The Index sAGP is Valuable for Distinguishing Atypical Hepatocellular Carcinoma from Atypical Benign Focal Hepatic Lesions

Abstract

Purpose: The differential diagnosis of atypical hepatocellular carcinoma (aHCC) and atypical benign focal hepatic lesions (aBFHL) usually depends on pathology. This study aimed to develop non-invasive approaches based on conventional blood indicators for the differential diagnosis of aHCC and aBFHL.

Patients and methods: Hospitalized patients with pathologically confirmed focal hepatic lesions and their clinical data were retrospectively collected, in which patients with HCC with serum alpha-fetoprotein (AFP) levels of ≤200 ng/mL and atypical imaging features were designated as the aHCC group (n = 224), and patients with benign focal hepatic lesions without typical imaging features were designated as the aBFHL group (n = 178). The performance of indexes (both previously reported and newly constructed) derived from conventional blood indicators by four mathematical operations in distinguishing aHCC and aBFHL was evaluated using the receiver operating characteristic (ROC) curve and diagnostic validity metrics.

Results: Among ten previously reported derived indexes related to HCC, the index GPR, the ratio of γ-glutamyltransferase (GGT) to platelet (PLT), showed the best performance in distinguishing aHCC from aBFHL with the area under ROC curve (AUROC) of 0.853 (95% CI 0.814-0.892), but the other indexes were of little value (AUROCs from 0.531 to 0.700). A new derived index, sAGP [(standardized AFP + standardized GGT)/standardized PLT], was developed and exhibited AUROCs of 0.905, 0.894, 0.891, 0.925, and 0.862 in differentiating overall, BCLC stage 0/A, TNM stage I, small, and AFP-negative aHCC from aBFHL, respectively.

Conclusion: The sAGP index is an efficient, simple, and practical metric for the non-invasive differentiation of aHCC from aBFHL.

Keywords: atypical hepatocellular carcinoma; conventional blood indicator; derived index; differential diagnosis; sAGP.

Figure 1

Flowchart of patient selection.

Figure 2

Receiver operating characteristic curves of derived indexes reported previously for the diagnosis of atypical hepatocellular carcinoma. (A) Inflammation-related derived indexes; (B) Liver function-related derived indexes.

Figure 3

Diagnostic performance of sAGP, AGP, GPR, and AFP in differentiating atypical hepatocellular carcinoma from atypical benign focal hepatic lesion. (A) Receiver operating characteristic curves; (B) Diagnostic validity metrics.

Figure 4

Receiver operating characteristic curves and diagnostic validity metrics of sAGP in the diagnosis of aHCC subgroups. (A) Early BCLC stage (0/A) aHCC vs aBFHL; (B) Early TNM stage (I) aHCC vs aBFHL; (C) Small aHCC (tumor diameter < 3 cm) vs aBFHL; (D) AFP-negative aHCC (AFP < 20 ng/mL) vs aBFHL.