High Frequency of BRCA2 c.5576_5579del Carriers in Kakogawa, Japan.

Background/Aim: Certain germline pathogenic variants (PVs), known as founder mutations, have been frequently observed in specific regions and ethnic groups. In Japan, several pathogenic variants of BRCA1/2 have been identified as founder mutations, with their distribution varying across different regions. This retrospective study aimed to further investigate the detailed distribution and correlation between genotype and clinical features among breast cancer patients. Patients and Methods: This study was conducted at Kobe University Hospital and three collaborating institutions. It included breast cancer patients who underwent BRCA1/2 genetic testing between July 1, 2018, and March 31, 2021, and were found to have germline PVs. Clinical characteristics and breast cancer subtypes were compared between carriers of BRCA2 c.5576_5579del and those with other PVs. Additionally, the detection rate of BRCA2 c.5576_5579del was compared with that observed in a previous report. Results: A total of 38 breast cancer patients were included; PVs in BRCA1 and BRCA2 were detected in 12 and 26 patients, respectively, 12 of whom were BRCA2 c.5576_5579del carriers. BRCA2 c.5576_5579del carriers were more likely to develop triple negative breast cancers among all BRCA2 PV carriers. BRCA2 c.5576_5579del accounted for 30.8% of the PVs detected, with a particularly high frequency of 72.7% at Kakogawa Central City Hospital. Conclusion: BRCA2 c.5576_5579del was detected with a particularly high frequency in Hyogo Prefecture, especially in Kakogawa city. In the future, a survey of the distribution of the BRCA2 c.5576_5579del carriers may provide more clarity regarding their localization.

Target-Oriented Classification of Triple-negative Breast Cancer.

BACKGROUND/AIM: Breast cancer that is estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and human epidermal growth factor receptor-2 (HER2)-negative is termed triple-negative breast cancer (TNBC). Cytotoxic chemotherapy remains the first choice of treatment against TNBC due to lack of specific therapeutic targets. TNBC is not classified based on therapeutic targets, but recently, the development of targeted therapies - including immune checkpoint inhibitors and poly (adenosine diphosphate-ribose) polymerase inhibitors - has gained attention. This study aimed to examine a novel target-oriented TNBC classification to further facilitate targeted therapy by classifying TNBC based on the breast cancer 1 (BRCA1)-like as well as the protein expression of HER2, programmed death ligand 1 (PD-L1), androgen receptor (AR), cytokeratin 5/6, and epidermal growth factor receptor (EGFR). PATIENTS AND METHODS: We enrolled 17 patients with primary TNBC who did not receive preoperative chemotherapy and underwent surgery at the Kobe University Hospital, Japan, between January 1, 2018, and July 31, 2019. Immunohistochemical staining was performed on tumor specimens, while a BRCAness test was performed using multiplex ligation-dependent probe amplification (MLPA) analysis. A BRCAness score 0.5 or higher was considered BRCA1-like. RESULTS: Tumors were classified as HER2-low (immunohistochemistry score 1+ or 2+ and FISH negative), PD-L1 positive, AR positive, or BRCA1-like. HER2-low, PD-L1 positive, AR positive, and BRCA1-like were detected in 11 (64.7%), 4 (23.5%), 6 (35.3%), and 6 (35.3%) samples. The tumor of only one patient could not be classified into any of these categories. CONCLUSION: Almost all TNBC cases can be classified according to treatable targets.

Methionine Restriction Increases Exosome Production and Secretion in Breast Cancer Cells.

