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.

[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.

Investigation of a Novel S-1 Administration Schedule for Treating Metastatic and Recurrent Breast Cancer (KBCOG13).

BACKGROUND/AIM: S-1, a 5-fluorouracil(5-FU) oral anti-cancer drug, has been traditionally used with a schedule of 4-week oral administration followed by 2-week rest for breast cancer treatment. We, herein, aimed to investigate the clinical efficacy and safety of a schedule of 2-week oral administration followed by 1-week rest for patients with metastatic breast cancer. PATIENTS AND METHODS: We enrolled patients with HER2-negative metastatic breast cancer who had not received prior chemotherapy. S-1 was administered consecutively for 2-weeks followed by a 1-week rest. RESULTS: Between September 1, 2013 and August 31, 2016, 32 patients were enrolled. The median follow-up time was 32.1 months. The median progression-free survival (PFS) was 9.4 months. Overall survival (OS) was 41.0 months, time to treatment failure (TTF) was 7.8 months, response rate (RR) was 31.3%, and disease control rate (DCR) was 78.1%. The incidence of grade 3 side-effects was not high. CONCLUSION: The 3-week schedule of S-1 can be considered useful as a treatment for patients with metastatic breast cancer, helping in maintaining a high quality of life.

Safety and Relative Dose Intensity of Dose-dense Doxorubicin and Cyclophosphamide Followed by Dose-dense Paclitaxel.

BACKGROUND/AIM: Dose-dense doxorubicin and cyclophosphamide (ddAC) followed by dose-dense paclitaxel (ddP) (ddAC-P) has improved disease-free survival of patients with breast cancer. The aim of this study was to evaluate the safety and relative dose intensity (RDI) of ddAC-P administered together with pegfilgrastim. PATIENTS AND METHODS: Between May 2015 and Aug 2017, 44 patients were retrospectively reviewed; they were administered 4 cycles of ddAC, followed by 4 cycles of ddP. Pegfilgrastim (3.6 mg) was administered in every cycle. RESULTS: The mean RDIs for ddAC-P, ddAC, and ddP were 95.0%, 94.5%, and 93.3%, respectively. The prevalence of high RDIs (≥85%) for ddAC-P, ddAC, and ddP was 90.9%, 84.1%, and 88.6%, respectively. Seven of the 10 patients with low RDIs experienced grade 1 or 2 fever. CONCLUSION: DdAC-P administered together with pegfilgrastim (3.6 mg) appears to be feasible and maintains RDI in most of Japanese patients with breast cancer. Rapid evaluation and proper management of fever may prevent low RDI.

Patient preference study comparing hypofractionated versus conventionally fractionated whole-breast irradiation after breast-conserving surgery.

OBJECTIVE: To compare patient preferences and acute adverse events of hypofractionated (HF) and conventionally fractionated (CF) whole-breast irradiation (WBI) after breast-conserving surgery in our institution. METHODS: We conducted a patient preference study comparing CF-WBI (50 Gy/25 fractions) and HF-WBI (41.6 Gy/16 fractions) after breast-conserving surgery. Eligible patients selected either type of fractionation following an explanation from the radiation oncologist. In this report, we analyzed the selection rate and acute toxicities. RESULTS: Between June 2009 and December 2013, 348 patients (349 breasts) were identified as eligible for the study. Among them, 259 patients (260 breasts [74.5%]) selected CF-WBI and 89 patients (89 breasts [25.5%]) selected HF-WBI. Factors significantly associated with the selection of HF-WBI were older age (P = 0.028) and no adjuvant chemotherapy (P = 0.041). Regarding acute adverse events, Grade 2 (G2) or higher radiation dermatitis was less frequently observed in HF-WBI than in CF-WBI (13.8% vs. 29.4%; P = 0.004). In addition, G2 or higher breast pain was only observed in the CF-WBI group (6.9%; P = 0.012). There were no significant differences in the presence of fatigue, wound pain or radiation pneumonitis of G2 or higher between the groups. CONCLUSIONS: In this study, in which patients themselves selected the irradiation method, more patients tended to select CF-WBI. The frequency of G2 or higher dermatitis and breast pain was significantly lower in the HF-WBI group than in the CF-WBI group. Our results support the evidence for recommending HF-WBI after breast-conserving surgery while presenting aspects of patient preferences.

[A case of locally advanced and metastatic breast cancer successfully treated with combination therapy of paclitaxel and bevacizumab].

The patient was a 53-year-old woman with a large left breast tumor. Triple-negative breast cancer with bilateral axillary lymph-node metastasis and bone metastasis was diagnosed. The primary treatment consisted of chemotherapy with a combination of paclitaxel(PTX 80mg/m 2)and bevacizumab(Bev 10 mg/kg). After chemotherapy, the tumor shrunk and showed an obvious decrease in size, eventually disappearing. After therapy, an ulcer was detected on the left breast, and mastectomy and axillary lymph node dissection were performed. The patient's postoperative course was uneventful and she has been receiving chemotherapy at our outpatient clinic. Thus, combination therapy with PTX and Bev may be useful for the local control of advanced breast cancer.