Breast cancer (Tokyo, Japan)最新文献

{"title":"Clinical significance on switching CDK4/6 inhibitors among 13,284 patients with metastatic breast cancer.","authors":"Takuya Nishina, Maki Tanioka, Kenji Takada, Takahiro Tsukioki, Yuko Takahashi, Tadahiko Shien, Shinichi Toyooka","doi":"10.1007/s12282-025-01768-6","DOIUrl":"https://doi.org/10.1007/s12282-025-01768-6","url":null,"abstract":"<p><p>Recent clinical trials have shown that switching to a combination therapy of a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) and endocrine therapy (ET) prolongs progression-free survival (PFS) compared with ET monotherapy. Reports indicate that abemaciclib provides benefits regardless of the PIK3CA mutation status; however, its clinical benefits remain insufficient. This study aimed to evaluate the clinical significance of switching CDK4/6i + ET in a large real-world cohort. Using a medical database, we identified 13,284 patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer who received CDK4/6i + ET between 2008 and 2022. Patients were categorized into five groups based on their first- and second-line therapy patterns. We compared the median time to discontinuation (TTD) among the groups. In patients who switched from one CDK4/6i + ET to another CDK4/6i + ET, the second-line TTD and total TTD of first- and second-line therapies (n = 542) were significantly longer than those in patients who switched from CDK4/6i + ET to ET monotherapy (n = 490) (the second-line TTD: 11.2 vs. 4.9 months, p < 0.01; total TTD: 25.1 vs. 20.5 months, p < 0.01). The order of palbociclib and abemaciclib administration did not significantly affect the second-line or total TTD in patients who switched from one CDK4/6i + ET to another CDK4/6i + ET. Switching from one CDK4/6i + ET to another CDK4/6i + ET resulted in a significantly longer TTD than switching to ET monotherapy. Considering the phase III clinical trial results of capivasertib, switching to CDK4/6i + ET is a viable therapeutic option regardless of the PIK3CA mutation status.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145276943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: The therapeutic potential of high-intensity interval training in a breast cancer model: focus on the Hippo signaling pathway.","authors":"Maryam Hossein Rezaei, Manzumeh Shamsi Meymandi, Amirhossein Moslemizadeh, Elham Madadizadeh, José Pinto-Fraga, Susana López-Ortiz, Sajad Haidari, Ladan Langroudi, Mohammad Amin Rajizadeh, Hamideh Bashiri, Kayvan Khoramipour","doi":"10.1007/s12282-025-01790-8","DOIUrl":"https://doi.org/10.1007/s12282-025-01790-8","url":null,"abstract":"","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145276976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of gut microbiota dysbiosis in breast cancer patients.","authors":"Mai Yamada, Makoto Kubo, Kazuhisa Kaneshiro, Masaya Kai, Takafumi Morisaki, Saori Hayashi, Yurina Ochiai, Yo Sato, Kimihisa Mizoguchi, Yuka Takao, Akiko Arimura, Masafumi Nakamura","doi":"10.1007/s12282-025-01782-8","DOIUrl":"https://doi.org/10.1007/s12282-025-01782-8","url":null,"abstract":"<p><strong>Background: </strong>While lifestyle factors are known to be associated with breast cancer development, the potential role of the gut microbiome, which is influenced by lifestyle, as a risk factor is not well understood. We conducted a comparative analysis of the intestinal microbiota between healthy individuals and breast cancer patients to investigate the potential impact of gut microbiome composition on breast cancer development. This study aimed to explore the role of intestinal microbial communities in breast cancer pathogenesis.</p><p><strong>Methods: </strong>We conducted a comparative analysis of fecal 16S rRNA amplicon sequencing data from 100 individuals in the general population and 79 breast cancer patients. We investigated the differences between the two groups in terms of relative abundance, absolute quantity, diversity, and functionality of the gut microbiota.</p><p><strong>Results: </strong>Breast cancer groups showed higher levels of Firmicutes and lower levels of Bacteroidota at the phylum level, and an increase in Fusobacteriota was found in the human epidermal growth factor receptor 2 (HER2)-negative breast cancer group. Additionally, certain genera were more or less common in breast cancer groups at the genus level. The study also indicated lower gut microbiota diversity and loss of heterogeneity in breast cancer groups and reduced functional genes and pathways.