Claudin-4-adhesion signaling drives breast cancer metabolism and progression via liver X receptor ß.

BACKGROUND: Cell adhesion is indispensable for appropriate tissue architecture and function in multicellular organisms. Besides maintaining tissue integrity, cell adhesion molecules, including tight-junction proteins claudins (CLDNs), exhibit the signaling abilities to control a variety of physiological and pathological processes. However, it is still fragmentary how cell adhesion signaling accesses the nucleus and regulates gene expression. METHODS: By generating a number of knockout and rescued human breast cell lines and comparing their phenotypes, we determined whether and how CLDN4 affected breast cancer progression in vitro and in vivo. We also identified by RNA sequencing downstream genes whose expression was altered by CLDN4-adhesion signaling. Additionally, we analyzed by RT-qPCR the CLDN4-regulating genes by using a series of knockout and add-back cell lines. Moreover, by immunohistochemistry and semi-quantification, we verified the clinicopathological significance of CLDN4 and the nuclear receptor LXRß (liver X receptor ß) expression in breast cancer tissues from 187 patients. RESULTS: We uncovered that the CLDN4-adhesion signaling accelerated breast cancer metabolism and progression via LXRß. The second extracellular domain and the carboxy-terminal Y197 of CLDN4 were required to activate Src-family kinases (SFKs) and the downstream AKT in breast cancer cells to promote their proliferation. Knockout and rescue experiments revealed that the CLDN4 signaling targets the AKT phosphorylation site S432 in LXRß, leading to enhanced cell proliferation, migration, and tumor growth, as well as cholesterol homeostasis and fatty acid metabolism, in breast cancer cells. In addition, RT-qPCR analysis showed the CLDN4-regulated genes are classified into at least six groups according to distinct LXRß- and LXRßS432-dependence. Furthermore, among triple-negative breast cancer subjects, the "CLDN4-high/LXRß-high" and "CLDN4-low and/or LXRß-low" groups appeared to exhibit poor outcomes and relatively favorable prognoses, respectively. CONCLUSIONS: The identification of this machinery highlights a link between cell adhesion and transcription factor signalings to promote metabolic and progressive processes of malignant tumors and possibly to coordinate diverse physiological and pathological events.

Telepathology in intraoperative frozen section consultation of breast cancer sentinel node biopsy in Fukushima, Japan following the 2011 triple disaster: diagnostic accuracy and required time during the early implementation phase.

In breast cancer surgery, some medical facilities lack the necessary resources to conduct sentinel lymph node biopsy and its intraoperative frozen section consultation. In the coastal rural area of Fukushima, Japan, which has suffered from physician undersupply following the 2011 triple disaster of earthquake, tsunami and nuclear disaster, we explored the feasibility of telepathology by evaluating the diagnostic accuracy in remote intraoperative frozen section consultation of sentinel lymph node biopsy and its required time. Although examination time has room for improvement, telepathology can be one possible solution in resource-limited areas.

Switch maintenance endocrine therapy plus bevacizumab after bevacizumab plus paclitaxel in advanced or metastatic oestrogen receptor-positive, HER2-negative breast cancer (BOOSTER): a randomised, open-label, phase 2 trial.

