Serum Proteomic Profile Based on the TGF‐β Pathway Stratifies Risk of Hepatocellular Carcinoma

Background Hepatocellular carcinoma (HCC) is the third leading cause of cancer‐related deaths, primarily due to late‐stage diagnosis. In this multicenter study, our goal is to identify functional biomarkers that stratify the risk of HCC in patients with cirrhosis (CP) for early diagnosis. Methods Five thousand and eight serum proteins (Somascan) were analysed in Cohort A (477 CP, including 125 HCC). Clustering analysis of the TGF‐β pathway‐associated protein signature was performed in a longitudinal, prospective Cohort B (312 CP, in which 18 cases developed HCC over a 5‐year follow‐up period). Next, a multivariable prediction model was built using logistic regression analysis of cross‐sectional data from a matched subgroup ( n = 328, Cohort C). Model performance was 10‐fold cross‐validated across the entire Cohort A ( n = 477). Results Longitudinal follow‐up analysis revealed that patients with elevated TGF‐β‐related protein signature displayed a five‐fold increased risk of developing HCC (9.68% vs. 1.91%). Compared to cirrhosis, serum MSTN, TGFBR2, and AFP levels raised in HCC were validated by ELISA ( n = 200, odds ratio = 1.4–2.9, p < 0.05). In Cohort C, 88 proteins were significantly altered in HCC compared to cirrhosis ( p < 0.05). The six‐protein panel (TGFBR2, MSTN, AFP, COL18A1, GLUL, TP63) displayed a strong performance in the matched cohort C (AUC 0.87, sensitivity 0.88, specificity 0.72), alongside four clinical factors (Age, Sex, BMI, Bilirubin). A 10‐fold cross‐validation demonstrated a mean AUC of 0.86 in cohort A, with strong predictive power in obese/MASLD/ALD‐related patients (AUCs: 0.862–0.921). Conclusions The mechanism‐based panel effectively stratifies HCC risk in cirrhotic patients, underscoring the need for Phase II/III validation.