Clinical manifestations and outcomes of patients with scirrhous hepatocellular carcinoma

Hypoxia-driven tumor stromal remodeling and immunosuppressive microenvironment in scirrhous HCC

BACKGROUND AND AIMS

Scirrhous HCC (SHCC) is one of the unique subtypes of HCC, characterized by abundant fibrous stroma in the tumor microenvironment. However, the molecular traits of SHCC remain unclear, which is essential to develop specialized therapeutic approaches for SHCC.

APPROACH AND RESULTS

We presented an integrative analysis containing single-cell RNA-sequencing, whole-exome sequencing, and bulk RNA-sequencing in SHCC and usual HCC samples from 134 patients to delineate genomic features, transcriptomic profiles, and stromal immune microenvironment of SHCC. Multiplexed immunofluorescence staining, flow cytometry, and functional experiments were performed for validation. Here, we identified SHCC presented with less genomic heterogeneity while possessing a unique transcriptomic profile different from usual HCC. Insulin-like growth factor 2 was significantly upregulated in SHCC tumor cells compared to usual HCC, and could serve as a potential diagnostic biomarker for SHCC. Significant tumor stromal remodeling and hypoxia were observed in SHCC with enrichment of matrix cancer-associated fibroblasts and upregulation of hypoxic pathways. Insulin-like growth factor 2 was identified as a key mediator in shaping the hypoxic stromal microenvironment of SHCC. Under this microenvironment, SHCC exhibited an immunosuppressive niche correlated to enhanced VEGFA signaling activity, where CD4 + T cells and CD8 + T cells were dysfunctional. Furthermore, we found that another hypoxic-related molecule SPP1 from SHCC tumor cells suppressed the function of dendritic cells via the SPP1-CD44 axis, which also probably hindered the activation of T cells.

CONCLUSION

We uncovered the genomic characteristics of SHCC, and revealed a hypoxia-driven tumor stroma remodeling and immunosuppressive microenvironment in SHCC.

Tumor-matrix interaction induces phenotypic switching in liver cancer cells

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is characterized by fibrous stroma and clinical behavior more aggressive than that of hepatocellular carcinoma (HCC). Scirrhous HCC is a subtype of HCC with fibrous stroma, frequently has partial cholangiocytic differentiation, and is more likely to have an aggressive behavior. This study explored the interaction of liver cancer cells with the extracellular matrix.

METHODS AND RESULTS

Liver cancer cells grown on collagen 1-coated plates showed upregulation of cholangiocytic marker expression but downregulation of hepatocytic marker expression. Three-dimensional sphere culture and Boyden chamber assay showed enhanced invasion and migration ability in collagen 1-conditioned liver cancer cells. Interaction with collagen 1 reduced liver cancer cell proliferation. RNA sequencing showed that in the liver cancer cells, collagen 1 upregulated cell cycle inhibitor expression and cell-matrix interaction, tumor migration, and angiogenesis pathways, but downregulated liver metabolic function pathways. Cholangiocytic differentiation and invasiveness induced by collagen 1 was mediated by the mitogen-activated protein kinase (MAPK) pathway, which was regulated by cell-matrix interaction-induced Src activation. Analysis of the Cancer Genome Atlas cohort showed that collagen 1 induced and suppressed genes were highly enriched in ICC and HCC, respectively. In HCC samples, collagen 1-regulated genes were strongly coexpressed and correlated with COL1A1 expression.

CONCLUSIONS

Liver cancer cell-matrix interaction induces cholangiocytic differentiation and switches liver cancer cells from a proliferative to an invasive phenotype through the Src/MAPK pathway, which may partly explain the differences in the behaviors of HCC and ICC.

Epidemiological and Clinical Characteristics of Five Rare Pathological Subtypes of Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is a highly heterogeneous tumor with several rare pathological subtypes and which is still poorly understood. This study aimed to describe the epidemiological and clinical spectrum of five rare HCC subtypes and develop a competing risk nomogram for cancer-specific survival prediction.

