Search

The Japanese Breast Cancer Society Clinical Practice Guidelines are published as timely guidance on clinical issues in breast cancer treatment in Japan. In the recent edition of these guidelines, we addressed a new clinical question 34 (CQ 34, systemic treatment part) "Is trastuzumab deruxtecan recommended for patients with unresectable or metastatic HER2-low breast cancer?" and a new future research question 7 (FRQ 7, pathological diagnosis part) "How is HER2-low breast cancer diagnosed for the indication of trastuzumab deruxtecan?". These questions address use of trastuzumab deruxtecan in patients with unresectable or metastatic HER2-low breast cancer who have previously received chemotherapy for metastatic disease. The strengths of evidence and recommendation were determined through a quantitative and qualitative systematic review using multiple outcomes, including efficacy and safety. We conclude that trastuzumab deruxtecan is recommended for this patient population (strength of recommendation: 1; strength of evidence: moderate; CQ34) and that HER2-low expression for the indication of trastuzumab deruxtecan should be diagnosed using companion diagnostics based on appropriate criteria (FRQ7)., (© 2024. The Author(s).)

In the treatment of an intracranial aneurysm with the flow diverter, the combined use of coil embolization can help promote subsequent progressive thrombosis within the aneurysm sac and reduce the risk of delayed aneurysm rupture. This study retrospectively reviewed outcomes of patients who had undergone the Pipeline Embolization Device (PED) with adjunctive coil embolization (PED/coil) at a single center to determine its safety and efficiency. Patients with internal carotid artery aneurysms following an intradural component were selected for PED/coil between 2015 and 2020. All patients were premedicated with dual antiplatelet therapy of aspirin plus clopidogrel or prasugrel. A minimal number of PEDs were deployed, with coils inserted using a stent-jail technique, avoiding dense packing. A total of 46 aneurysms (43 patients; median dome size, 11.6 mm; median neck width, 6.3 mm) were treated with PED/coil. The median volume embolization ratio was 14.8%. The degree of angiographic filling at the 6-month and latest angiography showed complete occlusion in 60.5% (26/43) and 70.5% (31/44), respectively. Small (< 10 mm) aneurysms achieved a higher complete occlusion rate in the early period; a lower cumulative incidence of aneurysm occlusion was observed in large and giant (≥ 10 mm) aneurysms (P = .024). The median clinical follow-up was 22 months, and no aneurysm ruptures occurred. Favorable clinical outcomes were achieved, with permanent neurological morbidity of 4.7% and no mortality. PED/coil demonstrated a high angiographic occlusion rate at an early stage. Loosely packed coils are sufficient to obliterate aneurysms effectively., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: The Japan Clinical Oncology Group 1505 trial is a single-arm multicentre prospective study that examined the possibility of non-surgical follow-up with endocrine therapy for patients with low-grade ductal carcinoma in situ. In that study, the eligible criteria included histopathological findings comprising low to intermediate nuclear grade and absence of comedo necrosis, and cases were entered according to the local histopathological diagnosis. Nuclear grade is largely based on the Consensus Conference criteria (1997), whereas comedo necrosis is judged according to the Rosen's criteria (2017). The purpose of this study was to standardize and examine the interobserver agreement levels of these histopathological criteria amongst the participating pathologists., Methods: We held slide conferences, where photomicrographs of haematoxylin-eosin-stained slides from 68 patients with ductal carcinoma in situ were presented using PowerPoint. The nuclear grade and comedo necrosis statuses individually judged by the pathologists were analysed using κ statistics., Results: In the first and second sessions, where 22 cases each were presented, the interobserver agreement levels of nuclear grade whether low/intermediate grade or high grade were moderate amongst 29 and 24 participating pathologists, respectively (κ = 0.595 and 0.519, respectively). In the third session where 24 cases were presented, interobserver agreement levels of comedo necrosis or non-comedo necrosis were substantial amongst 25 participating pathologists (κ = 0.753)., Conclusion: Although the concordance rates in nuclear grade or comedo necrosis were not high in a few of the cases, we believe that these results could provide a rationale for employing the present criteria of nuclear grade and comedo necrosis in the clinical study of ductal carcinoma in situ., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The Breast Cancer Clinical Practice Guidelines, 2018 edition, written in Japanese and organized by the Japanese Breast Cancer Society, were published in Japanese in May 2018. The process of making these guidelines, as well as the content, was largely changed and compared with previous editions. The concept of these guidelines is to act as a support tool for shared decision making between doctor and patient. The procedure of creating the guidelines referred to Minds Handbook for Clinical Practice Guideline Development 2014. This guideline, written in Japanese, consists of two booklets: (1) the epidemiology and diagnosis booklet covering screening, radiological, and pathological diagnosis and (2) the treatment booklet covering surgical therapy, radiation therapy, and systemic therapy. This review article consists of five parts, including the history of the Breast Cancer Clinical Practice Guidelines, the concept, process, content, and recommendation grade. I believe this brief summary concerning the Breast Cancer Clinical Practice Guidelines 2018 edition in English will be helpful for both Japanese and foreign investigators.

