A genome-wide CRISPR/Cas9 knockout screen identifies SEMA3F gene for resistance to cyclin-dependent kinase 4 and 6 inhibitors in breast cancer.

BACKGROUND: Palbociclib is a cell-cycle targeted small molecule agent used as one of the standards of care in combination with endocrine therapy for patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Although several gene alterations such as loss of Rb gene and amplification of p16 gene are known to be conventional resistance mechanisms to cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, the comprehensive landscape of resistance is not yet fully elucidated. The purpose of this study is to identify the novel resistant genes to the CDK4/6 inhibitors in HR-positive HER2-negative breast cancer. METHODS: The whole genome knockout screen using CRISPR/Cas9 genome editing was conducted in MCF7 to identify resistant genes to palbociclib. The candidate genes for resistance were selected by NGS analysis and GSEA analysis and validated by cell viability assay and mouse xenograft models. RESULTS: We identified eight genes including RET, TIRAP, GNRH1, SEMA3F, SEMA5A, GATA4, NOD1, SSTR1 as candidate genes from the whole genome knockout screen. Among those, knockdown of SEMA3F by siRNA significantly and consistently increased the cell viability in the presence of CDK4/6 inhibitors in vitro and in vivo. Furthermore, the level of p-Rb was maintained in the palbociclib treated SEMA3F-downregulated cells, indicating that the resistance is driven by increased activity of cyclin kinases. CONCLUSION: Our observation provided the first evidence of SEMA3F as a regulator of sensitivity to CDK4/6 inhibitors in breast cancer. The detailed mechanisms of resistance deserve further functional studies to develop the better strategy to overcome resistance in CDK4/6 inhibitors.

Effectiveness and safety of primary prophylaxis with G-CSF during chemotherapy for invasive breast cancer: a systematic review and meta-analysis from Clinical Practice Guidelines for the Use of G-CSF 2022.

INTRODUCTION: Chemotherapy for breast cancer can cause neutropenia, increasing the risk of febrile neutropenia (FN) and serious infections. The use of granulocyte colony-stimulating factors (G-CSF) as primary prophylaxis has been explored to mitigate these risks. To evaluate the efficacy and safety of primary G-CSF prophylaxis in patients with invasive breast cancer undergoing chemotherapy. METHODS: A systematic literature review was conducted according to the "Minds Handbook for Clinical Practice Guideline Development" using PubMed, Ichushi-Web, and the Cochrane Library databases. Randomized controlled trials (RCTs) and cohort studies assessing using G-CSF as primary prophylaxis in invasive breast cancer were included. The primary outcomes were overall survival (OS) and FN incidence. Meta-analyses were performed for outcomes with sufficient data. RESULTS: Eight RCTs were included in the qualitative analysis, and five RCTs were meta-analyzed for FN incidence. The meta-analysis showed a significant reduction in FN incidence with primary G-CSF prophylaxis (risk difference [RD] = 0.22, 95% CI: 0.01-0.43, p = 0.04). Evidence for improvement in OS with G-CSF was inconclusive. Four RCTs suggested a tendency for increased pain with G-CSF, but statistical significance was not reported. CONCLUSIONS: Primary prophylactic use of G-CSF is strongly recommended for breast cancer patients undergoing chemotherapy, as it has been shown to reduce the incidence of FN. While the impact on OS is unclear, the benefits of reducing FN are considered to outweigh the potential harm of increased pain.

Comparison between a single dose of PEG G-CSF and multiple doses of non-PEG G-CSF: a systematic review and meta-analysis from Clinical Practice Guidelines for the use of G-CSF 2022.

