Imaging features of primary hepatic sarcomatoid carcinoma: Differentiation from hepatocellular carcinoma and intrahepatic cholangiocarcinoma on CT: A preliminary study

Purpose

Primary hepatic sarcomatoid carcinoma (PHSC) is a rare type of malignant tumor in the liver. Nevertheless, few studies have focused on the imaging diagnosis of PHSC. In this study, we collected clinical and computed tomography (CT) imaging data of PHSC from two institutions, aiming to investigate the clinical and radiological characteristics of PHSC.

Methods

We retrospectively investigated the clinical characteristics and CT features of 22 PHSC patients (19 males and 3 females; mean age, 63.4 years; range, 49 to 76 years), 95 hepatocellular carcinoma (HCC) patients and 50 intrahepatic cholangiocarcinoma (ICC) patients. Two radiologists independently evaluated the CT features of the three groups. Subsequently, we analyzed the differences in the clinical characteristics and CT features between the PHSC and control groups.

Results

Most PHSCs were larger than 5 cm (72.7%). PHSC mainly showed irregular (81.8%), heterogeneous (100%) masses with ill-defined (72.7%) borders with necrosis (86.4%) on CT, which are more common CT features versus HCC (p < 0.001). In the arterial phase, PHSC always showed noticeable heterogeneous enhancement (100.0%), mainly manifesting as partial arterial phase hyperenhancement (APHE) (86.4%). The enhancement patterns of PHSC mainly included delayed progressive enhancement (72.7%), nonperipheral washout (22.7%), and unclassified enhancement (4.5%), which were significantly different from the HCC enhancement pattern but similar to the enhancement pattern of ICC. In addition, vein tumor thrombus (18.2%), intrahepatic metastasis (27.3%), and lymphadenopathy (27.3%) were relatively common in PHSC. Furthermore, most PHSC tumors classified as LR-M (66.7%) were similar to ICC.

Conclusions

PHSC generally presents as irregularly large masses with necrosis, intrahepatic metastasis, and lymphadenopathy. The CT enhancement of PHSC is mainly part of APHE and delayed progressive enhancement.

Enhancement of antitumor effect by peptide vaccine therapy in combination with anti-CD4 antibody: Study in a murine model

Purpose

The clinical efficacy of cancer peptide vaccine therapy is insufficient. To enhance the anti-tumor effect of peptide vaccine therapy, we combined this therapy with an anti-CD4 mAb (GK1.5), which is known to deplete CD4⁺ cells, including regulatory T cells (Tregs).

Methods

To determine the treatment schedule, the number of lymphocyte subsets in the peripheral blood of mice was traced by flow cytometry after administration of anti-CD4 mAb. The ovalbumin (OVA)_257–264 peptide vaccine was injected intradermally and anti-CD4 mAb was administered intraperitoneally into C57BL/6 mice at different schedules. We evaluated the enhancement of OVA peptide-specific cytotoxic T lymphocyte (CTL) induction in the combination therapy using the ELISPOT assay, CD107a assay, and cytokine assay. We then examined the in vivo metastasis inhibitory effect by OVA peptide vaccine therapy in combination with anti-CD4 mAb against OVA-expressing thymoma (EG7) in a murine liver metastatic model.

Results

We showed that peptide-specific CTL induction was enhanced by the peptide vaccine in combination with anti-CD4 mAb and that the optimized treatment schedule had the strongest induction effect of peptide-specific CTLs using an IFN-γ ELISPOT assay. We also confirmed that the CD107a⁺ cells secreted perforin and granzyme B and the amount of IL-2 and TNF produced by these CTLs increased when the peptide vaccine was combined with anti-CD4 mAb. Furthermore, metastasis was inhibited by peptide vaccines in combination with anti-CD4 mAb compared to peptide vaccine alone in a murine liver metastatic model.

Conclusion

The use of anti-CD4 mAb in combination with the OVA peptide vaccine therapy increased the number of peptide-specific CTLs and showed a higher therapeutic effect against OVA-expressing tumors. The combination with anti-CD4 mAb may provide a new cancer vaccine strategy.

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Peptide-specific CTL induction and function were enhanced by depletion of CD4⁺ cells.

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Anti-tumor effect by the peptide vaccine was enhanced by the depletion of CD4⁺ cells.

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Metastasis was inhibited by vaccine with depletion of CD4⁺ cells in a murine model.

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Combination with the depletion of CD4⁺ cells could be a new cancer vaccine strategy.