BACKGROUND: Anticancer treatment regimens typically cause unpleasant side-effects. We aimed to investigate the benefit of switch maintenance endocrine therapy plus bevacizumab after fixed cycles of first-line induction chemotherapy with weekly paclitaxel plus bevacizumab in patients with oestrogen receptor (ER)-positive, HER2-negative advanced or metastatic breast cancer. METHODS: BOOSTER was a prospective, open-label, multicentre, randomised, controlled, phase 2 study done in 53 hospitals in Japan. Eligible patients were women aged 20-75 years, with an Eastern Cooperative Oncology Group performance status of 0-1, who had not received chemotherapy for ER-positive, HER2-negative advanced or metastatic breast cancer. All patients received four to six cycles (in which 4 weeks of treatment constitute one cycle) of weekly paclitaxel plus bevacizumab induction therapy (weekly paclitaxel 90 mg/m2, administered intravenously on days 1, 8, and 15 of each cycle, plus bevacizumab 10 mg/kg administered intravenously on days 1 and 15 of each cycle; first registration). Patients with a complete response, partial response, or stable disease after induction therapy (responders) were then randomly assigned (1:1) using the randomisation enrolment form to either continue weekly paclitaxel plus bevacizumab or switch to maintenance endocrine therapy (an aromatase inhibitor or fulvestrant with or without ovarian-function suppression) plus bevacizumab. Randomisation was stratified by induction therapy period, response to induction therapy, age, history of endocrine therapy, and study site. Patients could receive weekly paclitaxel plus bevacizumab reinduction if they had disease progression with maintenance endocrine therapy plus bevacizumab. The primary endpoint was time to failure of strategy (TFS). Efficacy and safety analyses were done in all treated patients (full analysis set). This study is registered with ClinicalTrials.gov, NCT01989780, and registration and follow-up are closed. FINDINGS: Between Jan 1, 2014, and Dec 31, 2015, we enrolled 160 patients who began weekly paclitaxel plus bevacizumab induction therapy. 125 (78%) patients (responders) were randomly assigned to endocrine therapy plus bevacizumab (n=62; n=61 in the full analysis set) or weekly paclitaxel plus bevacizumab (n=63; n=63 in the full analysis set). Among 61 patients in the switch maintenance endocrine therapy plus bevacizumab group, 32 (52%) were reinitiated on weekly paclitaxel plus bevacizumab. At a median follow-up of 21·3 months (IQR 13·0-28·2), TFS was significantly longer in the endocrine therapy plus bevacizumab group than in the weekly paclitaxel plus bevacizumab group (median 16·8 months [95% CI 12·9-19·0] vs 8·9 months [5·7-13·8]; hazard ratio 0·51 [0·34-0·75]; p=0·0006). The most common grade 3-4 non-haematological adverse events after randomisation were proteinuria (in ten [16%] of 61 patients in the endocrine therapy plus bevacizumab group vs eight [13%] of 63 patients in the weekly paclitaxel plus bevacizumab group), hypertension (six [10%] vs six [10%]), and peripheral neuropathy (one [2%] vs six [10%]). One treatment-related death was reported in the weekly paclitaxel plus bevacizumab group (duodenal ulcer perforation). INTERPRETATION: Switch to maintenance endocrine therapy plus bevacizumab with the possibility of weekly paclitaxel reinduction if needed is an efficacious alternative, with a better safety profile, to continuing weekly paclitaxel plus bevacizumab in patients with ER-positive, HER2-negative advanced or metastatic breast cancer who have responded to induction therapy. FUNDING: Chugai Pharmaceutical. TRANSLATION: For the Japanese translation of the abstract see Supplementary Materials section.

Evaluation of a novel medical device for pegfilgrastim administration.

Pegfilgrastim, a pegylated form of granulocyte colony-stimulating factor, has reduced the risk of developing febrile neutropenia, which is associated with an increase in severe infection and prolonged hospitalization. However, pegfilgrastim administration requires that patients visit hospital following cancer chemotherapy, thus imposing a burden on patients and those around them. An on-body injector (OBI), which automatically administers pegfilgrastim about 27 hours after chemotherapy, was used in this study. The OBI, which consists of a main pump unit and infusion set, is a drug delivery device designed to be attached to the patient's body, with a timer-controlled dosing function. This study was conducted in breast cancer patients to evaluate the safety of pegfilgrastim administered subcutaneously via the OBI. The study period consisted of screening and treatment observation periods involving four cycles of neoadjuvant or adjuvant chemotherapy with docetaxel plus cyclophosphamide. One 3.6-mg pegfilgrastim dose was administered subcutaneously via OBI during each cycle of chemotherapy. The study enrolled 35 patients, and no serious adverse events or febrile neutropenia occurred. Administration of pegfilgrastim was successfully completed at all times when the OBI was attached to the patient, and no safety concerns associated with OBI function arose. For outpatients requiring pegfilgrastim following cancer chemotherapy, the use of an OBI was considered to be a safe option to reduce the need for outpatient visits that restrict their activities of daily living.

