{
  "abstract": "BACKGROUNDThe prescribing of adjuvant chemotherapy for patients with breast cancer must balance the survival benefit against treatment-related toxicities. TAILORx, a phase 3 randomized clinical trial, demonstrated that endocrine therapy alone was, on average, noninferior to chemoendocrine therapy for patients classified as intermediate risk by a 21-gene Recurrence Score (RS) assay. Uncertainty remains about the optimal strategy to identify which intermediate-RS individuals derive benefit from chemotherapy.\n\nMETHODSWe analyzed 6735 patients from the TAILORx trial using Ataraxis Breast CTX with pathology images (H&E slides) and RS available. CTX is an AI model which integrates morphologic features extracted from H&E-stained slides with clinical variables to generate individualized predictions of prognosis (CTX-prognostic) and chemotherapy benefit (CTX-benefit). No data from TAILORx were used to train CTX and CTX was not retrained or recalibrated for this study. Analyses were prespecified in a protocol approved by ECOG-ACRIN.\n\nRESULTSAmong patients treated with endocrine therapy alone, CTX-prognostic predicted disease-free interval (DFI), with a hazard ratio per 1 SD increase of 1.651 (95% CI, 1.511-1.803, p < 0.001) and C-index of 0.736 (95% CI, 0.697-0.770). Performance was similar in patients treated with chemoendocrine therapy (hazard ratio = 1.642 [95% CI, 1.495-1.804, p < 0.001], C-index = 0.720 [95% CI, 0.681-0.756]). After adjusting for the RS, CTX-prognostic remained significantly associated with DFI in both treatment groups. In the intermediate-RS subgroup, the treatment-by-biomarker interaction for CTX-benefit was significant (p = 0.016), with patients identified as high-benefit deriving a 5.6% increase in observed 5-year DFI rates from the addition of chemotherapy, compared with no detectable benefit in low-benefit patients. Stratifying the same subgroup by RS at a threshold selecting a similar proportion of patients yielded no significant interaction (p = 0.20).\n\nCONCLUSIONSIn an analysis of TAILORx, CTX-prognostic stratified patients according to their risk of recurrence. Among intermediate-RS patients, CTX-benefit identified who derived clinically meaningful benefit from adjuvant chemotherapy, a population currently not identifiable by the RS alone.",
  "abstract_shown": true,
  "affiliations": [
    "NYU Langone Laura and Isaac Perlmutter Cancer Center New York, NY United States"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 17,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "N. Chan"
    },
    {
      "name": "C. Tang"
    },
    {
      "name": "D. Biswas"
    },
    {
      "name": "J. Park"
    },
    {
      "name": "K. Zeng"
    },
    {
      "name": "J. Cappadona"
    },
    {
      "name": "C. Liu"
    },
    {
      "name": "A. McMclean"
    },
    {
      "name": "J. Berrevoets"
    },
    {
      "name": "L. Bao"
    },
    {
      "name": "B. Machura"
    },
    {
      "name": "R. J. Gray"
    },
    {
      "name": "V. Wang"
    },
    {
      "name": "J. Witowski"
    },
    {
      "name": "K. J. Geras"
    },
    {
      "name": "J. A. Sparano"
    },
    {
      "name": "TAILORx Investigators"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/asv4qqrc0ehdp.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.12.26362500",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.09.12.26362500v1.full",
  "id": "asv4qqrc0ehdp",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.09.12.26362500v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "oncology"
    ],
    [
      "openalex",
      "1306|Breast Cancer Treatment Studies"
    ]
  ],
  "openalex": "W7213785714",
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.09.12.26362500v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-12",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/asv4qqrc0ehdp.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:58Z",
      "native_id": "10.64898/2026.09.12.26362500",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.09.12.26362500v2"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "medrxiv:oncology",
      "subfield": "oncology"
    }
  ],
  "title": "An AI Model Identifies Chemotherapy Benefit in Node-Negative HR+/HER2- Breast Cancer Patients from TAILORx, a Phase 3 Randomized Clinical Trial",
  "title_text": "An AI Model Identifies Chemotherapy Benefit in Node-Negative HR+/HER2- Breast Cancer Patients from TAILORx, a Phase 3 Randomized Clinical Trial",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:11Z",
  "url": "https://research.draconitic.com/paper/asv4qqrc0ehdp",
  "venue": "medRxiv",
  "versions": []
}