BACKGROUD: Granulocyte colony-stimulating factor (G-CSF) is widely used for the primary prophylaxis of febrile neutropenia (FN). Two types of G-CSF are available in Japan, namely G-CSF chemically bound to polyethylene glycol (PEG G-CSF), which provides long-lasting effects with a single dose, and non-polyethylene glycol-bound G-CSF (non-PEG G-CSF), which must be sequentially administrated for several days. METHODS: This current study investigated the utility of these treatments for the primary prophylaxis of FN through a systematic review of the literature. A detailed literature search for related studies was performed using PubMed, Ichushi-Web, and the Cochrane Library. Data were independently extracted and assessed by two reviewers. A qualitative analysis or meta-analysis was conducted to evaluate six outcomes. RESULTS: Through the first and second screenings, 23 and 18 articles were extracted for qualitative synthesis and meta-analysis, respectively. The incidence of FN was significantly lower in the PEG G-CSF group than in the non-PEG G-CSF group with a strong quality/certainty of evidence. The differences in other outcomes, such as overall survival, infection-related mortality, the duration of neutropenia (less than 500/µL), quality of life, and pain, were not apparent. CONCLUSIONS: A single dose of PEG G-CSF is strongly recommended over multiple-dose non-PEG G-CSF therapy for the primary prophylaxis of FN.

Optimal timing of prophylactic pegylated G-CSF after chemotherapy administration for patients with cancer: a systematic review and meta-analysis from Clinical Practice Guidelines for the use of G-CSF 2022.

INTRODUCTION: The timing of prophylactic pegylated granulocyte colony-stimulating factor (G-CSF) administration during cancer chemotherapy varies, with Day 2 and Days 3-5 being the most common schedules. Optimal timing remains uncertain, affecting efficacy and adverse events. This systematic review sought to evaluate the available evidence on the timing of prophylactic pegylated G-CSF administration. METHODS: Based on the Minds Handbook for Clinical Practice Guideline Development, we searched the PubMed, Ichushi-Web, and Cochrane Library databases for literature published from January 1990 to December 2019. The inclusion criteria included studies among the adult population using pegfilgrastim. The search strategy focused on timing-related keywords. Two reviewers independently extracted and assessed the data. RESULTS: Among 300 initial search results, only four articles met the inclusion criteria. A meta-analysis for febrile neutropenia incidence suggested a potential higher incidence when pegylated G-CSF was administered on Days 3-5 than on Day 2 (odds ratio: 1.27, 95% CI 0.66-2.46, p = 0.47), with a moderate certainty of evidence. No significant difference in overall survival or mortality due to infections was observed. The trend of severe adverse events was lower on Days 3-5, without statistical significance (odds ratio: 0.72, 95% CI 0.14-3.67, p = 0.69) and with a moderate certainty of evidence. Data on pain were inconclusive. CONCLUSIONS: Both Day 2 and Days 3-5 were weakly recommended for pegylated G-CSF administration post-chemotherapy in patients with cancer. The limited evidence highlights the need for further research to refine recommendations.

MiR-181a targets STING to drive PARP inhibitor resistance in BRCA- mutated triple-negative breast cancer and ovarian cancer.

BACKGROUND: Poly (ADP-ribose) polymerase inhibitors (PARPi) are approved for the treatment of BRCA-mutated breast cancer (BC), including triple-negative BC (TNBC) and ovarian cancer (OvCa). A key challenge is to identify the factors associated with PARPi resistance; although, previous studies suggest that platinum-based agents and PARPi share similar resistance mechanisms. METHODS: Olaparib-resistant (OlaR) cell lines were analyzed using HTG EdgeSeq miRNA Whole Transcriptomic Analysis (WTA). Functional assays were performed in three BRCA-mutated TNBC cell lines. In-silico analysis were performed using multiple databases including The Cancer Genome Atlas, the Genotype-Tissue Expression, The Cancer Cell Line Encyclopedia, Genomics of Drug Sensitivity in Cancer, and Gene Omnibus Expression. RESULTS: High miR-181a levels were identified in OlaR TNBC cell lines (p = 0.001) as well as in tumor tissues from TNBC patients (p = 0.001). We hypothesized that miR-181a downregulates the stimulator of interferon genes (STING) and the downstream proinflammatory cytokines to mediate PARPi resistance. BRCA1 mutated TNBC cell lines with miR-181a-overexpression were more resistant to olaparib and showed downregulation in STING and the downstream genes controlled by STING. Extracellular vesicles derived from PARPi-resistant TNBC cell lines horizontally transferred miR-181a to parental cells which conferred PARPi-resistance and targeted STING. In clinical settings, STING levels were positively correlated with interferon gamma (IFNG) response scores (p = 0.01). In addition, low IFNG response scores were associated with worse response to neoadjuvant treatment including PARPi for high-risk HER2 negative BC patients (p = 0.001). OlaR TNBC cell lines showed resistance to platinum-based drugs. OvCa cell lines resistant to platinum showed resistance to olaparib. Knockout of miR-181a significantly improved olaparib sensitivity in OvCa cell lines (p = 0.001). CONCLUSION: miR-181a is a key factor controlling the STING pathway and driving PARPi and platinum-based drug resistance in TNBC and OvCa. The miR-181a-STING axis can be used as a potential marker for predicting PARPi responses in TNBC and OvCa tumors.