[A Case of Emergency Radiotherapy for Intramedullary Spinal Cord Metastasis from Breast Cancer].

Intramedullary spinal cord metastasis(ISCM)is rare. However, with advances in diagnostic imaging, the incidence of ISCM is increasing. We herein present a case of breast cancer metastasis in the lower thoracic spinal intramedullary area in a patient who was then successfully treated with emergency radiotherapy. A 56‒year‒old woman with breast cancer was admitted to our hospital due to rapidly progressing weakness in both legs and bladder and rectal disturbance. Spinal MRI revealed a gadolinium‒enhancing intramedullary lesion. The patient was treated with emergency radiotherapy and oral steroids. Although the prognosis of ISCM is extremely poor, emergency radiotherapy could be an effective treatment for ISCM to improve the patient's quality of life(QOL).

The 10-Min Holistic Self-Care for Patients with Breast Cancer-Related Lymphedema: Pilot Randomized Controlled Study.

About 20% of patients with breast cancer are likely to develop breast cancer-related lymphedema (BCRL) following an axillary clearance, and BCRL can be refractory or irreversible to treatment. The aim of this pilot randomized controlled study was to evaluate the effectiveness of a 10-min holistic self-care program for patients with BCRL in Japan. The intervention group (n = 22) practiced the BCRL self-care program including 1) modified Japanese Radio Taiso (Rajio Taiso, national calisthenics in Japan), 2) gentle arm exercises combined with deep breathing, 3) central lymphatic drainage, and 4) skin care using a traditional lymphatic drainage technique daily for 6 months, while the control group (n = 21) received usual care from their hospitals. There was significant group*time interaction in the relative edema volume and relative volume change of the hand, with the intervention group having the better outcome. The intervention group showed significant improvement in transepidermal water loss as well as the mental health component summary score of the SF-8, most of BCRL-related symptoms, self-care time and score, frequencies of exercise, self-lymphatic drainage and skin care, and perceived adherence and effectiveness to self-care, although we were unable to exclude the possibility of the Hawthorne effect. Notably, even in the control group, the self-care was similarly increased, but the significant improvements were detected only in transepidermal water loss on the forearm and upper arm, pain and coldness. In conclusion, the patients who practiced the holistic BCRL self-care for 6 months have shown greater improvement.

[A Case of Synchronous Bilateral Neuroendocrine Ductal Carcinoma In Situ].

Neuroendocrine ductal carcinoma in situ(NE-DCIS)is a unique subtype of ductal carcinoma in situ(DCIS)that is not described in the general rules for clinical and pathological recording of breast cancer. NE-DCIS is described as an unusual variant of DCIS in the 2012 World Health Organization(WHO)classification. The chief complaint in NE-DCIS is hemorrhagic nipple discharge. The histological characteristics of NE-DCIS are solid growth of cancer cells with granular and spindle-shaped nuclei. Histologically, NE-DCIS is suggestive of low malignancy but a poor prognosis of neuroendocrine carcinoma of the breast has been reported. The report by Honami et al was the only other report of synchronous bilateral neuroendocrine ductal carcinoma in situ. We report the second case of NE-DCIS diagnosed synchronously in both breasts in a patient who had visited our outpatient clinic with hemorrhagic nipple discharge.

[Indication for Radiotherapy for Breast Cancer Metastasis to the Skull Base Accompanied by Cranial Nerve Palsies].

