Clinical Trials of Carbon Ion Radiotherapy for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

Our institute conducted a clinical trial of curative partial breast irradiation using carbon ion radiotherapy (CIRT) to patients with stage 0 and I breast cancer since 2013. The purpose of this report is to evaluate treatment outcomes up to now.

MATERIALS/METHODS

To date, we have conducted three clinical trials and one advanced medical treatment (NIRS 9404 Comprehensive Research). The first study (UMIN000010848: commonly known as Breast I trial) was 4-split irradiation for stage I low-risk patients aged 60 years or older, and the next clinical study (UMIN000029478: commonly known as Breast II trial) was for Tis-1N0M0 cases of 2 cm or less. On the other hand, 4-split irradiation using standard adjuvant drug therapy according to risk combined with whole breast irradiation by X-ray, the latest clinical trial (UMIN000046859: commonly known as Breast III trial) is a single irradiation for Tis-1N0M0 patients aged 50 years or older. be. In each phase I, the dose increase test was performed, and in phase II, treatment was performed with the recommended dose determined in phase I. Advanced medical care was provided in parallel with breast I for stage I breast cancer that was difficult or rejected to participate in breast I trial.

RESULTS

By January 2023, 60 cases were enrolled. A total of 19 were enrolled In Breast I, 7 in Phase I, 12 in Phase II of the recommended dose of 60.0 Gy (RBE). A total of 14 were enrolled in the 9404 Comprehensive Research. A total of 17 were enrolled In Breast II, 5 cases in Phase I, 12 cases in Phase II of recommended dose 60.0 Gy (RBE). A total of 10 were enrolled in Breast III, 6 cases in Phase I, and 4 in Phase II of recommended dose 50.0 Gy (RBE). As acute adverse events, grade 2 of acute radiation dermatitis were observed in 1 case, grade 1 of acute radiation dermatitis was observed in 31 cases, and grade 1 of mastitis was observed in 6 cases. As a late adverse event, grade 3 of pneumonia of unknown causality were observed in one case, but there were no other problematic adverse events, and breast cosmetic outcome was excellent in all cases. Tumor disappearance after CIRT took 3 to 24 months. Local recurrence and axillary lymph node metastasis were observed in one high-risk case of advanced medical treatment who refused any other therapy. Two cases had ipsilateral intramammary metachronous breast cancer with different subtypes. To date, no other recurrences or metastases have been observed.

CONCLUSION

CIRT for early-stage breast cancer is expected to be effective with mild adverse events, and it is considered meaningful to continue research.

Orally administered low-molecular weight agaro-oligosaccharides are absorbed into the plasma of healthy humans

Agaro-oligosaccharides (AOSs) are known to have biological activities, such as anti-inflammatory, anti-tumor, and anti-obesity effects. Although existing evidence suggests the presence of AOSs in peripheral tissues after oral administration, whether AOSs permeate into the blood circulation remains unknown. Thus, we hypothesized that AOSs with low-molecular weight can permeate the human gastrointestinal tract. To test this hypothesis, the time course of absorption was examined by analyzing plasma samples before and 1, 2, and 4 h after ingestion. Analysis was performed using liquid chromatography/mass spectrometry after labeling with p-aminobenzoic ethyl ester. Our results showed that the plasma concentration of agarobiose (Abi) was higher than that of agarotetraose (Ate); however, agarohexaose was not detected. Additionally, plasma levels of Abi and Ate were proportional to the dose. These results suggest that permeation efficiency is dependent on the molecular weight and that the systemic absorption of Abi via the gastrointestinal tract is better than that of Ate. These findings will contribute to a better understanding of the bioactivity of orally administered AOSs in peripheral tissues.

Significance of Hypofractionated Radiotherapy in Postoperative Irradiation for Breast Cancer: An Asian Multi-institutional Prospective Study

AIMS

There is a need for the adequate distribution of healthcare resources in Southeast Asia. Many countries in the region have more patients with advanced breast cancer who are eligible for postmastectomy radiotherapy (PMRT). Therefore, it is critical that hypofractionated PMRT is effective in most of these patients. This study investigated the significance of postoperative hypofractionated radiotherapy in patients with breast cancer, including advanced breast cancer, in these countries.

MATERIALS AND METHODS

Eighteen facilities in 10 Asian countries participated in this prospective, interventional, single-arm study. The study included two independent regimens: hypofractionated whole-breast irradiation (WBI) for patients who had undergone breast-conserving surgery and hypofractionated PMRT for patients who had undergone total mastectomy at a dose of 43.2 Gy in 16 fractions. In the hypofractionated WBI group, patients with high-grade factors received additional 8.1 Gy boost irradiation sessions for the tumour bed in three fractions.

