Current evidence and the potential role of proton beam therapy for hepatocellular carcinoma

Mitochondria-Targeted Icaritin Nanoparticles Induce Immunogenic Cell Death in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a highly malignant tumor that is resistant to chemotherapy and immunotherapy. Icaritin (ICT), a traditional Chinese medicine, has been reported as an immunoregulatory agent for treating advanced unresectable HCC. ICT induces mitophagy to cause immunogenic cell death (ICD); however, the poor bioavailability of ICT limits its therapeutic efficacy and clinical use. Therefore, this study aimed to assess the effect of using the poly(2-(N-oxide-N,N-diethylamino) ethyl methacrylate)-b-poly(ε-caprolactone) copolymer (OPDEA-PCL) to encapsulate ICT into nanoparticles (ICT NPs). OPDEA-PCL/ICT NPs colocalized with the mitochondria, promoting the ICD induction effect of ICT in mouse HCC H22 cells. In the H22 subcutaneous tumor model, intravenously injected OPDEA-PCL/ICT NPs quickly accumulated in the tumor and efficiently activated systemic anticancer immunogenicity through their effects on mitophagy. The resulting tumor suppression rate was 60%, which was significantly higher than that of free ICT and poly(ethylene glycol) (PEG)-PCL/ICT NPs. Furthermore, mouse survival was also prolonged by nearly 2-fold with OPDEA-PCL/ICT NPs compared with PBS. In summary, this approach provides valuable insights into improving the immunotherapeutic efficacy of ICT for HCC.

Clinical outcomes and safety of external beam radiotherapy with extensive intrahepatic targets for advanced hepatocellular carcinoma: A single institutional clinical experience

BACKGROUND

This study observed the clinical outcome of radiotherapy to extensive intrahepatic targets for advanced hepatocellular carcinoma (HCC) in a single institution.

METHODS

From September 2009 to July 2021, patients who underwent fractionated radiotherapy to a planning target volume (PTV) of over 100 ml with biological effective dose >30 Gy 10 for advanced HCC were enrolled. Overall survival (OS) and radiation-induced liver toxicity (RILD) were evaluated. RILD was defined as an increase in Child-Pugh (CP) score ≥2 or liver function tests ≥2.5 times at 3 months after the end of radiotherapy.

RESULTS

A total of 136 patients were evaluated. Eighty-nine patients had portal vein tumor thrombus (PVTT), 37 patients were in CP B stage, and the median radiation dose to PTV was 48.8 Gy 10 . The median OS was 12.3 months. The factors most affecting OS were PVTT ( P = 0.001), PTV (>500 ml, P = 0.001), incomplete coverage of the intrahepatic tumor ( P = 0.004), and CP B ( P = 0.006) in Cox regression. RILD occurred in 22.4% of the patients and was affected by PVTT ( P = 0.003), PTV ( P = 0.010), pretreatment bilirubin levels (>1.5 mg/ml, P = 0.016), and the mean normal liver dose (MNLD) (≥ EQD 2 18 Gy 3 , P = 0.021) in binary logistic regression. As the PTV was in excess of >500 ml, RILD developed in 30.2% of patients and the prognostic importance of pretreatment bilirubin levels ( P = 0.006) and the MNLD ( P = 0.014) increased.

CONCLUSIONS

As PTV is more extensive, the bilirubin level and the MNLD have to be taken into consideration for safe radiotherapy, in addition to the traditional prognostic factors.

Intrahepatic IgA complex induces polarization of cancer-associated fibroblasts to matrix phenotypes in the tumor microenvironment of HCC

BACKGROUND AND AIMS

Cancer-associated fibroblasts (CAFs) play key roles in the tumor microenvironment. IgA contributes to inflammation and dismantling antitumor immunity in the human liver. In this study, we aimed to elucidate the effects of the IgA complex on CAFs in Pil Soo Sung the tumor microenvironment of HCC.