Multicentre, randomised, double-blind, placebo-controlled phase II study of prophylactic olanzapine for patients with metastatic breast cancer receiving T-DXd treatment: protocol for the ERICA study (WJOG14320B).

INTRODUCTION: The antibody-drug conjugate trastuzumab deruxtecan (T-DXd) has led to a change in the clinical management of breast cancer. Nausea and vomiting are the most common adverse events of T-DXd, which cannot be completely alleviated by standard prophylactic regimens. Olanzapine is particularly effective in preventing delayed nausea caused by chemotherapy. In this study, we will evaluate the efficacy of olanzapine in managing persistent nausea and vomiting during T-DXd treatment. METHODS AND ANALYSIS: The ERICA study is a multicentre, placebo-controlled, double-blind, randomised phase II study with the aim to evaluate the antiemetic effects of the prophylactic olanzapine (5 mg orally, on days 1-6) or placebo combined with a 1,5-hydroxytryptamine-3 (5-HT3)-receptor antagonist and dexamethasone in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer undergoing T-DXd treatment. For a period of 22 days from the day of T-DXd treatment, patients will document their experience in an electronic symptom diary daily during observational periods. The primary endpoint is the complete response rate, defined as no vomiting and no rescue medications during the 'delayed phase' of 24-120 hours post-T-DXd administration. In addition, we define 120-504 hour as the 'persistent phase' and 0-504 hours as the 'overall phase' for secondary endpoint analysis. We have estimated that a total sample size of at least 156 patients is needed to allow a power of 80% at a one-sided significance level of 20% in this study. The target sample size is set to 166 to account for possible case exclusions. ETHICS AND DISSEMINATION: The study protocol is approved by the West Japan Oncology Group protocol review committee and the SHOWA University Clinical Research Review Board. The study results will be presented at international conferences and published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: jRCTs031210410.

A Case of Brachial Lymph Node Recurrences after the Resection of Locally Advanced Breast Cancer.

We present a case of two recurrences in the brachial lymph nodes after initial resection, which was performed for radical cure. A 66-year-old woman was diagnosed with left breast cancer T4bN3cM0 Stage IIIC and an immunohistochemistry assay showed estrogen receptor (ER) positivity (5%), progesterone-receptor (PgR) positivity (1%), human epidermal growth factor receptor-2 (HER2) positivity (3+), and low Ki-67 (15%). After four courses of adriamycin and cyclophosphamide, followed by four courses of trastuzumab plus docetaxel, the patient underwent left mastectomy and axillary dissection. Postoperatively, she was diagnosed with breast cancer ypT1cN0M0, and trastuzumab and anastrozole were started. Postoperative irradiation was performed. Three years and 5 months after the initial breast cancer surgery, she had left brachial lymph node recurrence. It was resected, and tamoxifen was administered postoperatively. One year and 9 months after, she had another left brachial lymph node recurrence, and it was resected. She received radiation therapy to her upper limb and started taking exemestane. After 1 year and 3 months since the second recurrence surgery, there has been no recurrence. Our case suggests that the replacement of regional lymph nodes with tumor cells may result in the reconstruction of lymph flow to the upper arm and the development of brachial lymph node metastasis. There are no reports of resection of the recurrent tumor in the brachial lymph node for curative treatment. Therefore, careful follow-up is important in the future.