The standardized assessment of Ki67 labeling index (LI) is of clinical importance to identify patients with primary breast cancer who could benefit from chemotherapy. In this study, we evaluated the interobserver concordance of Ki67 LI assessment. Six surgical pathologists participated and all the slides were prepared from archival breast cancer tissues fixed in 10% buffered formalin for 24 h and stained with MIB-1. Three independent studies were conducted. In the first study, 30 stained slides were assessed using two different methods: the scoring system, with a positive rate scored from 1 (0-9%) to 10 (90-100%) by visual estimate; and the counting method, with approximately 1000 cells counted in hot spots. In the second study, 20 tumors with Ki67 LI 5-25% were assessed, and in the third study, 15 printed photographs of stained slides were assessed to avoid variations by selecting different fields. In study 1, the counting system (intraclass correlation coefficient [ICC], 0.66 [95% confidence interval 0.52-0.78]) demonstrated a better correlation than the scoring system (ICC, 0.57 [0.42-0.72]). In study 2, the assessment for Ki67 LI of 5-25% demonstrated a correlation (ICC, 0.68 [0.50-0.81]) similar to that of study 1 (unrestricted range of Ki67 LI). In study 3, the assessment of Ki67 LI by counting yielded a good concordance (ICC, 0.94 [0.88-0.97]). In conclusion, there was better concordance with the counting system, and concordance was high when the assessed field was predetermined, indicating that the selection of the evaluation area is critical for obtaining reproducible Ki67 LI in breast cancer., (© 2013 Japanese Cancer Association.)

A very rare case of muco-epidermoid carcinoma of the breast is reported. A 54-year-old woman noticed a breast lump and consulted the Cancer Institute Hospital, Tokyo. Physical examination revealed a mass with an unclear margin in the upper outer area of the left breast. Both mammography and ultrasonography showed an irregularly shaped mass, suggesting invasive carcinoma. Aspiration cytology revealed solid clusters of two types of cancer cells: ones with mucus in the cytoplasm, and others without mucus. Cytological features resembled muco-epidermoid carcinoma of the salivary gland but it was not possible to establish a diagnosis of the histological type because muco-epidermoid carcinoma of the breast had not previously been encountered by the authors. After incisional biopsy, left mastectomy with axillary lymph node dissection was performed. Histologically the tumor was surrounded by a fibrous pseudocapsule and was composed of intraductal carcinoma foci and invasive cancer nests. Intraductal carcinoma foci were the low papillary type. Stromal invasion showed many solid nests composed of mucus-containing and squamoid cancer cells. There was no common invasive ductal carcinoma component in this tumor. These histological features confirmed the diagnosis as muco-epidermoid carcinoma of the breast. This is the first report of muco-epidermoid carcinoma of the breast in Japan.

Background: Inflammatory breast cancer (IBC) is one of the most aggressive forms of breast cancer. Although the survival of patients with IBC has been greatly improved by the use of combined treatment modalities, women with IBC still have lower survival rates. We have summarized a single-center experience involving IBC patients. Our objectives are to clarify molecular alterations of HER-2/neu and p53 in IBC and to investigate the prognostic factors., Methods: Between January 1990 and December 2000, 57 patients with IBC were referred to the Cancer Institute Hospital of the Japanese Foundation for Cancer Research. The incidence of IBC among primary breast cancers was 1.0% (57/5,757) in our hospital. Forty-six patients meeting Haagensen's criteria for inflammatory breast carcinoma were evaluated. All patients had biopsy-proven carcinomas but no distant metastases at referral. The median age at diagnosis for IBC was 51.8 (range, 28 to 70). All patients underwent a mastectomy. Chemotherapy was performed pre- or post-operatively. Three-year and 5-year survival rates were 56.5%, and 40.7%, respectively. Expressions of HER-2/neu and the p53 protein were determined retrospectively by immunohistochemical (IHC) staining of thin paraffin-embedded sections of primary tumors., Results: Of 46 patients, 23 (50.0%) with tumors testing positive for HER-2/neu fared somewhat worse than those with negative tumors, but the differences were not significant for either overall survival (OS) or disease-free survival (DFS). Of 46 patients, 19 (41.3%) whose tumors were positive for p53 fared somewhat better than patients with negative tumors, with no significant differences in either OS or DFS. Patients presenting with less than ten pathologically involved axillary lymph nodes showed significantly better OS and DFS., Conclusions: Overexpression of HER-2/neu and the p53 protein were not significant prognostic factors in inflammatory breast cancer. However, the increased incidence of HER-2/neu and the poor outcome of IBC may be of clinical interest, suggesting the need for clinical trials of antibody therapy targeted to HER-2/neu. Moreover, a high prevalence of p53 may be useful in determining the specific use of chemotherapy.