Therapeutic response to a novel enzyme-targeting radiosensitization treatment (Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas) in patients with recurrent breast cancer

Radiosensitization treatment using hydrogen peroxide for inoperable rectal cancer

The treatment outcomes of patients with unresectable rectal cancer are complex, and concurrent chemoradiation therapy is the main treatment option. Radiosensitizers can enhance the effect of localized intratumoral hypoxia, contributing to local control and symptomatic relief. The present study evaluated the feasibility and safety of radiosensitization using hydrogen peroxide combined with radiation therapy (RT) in patients with unresectable rectal cancer. A total of 13 patients with rectal cancer were recruited in the present study. Radiosensitization was performed twice weekly in combination with RT. Gauze soaked in 3% hydrogen peroxide solution was inserted into the anus, ensuring firm contact with the lesion. In total, 45-65 Gy was delivered in 25-33 fractions to the whole pelvis from four directions using 10 MV X-rays 5 days per week. Acute and late adverse events were evaluated 1 and 6 months after the completion of RT. Treatment was well tolerated, with no acute grade 3 or worse events noted, and no patient developed rectal fistula, necrosis, obstruction, perforation, stenosis, ulcer or retroperitoneal hemorrhage. No notable late adverse events, beyond 6 months, were observed at the end of the analysis. All patients experienced pain relief, hemostatic effects and tumor shrinkage. Therefore, the use of a hydrogen peroxide solution-soaked gauze in the rectum may be a promising option for patients with inoperable rectal tumors. The limitations of the present study are that the patient population was small and the observation time was relatively short. This study was retrospectively registered with the University Hospital Medical Information Network Center (trial registration no. R000061902) on April 21, 2024.

New enzyme-targeting radiosensitizer (KORTUC II) treatment for locally advanced or recurrent breast cancer

Kochi oxydol radiation therapy for unresectable carcinomas II (KORTUC II) is currently the most widely used radiosensitizer in Japan. This sensitizer is a solution consisting of 0.83% sodium hyaluronate and 0.5% hydrogen peroxide. The mixture is injected intratumorally just before radiation therapy (RT) several times. KORTUC II has the effect of neutralizing antioxidant enzymes, while increasing the oxygen tension into the tumor tissue, and achieves marked local effects without notable adverse events. The present report describes cases in which KORTUC II was used to treat patients with locally advanced breast cancer (LABC) or recurrent breast cancer (LRBC). The present study included 30 patients with LABC (n=9) or LRBC (n=21) aimed at local control of tumors, who were followed up for ≥3 months after treatment. The irradiation dose and extent fields were determined by the attending physicians considering various patient factors, such as a performance status, prognosis and presence or absence of adjuvant therapy. The median irradiation dose was 60.4 Gy3.5 (43.6-76.1 Gy3.5) based on the calculation of equivalents of 2 Gy fractions, and the median total number of sensitizer injections was 5 (2-7) times. The median maximum tumor shrinkage was 97.0% and 15 patients (50%) were assessed to have achieved a clinical complete response. The proportion with loco-regional control at 1, 2 and 3 years was 100, 94.7 and 75.4%, respectively, and progression free survival after RT at 1 and 2 years was 59.0 and 24.1%, respectively. KORTUC II exhibited high rates of local tumor control for LABC and LRBC. KORTUC II is expected to be an inexpensive and promising RT method because it is safe and has an excellent radio-sensitizing effect.

Radiosensitization using hydrogen peroxide in patients with cervical cancer

The purpose of the present study was to analyze the feasibility and safety of radiosensitization using hydrogen peroxide for cervical cancer. In superficial tumors, breast cancer and hepatocellular carcinoma, the safety and effectiveness of radiosensitization has been reported; to the best of our knowledge, however, there are no reports on cervical cancer. A total of 20 patients with cervical cancer were recruited. Inclusion criteria were as follows: Patients who required radical external beam radiotherapy (RT); ineligible for or refused brachytherapy; age, ≥20 years; no hematogenous metastasis; Eastern Cooperative Oncology Group Performance Status up to 2; and had not undergone prior treatment. Hydrogen peroxide was used twice a week in combination with RT. A 3% hydrogen peroxide solution-soaked gauze was inserted into the vagina during RT. A total of 45 Gy was delivered in 25 fractions to the whole pelvis with a boost of 10 Gy in 5 fractions if pelvic or para-aortic metastatic lymph nodes were observed. Ultimately, 18 patients were evaluated. Among the 17 patients (excluding one patient with tumor in situ), the one- and two-year overall survival rates were both 90% in patients with stage I/II and 86% in stage III/IV cervical cancer. The adverse events were well tolerated with no severe acute or late adverse events. Although limited by small sample size, short observation time and low radiation dose, the present study demonstrated that radiosensitization treatment may be an option for patients who cannot undergo brachytherapy. The study was retrospectively registered at the university hospital medical information network center (no. UMIN000039045) on January 6, 2020.