</p><p><strong>Conclusion: </strong>Compared to the general population, breast cancer patients exhibited a distinct dysbiosis in their gut microbiota. Further investigation is warranted to determine if this dysbiotic state, linked to a predicted downregulation of functional pathways critical for homeostasis, plays a role in breast cancer development.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145208941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TAMs-derived exosomes promote breast cancer progression by regulating the IRF9/IFI6 axis.","authors":"Xingjuan Zhao, Yajue Wang, Xuan Yang, Huifang Guo","doi":"10.1007/s12282-025-01789-1","DOIUrl":"https://doi.org/10.1007/s12282-025-01789-1","url":null,"abstract":"<p><strong>Background: </strong>Breast cancer (BC) is the most prevalent cancer diagnosed in women across the globe and is the main factor behind cancer-related deaths in women. There is an increasing amount of evidence, suggesting that tumor microenvironment is controlled by tumor-associated macrophages (TAMs) and exosomes. Nevertheless, the precise mechanism of TAMs-derived exosomes to regulate the advancement of BC is not entirely clear.</p><p><strong>Methods: </strong>The proliferation, migration, invasion, apoptosis, glycolysis, and the level of reactive oxygen species (ROS) in BC cells were evaluated using EdU, Transwell assays, flow cytometry, and corresponding kits. RT-qPCR and western blotting were employed to examine mRNA and protein expression. Exosomes were isolated from TAMs culture supernatant and confirmed through transmission electron microscopy, western blotting, and immunofluorescence assay. Bioinformatics, dual-luciferase reporter assay, and chromatin immunoprecipitation (ChIP) assay were utilized to determine the binding of IRF9 to the IFI6 promoter. A mouse xenograft model was established for in vivo analysis. Transcriptomic analysis was conducted on a pre-selected interferon-related gene set, which may limit the discovery of other relevant genes and pathways.</p><p><strong>Results: </strong>Interferon alpha-inducible protein 6 (IFI6) was highly expressed in TAMs-originated exosomes. TAMs promoted BC cells' proliferation, migration, invasion, and glycolysis through the transmission of exosomal IFI6 while inhibiting apoptosis and ROS accumulation. Interferon regulatory factor 9 (IRF9) promoted IFI6 transcription in TAMs. Mechanistically, IRF9 in TAMs-secreted exosomes promoted the function of BC cells by mediating IFI6. Furthermore, TAMs-derived exosomes influenced the growth of BC tumors by regulating the IRF9/IFI6 axis in vivo.</p><p><strong>Conclusion: </strong>Generally, TAMs-derived exosomes could promote BC progression via the IRF9/IFI6 axis.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145208899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Postmastectomy radiation therapy for implant-based breast reconstruction: a systematic review and meta-analysis for the 2022 Japanese Breast Cancer Society Clinical Practice Guideline.","authors":"Mami Ogita, Subaru Sawayanagi, Haruka Jinnouchi, Michio Yoshimura, Chikako Yamauchi, Naoko Sanuki, Yasushi Hamamoto, Kimiko Hirata, Mariko Kawamura, Yutaka Yamamoto, Shigehira Saji, Tatsuya Toyama","doi":"10.1007/s12282-025-01788-2","DOIUrl":"https://doi.org/10.1007/s12282-025-01788-2","url":null,"abstract":"<p><strong>Background: </strong>Implant-based breast reconstruction is the most commonly performed reconstructive technique following mastectomy. With an increasing number of patients undergoing implant-based breast reconstruction, concerns have arisen regarding the safety of postmastectomy radiation therapy (PMRT) in reconstructed breasts. This study aimed to investigate the safety of PMRT in implant-based breast reconstruction.</p><p><strong>Methods: </strong>A comprehensive literature search was conducted for articles published up to March 2021. Eligible studies included clinical trials and observational studies comparing outcomes between patients with breast cancer undergoing immediate implant-based breast reconstruction with PMRT and those without PMRT. The primary outcomes included major complications, reconstruction failure, capsular contracture, and cosmetic outcomes. Pooled odds ratio (OR) with 95% confidence interval (CI) were calculated using a random-effects model.