Exploring multidimensional cfDNA methylation fragmentomics for non-invasive postoperative assessment in early-stage lung cancer.

BACKGROUND: Effective postoperative monitoring remains an important area of investigation for early-stage lung cancer patients after curative resection. This exploratory technical feasibility study evaluated a methylation-based fragmentomics approach by analyzing paired pre- and post-operative plasma cfDNA from 10 patients. RESEARCH DESIGN AND METHODS: Paired pre- and post-operative blood samples were collected from 10 patients with early-stage lung cancer who underwent curative-intent surgical resection. cfDNA was extracted, enriched for methylated fragments, and subjected to deep sequencing. Multidimensional cfDNA features including methylated cfDNA load, fragment length distribution, GC content, and copy number variations were analyzed. RESULTS: Postoperative samples showed decreased methylated cfDNA concentration and GC content. Fragment length analysis revealed a shift from shorter (mean 164 bp) to longer fragments (mean 200 bp) after surgery, along with the emergence of a ~ 336 bp sub-peak in postoperative samples. Methylation enrichment enabled detection of copy number variations that were attenuated post-operatively. CONCLUSIONS: Multi-dimensional cfDNA analysis can detect molecular changes after surgery in this small exploratory cohort. Further validation in larger prospective cohorts with longitudinal follow-up is warranted to assess potential clinical utility.