Efficacy and safety of carbon-ion radiotherapy for the malignant melanoma: A systematic review

Carbon Ions Suppress Angiogenesis and Lung Metastases in Melanoma by Targeting CXCL10

Carbon-ion radiotherapy (CIRT) enhanced local control in patients with malignant melanoma. In several in vitro studies, carbon ions (C ions) have been also shown to decrease the metastatic potential of melanoma cells. CXC motif 10 (CXCL10) has been shown to play a crucial role in regulating tumor metastasis and it significantly increase in human embryonic kidney cells after heavy ion irradiations. This study sought to explore the regulatory effect of C ions on melanoma metastasis, emphasizing the role of CXCL10 in this process. To explore the potential regulatory effect of C ions on tumor metastasis in vivo, we developed a lung metastasis mouse model by injecting B16F10 cells into the footpad and subjected all mice to treatment with X rays and C ions. Subsequently, a series of assays, including histopathological analysis, enzyme-linked immunosorbent assay, real-time PCR, and western blotting, were conducted to assess the regulatory effects of C ions on melanoma. Our results showed that mice treated with C ions exhibited significantly less tumor vascularity, enhanced tumor necrosis, alleviated lung metastasis, and experienced longer survival than X-ray irradiated mice. Moreover, VEGF expression in B16F10 cells was significantly reduced by C-ion treatment, which could be alleviated by CXCL10 knockdown in vitro. Further investigations revealed that co-culturing with HUVECs resulted in a significant inhibition of proliferation, migration, and tube formation ability in the C-ion treated group, while the opposite effect was observed in the C-ion treated with si-CXCL10 group. In conclusion, our findings demonstrate that treatment with carbon-ion radiation can suppress angiogenesis and lung metastases in melanoma by specifically targeting CXCL10. These results suggest the potential utility of carbon ions in treating melanoma.

Enhancing Immunogenicity in Metastatic Melanoma: Adjuvant Therapies to Promote the Anti-Tumor Immune Response

Advanced melanoma is an aggressive form of skin cancer characterized by low survival rates. Less than 50% of advanced melanoma patients respond to current therapies, and of those patients that do respond, many present with tumor recurrence due to resistance. The immunosuppressive tumor-immune microenvironment (TIME) remains a major obstacle in melanoma therapy. Adjuvant treatment modalities that enhance anti-tumor immune cell function are associated with improved patient response. One potential mechanism to stimulate the anti-tumor immune response is by inducing immunogenic cell death (ICD) in tumors. ICD leads to the release of damage-associated molecular patterns within the TIME, subsequently promoting antigen presentation and anti-tumor immunity. This review summarizes relevant concepts and mechanisms underlying ICD and introduces the potential of non-ablative low-intensity focused ultrasound (LOFU) as an immune-priming therapy that can be combined with ICD-inducing focal ablative therapies to promote an anti-melanoma immune response.

Basic and translational research on carbon-ion radiobiology

Carbon-ion beam irradiation (IR) has evident advantages over the conventional photon beams in treating tumors. It releases enormous amount of energy in a well-defined range with insignificant scatter in surrounding tissues based on well-localized energy deposition. Over the past 28 years, more than 14,000 patients with various types of cancer have been treated by carbon ion radiotherapy (CIRT) with promising results at QST. I have provided an overview of the basic and translational research on carbon-ion radiobiology including mechanisms underlying high linear energy transfer (LET) carbon-ion IR-induced cell death (apoptosis, autophagy, senescence, mitotic catastrophe etc.) and high radiocurability produced by carbon-ion beams in combination with DNA damaging drugs or with molecular-targeted drugs, micro-RNA therapeutics and immunotherapy. Additionally, I have focused on the application of these treatment in human cancer cells, especially cancer stem cells (CSCs). Finally, I have summarized the current studies on the application of basic carbon-ion beam IR according to the cancer types and clinical outcomes.

Carbon Ion Induces Cell Death and G2/M Arrest Through pRb/E2F1Chk2/Cdc2 Signaling Pathway in X-ray Resistant B16F10 Melanoma Cells

To explore the effect of high-LET carbon ion (C-ion) radiation on malignant melanoma, we systematically compared the radiobiological effects of C-ion with that of X-rays in B16F10 melanoma cells. Results showed that C-ion radiation statistically inhibited clonogenic survival capacity of B16F10 melanoma cells. The RBE was 3.7 at D10 levels, meaning 1.0 Gy C-ion should cause the same biological effect as ≥ 3.0 Gy X-rays. In addition, we also observed a stronger proliferation-inhibiting and higher ratio of cell apoptosis and necrosis in B16F10 cells treated with C-ion than X-rays. Moreover, C-ion radiation exhibited stronger and long-lasting G2/M arrest than X-rays. As an underlying mechanism, we speculated that C-ion radiation-induced G2/M block through activating pRb/E2F1/Chk2 pathway. With these results, we highlighted the potential of C-ion in treatment of cutaneous melanoma. Further, in vitro experiments as well as clinical trials are needed to further evaluate the effect of carbon ion radiotherapy in melanoma.