</p><p><strong>Results: </strong>A total of 23 studies were identified, comprising one case-control study, one prospective cohort study, and 21 retrospective cohort studies. PMRT was significantly associated with increased rates of major complications (OR 2.62, 95% CI 1.82-3.77, P < 0.00001), reconstruction failure (OR 2.53, 95% CI 2.00-3.20, P < 0.00001), and capsular contracture (OR 9.63, 95% CI 5.77-16.06, P < 0.00001). Furthermore, cosmetic outcomes were significantly poorer in patients undergoing PMRT compared with those not receiving PMRT (OR 3.55, 95% CI 1.80-6.98, P < 0.003).</p><p><strong>Conclusions: </strong>This meta-analysis demonstrated that PMRT in implant-based breast reconstruction is associated with a significantly increased risk of adverse outcomes. Given these risks, treatment decisions should involve through discussions with patients to ensure that they are fully informed of the potential benefits and complications.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145202909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global mapping of artificial intelligence applications in breast cancer from 1988-2024: a machine learning approach.","authors":"Thi Huyen Trang Nguyen, Somin Jeon, Junghyun Yoon, Boyoung Park","doi":"10.1007/s12282-025-01783-7","DOIUrl":"https://doi.org/10.1007/s12282-025-01783-7","url":null,"abstract":"<p><strong>Background: </strong>Artificial intelligence (AI) has become increasingly integral to various aspects of breast cancer care, including screening, diagnosis, and treatment. This study aimed to critically examine the application of AI throughout the breast cancer care continuum to elucidate key research developments, emerging trends, and prevalent patterns.</p><p><strong>Methods: </strong>English articles and reviews published between 1988 and 2024 were retrieved from the Web of Science database, focusing on studies that applied AI in breast cancer research. Collaboration among countries was analyzed using co-authorship networks and co-occurrence mapping. Additionally, clustering analysis using Latent Dirichlet Allocation (LDA) was conducted for topic modeling, whereas linear regression was employed to assess trends in research outputs over time.</p><p><strong>Results: </strong>A total of 8,711 publications were included in the analysis. The United States has led the research in applying AI to the breast cancer care continuum, followed by China and India. Recent publications have increasingly focused on the utilization of deep learning and machine learning (ML) algorithms for automated breast cancer detection in mammography and histopathology. Moreover, the integration of multi-omics data and molecular profiling with AI has emerged as a significant trend. However, research on the applications of robotic and ML technologies in surgical oncology and postoperative care remains limited. Overall, the volume of research addressing AI for early detection, diagnosis, and classification of breast cancer has markedly increased over the past five years.</p><p><strong>Conclusions: </strong>The rapid expansion of AI-related research on breast cancer underscores its potential impact. However, significant challenges remain. Ongoing rigorous investigations are essential to ensure that AI technologies yield evidence-based benefits across diverse patient populations, thereby avoiding the inadvertent exacerbation of existing healthcare disparities.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of level II oncoplastic surgery and conventional breast-conserving surgery in breast cancer with a ductal carcinoma in situ component.","authors":"Ömer Çelik, Halit Özgül, Remzi Can Çakır, Azmi Lale, Turan Can Yıldız, Erhan Aydemir, Betül Dağoğlu Hark","doi":"10.1007/s12282-025-01786-4","DOIUrl":"https://doi.org/10.1007/s12282-025-01786-4","url":null,"abstract":"<p><strong>Background: </strong>To investigate the pathological outcomes, re-excision rates, local recurrence, patient satisfaction, and cosmetic results associated with level II oncoplastic surgery (OBS) techniques compared to conventional breast-conserving surgery (BCS) in the treatment of breast cancer with a ductal carcinoma in situ (DCIS) component.</p><p><strong>Methods: </strong>Between January 2020 and December 2023, 163 patients with invasive carcinoma associated with DCIS were deemed suitable for breast-conserving surgery. The patients were divided into two groups: those who underwent conventional BCS and those who underwent level II OBS.