SAGE: Semantic Anchor-Guided Evolution for Grounded Medical QA Data Synthesis

Chuan Li, Chengyu Wang, Cen Chen, Ye Lyu, Mingyuan Fan, Ming Gao


Abstract
Developing reliable models for clinical tasks, such as Medical Question Answering (QA), is severely constrained by the limited availability of high-quality, expert-annotated training data. This challenge is exacerbated by stringent privacy requirements and the impracticality of utilizing large open-source corpora or proprietary cloud APIs within resource-limited clinical settings. To address these obstacles, we introduce SAGE (Semantic Anchor-Guided Evolution), a novel data synthesis framework that enables small, locally deployed models to generate high-quality medical training data. SAGE leverages lightweight, publicly available taxonomies such as MeSH as semantic anchors, imposing a structured prior to effectively guide and ground the data generation process. At its core, SAGE iteratively interleaves atomic (individual concept-based) and associative (relation-based) synthesis, bootstrapping training data from minimal seeds. This approach eliminates the need for large collections of medical documents or reliance on external APIs, providing a practical solution for on-premises data creation. Extensive experiments across multiple medical question-answering benchmarks demonstrate that models fine-tuned with SAGE-synthesized data consistently outperform those trained using self-derived or conventional document-based paradigms, highlighting tangible improvements in data efficiency and resource utilization for medical LLM development.
Anthology ID:
2026.emnlp-main.176
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
4027–4046
Language:
URL:
https://aclanthology.org/2026.emnlp-main.176/
DOI:
Bibkey:
Cite (ACL):
Chuan Li, Chengyu Wang, Cen Chen, Ye Lyu, Mingyuan Fan, and Ming Gao. 2026. SAGE: Semantic Anchor-Guided Evolution for Grounded Medical QA Data Synthesis. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 4027–4046, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SAGE: Semantic Anchor-Guided Evolution for Grounded Medical QA Data Synthesis (Li et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.176.pdf