APPROACH AND RESULTS

CAF dynamics in HCC tumor microenvironment were analyzed through single-cell RNA sequencing of HCC samples. CAFs isolated from 50 HCC samples were treated with mock or serum-derived IgA dimers in vitro. Progression-free survival of patients with advanced HCC treated with atezolizumab and bevacizumab was significantly longer in those with low serum IgA levels ( p <0.05). Single-cell analysis showed that subcluster proportions in the CAF-fibroblast activation protein-α matrix were significantly increased in patients with high serum IgA levels. Flow cytometry revealed a significant increase in the mean fluorescence intensity of fibroblast activation protein in the CD68 + cells from patients with high serum IgA levels ( p <0.001). We confirmed CD71 (IgA receptor) expression in CAFs, and IgA-treated CAFs exhibited higher programmed death-ligand 1 expression levels than those in mock-treated CAFs ( p <0.05). Coculture with CAFs attenuated the cytotoxic function of activated CD8 + T cells. Interestingly, activated CD8 + T cells cocultured with IgA-treated CAFs exhibited increased programmed death-1 expression levels than those cocultured with mock-treated CAFs ( p <0.05).

CONCLUSIONS

Intrahepatic IgA induced polarization of HCC-CAFs into more malignant matrix phenotypes and attenuates cytotoxic T-cell function. Our study highlighted their potential roles in tumor progression and immune suppression.

Dosimetric Evaluation of Beam-specific PTV and Worst-case Optimization Methods for Liver Proton Therapy

BACKGROUND/AIM

In spot-scanning proton therapy, intra-fractional anatomical changes by organ movement can lead to deterioration in dose distribution due to beam range variation. To explore a more robust treatment planning method, this study evaluated the dosimetric characteristics and robustness of two proton therapy planning methods for liver cancer.

PATIENTS AND METHODS

Two- or three-field treatment plans were created for 11 patients with hepatocellular carcinoma or metastatic liver cancer using a single-field uniform dose (SFUD) technique. The plans were optimized using either beam-specific planning target volume (BSPTV) or worst-case optimization (WCO). The target coverage for the gross tumor volume (GTV), planning target volume (PTV), and organs at risk (OAR) parameters related to toxicity were calculated from the perturbed dose distributions, considering setup and range uncertainties. Statistical analyses of the BSPTV and WCO plans were performed using the Wilcoxon signed-rank sum test (p<0.05). The calculation times for a single optimization process were also recorded and compared.

RESULTS

The robustness of the WCO plans in the worst-case scenario was significantly higher than that of the BSPTV plan in terms of GTV target coverage, prevention of maximum dose increase to the gastrointestinal tract, and the dose received by normal liver regions. However, there were no significant differences in PTV, and the calculation time required to create the WCO plan was considerably longer.

CONCLUSION

In SFUD proton therapy for liver cancer, the WCO plans required a longer optimization time but exhibited superior robustness in GTV coverage and sparing of OARs.

Comparison of Prognostic Outcomes Between Repeat Liver Resection and Particle Therapy for Patients with Recurrent Hepatocellular Carcinoma

BACKGROUND

Particle therapy (PT) as an initial hepatocellular carcinoma (HCC) treatment has been reported to be effective; however, its efficacy for the treatment of recurrent HCC remains unclear.

OBJECTIVE

This study aimed to evaluate the efficacy of PT compared with repeat liver resection for treating recurrent HCC after initial LR, with a focus on prognostic outcomes.

METHODS

Between 2005 and 2019, 89 and 49 patients underwent repeat LR and PT for recurrent HCC after initial LR, respectively. The 5-year overall survival (OS) and recurrence-free survival (RFS) were evaluated using propensity score matching. Treatment-related complications were scored using the National Institute Common Terminology Criteria for Adverse Events (CTCAE) and were compared between the repeat LR and PT groups.

RESULTS

In the entire cohort, the 5-year OS was significantly better in the repeat LR group than in the PT group (75% vs. 48%; p = 0.0003), and the 5-year RFS was comparable in both groups (22% vs. 13%; p = 0.088). Propensity score matching created 34 pairs of patients; no significant differences in the 5-year OS (65% vs. 48%; p = 0.310) and RFS (21% vs. 8%; p = 0.271) were observed between the repeat LR and PT groups. The proportion of CTCAE grade ≥3 complications was 8.8% and 5.9% in the repeat LR and PT groups, respectively (p = 0.641).

CONCLUSIONS

After initial LR, the prognosis and treatment-related complications in patients with recurrent HCC were comparable between the repeat LR and PT groups in the matched cohort; therefore, PT may remain one of the multidisciplinary treatment options for recurrent HCC.