</p><p><strong>Results: </strong>Forty patients underwent level II OBS, while 123 patients underwent conventional BCS. The median age was 50 (range 29-65) years for the patients in the level II OBS group and 52 (range 25-68) years for those in the conventional BCS group. Re-excision was performed in three patients (10%) in the level II OBS group compared to 37 patients (30%) in the conventional BCS group, indicating a statistically significant difference (p = 0.035). The median tumor size was 16 (range 3-45) mm in the OBS cohort and 15 (range 4-50) mm in the BCS cohort. Donut mastopexy was the most commonly performed level II oncoplastic procedure (50%). No statistically significant differences were found between the groups in terms of other demographic and histopathological parameters (e.g., tumor laterality, menopausal status, ER, PR, and HER2 positivity, and E-cadherin expression). According to the BREAST-Q survey, the patients in the OBS group reported higher satisfaction with their breasts, better psychosocial well-being, and improved sexual well-being compared to those in the BCS group, with these differences being statistically significant (p < 0.001).</p><p><strong>Conclusion: </strong>In breast cancer with a DCIS component, patients who underwent level II OBS had significantly lower re-excision rates, higher patient satisfaction, and better cosmetic outcomes compared to those who underwent conventional BCS.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145188242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The therapeutic potential of high-intensity interval training in a breast cancer model: focus on the Hippo signaling pathway.","authors":"Maryam Hossein Rezaei, Manzumeh Shamsi Meymandi, Amirhossein Moslemizadeh, Elham Madadizadeh, Francisco José Pinto Fraga, Susana López Ortiz, Sajad Haidari, Ladan Langroudi, Mohammad Amin Rajizadeh, Hamideh Bashiri, Kayvan Khoramipour","doi":"10.1007/s12282-025-01773-9","DOIUrl":"10.1007/s12282-025-01773-9","url":null,"abstract":"<p><strong>Background: </strong>Contact inhibition regulates cell proliferation via E-cadherin and the Hippo pathway, the dysregulation of which contributes to breast cancer; while physical exercise correlates negatively with breast cancer risk, our study proposes high-intensity interval training (HIIT) as a potential modulator of Hippo signaling to mitigate tumorigenesis, explored through experimental models.</p><p><strong>Methods: </strong>Healthy control (CTL), breast cancer (BC), healthy exercise (Ex), and cancer with exercise (BC + Ex) were the four groups into which 48 BALB/c female mice were randomly assigned. Mouse breast cancer cells (4T1) were orthotopically injected into all other groups except the CTL and Ex groups. On a treadmill, the Ex and BC + Ex groups ran for 4-10 periods at 80-100% of their maximal velocity (Vmax). Western blot analysis was used to evaluate neurofibromatosis type II (NF2), macrophage-stimulating 1 (MST1/2), large tumor suppressor kinase 1/2(LATS1/2), transcriptional enhancer factor (TEAD), vestigial-like family member 4 (VGLL4), epidermal growth factor receptor tyrosine kinase (EGFR), E-cadherin, α-catenin, β-catenin, kidney and brain expressed protein (Kibra), yes-associated protein (YAP), and transcriptional coactivator with a PDZ-bindingdomain (TAZ), as well as their phosphorylated forms.</p><p><strong>Results: </strong>When compared to the BC group, the BC + Ex group had higher levels of EGFR, E-cadherin, α-catenin, β-catenin, Kibra, NF2, MST1, MST 2, LATS1, LATS 2, P-YAP, VGLL4, and P-TAZ (P < 0.01). Conversely, Ex and BC + Ex had lower levels of YAP, TAZ, and TEAD than CTL and BC (P < 0.01). In addition, tumor volume was lower in BC + Ex compared to BC (P < 0.001).</p><p><strong>Conclusions: </strong>Our observations shed light on the potential molecular mechanisms by which exercise influences cancer development and provide insights into novel therapeutic strategies targeting these pathways.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145180813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scaffold-based breast conserving surgery in patients with non-malignant breast lesions: long-term follow-up of a first-in-human pilot study on the REGENERA™ biomimetic breast implant.","authors":"Maria Donatella Mariniello, Manuela Roncella, Dionisia Mazzotta, Irini Gerges, Livio Colizzi, Margherita Tamplenizza, Alessandro Tocchio, Federico Martello, Maria Ghilardi, Maria Cristina Cossu, Serena Danti, Matteo Ghilli","doi":"10.1007/s12282-025-01780-w","DOIUrl":"https://doi.org/10.1007/s12282-025-01780-w","url":null,"abstract":"<p><strong>Background: </strong>Frequently, the breast surgeon must employ complex oncoplastic techniques (OBS) to guarantee optimal cosmetic results. The success of the REGENERA™ implant in combining the benefits of OBS with the simplicity of breast conserving surgery (BCS) has been previously reported in five patients with short follow-up. The goal of this study was to build on these promising data by reporting safety and efficacy results in a larger population with a longer follow-up.