The Effects of Hydrogen Peroxide and/or Radiation on the Survival of Clinically Relevant Radioresistant Cells

BACKGROUND

Radiation therapy is a highly cost-effective treatment for cancer, but the existence of radio-resistant cells remains the most critical obstacle in radiotherapy. We have been established clinically relevant radioresistant (CRR) cell lines by exposure to a stepwise increase of fractionated X-rays. We are trying to overcome the radio-resistance by analyzing the properties of these cells. In this study, we tried to evaluate the effects of hydrogen peroxide (H₂O₂) on the CRR cells because this can evaluate the efficacy of Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas (KORTUC) that treats H₂O₂ before irradiation. We also established H₂O₂-resistant cells to compare the radiation and H₂O₂ resistant phenotype.

MATERIALS AND METHODS

We used human cancer cell lines derived from hepatoblastoma (HepG2), oral squamous cell carcinoma (SAS), and cervical cancer (HeLa). We established HepG2, SAS, and HeLa CRR cells and HepG2, SAS, and HeLa H₂O₂-resistant cells. To evaluate their sensitivity to radiation or H₂O₂, high-density survival assay, or WST assay was performed. CellROX^TM was used to detect intracellular Reactive Oxygen Species (ROS).

RESULTS

CRR cells were resistant to H₂O₂-induced cell death but H₂O₂-resistant cells were not resistant to irradiation. This phenotype of CRR cells was irreversible. The intracellular ROS was increased in parental cells after H₂O₂ treatment for 3 h, but in CRR cells, no significant increase was observed.

CONCLUSION

Fractionated X-ray exposure induces H₂O₂ resistance in CRR cells. Therefore, it is necessary to carry out cancer therapy such as KORTUC with the presence of these resistant cells in mind, and as the next stage, it would be necessary to investigate the appearance rate of these cells immediately and take countermeasures.

Intratumoral Hydrogen Peroxide With Radiation Therapy in Locally Advanced Breast Cancer: Results From a Phase 1 Clinical Trial

PURPOSE

Hydrogen peroxide (H2O2) plays a vital role in normal cellular processes but at supraphysiological concentrations causes oxidative stress and cytotoxicity, a property that is potentially exploitable for the treatment of cancer in combination with radiation therapy (RT). We report the first phase 1 trial testing the safety and tolerability of intratumoral H2O2 + external beam RT as a novel combination in patients with breast cancer and exploratory plasma marker analyses investigating possible mechanisms of action.

METHODS AND MATERIALS

Twelve patients with breast tumors ≥3 cm (surgically or medically inoperable) received intratumoral H2O2 with either 36 Gy in 6 twice-weekly fractions (n = 6) or 49.5 Gy in 18 daily fractions (n = 6) to the whole breast ± locoregional lymph nodes in a single-center, nonrandomized study. H2O2 was mixed in 1% sodium hyaluronate gel (final H2O2 concentration 0.5%) before administration to slow drug release and minimize local discomfort. The mixture was injected intratumorally under ultrasound guidance twice weekly 1 hour before RT. The primary endpoint was patient-reported maximum intratumoral pain intensity before and 24 hours postinjection. Secondary endpoints included grade ≥3 skin toxicity and tumor response by ultrasound. Blood samples were collected before, during, and at the end of treatment for cell-death and immune marker analysis.

RESULTS

Compliance with H2O2 and RT was 100%. Five of 12 patients reported moderate pain after injection (grade 2 Common Terminology Criteria for Adverse Events v4.02) with median duration 60 minutes (interquartile range, 20-120 minutes). Skin toxicity was comparable to RT alone, with maintained partial/complete tumor response relative to baseline in 11 of 12 patients at last follow-up (median 12 months). Blood marker analysis highlighted significant associations of TRAIL, IL-1β, IL-4, and MIP-1α with tumor response.

CONCLUSIONS

Intratumoral H2O2 with RT is well tolerated with no additional toxicity compared with RT alone. If efficacy is confirmed in a randomized phase 2 trial, the approach has potential as a cost-effective radiation response enhancer in multiple cancer types in which locoregional control after RT alone remains poor.

Oxidative stress: therapeutic approaches for cervical cancer treatment

Oxidative stress results from an imbalance between the generation and elimination of oxidant species. This condition may result in DNA, RNA and protein damage, leading to the accumulation of genetic alterations that can favor malignant transformation. Persistent infection with high-risk human papillomavirus types is associated with inflammatory responses and reactive oxygen species production. In this context, oxidative stress, chronic inflammation and high-risk human papillomavirus can act in a synergistic manner. To counteract the harmful effects of oxidant species, protective molecules, known as antioxidant defenses, are produced by cells to maintain redox homeostasis. In recent years, the use of natural antioxidants as therapeutic strategies for cancer treatment has attracted the attention of the scientific community. This review discusses specific molecules and mechanisms that can act against or together with oxidative stress, presenting alternatives for cervical cancer prevention and treatment.