RESULTS

Between February 2013 and October 2019, 227 and 222 patients were enrolled in the hypofractionated WBI and hypofractionated PMRT groups, respectively. The median follow-up periods in the hypofractionated WBI and hypofractionated PMRT groups were 61 and 60 months, respectively. The 5-year locoregional control rates were 98.9% (95% confidence interval 97.4-100.0) and 96.3% (95% confidence interval 93.2-99.4) in the hypofractionated WBI and hypofractionated PMRT groups, respectively. Regarding adverse events, grade 3 acute dermatitis was observed in 2.2% and 4.9% of patients in the hypofractionated WBI and hypofractionated PMRT groups, respectively. However, no other adverse events were observed.

CONCLUSION

Although further follow-up is required, hypofractionated radiotherapy regimens for postoperative patients with breast cancer in East and Southeast Asian countries are effective and safe. In particular, the proven efficacy of hypofractionated PMRT indicates that more patients with advanced breast cancer can receive appropriate care in these countries. Hypofractionated WBI and hypofractionated PMRT are reasonable approaches that can contain cancer care costs in these countries. Long-term observation is required to validate our findings.

Intestinal permeability of agaro-oligosaccharides: Transport across Caco-2 cell monolayers and pharmacokinetics in rats

Agaro-oligosaccharides (AOSs), even-numbered oligosaccharides prepared from agar, are applied to various food, including supplements, drinks, and jellies because of their biological activities. This study aimed to evaluate the AOS permeation in the gastrointestinal tract in vivo and in vitro. Agarobiose (Abi), agarotetraose (Ate), and agarohexaose (Ahe) were detected in rat plasma after oral administration of AOSs. The detection level of agarobiose in the plasma was higher than that of agarohexaose, which was consistent with the permeation study using Caco-2 cell monolayers. Further, the adenosine triphosphate inhibitor (sodium azide) or endocytosis inhibitor (colchicine) did not inhibit AOS permeation through Caco-2 cell monolayers. Conversely, AOS permeation enhanced upon treatment with cytochalasin B, a tight junction disrupter, suggesting that AOSs might have passed mainly through the tight junctions between the intestinal epithelial cells. These results indicate that AOSs, especially agarobiose, can be absorbed as an intact form via the gastrointestinal tract across the intestinal epithelium through the paracellular pathway.

Relationship between Disease Avoidance and Attitudes toward Older People

Negative attitudes toward older people persist, leading to the neglect and marginalization of older adults’ will. The social group of older people is often perceived as being overly associated with disease, and disease avoidance is related to negative attitudes. Meanwhile, people with higher disease avoidance tend to avoid others, not just older adults. Therefore, whether disease avoidance and attitudes toward older people have a significant relationship should be examined, even after controlling for attitudes toward general others (i.e., younger people) and other personality determinants of social interactions (i.e., extroversion, general trust). We conducted an online survey of Japanese participants (n = 962). The results showed that the relationship between higher disease avoidance and ageist attitudes was significant, even after controlling for the above variables. Psychological interventions that weaken the cognitive link between older adults and disease would effectively reduce ageism. The limitations and future directions of this study are discussed.

Methylnigakinone content determination and geographical origin discrimination for P. quassioides via fluorescence fingerprint and principal component analyses

Picrasma quassioides is used as a bittersweet stomach medicine. Because it is a natural product obtained from various geographical regions, the production area is important when P. quassioides is used as a crude drug. Herein, we developed a method to determine the content of methylnigakinone, one of the major active ingredients in P. quassioides, and a protocol for discriminating the geographical origin of this natural product using a fluorescence fingerprint analysis and principal component analysis (PCA). Because methylnigakinone is fluorescent (excitation wavelength: 352 nm, emission wavelength: 458 nm), the content of this molecule can be determined in the concentration range of 0.1-1 μg/mL. The quantification results of methylnigakinone obtained using the developed method were similar to those obtained from an HPLC analysis. Furthermore, the PCA of the fluorescence fingerprint of P. quassioides produced a score plot with the three different geographical origins (Kyushu island (Japan), Shikoku island (Japan), and China) plotted in the regions. Thus, it was possible to discriminate the geographical origin of the P. quassioides samples. The developed method is simple, quick, and has a minimal environmental impact. Therefore, the developed method will be useful for confirming the origin of P. quassioides.