BACKGROUND/AIM: Methionine addiction is the elevated requirement for exogenous methionine for growth and survival of cancer cells, termed the Hoffman effect. Methionine-addicted cancer cells synthesize normal or excess amounts of methionine but still need an external source of methionine. Methionine restriction (MR) by either a methionine-free medium or in vivo by a low-methionine diet or by methioninase, selectively arrests cancer cells in the late S/G2 cell cycle phase, but not normal cells. The present study focuses on the comparison of production and secretion of exosomes by cancer cells under MR and normal conditions. MATERIALS AND METHODS: MDA-MB-231 cells (triple-negative breast cancer), containing exosomes labeled with CD63-GFP (CD63-GFP exosomes), were visualized by fluorescence microscopy. MDA-MB-231 cells expressing exosome-specific CD63-GFP were cultured in methionine-containing (MET+) or in methionine-free (MET-) DMEM conditions. Exosomes were isolated from conditioned medium of cultured MDA-MD-231 cells by ultracentrifugation and characterized by nanoparticle tracking analysis (NTA) and Western blotting. RESULTS: When MDA-MB-231-CD63-GFP cells were cultured under MR conditions, they arrested their growth and CD63-GFP-expressing exosomes were strongly increased in the cells. MR resulted in approximately a 2-fold increase in exosome production and secretion per cell, even though cell growth was arrested. Methionine restriction thus resulted in elevated exosome production and secretion per surviving cell. CONCLUSION: Exosome production and secretion in the cancer cells increased under MR, suggesting a relation between MR and exosome production and secretion.

A Rare Case of Bilateral Pectoralis Major Muscle Defect and Abnormal Muscle.

A 56-year-old female patient with left breast cancer presented at our hospital. Preoperative CT scan showed an isolated bilateral pectoralis major muscle defect and abnormal muscle originating from the entire sternum and inserting in the lower ribs and rectus sheath. Total mastectomy and axillary lymph node dissection were performed. We believe that this case is unique and that others like it have never been reported. If there is a defect in the pectoralis major muscle, reconstructive surgery with a tissue expander is contraindicated. Therefore, preoperative evaluation of the chest wall musculature on imaging is recommended.

Size Dependency of Selective Cellular Uptake of Epigallocatechin Gallate-modified Gold Nanoparticles for Effective Radiosensitization.

The high incidence and mortality of cancer make it a global health issue. However, conventional cancer therapies have several disadvantages, especially serious side effects due to low selective toxicity to cancer cells. Gold nanoparticles (AuNPs) are an excellent drug carrier, enhance drug delivery efficiency, and hold promise for photothermal and radiation therapies. (-)-Epigallocatechin-3-gallate (EGCG) is the major polyphenolic antioxidant constituent of green tea, has a potent antitumor effect, and binds specifically to the 67 kDa laminin receptor, which is overexpressed on the surface of several cancer cell lines such as HeLa and MDA-MB-231 cells. We synthesized EGCG-modified AuNPs (EGCG-AuNPs) using ratios (nEGCG/ngold) from 1:2 to 10:1 and evaluated their size, morphology, stability, antioxidant ability, cytotoxicity, cellular uptake, and uptake mechanisms in vitro in comparison with the conventional AuNPs prepared by using citrate as the reducing agent (citrate-AuNPs). In HeLa cells, EGCG-AuNPs (10:1) (135 nm diameter, sea-urchin-like shape) exhibited the highest cellular uptake. Conversely, EGCG-AuNPs (1:2) (39 nm diameter, spherical shape) were preferentially taken up by MDA-MB-231 cells. Cellular uptake of EGCG-AuNPs toward normal cells (NIH3T3 cells) was found to be in a nonspecific manner, and the amount of uptake was suppressed. X-ray irradiation after cellular uptake of EGCG-AuNPs (1:2) in MDA-MB-231 cells significantly enhanced irradiation-induced cell death. These findings suggest enhanced cellular uptake of EGCG-AuNPs with a 39 nm diameter and their potential use in combinatorial therapeutics of EGCG-AuNPs for breast cancer.

[A Case of Metastatic Recurrent Breast Cancer Successfully with Olaparib in Late Line Therapy].

A 44-years-old woman who underwent bilateral mastectomy was treated with chemotherapy after axillary lymph nodes and liver metastases recurrence. She was referred to our hospital for BRCA1/2 germline test and the test revealed BRCA2 pathogenic mutation. Before the administration of olaparib as the fourth-line therapy, liver dysfunction, caused by extensive liver metastasis, was observed. The liver damage improved, and tumor markers decreased immediately as shown in the blood test and CT examination results after 2 months; indicating marked reduction of liver metastasis. In the OlympiAD trial, the patients received olaparib as either the first-, second- or third-line treatment; however, few data on the efficacy of olaparib in the patients, as a late line treatment, were reported. In this article, we report a case of a woman in whom olaparib was used as the fourth-line treatment for metastatic recurrent breast cancer. A high therapeutic effect was obtained and the quality of life has been maintained in her for the past 1 year.