Therapeutic results of a novel enzyme-targeting radiosensitization treatment, Kochi oxydol-radiation therapy for unresectable carcinomas II, in patients with stage I primary breast cancer

Linac-based stereotactic radiotherapy has little effect on the majority of advanced neoplasms. Therefore, the novel radiosensitizer Kochi oxydol-radiation therapy for unresectable carcinomas (KORTUC) II, which contains hydrogen peroxide and sodium hyaluronate, was developed. The effectiveness of KORTUC II for the treatment of chemotherapy-resistant supraclavicular lymph node metastases, recurrent breast cancer and stage IV primary breast cancer has previously been demonstrated. The present study evaluated the safety and efficacy of KORTUC II for patients with stage I primary breast cancer. A total of 15 patients (age range, 40–76 years) were enrolled. The injection of 3 ml of KORTUC II agent was initiated from the sixth radiotherapy fraction and was performed twice a week, under ultrasonographic guidance. The therapeutic effects were evaluated by PET-CT and/or MRI examinations prior to and following KORTUC II treatment. All patients exhibited complete responses and the overall survival rate was 100% after a follow-up period of five years. The mean duration of follow-up at the end of March 2015 was 53 months. Based on these results, KORTUC II treatment exhibited marked therapeutic effects with satisfactory treatment outcomes and an acceptable extent of adverse events.

Therapeutic response to a novel enzyme-targeting radiosensitization treatment (KORTUC II) for residual lesions in patients with stage IV primary breast cancer, following induction chemotherapy with epirubicin and cyclophosphamide or taxane

Linac-based radiotherapy has a negligible effect on the majority of advanced neoplasms. Therefore, a novel radiosensitization treatment Kochi Oxydol Radiation Therapy for Unresectable Carcinomas II (KORTUC II), which utilizes hydrogen peroxide and sodium hyaluronate was developed. The effectiveness of KORTUC II for the treatment of chemotherapy-resistant supraclavicular lymph node metastases and recurrent breast cancers has previously been demonstrated. The present study evaluated the safety and efficacy of KORTUC II in patients with stage IV primary breast cancer. Seven patients (age range, 36–65 years) were enrolled. All patients received induction chemotherapy prior to KORTUC II treatment and underwent positron emission tomography-computed tomography (PET-CT) examinations prior to and 2–7 months following KORTUC II treatment, and every six months thereafter where possible. The radiotherapy regimen (x-ray irradiation) was 2.75 gray (Gy)/fraction, 5 fractions/week for 16–18 fractions with a total radiation dose of 44–49.5 Gy. Administration of the KORTUC II agent (3–6 ml: 3 ml for a lesion <3 cm in diameter and 6 ml for a lesion ≥3 cm) was initiated from the sixth radiotherapy fraction, and was conducted twice a week under ultrasonographic guidance. The therapeutic effects were evaluated by PET-CT examinations prior to and following KORTUC II treatment. Of the seven lesions from the seven patients, five exhibited complete responses, two exhibited partial responses and none exhibited stable disease or progressive disease. The overall survival rate was determined to be 100% at 1 and 86% at 2 years post-treatment. The mean duration of follow-up by December 2014 was 51 months. The results of the PET-CT studies indicated that KORTUC II treatment demonstrated marked therapeutic effects with satisfactory treatment outcomes and acceptable adverse effects.

Computed Tomography Demonstration of the Production and Distribution of Oxygen Gas Following Intratumoral Injection of a New Radiosensitizer (KORTUC) for Patients with Breast Cancer-Is Intratumoral Injection Not an Ideal Approach to Solve the Major Problem of Tumor Hypoxia in Radiotherapy?

We previously developed a new enzyme-targeting radiosensitization treatment named Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II), which contains hydrogen peroxide and sodium hyaluronate for injection into various types of tumors. For breast cancer treatment, the radiosensitization agent was injected into the tumor tissue twice a week under ultrasonographic guidance, immediately prior to each administration of radiation therapy. At approximately three hours after the second or third injection, computed tomography (CT) was performed to confirm the production and distribution of oxygen gas generated from the KORTUC radiosensitization agent by catalysis of peroxidases contained mainly in tumor tissue. The purpose of this study was to demonstrate that tumor hypoxia could be overcome by such a procedure and to evaluate the method of intratumoral injection in terms of confirming oxygen distribution in the target tumor tissue and around the tumor to be visualized on dedicated CT imaging. Three-dimensional reconstructed maximum intensity projection imaging of contrast-enhanced breast magnetic resonance imaging was used to compare the position of the tumor and that of the generated oxygen. Distributed oxygen gas was confirmed in the tumor tissue and around it in all 10 patients examined in the study. A region of oxygen gas was measured as an average value of −457.2 Hounsfield units (HU) as a region of interest. A slightly increased HU value compared to the density of air or oxygen was considered due to the presence of tumor tissue in the low-density area on 5-mm-thick reconstructed CT imaging. The results of this study showed that intratumoral oxygen was successfully produced by intratumoral KORTUC injection under ultrasonographic guidance, and that tumor hypoxia, which is considered a main cause of radioresistance in currently used Linac (linear accelerator) radiation therapy for malignant neoplasms, could be resolved by this method.