Associations between diffusion-weighted imaging and immunohistochemical features in hepatocellular carcinoma: a preliminary analysis of tumor-infiltrating lymphocytes and microvessel density expression.

INTRODUCTION

Imaging modalities can predict histopathological characteristics of tumors such as cellularity and proliferation potential, which has also been shown for hepatocellular carcinoma (HCC). Diffusion-weighted imaging can reflect cellularity of tumors and provide apparent diffusion coefficient (ADC) values as a quantitative imaging marker. This analysis elucidates possible associations between ADC values and several immunohistochemical features of HCC.

MATERIAL AND

METHODS

A cohort of 25 patients (4 female; 16%) with a mean age of 63 ±8.9 years met the inclusion criteria of this analysis. The main inclusion criteria were the availability of an MRI pre-interventional examination within 9 months before surgery and the availability of the histopathologic analysis. Immunohistochemical features included programmed cell death-ligand 1 (PD-L1) scores (immune cell score [ICS], tumor proportion score [TPS], and combined positive score [CPS]), glypican-3, tumor-infiltrating lymphocytes (TIL), stroma infiltrating lymphocytes (SIL), CD68 positive cells and microvessel density (MVD). ADC values were measured as ADCmax, ADCmean, and ADCmin.

RESULTS

CD3+ TIL showed a moderate inverse correlation with ADCmax (r = -0.50, p = 0.01), ADCmean (r = -0.52, p = 0.008). CD34+ MVD showed higher expression in the group that showed diffusion restriction (mean 40 ±10.8 vs. 54 ±5.5, p = 0.0046). There was no correlation between ADC values and CD68+ positive cells, PDL-1, glypican-3 expression, or CD3+ SIL.

CONCLUSIONS

The present analysis demonstrated an inverse correlation between CD3-positive tumor-infiltrating lymphocytes and ADCmean and ADCmax. Diffusion restriction is correlated with increased microvessel density in HCC. ADC values could help to better characterize the tumor microenvironment of HCC in a non-invasive manner.