Establishment of a deep-learning system to diagnose BI-RADS4a or higher using breast ultrasound for clinical application.

Although the categorization of ultrasound using the Breast Imaging Reporting and Data System (BI-RADS) has become widespread worldwide, the problem of inter-observer variability remains. To maintain uniformity in diagnostic accuracy, we have developed a system in which artificial intelligence (AI) can distinguish whether a static image obtained using a breast ultrasound represents BI-RADS3 or lower or BI-RADS4a or higher to determine the medical management that should be performed on a patient whose breast ultrasound shows abnormalities. To establish and validate the AI system, a training dataset consisting of 4028 images containing 5014 lesions and a test dataset consisting of 3166 images containing 3656 lesions were collected and annotated. We selected a setting that maximized the area under the curve (AUC) and minimized the difference in sensitivity and specificity by adjusting the internal parameters of the AI system, achieving an AUC, sensitivity, and specificity of 0.95, 91.2%, and 90.7%, respectively. Furthermore, based on 30 images extracted from the test data, the diagnostic accuracy of 20 clinicians and the AI system was compared, and the AI system was found to be significantly superior to the clinicians (McNemar test, p < 0.001). Although deep-learning methods to categorize benign and malignant tumors using breast ultrasound have been extensively reported, our work represents the first attempt to establish an AI system to classify BI-RADS3 or lower and BI-RADS4a or higher successfully, providing important implications for clinical actions. These results suggest that the AI diagnostic system is sufficient to proceed to the next stage of clinical application.

Genomic profiling reveals heterogeneous populations of ductal carcinoma in situ of the breast.

In a substantial number of patients, ductal carcinoma in situ (DCIS) of the breast will never progress to invasive ductal carcinoma, and these patients are often overtreated under the current clinical criteria. Although various candidate markers are available, relevant markers for delineating risk categories have not yet been established. In this study, we analyzed the clinical characteristics of 431 patients with DCIS and performed whole-exome sequencing analysis in a 21-patient discovery cohort and targeted deep sequencing analysis in a 72-patient validation cohort. We determined that age <45 years, HER2 amplification, and GATA3 mutation are possible indicators of relapse. PIK3CA mutation negativity and PgR negativity were also suggested to be risk factors. Spatial transcriptome analysis further revealed that GATA3 dysfunction upregulates epithelial-to-mesenchymal transition and angiogenesis, followed by PgR downregulation. These results reveal the existence of heterogeneous cell populations in DCIS and provide predictive markers for classifying DCIS and optimizing treatment.

Comprehensive analysis of the homeobox family genes in breast cancer demonstrates their similar roles in cancer and development.

BACKGROUND: The homeobox (HOX) family consists of 39 genes whose expressions are tightly controlled and coordinated within the family, during development. We performed a comprehensive analysis of this gene family in cancer settings. METHODS: Gene correlation analysis was performed using breast cancer data available in The Cancer Genome Atlas (TCGA) and data from the patients admitted to our hospital. We also analyzed the data of normal breast tissue (GSE20437). We next collected gene expression and prognosis data of breast cancer patients (GSE11121, GSE7390, GSE3494, and GSE2990) and performed unsupervised hierarchal clustering by the HOX gene expression pattern and compared prognosis. We additionally performed this analysis to leukemia (available in TCGA) and sarcoma (GSE20196) data. RESULTS: Gene correlation analysis showed that the proximal HOX genes exhibit strong interactions and are expressed together in breast cancer, similar to the expression observed during development. However, in normal breast tissue, less interactions were observed. Breast cancer microarray meta-data classified by the HOX gene expression pattern predicted the prognosis of luminal B breast cancer patients (p = 0.016). Leukemia (p = 0.00016) and sarcoma (p = 0.018) presented similar results. The Wnt signaling pathway, one of the major upstream signals of HOX genes in development, was activated in the poor prognostic group. Interestingly, poor prognostic cancer presented stronger correlation in the gene family compared to favorable prognostic cancer. CONCLUSION: Comprehensive analysis of the HOX family demonstrated their similar roles in cancer and development, and indicated that the strong interaction of HOX genes might be specific to malignancies, especially in the case of poor prognostic cancer.