Secondary cancers after carbon-ion radiotherapy and photon beam radiotherapy for uterine cervical cancer: A comparative study

BACKGROUND

There are limited studies on the risk of secondary cancers after carbon-ion radiotherapy (CIRT). We assessed the incidence of secondary cancers in patients treated with CIRT for cervical cancer. We also evaluated the incidence of secondary cancers in patients who received standard photon radiotherapy (RT) throughout the same period.

METHODS

This retrospective study included patients with cervical cancer who underwent curative RT at our hospital. All cancers discovered for the first time after RT were classified as secondary cancers. To compare the risk of secondary cancers among cervical cancer survivors to the general population, standardized incidence ratios (SIRs) were calculated.

RESULTS

The analysis included a total of 197 and 417 patients in the CIRT and photon RT groups, respectively. The total person-years during the observation period were 1052.4 in the CIRT group and 2481.5 in the photon RT group. The SIR for all secondary cancers was 1.1 (95% confidence interval [CI], 0.6-2.1) in the CIRT group and 1.4 (95% CI, 1.0-2.1) in the photon RT group. The 10-year cumulative incidence of all secondary cancers was 9.5% (95% CI, 4.0-21.5) in the CIRT group and 9.4% (95% CI, 6.2-14.1) in the photon RT group. The CIRT and photon RT groups were not significantly different in incidence (p = 0.268).

CONCLUSIONS

The incidence of secondary cancers after CIRT for cervical cancer was similar to that after photon RT. Validation of our findings after long-term observation is warranted.

Cucurbitacin E inhibits cellular proliferation and induces apoptosis in melanoma by suppressing HSDL2 expression

BACKGROUND

Melanoma is among the most aggressive types of skin malignancy and can have an unpredictable clinical course. Exploration of novel therapeutic targets and their regulators remains essential for the prevention and treatment of melanoma.

METHODS

HSDL2 protein levels were examined by immunohistochemistry. The roles of HSDL2 in cell proliferation and apoptosis were identified by CCK-8 and colony formation assays. The function of HSDL2 in cell apoptosis was analysed by flow cytometry. Western blotting, cell proliferation and apoptosis and a xenograft tumour model were utilized to explore the inhibitory functions and mechanisms of CuE in melanoma.

RESULTS

HSDL2 is overexpressed in melanoma and promotes melanoma progression by activating the ERK and AKT pathways. CuE could inhibit the ERK and AKT pathways by decreasing HSDL2 expression; therefore, CuE could inhibit melanoma growth in vitro and in vivo.

CONCLUSION

HSDL2 may be a promising therapeutic target against melanoma, and CuE can inhibit melanoma by downregulating HSDL2 expression.

Carbon ion radiotherapy with complete tumor regression for primary malignant melanoma of female urethra orifice: a case report

Primary malignant melanoma of the female urethra (PMMFU) is extremely rare, accounting for 0.2% of all melanomas, and fewer than 200 cases have been reported worldwide. Because of the small number of clinical cases and unclear biological characteristics, there is no uniform and standard treatment protocol. We herein describe the treatment of PMMFU using carbon ion radiotherapy. The radiotherapy was delivered at 60.8 Gy (RBE) in 16 fractions, once daily, five times per week. The patient achieved complete tumor disappearance within 1 year after carbon ion radiotherapy and remained disease-free thereafter. She developed acute grade 1 radiation dermatitis and urethritis, which resolved quickly; no other toxic effects were observed. At the time of this writing, her survival duration was 33 months. This case demonstrates that carbon ion radiotherapy may be a good option for primary genitourinary mucosal malignancies.

Comparative analysis of postoperative adjuvant therapy for head and neck mucosal melanoma in China

BACKGROUND

Head and neck mucosal melanoma is a rare malignant disease with no clear and effective treatment to control the prognosis of patients.

AIM

To analyze the effects of different postoperative adjuvant treatments on the survival and prognosis of patients.

MATERIAL AND METHODS

A retrospective analysis of 163 patients which were divided into five groups: no adjuvant therapy, postoperative radiotherapy, postoperative chemotherapy, postoperative chemotherapy and radiotherapy, and postoperative immunotherapy. Kaplan-Meier method and Cox regression analysis were used to analyze the prognosis in the different groups.

RESULTS

Postoperative radiotherapy had statistically significant effects on local recurrence, distant metastasis, overall survival, progression-free survival (PFS) and recurrence-free survival (RFS); Postoperative chemotherapy and postoperative chemotherapy/radiotherapy had effects on distant metastasis, overall survival, PFS and RFS. However, postoperative immunotherapy did not show any significant effects. For patients with limited lesions who underwent endoscopic surgery, receive postoperative radiotherapy and postoperative chemotherapy/radiotherapy seem to have better prognosis.

CONCLUSIONS AND SIGNIFICANCE

For the head and neck mucosal melanoma, different types adjuvant therapy can prolong the survival of patients to varying degrees compared with no postoperative treatment, but immunotherapy as a single adjuvant therapy does not show any advantages. We recommended that patients should receive radiotherapy and/or chemotherapy after surgery.