Distant metastasis to the skull base region frequently manifests various cranial nerve symptoms and reduces patients' quality of life(QOL). We report a 62-year-old woman with skull base metastasis of breast cancer, whose condition clinically improved following palliative radiotherapy. The patient presented to our hospital with hoarseness. CT screening revealed a tumor in the right breast, axial lymph node swelling, and osteoblastic change at multiple sites. A core needle biopsy of the breast tumor revealed invasive lobular carcinoma. She also had nausea, anorexia, vertigo, lower left angle of the mouth, apraxia of lid closing, and dysphagia owing to several cranial nerve palsies. MRI T1- and T2-weighted images showed a diffuse low-signal intensity of the skull base region, and the patient was diagnosed as having breast cancer with symptomatic skull base metastases. Her cranial nerve symptoms improved after 1 week of palliative irradiation to the skull base. We conclude that, even among terminal-stage patients, palliative radiotherapy to the skull base region is an effective treatment option to improve patients' QOL.

[A Case of Encapsulated Papillary Carcinoma of the Breast].

An 84-year-old woman was revealed to have focal asymmetric density(FAD)based on mammography, and ultrasonography showed a 0.5 cm sized cyst in the left breast. It gradually increased in size and contained solid components. A core needle biopsy revealed an intracystic papillary carcinoma of the breast. Partial mastectomy and sentinel lymph node biopsy were performed. Histopathological examination revealed an encapsulated papillary carcinoma and a papillary lesion surrounded by a thick fibrous capsule. Myoepithelial cells were not found at the periphery of the lesion or within fibrovascular cores. Currently, it is classified as non-invasive carcinoma, and the patient has a good prognosis.

[A Case of Occult Breast Cancer].

We report a case of occult breast cancer. A 61-years-old woman underwent tumorectomy of right axillary mass. Pathological diagnosis was adenocarcinoma. Two years after, right axillary mass was discovered again. Wide local excision, axillary lymph node dissection and radiation therapy of the breast was performed. Pathological findings showed lymph node metastasis of breast cancer, or primary cancer of the axially tail of the breast. Ten months after second operation, she presented an axillary mass again. She underwent resection of the axillary tumor. The pathological findings showed lymph node metastasis of breast cancer. There was no evidence of primary tumor of the breast during the period. We suspected lymph node metastasis of occult breast cancer. Irradiation was administered to the right axilla, and she is receiving endocrine therapy.

[A Case of Breast Carcinoma Associated with Osteoclast-Like Giant Cells].

Mammary carcinoma with osteoclast-like giant cells is uncommon, and its onset mechanism and malignancy are unknown. We report a case of mammary carcinoma with osteoclast-like giant cells. A 41-year-old woman noticed a lump in her left breast. Ultrasound sonography findings suggested breast cancer. A core needle biopsy revealed invasive ductal carcinoma of the breast. Modified radicalmastectomy and sentinell ymph node biopsy were performed. Histopathologicalexamination revealed papillotubular carcinoma with osteoclast-like giant cells. Cells were positive for estrogen receptor and progesterone, and negative for HER2. MIB-1 index was under 5%. The giant cells were generally associated with an inflammatory, fibroblastic, hyper-vascular stroma. The carcinomatous part of the lesion was most frequently a well-to moderately differentiated invasive ductalcarcinoma. Immunohistochemicaland ultrastructuralstudies suggested that the osteoclast-like giant cells were of stromalhistiocytic origin. To understand biochemicalfindings of this carcinoma, more case studies are required to be reported.

[Combination Therapy of Molecular-Targeted Drugs for Breast Cancer -- Their Potential in the Future].

