Breast cancer PAINT: a first-in-human, dose-escalation study to determine the safety of Plasma Adjuvant INtra-operative Treatment in breast cancer patients

BACKGROUND

Non-thermal plasma (NTP) refers to an ionized gas composed of ions, electrons and other reactive agents. The anticancer properties of NTP have been proven in vitro and in vivo. The 10-year local recurrence risk (LRR) in breast cancer patients after breast conservation therapy (i.e., lumpectomy, typically followed by radiation therapy) is still as high as 15-20%. NTP could be used to further treat the tumor bed to reduce the LRR.

METHODS

Our primary objective is to determine the safe and tolerable dose of NTP treatment following breast cancer lumpectomy. Our secondary objectives are to assess the safety and tolerability of NTP and to assess the cosmetic effects of NTP treatment in patients with breast cancer. Our exploratory objective is to assess the impact of NTP treatment on cancerous and normal tissues. Patients are followed for up to 3 months after NTP treatment. The patients are divided into 3 groups: group A (n = 3): NTP treatment of part of the tumor bed ex vivo. Group B (n = 3): NTP treatment of part of the tumor bed in situ (all treated tissues are removed for analysis). Group C (n = 6-24): dose escalation per "3 + 3 Design" up to a maximum dose level of 3. NTP treatment of part of the tumor bed in situ (the treated parts of the tumor bed will not be excised, except for a small portion for analysis).

DISCUSSION

The safety and tolerability of treatment will be evaluated by means of dose-limiting toxicity, adverse event (AE) and serious adverse event reports; physical examinations; and laboratory safety evaluations. AEs will be coded according to CTCAE v5.0. The results will be tabulated to examine their frequency, grade, and relationship to the study treatment. The results of laboratory assessments will be evaluated similarly. The number of patients with cosmetic alterations linked to NTP treatment and the type of alteration will be assessed through quality of life questionnaires (questions about breast appearance and texture) and through photo collection. This is the first clinical trial to study the safety and tolerability of NTP in an all-breast cancer patient cohort.

TRIAL REGISTRATION

Name of the registry: ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT06222788. Date of registration: 01/15/2024. URL of trial registry record: https://clinicaltrials.gov/study/NCT06222788 .

Helium and argon cold plasma effects on the 4T1 cancer cells and a triple negative mouse model of breast cancer

Nowadays, cold atmospheric plasma (CAP) technology has developed as an innovative tool for cancer therapy. Although many studies have reported the antitumor effects of plasma in vivo and in vitro, there are many challenges, including standardization of plasma devices and treatment time for different tumors. For the first time, we aimed to evaluate and compare optimal exposure time and direction-dependent cellular effects of helium and argon plasma on the 4T1 cancer cells and a triple-negative mouse model of breast cancer. This study used two types of helium and argon plasma jet devices with different input parameters. In vitro evaluations on 4T1 cell line using the MTT assays and flow cytometry analysis demonstrate CAP-induced apoptosis in all treated groups, especially in the direct approach. These changes were concurrent with increased intracellular reactive oxygen species levels and decreased total antioxidant capacity in these cells. In vivo studies concurrent with in vitro results revealed that CAP therapy reduces tumor size, decreases Nottingham histological score, prevents weight loss, and increases the survival rate in all treated groups. These results suggest that plasma therapy may overcome the adverse effects of approved cancer therapeutic strategies and seems to be a significant issue for cancer patients in the clinical stage, alone or in combination with current therapeutic programs.

The potential of gas plasma technology for targeting breast cancer

Despite therapeutic improvements in recent years, breast cancer remains an often fatal disease. In addition, breast cancer ulceration may occur during late stages, further complicating therapeutic or palliative interventions. In the past decade, a novel technology received significant attention in the medical field: gas plasma. This topical treatment relies on the partial ionization of gases that simultaneously produce a plethora of reactive oxygen and nitrogen species (ROS/RNS). Such local ROS/RNS overload inactivates tumour cells in a non-necrotic manner and was recently identified to induce immunogenic cancer cell death (ICD). ICD promotes dendritic cell maturation and amplifies antitumour immunity capable of targeting breast cancer metastases. Gas plasma technology was also shown to provide additive toxicity in combination with radio and chemotherapy and re-sensitized drug-resistant breast cancer cells. This work outlines the assets of gas plasma technology as a novel tool for targeting breast cancer by summarizing the action of plasma devices, the roles of ROS, signalling pathways, modes of cell death, combination therapies and immunological consequences of gas plasma exposure in breast cancer cells in vitro, in vivo, and in patient-derived microtissues ex vivo.

ROS Pleiotropy in Melanoma and Local Therapy with Physical Modalities

Metabolic energy production naturally generates unwanted products such as reactive oxygen species (ROS), causing oxidative damage. Oxidative damage has been linked to several pathologies, including diabetes, premature aging, neurodegenerative diseases, and cancer. ROS were therefore originally anticipated as an imperative evil, a product of an imperfect system. More recently, however, the role of ROS in signaling and tumor treatment is increasingly acknowledged. This review addresses the main types, sources, and pathways of ROS in melanoma by linking their pleiotropic roles in antioxidant and oxidant regulation, hypoxia, metabolism, and cell death. In addition, the implications of ROS in various physical therapy modalities targeting melanoma, such as radiotherapy, electrochemotherapy, hyperthermia, photodynamic therapy, and medical gas plasma, are also discussed. By including ROS in the main picture of melanoma skin cancer and as an integral part of cancer therapies, a greater understanding of melanoma cell biology is presented, which ultimately may elucidate additional clues on targeting therapy resistance of this most deadly form of skin cancer.

Antitumor Effects in Gas Plasma-Treated Patient-Derived Microtissues—An Adjuvant Therapy for Ulcerating Breast Cancer?

Despite global research and continuous improvement in therapy, cancer remains a challenging disease globally, substantiating the need for new treatment avenues. Medical gas plasma technology has emerged as a promising approach in oncology in the last years. Several investigations have provided evidence of an antitumor action in vitro and in vivo, including our recent work on plasma-mediated reduction of breast cancer in mice. However, studies of gas plasma exposure on patient-derived tumors with their distinct microenvironment (TME) are scarce. To this end, we here investigated patient-derived breast cancer tissue after gas plasma-treated ex vivo. The tissues were disjoint to pieces smaller than 100 µm, embedded in collagen, and incubated for several days. The viability of the breast cancer tissue clusters and their outgrowth into their gel microenvironment declined with plasma treatment. This was associated with caspase 3-dependent apoptotic cell death, paralleled by an increased expression of the anti-metastatic adhesion molecule epithelial (E)-cadherin. Multiplex chemokine/cytokine analysis revealed a marked decline in the release of the interleukins 6 and 8 (IL-6, IL-8) and monocyte-chemoattractant-protein 1 (MCP) known to promote a cancer-promoting milieu in the TME. In summary, we provide here, for the first time, evidence of a beneficial activity of gas plasma exposure on human patient-derived breast cancer tissue.