Potential role of functional imaging in predicting outcome for patients treated with carbon ion therapy: a review

OBJECTIVE

Carbon ion radiation therapy (CIRT) is an emerging radiation technique with advantageous physical and radiobiologic properties compared to conventional radiotherapy (RT) providing better response in case of radioresistant and hypoxic tumors. Our aim is to critically review if functional imaging techniques could play a role in predicting outcome of CIRT-treated tumors, as already proven for conventional RT.

METHODS

14 studies, concerning Magnetic resonance imaging (MRI) and Positron Emission Tomography (PET), were selected after a comprehensive search on multiple electronic databases from January 2000 to March 2020.

RESULTS

MRI studies (n = 5) focused on diffusion-weighted MRI and, even though quantitative parameters were the same in all studies (apparent diffusion coefficient, ADC), results were not univocal, probably due to different imaging acquisition protocols and tumoral histology. For PET studies (n = 9), different tracers were used such as [¹⁸F]FDG and other uncommon tracers ([¹¹C]MET, [¹⁸F]FLT), with a relevant heterogeneity regarding parameters used for outcome assessment.

CONCLUSION

No conclusion can be drawn on the predictive value of functional imaging in CIRT-treated tumors. A standardization of image acquisition, multi-institutional large trials and external validations are needed in order to establish the prognostic value of functional imaging in CIRT and to guide clinical practice.

ADVANCES IN KNOWLEDGE

Emerging studies focused on functional imaging's role in predicting CIRT outcome. Due to the heterogeneity of images acquisition and studies, results are conflicting and prospective large studies with imaging standardized protocol are needed.

Toxicity of carbon ion radiotherapy and immune checkpoint inhibitors in advanced melanoma

We analyzed CTCAE adverse events of sequential Carbon Ion radiotherapy (CIRT) and immune checkpoint inhibitors (ICIs) in advanced melanoma patients. The frequencies of early and late adverse events (AEs) were 100% and 82% of patients, respectively. The frequency of G3+ AEs was in line with the literature.

The Efficacy and Safety of Carbon Ion Radiotherapy for Meningiomas: A Systematic Review and Meta-Analysis

Objective

The purpose of this systematic review and meta-analysis is to evaluate the efficacy and safety of carbon ion radiotherapy (CI-RT) in improving meningioma by comparing photon and protons radiotherapy.

Methods

A comprehensive search for relevant studies published until March 17, 2021, was conducted in PubMed, the Cochrane Library, Chinese Biomedical Literature Database and EMBASE. Statistical analyses were performed with R 4.0.3.

Results

We identified 396 studies, of which 18 studies involving 985 participants were included. Except for one low quality study, the quality of the included studies was found to be either moderate or high quality. The analyses conducted according random effects model indicated that the 1-year overall survival rate (OS) of benign and non-benign meningiomas after the CI-RT treatment was 99% (95%CL=.91-1.00, I² = 0%). The overall average 5-year OS for meningiomas was 72% (95%CL=0.52-0.86, I² = 35%), not as effective as proton radiotherapy (PR-RT) 85% (95%CL=.72-.93, I² = 73, Q=4.17, df=2, p=.12). Additionally, 5-year OS of atypical meningiomas (81%) was found to be significantly higher than anaplastic meningiomas (52%). The 10-year OS after CI-RT of patients with mixed grade meningioma was 91% (95%CL=.75-.97, I² = 73%). The 15-year OS after CI-RT 87% (95%CL=.11-1.00) or PR-RT 87% (95%CL=.23-.99, I² = 79%) were the same (Q=0, df=1, p=.99). After undergoing CI-RT for 3 and 5 years, the LC for benign meningioma was 100% and 88%, respectively, while the 2-year LC of non-benign meningiomas (atypical/anaplastic) was 33%. Headache, sensory impairment, cognitive impairment, and hearing impairment were found to be the most common adverse reactions, with individual incidences of 19.4%, 23.7%, 9.1%, and 9.1%, respectively.

Conclusion

CI-RT is a rapidly developing technique that has been proven to be an effective treatment against meningioma. The efficacy and safety of CI-RT for meningiomas were similar to those of PR-RT, better than photon radiotherapy (PH-RT). However, there is a need for more prospective trials in the future that can help provide more supportive evidence.

Efficacy and safety of carbon-ion radiotherapy for the malignant melanoma: A systematic review

Malignant melanomas (MMs) were the fifth most common cancer in men and the sixth most common cancer in women in 2018, respectively. These are characterized by high metastatic rates and poor prognoses. We systematically reviewed safety and efficacy of carbon-ion radiotherapy (CIRT) for treating MMs. Eleven studies were eligible for review, and the data showed that MM patients showed better local control with low recurrence and mild toxicities after CIRT. Survival rates were slightly higher in patients with cutaneous or uveal MMs than in those with mucosal MMs. CIRT in combination with chemotherapy produced higher progression-free survival rates than CIRT only. In younger patients, higher rates of distant metastases of gynecological MMs were observed. The data indicated that CIRT is effective and safe for treating MMs; however, a combination with systemic therapy is recommended to ensure the best possible prognosis for MMs.