Barboza Nascimento",
      "orcid": "0000-0003-1146-9376"
    },
    {
      "affs": [
        0
      ],
      "name": "Luiz Vinicius de Alcantara Sousa",
      "orcid": "0000-0002-6895-4914"
    },
    {
      "affs": [
        0
      ],
      "name": "Daniel Iracema Gomes Cubero",
      "orcid": "0000-0002-1936-2605"
    },
    {
      "affs": [
        0
      ],
      "name": "Daniele Evaristo Vieira Alves",
      "orcid": "0009-0007-3426-330X"
    },
    {
      "affs": [
        0
      ],
      "name": "Janine Capobiango Martins",
      "orcid": "0000-0002-3552-749X"
    },
    {
      "affs": [
        0
      ],
      "name": "Auro Del Giglio",
      "orcid": "0000-0002-2009-824X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/29q0atrs7ah4g.bib",
  "cited_by": 0,
  "doi": "10.1186/s12885-026-16627-6",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13737820/",
  "id": "29q0atrs7ah4g",
  "issns": [
    "1471-2407"
  ],
  "landing_url": "https://doi.org/10.1186/s12885-026-16627-6",
  "language": "en",
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Research"
    ],
    [
      "openalex",
      "2717|Frailty in Older Adults"
    ]
  ],
  "openalex": "W7197028010",
  "pdf_url": null,
  "pmcid": "PMC13737820",
  "pmid": "42983708",
  "published": "2026-08-07",
  "publisher": "BMC",
  "ris": "https://research.draconitic.com/paper/29q0atrs7ah4g.ris",
  "sources": [
    {
      "first_seen": "2026-11-09T12:22:55Z",
      "native_id": "PMC13737820",
      "source": "pmc",
      "url": "https://doi.org/10.1186/s12885-026-16627-6"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2717|Frailty in Older Adults",
      "subfield": "general"
    }
  ],
  "title": "Development and internal validation of the ABC score for overall survival prediction in cancer patients aged 80 years and older",
  "title_text": "Development and internal validation of the ABC score for overall survival prediction in cancer patients aged 80 years and older",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T12:22:55Z",
  "url": "https://research.draconitic.com/paper/29q0atrs7ah4g",
  "venue": "BMC Cancer",
  "versions": []
}