In breast cancer treatment, molecular-targeted drugs such as trastuzumab and lapatinib have been used for many y ears, and the benefits have been seen in many patients. The molecular-targeted drugs have mainly been used in combination with cytotoxic agents; however, combination therapies with 2 molecular-targeted drugs are currently being investigated. The combination therapy of 2 HER2 receptor antibodies, pertuzumab and trastuzumab, has tremendous benefit for HER2 positive metastatic breast cancer patients. However, the combination of trastuzumab with tyrosine-kinase inhibitor lapatinib showed small benefits and its usage is limited. The combination of T-DM1 plus pertuzumab was not anymore effective than T-DM1 alone. The potentials of combined hormone therapies have been examined for ages. The combination of fulvestrant and aromatase inhibitor(AI)was shown to be beneficial in one phase III study; however, a conflicting result was reported by another large trial. To overcome hormone therapy resistance, the combinations of hormone therapy drugs with mTOR inhibitors(everolimus), pan-PI3K inhibitor(buparlisib), and CDK4/6 inhibitors(palbociclib, ribociclib, abemaciclib)are being investigated in various settings.

[Use of Pegfilgrastim in Adjuvant and Neoadjuvant Chemotherapy for Breast Cancer].

We assessed the incidence of febrile neutropenia(FN), infection, and relative dose intensity(RDI)with or without the use of pegfilgrastim in breast cancer patients receiving adjuvant or neoadjuvant chemotherapy. Twenty-five patients received 4 cycles of FEC(5-FU 500mg/m2 plus epirubicin 100 mg/m2 plus cyclophosphamide 100 mg/m2 q3w)followed by 4 cycles of docetaxel(75mg/m2 q3w). Ten patients were administered pegfilgrastim as primary prophylaxis throughout all cycles of chemotherapy, and 15 patients were not. The rate of FN was only 7% in patients not undergoing pegfilgrastim therapy. The infection rate and RDI were not significantly different between the 2 groups, but the incidence of fever was lower in patients treated with pegfilgrastim. In patients with early stage breast cancer, the use of primary pegfilgrastim during all chemotherapy cycles should be considered a safe option.

[A Case of Primary Poorly Differentiated/Small Cell Carcinoma of the Breast in a Patient with Von Recklinghausen's Disease].

We report a case of neuroendocrine carcinoma and poorly differentiated/small cell carcinoma ofthe breast in a patient with von Recklinghausen's disease. The patient was a 46-year-old woman who was diagnosed with von Recklinghausen's disease when she was 22 years old. She presented with left breast pain, and physical examination revealed a firm mass in the left breast. A core needle biopsy of the tumor revealed triple negative breast cancer with neuroendocrine features. We performed a simple mastectomy with lymph node dissection. We did not plan neoadjuvant chemotherapy because the tumor would be possibly inoperative if neoadjuvant chemotherapy was not effective for this neuroendocrine cancer. The tumor was diagnosed as a neuroendocrine carcinoma and poorly differentiated/small cell carcinoma. The patient was treated with CDDP and CPT- 11, which is a regimen often used to treat small cell lung cancer.

[A Case of Axillary Arterial Bleeding after Axillary Metastatic Lymph Node Necrosis during Treatment with Paclitaxel and Bevacizumabfor Breast Cancer].

A 44-year-old woman was diagnosed cT4bcN3cM1(LYM), Stage IV triple-negative breast cancer.Enhanced computed tomography revealed ipsilateral axillary lymph node metastasis, 10 cm in diameter.The supraclavicular and cervical lymph nodes also had metastases.She received paclitaxel(90mg/m2, on days 1, 8, and 15 every 4 weeks)in combination with bevacizumab(10mg/kg, on days 1 and 15 every 28 days).Her height was 165 cm, and her body weight was 100 kg.After 1 course of chemotherapy, a metastatic axillary lymph node with necrotic changes was removed spontaneously.A few days later, she experienced severe bleeding from her axillary artery, and she went into hypovolemic shock.Despite undergoing surgical hemostasis, the bleeding recurred twice, so we performed coil embolization of her subclavian artery.Thirty -five days after the first occurrence of bleeding, the patient died of sepsis and ARDS due to left arm necrosis.Bevacizumab is effective for the treatment of large tumors, but when the tumor is close to an artery, clinicians should be wary of fatal bleeding after necrosis.