Clinical benefit of treatment after trastuzumab emtansine for HER2-positive metastatic breast cancer: a real-world multi-centre cohort study in Japan (WJOG12519B).

BACKGROUND: Trastuzumab emtansine (T-DM1) treatment for human epidermal growth factor receptor-2 (HER2)-positive metastatic breast cancer after taxane with trastuzumab and pertuzumab is standard therapy. However, treatment strategies beyond T-DM1 are still in development with insufficient evidence of their effectiveness. Here, we aimed to evaluate real-world treatment choice and efficacy of treatments after T-DM1 for HER2-positive metastatic breast cancer. METHODS: In this multi-centre retrospective cohort study involving 17 hospitals, 325 female HER2-positive metastatic breast cancer patients whose post-T-DM1 treatment began between April 15, 2014 and December 31, 2018 were enrolled. The primary end point was the objective response rate (ORR) of post-T-DM1 treatments. Secondary end points included disease control rate (DCR), progression-free survival (PFS), time to treatment failure (TTF), and overall survival (OS). RESULTS: The median number of prior treatments of post-T-DM1 treatment was four. The types of post-T-DM1 treatments included (1) chemotherapy in combination with trastuzumab and pertuzumab (n = 102; 31.4%), (2) chemotherapy concomitant with trastuzumab (n = 78; 24.0%), (3), lapatinib with capecitabine (n = 63; 19.4%), and (4) others (n = 82; 25.2%). ORR was 22.8% [95% confidence interval (CI): 18.1-28.0], DCR = 66.6% (95% CI 60.8-72.0), median PFS = 6.1 months (95% CI 5.3-6.7), median TTF = 5.1 months (95% CI 4.4-5.6), and median OS = 23.7 months (95% CI 20.7-27.4). CONCLUSION: The benefits of treatments after T-DM1 are limited. Further investigation of new treatment strategies beyond T-DM1 is awaited for HER2-positive metastatic breast cancer patients.

Predictors of invasive disease in patients preoperatively diagnosed with ductal carcinoma without stromal invasion, with breast magnetic resonance imaging (MRI) and ultrasound (US).

BACKGROUND: A preoperative diagnosis of ductal carcinoma in situ (DCIS) is sometimes upstaged to invasive disease postoperatively. Our objective was to clarify the predictive factors of invasive disease using preoperative imaging and to investigate the positive ratio of sentinel lymph nodes (SLN) and the incidence of invasive disease. METHODS: The subjects were 402 patients with preoperatively diagnosed ductal carcinoma without stromal invasion who underwent breast surgery with concomitant SLN surgery in January 2007 to December 2016. Of the 306 included patients, all 306 patients underwent preoperative MRI and US assessment. Outcomes were analyzed for significance using univariate and multivariate analyses. RESULTS: Of the 306 patients, 115 (37.6%) had invasive disease and 191 (62.4%) had DCIS only. Of the 115 patients with invasive disease, 5 (4.4%) and 4 (3.5%) had macro- and micrometastases in SLN. On the other hand, of the 191 patients with DCIS, only 1 (0.5%) had a micrometastasis. Predictors of invasive disease in the univariate analysis included having a palpable mass, were varied by biopsy method, having a US hypoechoic mass, MRI enhancement, or MRI large enhanced lesion; the size of the mass enhancement ≥ 1.1 cm or a spread of non-mass enhancement ≥ 3.1 cm (P = 0.003). Predictors of invasive disease in the multivariate analysis included US hypoechoic mass and MRI large enhanced lesion. CONCLUSION: We need to perform SLN biopsy for preoperatively diagnosed DCIS when patients have predictors of invasive disease, but SLN biopsy will no longer be essential for patients when they have no predictors of invasive disease.