Detection of micro-RNA by a combination of nucleic acid sequence-based amplification and a novel chemiluminescent pyrophosphate assay

Micro-RNA has attracted much attention as a biomarker for disease progression and malignancy. A compact, simple, rapid, and highly sensitive method is required to perform simple genetic analyses, such as point-of-care testing (POCT), at the clinic or bedside. Nucleic acid sequence-based amplification (NASBA) is a specific amplification method for a single-stranded RNA fragment that is useful for the highly sensitive detection of miRNAs. In this work, we developed a novel miRNA analytical system for POCT by combining the NASBA and chemiluminescence methods. Because the NASBA reaction is conducted at a constant temperature (41 °C) and detection by chemiluminescence reaction does not require a light source, these methods could be combined to amplify 100 ng/assay miRNA. This combined miRNA detection method could be useful for the future development of compact POCT systems.

Simple and Rapid Evaluation of the Unique Manuka Factor in Manuka Honey Using Fluorescence Fingerprints and Principal Component Analysis

The excellent antibacterial activity of manuka honey has been well-documented and is often evaluated according to the unique manuka factor (UMF) index. UMF is determined by an assay based on a bacterial culture, which is time-consuming and does not allow for quantitative analysis. This study developed a simple and rapid method for UMF evaluation using fluorescence fingerprints, principal component analysis (PCA), and partial least squares (PLS) regression. Manuka honey samples were diluted four times with water and fluorescence was observed at three wavelength combinations, namely 260-300 (excitation; ex) to 370 (emission; em) nm, 340 (ex) to 480 nm (em), and 440 (ex) to 520 nm (em), that are mainly attributed to lepteridine, leptosperin, 2-methoxybenzoic acid, and N-methyl phenazinium. Analyzing fluorescence fingerprints using PCA and PLS regression provided a reliable evaluation of the UMF in manuka honey and could be used to differentiate between manufacturers.

Trimethylammonium modification of a polymer-coated monolith column for rapid and simultaneous analysis of nanomedicines

Drug-containing nanoparticles (nanomedicine) are ideal targeted-drug-delivery systems. However, methods for the simultaneous analysis of the drug within the nanoparticle and free drug in a short time are rather limited. In this study, we developed a polymer-modified monolithic column with cationic groups (trimethylammonium) for the simultaneous analysis of the drug within the nanoparticle and the free drug. The use of the acrylamide group was determined as the optimum connecting group, and the optimum concentration of the modifier was 6%. The prepared column retained the drug within the nanoparticle by anion exchange, and its elution time was controlled by the ionic concentration (tris(hydroxymethyl)aminomethane, Tris) of the mobile phase. The separation of two typical nanomedicines was studied on the prepared column. For DOXIL and Abraxane, the drugs within the nanoparticle were well separated from the free drugs, on the developed column. The developed polymer-coated monolithic column with trimethylammonium modification is expected to enable the rapid analysis of various nanomedicines.

A Simple and Easy Method of Monitoring Doxorubicin Release from a Liposomal Drug Formulation in the Serum Using Fluorescence Spectroscopy

Formulation of a drug as liposomes facilitates its delivery to the disease target. Rightly, liposomes are gaining popularity in the medical field. In order for the drug to show efficacy, release of the encapsulated drug from the liposome at the target site is required. However, the release is affected by the permeability of the lipid bilayer of the liposome, and it is important to examine the effect of the surrounding environment on the permeability. In this study, we showed the usefulness of fluorescence analysis, especially fluorescence fingerprint, for a rapid and simple monitoring of release of an encapsulated anticancer drug (doxorubicin) from its liposomal formulation (DOXIL). Our result indicated that the release is accelerated by the existence of membrane permeable ions, such as tris(hydroxymethyl)aminomethane, and blood proteins like albumin. Hence, monitoring of doxorubicin release by fluorescence analysis is useful for the efficacy evaluation of DOXIL in a biomimetic environment.

Abstract OT2-02-01: A confirmation study of omitting axillary dissection in patients with breast cancer and positive sentinel nodes

Background

The omission of axillary dissection for positive sentinel-node breast cancer is considered the standard treatment for patients who undergo breast conserving surgery and radiation therapy, according to the results of ACOSOG-Z0011 and AMAROS trials. On the other hand, some surgeons still think that the surgical stress of axillary dissection is minimal, and dissection is permitted. Furthermore, Z0011 contains several problems, such as insufficient number of entry cases and lack of radiation field unity. Thus, we planned a prospective trial to confirm the safety of omitting axillary dissection in patients with breast cancer and positive sentinel nodes.

Trial design

This is a single arm, confirmation study of three medical centers. Prior to surgery, informed consent is obtained, and patients are registered primarily. After surgery, patients with 1 to 2 positive sentinel nodes, for whom axillary dissection was omitted, are finally included in this trial at final registration.

