A progressive and refractory case of breast cancer with Cowden syndrome.

BACKGROUND: Cowden syndrome is a rare autosomal-dominant disease with a high risk of malignant tumors of the breast, commonly caused by germline mutations in the PTEN gene. Most breast cancers related to Cowden syndrome showed typically a slow-growing and favorable clinical course. Here, we report a progressive case of triple-negative breast cancer in a patient who was diagnosed with Cowden syndrome. CASE PRESENTATION: A 35-year-old female with breast cancer was referred to our hospital. Histopathological examination of the tumor showed that it was triple-negative breast cancer with high proliferation marker. Preoperative positron emission tomography-computed tomography showed abnormal uptake in the left cerebellar hemisphere in addition to the right breast and axillary lymph node. Brain T2-weighted magnetic resonance imaging revealed hyperintense bands in the left cerebellar hemisphere lesion, which demonstrated a "tiger-stripe" appearance. The patient's mother had died of endometrial cancer. Subsequently, she underwent genetic testing, leading to a diagnosis of Cowden syndrome with a pathogenic variant c.823_840del.18 at exon 8 in PTEN. She was treated with neoadjuvant chemotherapy of eribulin and cyclophosphamide followed by adriamycin and cyclophosphamide. However, her tumors increased after these treatments. She was immediately surgically treated and received adjuvant chemotherapy of capecitabine. Unfortunately, the cancer recurred in the lung nine months after surgery. We then administered paclitaxel and bevacizumab therapy, but the disease rapidly progressed. Consequently, the patient died due to breast cancer about three months after recurrence. CONCLUSION: We report an aggressive case of cancer with Cowden syndrome which was resistant to standard chemotherapy. Alteration of the phosphatidylinositol-3 kinase/Akt/mammalian target of rapamycin pathway due to inactivating PTEN protein may be associated with chemoresistance and serves as a candidate for therapeutic intervention in PTEN-related cancers.

Clinical significance of plasma cell-free DNA mutations in PIK3CA, AKT1, and ESR1 gene according to treatment lines in ER-positive breast cancer.

The somatic activation of PI3K/AKT pathway mutations, PIK3CA and AKT1, and ESR1 mutations in plasma cell-free DNA (cfDNA) has been studied as a non-invasive procedure to quickly assess and monitor disease progression or therapeutic effect in breast cancer (BC) patients, but the clinical significance of these mutations in late treatment lines (TLs) remains unclear. The subjects of this study were a total of 251 plasma samples from 128 estrogen receptor-positive (ER+) BC patients. Of these plasma samples, 133 were from 73 primary BC (PBC) patients, and 118 plasma samples were from 68 metastatic BC (MBC) patients. We developed droplet digital PCR (ddPCR) assays to verify the clinical significance of PIK3CA, AKT1, and ESR1 mutations in these patients. cfDNA PIK3CA mutations were observed in 15.1% of the PBC patients, while a cfDNA AKT1 mutation was observed in 1.4% of patients, and cfDNA ESR1 mutations were observed in 2.7% of patients. Patients with detectable cfDNA PIK3CA mutations were not associated with clinical outcomes. According to the TL, the prevalence of the PIK3CA and ESR1 mutations in cfDNA were lower in early TLs compared with late TLs. In the early TL group, patients with cfDNA PIK3CA mutations had a shorter time to treatment failure (TTF) than patients without mutations (P = 0.035). However, there was no statistically significant difference between patients with or without cfDNA ESR1 mutations. However, in the late TL group, patients with cfDNA ESR1 mutations had a shorter TTF than patients without mutations (P = 0.048). However, there was no statistically significant difference between patients with or without cfDNA PIK3CA mutations. Since the prevalence of cfDNA AKT1 mutation is low in both PBC and MBC patients, the impact of AKT1 mutations on the prognosis remains unclear. We have demonstrated the difference in the clinical significance of the hotspot PIK3CA, AKT1, and ESR1 mutations in cfDNA for each TL in ER+ BC patients.

Therapeutic predictors of neoadjuvant endocrine therapy response in estrogen receptor-positive breast cancer with reference to optimal gene expression profiling.

PURPOSE: Neoadjuvant endocrine therapy (NAET) for estrogen receptor-positive primary breast cancer causes adequate tumor shrinkage, and is expected to be helpful for breast-conserving surgery, but the adaptation criteria, especially in regard to treatment duration, have never been elucidated. Re-visiting past gene expression profiles, we explored the data for specialized pre-therapeutic predictors and validated the results using our in-house clinical cohorts. METHODS: We sorted the genes related to a > 30% tumor volume reduction through NAET from a cDNA microarray data-set of GSE20181, then selected the top 40 genes. We validated these gene expression levels using pre-therapeutic biopsy samples obtained from patients treated with long-term NAET (over 4 months; N = 40). A short-term (2-8 weeks; N = 37) NAET cohort was also validated to clarify whether expression of these genes is also related to a rapid response of Ki67 and PEPI score. RESULTS: In the long-term group, higher expression of KRAS, CUL2, FAM13A, ADCK2, and LILRA2 was significantly associated with tumor shrinkage, and KRAS, MMS19, and IVD were related to lower PEPI score (≤ 3). Meanwhile in the short-term group, none of these genes except CUL2 showed a direct correlation with Ki67 reduction or PEPI score. This suggested that tumor shrinkage by NAET might be induced by response to the hypoxic environment (CUL2, FAM13A, KRAS) and activation of tumor immune system (LILRA2), without involving inhibition of proliferation. CONCLUSION: Expression of specific genes may allow selection of the most responsive patients for maximum tumor shrinkage with NAET.

High density of CD204-positive macrophages predicts worse clinical prognosis in patients with breast cancer.