Increased frequency of ESR1 mutation in metastatic breast cancer by dosing selective estrogen receptor modulator followed by aromatase inhibitor.

In several recent studies on metastatic breast cancer (MBC), ligand binding domain mutations of the estrogen receptor, which is coded by the ESR1 gene, were induced by long-term endocrine therapy and resulted in acquired endocrine therapy resistance and poor outcomes. Knowledge of the association between the development of ESR1 mutation and the clinicopathologic features may guide the decision-making process of metastatic breast cancer treatment, including endocrine therapy. The aim of the present study was to evaluate the association between the development of ESR1 mutation and the clinicopathologic characteristics of patients with MBC. To evaluate the association between the development of ESR1 mutation and clinicopathologic features, a cohort of 22 patients with MBC were retrospectively analyzed using next generation sequencing. In 14 of 22 patients, four mutations were detected on the metastatic site, including Tyr537Ser, Glu542Asp, Leu536Arg and Arg548Cys. Univariate analysis demonstrated that the duration of aromatase inhibitor and selective estrogen receptor modulator treatment, as well as the age of treatment initiation for early-stage breast cancer, were significantly associated with the development of ESR1 mutation. ESR1 mutation was identified in all five patients who received selective estrogen receptor modulators in the adjuvant setting followed by aromatase inhibitors in the metastatic setting, as well as in two of the three patients who received no selective estrogen receptor modulators in adjuvant setting followed by aromatase inhibitors in the metastatic setting. In conclusion, the results of the present study suggested that administrating adjuvant selective estrogen receptor modulator followed by aromatase inhibitor for metastasis may increase the frequency of ESR1 mutation.

Avoidance and Period-Shortening of Neoadjuvant Chemotherapy Against Triple-Negative Breast Cancer in Stages I and II: Importance of Ki-67 Labeling Index and the Recognition of Apocrine-Type Lesions.

BACKGROUND: Triple-negative breast cancer encompasses heterogeneous subtypes. Neoadjuvant chemotherapy is ineffective against some triple-negative breast cancers, while others show a favorable prognosis despite chemoresistance. METHODS: A total of 51 cases with stages I and II triple-negative breast cancer were analyzed; 34 triple-negative breast cancers treated with neoadjuvant chemotherapy were divided into "good responders" (n = 22), showing therapeutic effect G2b or G3 in surgical specimens, and "poor responders" with therapeutic effect G0, G1a, G1b, and G2a (n = 12). Neoadjuvant chemotherapy was spared in 17 cases (non-neoadjuvant chemotherapy group). Apocrine-type triple-negative breast cancer was defined as triple-negative breast cancer immunoreactive for both androgen receptor and forkhead-box protein A1. Triple-negative breast cancer other than apocrine-type (n = 16) and special types (myoepithelial, medullary, adenoid cystic, and spindle cell carcinomas, n = 6) was categorized as basal-like subtype (n = 29). Prognosis was evaluated in each category. RESULTS: Neoadjuvant chemotherapy provoked significant effects against basal-like triple-negative breast cancer with high Ki-67 labeling (≧50%), and tumor-infiltrating lymphocytes predicted high chemosensitivity. Neoadjuvant chemotherapy was avoidable in triple-negative breast cancer of apocrine- and special types showing low (<50%) Ki-67 labeling. Ten (59%) lesions in the non-neoadjuvant chemotherapy group belonged to the apocrine-type. When clinical complete remission shown by contrast-enhanced magnetic resonance imaging was reached in the course of neoadjuvant chemotherapy against basal-like triple-negative breast cancer, the neoadjuvant chemotherapy period was shortened in 14 (64%) of 22 good responders. Disease-free and overall survival rates were excellent in all groups. CONCLUSIONS: The following 2 hypothetical proposals should be proven by large-scale clinical trials. Immunohistochemical recognition of apocrine-type triple-negative breast cancer with low Ki-67 labeling is important for avoiding ineffective/unnecessary neoadjuvant chemotherapy. By employing appropriate clinical imaging, period-shortening is achievable in basal-like triple-negative breast cancer with high Ki-67 labeling.