Eligibility criteria

Patients with histologically-diagnosed breast cancer, Tis–2, N0 based on a core needle biopsy, will be included in this trial. Eligible patients must be between 20 and 80 years of age, with a performance status of 0–2 and adequate organ function. They must not have undergone any prior operation, radiation therapy, chemotherapy, endocrine therapy, or immunotherapy.

Specific aims

The primary endpoint is 5-year (y) axillary recurrence rate. Secondary endpoints are 5-y overall survival, 5-y recurrence-free survival, 5-y local recurrence-free survival, the rate of upper-limb lymphedema, quality of life, and comparison of axillary recurrence rates between patients with two or more dissected nodes and those with only one positive node.

Statistical methods

The expected rate of axillary recurrence is 2.0%, and non-inferiority is defined as an axillary recurrence lesser than or equal to 5% in the axillary radiotherapy group. The sample size was calculated with a study power of 80% and type I error of 10% (two-sided). The required number of patients is estimated to be 189.

Present and target accrual

Patient accrual from the three medical centers was initiated in July 2016. We plan to enroll a total of 189 patients at final registration in this trial.

Citation Format: Jibiki N, Hirano A, Ochi T, Sakamoto A, Horiuchi K, Noguchi E, Omi Y, Ogura K, Inoue H, Kamio T, Naritaka Y, Fujibayashi M, Hiroshima K, Nagashima Y, Sakai S, Karasawa K, Okamoto T. A confirmation study of omitting axillary dissection in patients with breast cancer and positive sentinel nodes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-02-01.

Linoleic acid salt with ultrapure soft water as an antibacterial combination against dermato-pathogenic Staphylococcus spp

AIMS

Skin colonization of Staphylococcus spp. critically affects the severity of dermatitis in humans and animals. We examined different types of fatty acid salts for their antibacterial activity against Staphylococcus spp. when used in ultrapure soft water (UPSW). We also evaluated their therapeutic effect on a spontaneous canine model of dermatitis.

METHODS AND RESULTS

UPSW, in which Ca(++) and Mg(++) were replaced with Na(+) , was generated using a water softener with cation-exchange resin. Staphylococcus aureus (Staph. aureus), Staphylococcus intermedius (Staph. intermedius), and Staphylococcus pseudintermedius (Staph. pseudintermedius) were incubated with various fatty acid salts in distilled water (DW) or UPSW and the number of bacteria was counted. Among the fatty acids, oleic acid salt and linoleic acid (LA) salt reduced the number of these bacteria. Also, UPSW enhanced the antibacterial effect of LA on Staph. spp. In spontaneously developed itchy dermatitis in companion dogs, shampoo treatment with liquid soap containing 10% LA in UPSW improved skin conditions.

CONCLUSIONS

LA salt showed antibacterial activity against Staph. spp. Treatment with soap containing LA with UPSW reduced clinical conditions in dogs with dermatitis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Because colonization of Staph. spp. on the skin exacerbates dermatitis, the use of LA-containing soap in UPSW may reduce unpleasant clinical symptoms of the skin.

Development of a highly specific enzyme immunoassay for oxytocin and its use in plasma samples

Background

The peptide hormone oxytocin acts in the central nervous system and plays an important role in various complex social behaviours. We report the production of a high affinity and specificity antibody for oxytocin and its use in a highly sensitive enzyme immunoassay. Biotin that was chemically bound to oxytocin derivative containing zero to six lysines as bridge was the labelled antigen. Seven labelled antigens were used to develop a highly sensitive enzyme immunoassay.

Methods

Antioxytocin antiserum was obtained by immunization of oxytocin-bovine thyrogloblin conjugate to rabbit. Oxytocin sample was added to the second antibody-coated microtitre plate and allowed to react overnight at 4℃, then biotinylated oxytocin was added 1 h at 4℃, and horseradish peroxidase-labelled avidin was added and incubated for 1 h at room temperature. The plate was then washed. Horseradish peroxidase activity was measured by a colorimetric method using o-phenylenediamine (490 nm).

Results

The sensitivity of the enzyme immunoassay improved as the number of lysine residues increased; consequently, biotinylated oxytocin bridged with five lysines was used. A standard curve for oxytocin ranged from 1.0 to 1000 pg/assay. The detection limit of the assay was 2.36 pg, and the reproducibility was 3.6% as CV% ( n = 6). Cross-reactivity with vasopressin and vasotocin was less than 0.01%.

Conclusion

The sensitivity of the enzyme immunoassay could be improved by increasing the number of lysine residues on the biotin-labelled antigen. The proposed method is sensitive and more specific than conventional immunoassays for oxytocin and can be used to determine plasma oxytocin concentrations.