Co-expression of S100A14 and S100A16 correlates with a poor prognosis in human breast cancer and promotes cancer cell invasion.

BACKGROUND: S100 family proteins have recently been identified as biomarkers in various cancers. Of this protein family, S100A14 and S100A16 are also believed to play an important role in tumor progression. The aim of the present study was to clarify the clinical significance and functional role of these molecules in breast cancer. METHODS: In a clinical study, an immunohistochemical analysis of S100A14 and S100A16 expression in archival specimens of primary tumors of 167 breast cancer patients was performed. The relationship of S100A14 and S100A16 expression to patient survival and clinicopathological variables was statistically analyzed. In an experimental study, the subcellular localization and function of these molecules was examined by using the human breast cancer cell lines MCF7 and SK-BR-3, both of which highly express S100A14 and S100A16 proteins. Cells transfected with expression vectors and siRNA for these genes were characterized using in vitro assays for cancer invasion and metastasis. RESULTS: Immunohistochemical analysis of 167 breast cancer cases showed strong cell membrane staining of S100A14 (53% of cases) and S100A16 (31% of cases) with a significant number of cases with co-expression (p < 0.001). Higher expression levels of these proteins were significantly associated with a younger age (<60 years), ER-negative status, HER2-positive status and a poorer prognosis. Co-expression of the two proteins showed more aggressive features with poorer prognosis. In the human breast cancer cell lines MCF7 and SK-BR-3, both proteins were colocalized on the cell membrane mainly at cell-cell attachment sites. Immunoprecipitation and immunofluorescence analyses demonstrated that the 100A14 protein can bind to actin localized on the cell membrane in a calcium-independent manner. A Boyden chamber assay showed that S100A14 and S100A16 knockdown substantially suppressed the invasive activity of both cell lines. Cell motility was also inhibited by S100A14 knockdown in a modified dual color wound-healing assay. CONCLUSIONS: To our knowledge, this is the first report showing the correlation of expression of S100A14, S100A16, and co-expression of these proteins with poor prognosis of breast cancer patients. In addition, our findings indicate that S100A14 and S100A16 can promote invasive activity of breast cancer cells via an interaction with cytoskeletal dynamics. S100A14 and S100A16 might be prognostic biomarkers and potential therapeutic targets for breast cancer.

Endosomal protein expression of γ1-adaptin is associated with tumor growth activity and relapse-free survival in breast cancer.

BACKGROUND: γ1-Adaptin is a subunit of adaptor protein complex-1 (AP-1), which regulates intracellular transport between the trans-Golgi network (TGN) and endosomes. Since expression levels of AP-1 subunits have been reported to be associated with cell proliferation and cancer malignancy, we investigated the relationships between the immunohistochemical expression of γ1-adaptin and both clinicopathological factors and relapse-free survival (RFS) in breast cancer tissue. MATERIALS AND METHODS: SK-BR-3 cell line depleted of γ1-adaptin was used for cell proliferation, migration, and invasion assay. Intracellular localization of γ1-adaptin was examined with immunohistochemistry (IHC) using an antibody against γ1-adaptin, and with double immunohistofluorescence (IHF) microscopy using markers for the TGN and endosome. γ1-Adaptin intensities in IHC samples from 199 primary breast cancer patients were quantified and assessed in relation to clinicopathological factors and RFS. RESULTS: Cell growth, migration, and invasion of SK-BR-3 cells were significantly suppressed by the depletion of γ1-adaptin. Although the staining patterns in the cancer tissues varied among cases by IHC, double IHF demonstrated that γ1-adaptin was mainly localized in EEA1-positive endosomes, but not in the TGN. γ1-Adaptin intensity was significantly higher in the tumor regions than in non-tumor regions. It was also higher in patients with Ki-67 (high), ER (-), PgR (-), and HER2 (+). Among subtypes of breast cancer, γ1-adaptin intensity was higher in HER2 than in luminal A or luminal B. The results of the survival analysis indicated that high γ1-adaptin intensity was significantly associated with worse RFS, and this association was also observed in group with ER (+), PgR (+), HER2 (-), Ki-67 (high), or luminal B. In addition, the Cox proportional hazards model showed that high γ1-adaptin intensity was an independent prognostic factor. CONCLUSION: These results suggest that the endosomal expression of γ1-adaptin is positively correlated with breast cancer malignancy and could be a novel prognostic marker.