Impact of neoadjuvant and adjuvant chemotherapy on invasive lobular carcinoma: A propensity score-matched analysis of SEER data.

Invasive lobular carcinoma (ILC) has a different treatment response from invasive ductal carcinoma (IDC). We assessed whether perioperative chemotherapy was associated with improved prognosis in patients with ILC. Retrospective data of women who underwent surgery for ILC were extracted from the SEER database. Subjects were divided into non-chemotherapy and chemotherapy groups. Overall, 10 537 patients were included, and 2107 patients were stratified into each group after propensity score matching. Perioperative chemotherapy significantly improved 10-year survival rates for ILC, particularly in patients with large tumor size and lymph node metastases. Perioperative chemotherapy is effective for ILC patients with proper selection.

Heterochronous Suture Line Recurrences in the Jejunal Pouch following Total Gastrectomy for Stage II Gastric Cancer: A Case Report and Literature Review.

We report the case of a 65-year-old male who developed heterochronous local recurrences of gastric cancer in the jejunal pouch (J-pouch) four times after total gastrectomy. He underwent total gastrectomy, J-pouch, and Roux-en-Y reconstruction for stage II gastric cancer in 2005. Four local recurrences appeared on the esophago-jejunal anastomosis, the suture line within the pouch, the esophago-jejunal anastomosis, and the anastomosis between the jejunum and Y-loop, which were resected by partial excision or endoscopic submucosal dissection. Suture line recurrence of gastric cancer is rare. The common features for each recurrence included the surgically negative resection margins, observation of the same histopathological subtype, absence of remote metastasis or peritoneal seeding, and the recurrence on the anastomotic suture line, suggesting that the cause of recurrence was the implantation of exfoliated cancer cells probably in the suture line. However, there is no established procedure for preventing implantation recurrence currently, the effectiveness of lumen lavage is suggested.

Identification of a Modified HOXB9 mRNA in Breast Cancer.

First identified as a developmental gene, HOXB9 is also known to be involved in tumor biological processes, and its aberrant expression correlates with poor prognosis of various cancers. In this study, we isolated a homeodomain-less, novel HOXB9 variant (HOXB9v) from human breast cancer cell line-derived mRNA. We confirmed that the novel variant was produced from variationless HOXB9 genomic DNA. RT-PCR of mRNA isolated from clinical samples and reanalysis of publicly available RNA-seq data proved that the new transcript is frequently expressed in human breast cancer. Exogenous HOXB9v expression significantly enhanced the proliferation of breast cancer cells, and gene ontology analysis indicated that apoptotic signaling was suppressed in these cells. Considering that HOXB9v lacks key domains of homeobox proteins, its behavior could be completely different from that of the previously described variationless HOXB9. Because none of the previous studies on HOXB9 have considered the presence of HOXB9v, further research analyzing the two transcripts individually is warranted to re-evaluate the true role of HOXB9 in cancer.

Optimal use of anthracycline-free perioperative chemotherapy in HER2-positive breast cancer patients.

PURPOSE: In adjuvant settings of human epidermal growth factor receptor 2 (HER2)-positive breast cancer, anthracycline-based chemotherapy followed by taxane and trastuzumab is a standard regimen. Recent studies have reported the use of anthracycline-free adjuvant chemotherapy in selected HER2-positive breast cancer patients. We conducted a single-center retrospective study to identify the characteristics of HER2-positive breast cancer patients for whom anthracyclines can be safely omitted. METHODS: A total of 238 women were diagnosed with HER2-positive breast cancer and treated with neoadjuvant and/or adjuvant chemotherapy between January 1, 2008 and December 31, 2015 at Keio University Hospital. They were divided in two cohorts: an "anthracycline" cohort of 112 anthracycline-treated women and a "no anthracycline" cohort of 126 anthracycline-untreated women. Survival outcomes were estimated by Kaplan-Meier method. RESULTS: The 3-year disease-free survival rates in the no-anthracycline and anthracycline cohorts were 91.3% and 93.1%, respectively (P = 0.692). After using a statistical method with inverse probability of treatment weighting to minimize the selection bias, no significant differences were observed between the two cohorts (adjusted hazard ratio for disease-free survival: 1.042; P = 0.909). Stratified by tumor size, no significant differences were observed between the two cohorts in the cT1N0 and cT2N0 subsets (P = 0.516 and P = 0.579, respectively). The recurrence rate was low among patients who achieved pathological complete response after receiving neoadjuvant chemotherapy with or without anthracyclines. CONCLUSION: Our study suggests that anthracyclines can be safely omitted in selected patients with HER2-positive breast cancer, who have cT1N0 or cT2N0 and achieved pathological complete response after receiving neoadjuvant chemotherapy.

