Serum small extracellular vesicle-associated snoRNA panel adds diagnostic value to CEA and CYFRA21-1 for non-small cell lung cancer: an exploratory single-center study.

Plain-language summary

Serum small extracellular vesicles were profiled for small nucleolar RNAs in a single-centre study of 240 patients with untreated non-small cell lung cancer and 205 healthy controls. A panel of four snoRNAs separated cases from controls with a cross-validated AUC of 0.924, marginally above the 0.903 achieved by the two standard serum markers CEA and CYFRA21-1. Combining all six markers performed best, reaching an AUC of 0.970 under repeated stratified cross-validation, and held up in stage 0 to II disease. Several caveats matter: the design was retrospective, exploratory and single-centre, the two groups differed substantially in age, and no individual snoRNA survived correction for multiple testing in the discovery analysis.

Key findings

• Small extracellular vesicle snoRNAs were measured in serum from 240 untreated non-small cell lung cancer patients and 205 healthy controls.
• A four-snoRNA panel reached a cross-validated AUC of 0.924, compared with 0.903 for CEA plus CYFRA21-1.
• Adding the panel to both standard markers gave the best discrimination, with an AUC of 0.970 and a Brier score of 0.064.
• Discrimination was similar in early-stage disease and in age- and sex-matched sensitivity analyses.
• Caution is warranted: the design was retrospective, exploratory and single-centre, and cases were far older than controls (62.5 versus 42.3 years).
• No snoRNA probe remained significant after false-discovery-rate correction in the discovery microarray, so the panel still needs external validation.

Why this matters for lung repair

The value of a new lung biomarker now depends less on whether it works alone than on whether it adds anything to tests already in the clinic. This study is framed around that incremental question, which is the right one, and it states its limitations explicitly. For anyone following liquid-biopsy research in the lung, it is a useful example of a vesicle-derived signal being benchmarked against standard serum markers rather than against nothing.

Original abstract

Background: Circulating small extracellular vesicle (sEV)-associated small nucleolar RNAs (snoRNAs) have emerged as candidate biomarkers because of their stability in biofluids. However, whether these molecular signals provide diagnostic information beyond established serum tumor markers remains uncertain. This study evaluated a four-snoRNA panel and investigated its incremental value when combined with carcinoembryonic antigen (CEA) and cytokeratin-19 fragment (CYFRA21-1) for NSCLC discrimination. Methods: This retrospective single-center case-control study included 240 Untreated patients with pathologically or cytologically confirmed NSCLC and 205 healthy controls. A discovery microarray was performed using RNA isolated from the sEV-enriched fraction of three NSCLC samples and three controls. Four candidate snoRNAs (AC007956.1, AC093523.1, AL358875.1, and SNORA51) were subsequently quantified by quantitative reverse-transcription PCR using ΔCt values. Logistic regression models were developed for the four-snoRNA panel, the clinical marker model (CEA plus CYFRA21-1), and the combined six-marker model. Model performance was assessed using repeated stratified 10-fold cross-validation (20 repetitions), training-fold-derived thresholds, 2,000 stratified bootstrap resamples, calibration metrics, paired DeLong comparisons, subgroup analyses, and age/sex-matched sensitivity analyses. Results: The discovery dataset contained 936 analyzable snoRNA probes. Although 134 probes showed nominal differential expression (P < 0.05), none remained significant after false-discovery-rate correction. NSCLC cases were older than controls (62.5 vs. 42.3 years; standardized mean difference, 1.73), whereas sex distributions were comparable. The four-snoRNA model achieved a cross-validated AUC of 0.924 (95% CI, 0.898-0.948), compared with 0.903 (95% CI, 0.874-0.931) for the CEA plus CYFRA21-1 model. The combined six-marker model showed the highest discrimination, with an AUC of 0.970 (95% CI, 0.955-0.983), sensitivity of 87.1%, specificity of 96.6%, calibration intercept of -0.018, calibration slope of 0.923, and Brier score of 0.064. Compared with the clinical model, the six-marker model increased AUC by 0.067 (95% CI, 0.043-0.092; paired DeLong P < 0.001). Model performance remained consistent in stage 0-II disease (AUC, 0.963; 95% CI, 0.940-0.980) and age/sex-matched analyses (AUC, 0.964; 95% CI, 0.941-0.983). No snoRNA marker retained significant associations with clinical characteristics after multiple-testing correction. Conclusions: A serum sEV-associated four-snoRNA panel showed incremental diagnostic value when combined with CEA and CYFRA21-1 in this exploratory NSCLC case-control study. The resulting six-marker model maintained discrimination during repeated internal cross-validation, including analyses restricted to early-stage disease and age/sex-matched cohorts.

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How to cite this paper

Wang Liguang, Wang Mei, Zhang Qun, Li Xinyi, Zhang Zhijun, Wang Kangyu. Serum small extracellular vesicle-associated snoRNA panel adds diagnostic value to CEA and CYFRA21-1 for non-small cell lung cancer: an exploratory single-center study.. Frontiers in oncology. 2026, 2026-09-26. DOI: 10.3389/fonc.2026.1881438

Source & verification

• Journal: Frontiers in oncology
• Published: 26 September 2026
• DOI: 10.3389/fonc.2026.1881438
• PubMed ID: 42798416
• Indexed via: pubmed
• MeSH terms: —

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