Oncogenic miRNAs Identified in Tear Exosomes From Metastatic Breast Cancer Patients.

BACKGROUND/AIM: Exosomes are produced by normal and cancer cells. Exosomes are found in the serum of cancer patients and have been used for diagnosis and prognosis. Recently tears from non-cancer patients have been found to contain exosomes. In the present report we describe tears from advanced breast-cancer patients. MATERIALS AND METHODS: We found oncogenic miRNAs in the exosomes isolated from tear fluids obtained from five patients with metastatic breast cancer and compared them with tear exosomes form eight healthy volunteers. RESULTS: Tear exosomes had a significantly higher quantity of exosome markers than serum exosomes (CD9, CD63). Tear exosomes were subjected to quantitative reverse-transcription polymerase reaction (qRT-PCR), and western blot analysis to elucidate the status of miRNAs, previously reported in serum from patients with metastatic breast cancer. qRT-PCR and western-blot analysis revealed that breast-cancer-specific miR-21 and miR-200c were highly expressed in tear exosomes from metastatic breast cancer patients in contrast to tear exosomes from healthy volunteers. CONCLUSION: Tear exosomes can be a potential source of diagnostic and prognostic biomarkers for metastatic breast cancer, and possibly other cancers or diseases.

[Response to neoadjuvant chemotherapy in breast cancer as assessed by subtype].

The aim of this study was to investigate the responses to neoadjuvant chemotherapy (NAC) in breast cancer according to subtype. The study included 69 women who received NAC at our hospital between January 2004 and January 2013. Complete response( CR) was achieved in 14 patients( 20.3%) and partial response( PR) was achieved in 37 patients (53.6%).CR and PR rates according to subtype were as follows: 0% and 57.1% for the luminal type, 0% and 66.7% for the luminal-human epidermal growth factor receptor (HER)-2 type, 16% and 56% for the triple negative type, and 58.8% and 41.2% for the HER2 type, respectively. The CR rate was the highest among patients with HER2-type breast cancer. Trastuzumab was additionally administered to 12 patients with HER2-type breast cancer, and the CR rate among these patients was significantly higher after trastuzumab treatment( 75%).Thus, it is important to select a treatment strategy for breast cancer on the basis of the subtype diagnosed.

[Two long-term survival cases of Stage IV colon cancer through multidisciplinary treatment].

We report the long-term survival in two cases of colon cancer through multidisciplinary treatment, including surgery. Case 1: A 67-year-old male patient underwent anterior rectal resection, partial hepatectomy(S4, S5, S5/8) and cholecystectomy for rectal cancer with liver metastasis in July 2006(pSS, pN0, sH1, sP0, sM0, Stage IV, Cur B). Liver metastasis, lung metastasis, and metastatic colon cancer occurred 5 times during the 59 months following the first operation. We performed surgery and adjuvant chemotherapy to treat each recurrence. Case 2: A 42-year-old male patient underwent sigmoidectomy for sigmoid colon cancer with multiple liver metastasis in May 2007 (pSS, pN0, sH2, sP0, sM0, Stage IV, Cur C). Recurrence occurred 7 times at the liver and lung during the 58 months after the first operation. We performed surgery and adjuvant chemotherapy to treat each recurrence.

[Three cases of sigmoid colon cancer accompanied by invagination].

Invagination in adults is rare compared to children. We experienced 3 sigmoid colon cancers in which symptoms of invagination were discovered. Because the tumors in 2 of the 3 cases could be reduced, operations were electively performed. The tumor in the remaining case could not be reduced and an urgent operation was required. Because all cases responded in the early stage, their postoperative progress was good. Invagination in adults is typically caused by an organic disease, particularly cancer. It is necessary to consider not only reduction of the invagination but also treatment of the primary disease causing invagination. It is important that the malignant symptoms be detected promptly in order to develop a suitable treatment strategy.