</p><p><strong>Methods: </strong>Fifteen females with non-malignant breast lesions who underwent lumpectomy and implantation of REGENERA™ device, followed-up for six months, were included in this interventional FIH study. Fourteen of these, were included in a long-term observational study (LTFU) and followed-up for 24 months. Safety (incidence of adverse events [AEs]) and performance (changes in breast appearance, interference with imaging) of the device, and investigator and patient satisfaction were evaluated. Data from these two studies are reported herein. (Registered on clinicaltrials.gov: NCT05533099 and NCT04131972).</p><p><strong>Results: </strong>A total of 113 AEs were reported. Only 3 (2.6%) were considered possibly device-related. The great majority (91,2%) were mild/moderate and only in one case the device was explanted. The REGENERA™ implant demonstrated high levels of performance, with an aesthetic score of 'Excellent' in 85.7% of patients, no interference with imaging, and high levels of patients and investigator satisfaction.</p><p><strong>Conclusions: </strong>Data continue to be strongly supportive of the use of the REGENERA™ implant in BCS, further paving the way for an innovative surgical approach.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145180847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Timing of postmastectomy radiation therapy in two-stage expander/implant-based breast reconstruction: a systematic review and meta-analysis for the 2022 Japanese breast cancer society clinical practice guideline.","authors":"Mami Ogita, Subaru Sawayanagi, Haruka Jinnouchi, Michio Yoshimura, Chikako Yamauchi, Naoko Sanuki, Yasushi Hamamoto, Kimiko Hirata, Mariko Kawamura, Yutaka Yamamoto, Shigehira Saji, Tatsuya Toyama","doi":"10.1007/s12282-025-01785-5","DOIUrl":"https://doi.org/10.1007/s12282-025-01785-5","url":null,"abstract":"<p><strong>Background: </strong>In immediate expander/implant reconstruction, postmastectomy radiation therapy (PMRT) can be administered at two different time points: during tissue expander insertion or after exchange with an implant. The optimal timing for PMRT remains unclear. We conducted a systematic review and meta-analysis to evaluate the impact of PMRT timing on the outcomes of patients with breast cancer undergoing two-stage expander/implant breast reconstruction.</p><p><strong>Methods: </strong>A literature review of articles in English and Japanese up to March 2021 was performed using PubMed/MEDLINE, the Cochrane Library, and Ichushi-Web. Studies comparing the timing of PMRT in patients with breast cancer undergoing immediate two-stage expander/implant breast reconstructions and PMRT were included. The assessed outcomes included major complications, reconstruction failure, cosmesis, capsular contractures, and local recurrence.</p><p><strong>Results: </strong>Eleven studies encompassing 1,628 cases were identified. These included one prospective cohort study, one prospective case-control study, and nine retrospective cohort studies. No significant differences were observed in major complications between PMRT to expander and PMRT to implant (odds ratio [OR] 1.11, 95% confidence intervals [CI] 0.72-1.73, P = 0.64). Reconstruction failure was more prevalent in the expander group (OR 2.33, 95% CI 1.43-3.82, P = 0.0007), while severe capsular contractures occurred less frequently in the expander group (OR 0.33, 95% CI 0.12-0.92, P = 0.03).</p><p><strong>Conclusions: </strong>PMRT to expander was associated with higher reconstruction failure and lower severe capsular contracture rates, with no significant differences in major complications by timing. There is insufficient evidence to favor one approach over the other.</p>","PeriodicalId":520574,"journal":{"name":"Breast cancer (Tokyo, Japan)","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145139984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}