Long-term Experience on Breast Cancer-related Lymphedema in the Coastal Area of Fukushima, Japan After the 2011 Triple Disaster.

BACKGROUND/AIM: Disasters can jeopardize breast cancer care and Japan's triple disaster in 2011 (earthquake, tsunami, and nuclear accident) is no exception. However, detailed information is lacking regarding the care of breast cancer related lymphedema (BCRL) following the disaster. We aimed to explore the process by which local patients become aware of BCRL, the problems faced, and the support they require. We also aimed to clarify the effects of the 2011 disaster on experiences related to lymphedema in the target population. PATIENTS AND METHODS: Patients who developed BCRL after breast cancer treatment were recruited from Iwaki city, a municipality located in the southern coastal region of Fukushima (N=16). In-depth, semi-structured, face-to-face interviews were conducted, and the obtained data were appraised using thematic analysis. RESULTS: Five themes related to BCRL were identified: 1) the process of becoming aware of BCRL, 2) troubles or worries/concerns due to BCRL, 3) information sources regarding BCRL management, 4) strategies to cope with BCRL, and 5) the adverse impacts of the 2011 disaster on BCRL management. CONCLUSION: Except for the disaster context, the themes are in line with those of previous studies conducted in the non-disaster context. Nonetheless, there were limited but non-negligible adverse effects of the 2011 disaster on long-term local BCRL management. The findings of this study demonstrate the necessity for individualizing coping strategies against BCRL among healthcare professionals in the Fukushima coastal area and beyond.

E3 Ubiquitin Ligase NEDD4 Affects Estrogen Receptor α Expression and the Prognosis of Patients with Hormone Receptor-Positive Breast Cancer.

Neural precursor cell-expressed developmentally downregulated 4-1 (NEDD4) is an E3 ligase that leads to the degradation of proteins, including estrogen receptor α. We evaluated whether the expression level of NEDD4 affected the outcome of breast cancer patients. We performed a retrospective cohort study enrolling 143 patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer. Of the 66 patients with high NEDD4 mRNA levels (high NEDD4 group) and 77 patients with low NEDD4 mRNA levels (low NEDD4 group), 98.4% and 96.1%, respectively, of the patients had received neoadjuvant/adjuvant hormone therapy. Disease-free survival and overall survival were significantly longer in the low NEDD4 group than in the high NEDD4 group (p = 0.048 and p = 0.022, respectively). Western blotting revealed a high expression of estrogen receptor α in the NEDD4-knockdown culture cells. The proliferation of NEDD4-knockdown cells treated with tamoxifen or estradiol deprivation was suppressed, compared with that of NEDD4-expressing cells. Knockdown of NEDD4 in breast cancer cells induced the accumulation of estrogen receptor α and increased sensitivity to hormone therapy. In summary, this mechanism may lead to a better prognosis in hormone receptor-positive breast cancer patients with a low expression of NEDD4.

The necessity of proactive measures from healthcare providers highlighted by delayed breast cancer diagnosis due to COVID-19: A case report.

Key Clinical Message: During disasters, multiple factors can cause significant delays in medical visits. Regular patient monitoring, high-risk individual alerts, and telemedicine enhancements can potentially alleviate these issues and ensure timely interventions. Abstract: During the COVID-19 pandemic, a Japanese woman in her 70s delayed her regular breast cancer checkup for over 2 years. During disasters, health priorities tend to decline, necessitating proactive measures from healthcare providers, such as augmenting collaboration among healthcare professionals and identifying high-risk individuals.