Methods

The study cohort was recruited from the Surveillance, Epidemiology, and End Results database. The clinicopathological data of 50,218 patients histologically diagnosed with classic HCC and five rare subtypes (ICD-O-3 Histology Code = 8170/3-8175/3) between 2004 and 2018 were reviewed. The annual percent change (APC) was calculated utilizing Joinpoint regression. The nomogram was developed based on multivariable competing risk survival analyses. Akaike information criterion, Bayesian information criterion, C-index, calibration curve, and area under the receiver operating characteristic curve were obtained to evaluate the prognostic performance. A decision curve analysis was introduced to examine the clinical value of the models.

Results

Despite scirrhous carcinoma, which showed a decreasing trend (APC = -6.8%, P = 0.025), the morbidity of other rare subtypes remained stable from 2004 to 2018. The incidence-based mortality was plateau in all subtypes during the period. Clear cell carcinoma is the most common subtype (n = 551, 1.1%), followed by subtypes of fibrolamellar (n = 241, 0.5%), scirrhous (n = 82, 0.2%), spindle cell (n = 61, 0.1%), and pleomorphic (n = 17, ~0%). The patients with fibrolamellar carcinoma were younger and more likely to have a non-cirrhotic liver and better prognoses. Scirrhous carcinoma shared almost the same macro-clinical characteristics and outcomes as the classic HCC. Clear cell carcinoma tended to occur in the Asia-Pacific elderly male population, and more than half of them were large HCC (Size>5cm). Sarcomatoid (including spindle cell and pleomorphic) carcinoma was associated with a larger tumor size, poorer differentiation, and more dismal prognoses. The pathological subtype, T stage, M stage, surgery, alpha-fetoprotein, and cancer history were confirmed as the independent predictors in patients with rare subtypes. The nomogram showed good calibration, discrimination, and net benefits in clinical practice.

Conclusion

The rare subtypes had unique clinicopathological features and biological behaviors compared with the classic HCC. Our findings could provide a valuable reference for clinicians. The constructed nomogram could predict the prognoses with good performance, which is meaningful to individualized management.

Scirrhous Hepatocellular Carcinoma: Systematic Review and Pooled Data Analysis of Clinical, Radiological, and Histopathological Features

Background

Aberrant subtypes of hepatocellular carcinoma (HCC) account for 20–30% of all HCCs and habitually present a challenge in diagnosis and treatment. Scirrhous hepatocellular carcinoma (s-HCC) is often misdiagnosed as cholangiocarcinoma, fibrolamellar hepatocellular carcinoma, or metastasis.

Methods

Electronic databases (PubMed, Web of Knowledge, Google Scholar, Cochrane Library, and WHO International Clinical Trials Registry Platform) were searched for publications on scirrhous hepatocellular carcinoma without date or language restrictions. Quality assessment was performed using a tool proposed by Murad et al for case reports and series. For observational studies, MINORS quality assessment tool was used. This study was registered at PROSPERO (CRD42020212323).

Results

S-HCC arises in patients with chronic hepatitis (hepatitis B in 60% and hepatitis C in 21%). S-HCC primarily affects men with a mean age of 55.8 years. Serum AFP is elevated above 20IU/mL in 66.7% of the patients. On ultrasound, s-HCC presents as hypoechoic or mosaic pattern lesions (47.6% each) and causes a retraction of the liver surface (70%) when near the capsule. Delayed enhancement of the tumor is evident in 87.0%. On MRI, 65.0% of s-HCCs show a target appearance. Histopathologic pattern is mostly irregular (97.6%). Lesions show a bulging appearance (100%), septae (85.6%) and a central scar (63.5%), and usually lack central necrosis (75%). Immunohistochemistry shows HepPar 1 positivity in 64.6%, CK7 in 40.7%, and EMA in 41.9%. The 5-year overall survival rate estimates 45.2% and 45.5% of the patients experience a recurrence after hepatectomy.

Conclusion

S-HCC is a rare subtype of HCC primarily arising in hepatitis- or cirrhosis-afflicted livers and incorporates atypical radiological and histopathological HCC features. Despite lower recurrence rates, overall survival of patients with s-HCC is poorer than generally for HCC, underlining the need for individualized treatment. Patients with atypical lesions of the liver should be referred to tertiary hospitals for interdisciplinary assessment and treatment.