Effectiveness of Antiemetic Regimens for Highly Emetogenic Chemotherapy-Induced Nausea and Vomiting: A Systematic Review and Network Meta-Analysis.

BACKGROUND: It is important to control chemotherapy-induced nausea and vomiting (CINV) to maintain dose intensity and patients' quality of life. The National Comprehensive Cancer Network guidelines suggest combination therapy of antiemetic agents. The growing number of antiemetic regimens, and in particular the growing use of regimens containing antagonists to the Nk-1 receptor (NK1RAs) and the antipsychotic drug olanzapine (OLZ), call for the re-evaluation of the optimal regimen for CINV. This study assessed the efficacy and safety of antiemetic regimens for highly emetogenic chemotherapy, using Bayesian network meta-analysis. METHODS: Randomized trials that compared different antiemetic regimens were included. We strictly followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The main outcomes were the odds ratio (OR) for overall complete response (absence of vomiting). We conducted network meta-analysis within a Bayesian model to combine the direct and indirect evidence. Safety was assessed from the trial description. All statistical tests were two-sided. RESULTS: We systematically reviewed 27 randomized control trials (13,356 participants), which compared 12 different antiemetic regimens: serotonin-3 receptor antagonist (5HT3), 5HT3 + dexamethasone (Dex), palonosetron (PAL), PAL + Dex, PAL at 0.75 mg (PAL0.75), PAL0.75 + Dex, NK1RA + 5HT3 + Dex, NK1RA + PAL + Dex, an oral combination of netupitant and palonosetron (NEPA) + Dex, OLZ + 5HT3 + Dex, OLZ + PAL + Dex, and OLZ + NK1RA + 5HT3 + Dex. An NK1RA + 5HT3 + Dex regimen and an NK1RA + palonosetron + Dex regimen gave a higher complete response (CR) rate than the reference regimen, 5HT3 + Dex (OR, 1.75; 95% credibility interval [95% CrI], 1.56-1.97, and OR, 2.25; 95% CrI, 1.66-3.03, respectively). A regimen containing NEPA was more effective in producing CR than conventional regimens without NEPA or olanzapine. Further analysis, based on the surface under the cumulative ranking probability curve, indicated that olanzapine-containing regimens were the most effective in producing CR. CONCLUSION: Our meta-analysis supports the conclusion that olanzapine-containing regimens are the most effective for CINV of highly emetogenic chemotherapy. We confirmed that NK1RA + PAL + Dex is the most effective of conventional regimens. Substituting olanzapine for an Nk-1 receptor antagonist may offer a less costly and more effective alternative for patients. IMPLICATIONS FOR PRACTICE: Nausea and vomiting during chemotherapy often pose difficulties for patients and doctors, making it hard to continue the proper therapy and to maintain the quality of life. This article gives insights into the optimal choice of medicine to treat nausea during chemotherapy. The findings reported here provide readers with a robust efficacy ranking of antinausea medicine, which can be used as a reference for the best possible treatment. Furthermore, the 70% less costly drug, olanzapine, is suggested to be equally effective to aprepitant in reducing nausea and vomiting. The possibility of offering a cost-effective treatment to a wider range of the population is discussed.