Recent studies have indicated the clinical significance of tumor-associated macrophages (TAM) in several malignant tumors including breast cancer. Although recent studies have focused on CD68-positive or CD163-positive TAM in breast cancer, no study has investigated the significance of CD204-positive TAM in breast cancer. We found that CD204 expression on macrophages was evaluated following stimulation with the conditioned medium (CM) of breast cancer cell lines. Paraffin sections of 149 breast cancer samples which were diagnosed as invasive ductal carcinoma were immunohistochemically analyzed for CD68, CD163 and CD204 expression. The results of analyses indicated that a high number of CD204-positive TAM was associated with worse clinical prognoses, including relapse-free survival, distant relapse-free survival and breast cancer-specific survival; however, neither the numbers of CD68-positive or CD163-positive TAM were associated with clinical courses. Of the clinicopathological factors investigated, estrogen receptor, Ki-67 index, hormone subtype, and histological grade were significantly related to the increased number of CD163-positive and CD204-positive TAM. These data indicate the clinical significance of CD204-positive TAM in breast cancer progression and CD204 is a marker for predicting clinical prognosis in breast cancer.

Prevalence of ESR1 E380Q mutation in tumor tissue and plasma from Japanese breast cancer patients.

BACKGROUND: ESR1 mutations have attracted attention as a potentially important marker and treatment target in endocrine therapy-resistant breast cancer patients. The E380Q mutation, which is one of the ESR1 mutations, is associated with estradiol (E2) hypersensitivity, increased DNA binding to the estrogen response element, and E2-independent constitutive trans-activation activity, but its frequency in ESR1 mutations remains unknown. The present study aimed to investigate the E380Q mutation in comparison with the other representative ESR1 mutations. METHODS: We screened a total of 62 patients (66 tumor tissues and 69 plasma cell-free DNA (cfDNA)) to detect ESR1 mutations (E380Q, Y537S, Y537N, Y537C, and D538G) using droplet-digital polymerase chain reaction. Plasma was collected at more than two points of the clinical course, in whom changes of ESR1 mutations under treatment were investigated. RESULTS: We detected ESR1 mutations in 21% (12/57) of MBCs. The E380Q ESR1 mutation was found in 16% (2/12) and the other ESR1 LBD mutations were five (41.6%) of Y537S, and four each (33.3%) of D538G, Y537N, and Y537C, in 12 ESR1 mutant breast cancer patients. Five tumors had multiple ESR1 mutations: three had double ESR1 mutations; Y537S/E380Q, Y37S/Y537C, and Y537S/D538G, and two had triple ESR1 mutations; Y537S/Y537N/D538G. In plasma cfDNA analysis, the E380Q mutation was not detected, but increases in other ESR1 mutations were detected in 46.2% (6/13) of MBC patients under treatment. CONCLUSIONS: We have shown that there are distinct populations of ESR1 mutations in metastatic tissue and plasma. Each ESR1 mutation may have different clinical significance, and it will be necessary to investigate them all.

Fibroblast growth factor receptor-1 protein expression is associated with prognosis in estrogen receptor-positive/human epidermal growth factor receptor-2-negative primary breast cancer.

Recently, research into the development of new targeted therapies has focused on specific genetic alterations to create advanced, more personalized treatment. One of the target genes, fibroblast growth factor receptor-1 (FGFR1), has been reported to be amplified in estrogen receptor (ER)-positive subtype breast cancer, and is considered one possible mechanism of endocrine resistance through cross-talk between ER and growth factor receptor signaling. We performed a comprehensive analysis of FGFR1 at the levels of gene copy number, transcript and protein expression, and examined the relationships between FGFR1 status and clinicopathological parameters, including prognosis in 307 ER-positive/HER2-negative primary breast cancer patients treated with standard care at our institute. Most notably, a high level of FGFR1 protein expression was observed in 85 patients (27.7%), and was positively associated with invasive tumor size (P = 0.039). Furthermore, univariate analysis revealed that high FGFR1 protein expression was significantly correlated with poor relapse-free survival rate (P = 0.0019, HR: 2.63, 95% confidence interval: 1.17-5.98), and showed a tendency towards an increase in recurrent events if the observation period extended beyond the 5 years of the standard endocrine treatment term. FGFR1 gain/amplification was found in 43 (14.0%) patients, which was only associated with higher nuclear grade (P = 0.010). No correlation was found between FGFR1 mRNA expression levels and any clinicopathological factors. Overall, the level of FGFR1 protein expression may be a biomarker of ER-positive/HER2-negative primary breast cancer with possible resistance to standard treatment, and may be a useful tool to identify more specific patients who would benefit from FGFR-1 targeted therapy.

GANP protein encoded on human chromosome 21/mouse chromosome 10 is associated with resistance to mammary tumor development.

Human chromosome 21 is known to be associated with the high risk of hematological malignancy but with resistance to breast cancer in the study of Down syndrome. In human cancers, we previously observed the significant alterations of the protein expression encoded by the ganp/MCM3AP gene on human chromosome 21q22.3. Here, we investigated GANP protein alterations in human breast cancer samples (416 cases) at various stages by immunohistochemical analysis. This cohort study clearly showed that expression of GANP is significantly decreased in human breast cancer cases with poor prognosis as an independent risk factor (relapse-free survival, hazard ratio = 2.37, 95% confidence interval, 1.27-4.42, P = 0.007 [univariate analysis]; hazard ratio = 2.70, 95% confidence interval, 1.42-5.13, P = 0.002 [multivariate analysis]). To investigate whether the altered GANP expression is associated with mammary tumorigenesis, we created mutant mice that were conditionally deficient in the ganp/MCM3AP gene using wap-cre recombinase transgenic mice. Mammary gland tumors occurred at a very high incidence in female mammary gland-specific GANP-deficient mice after severe impairment of mammary gland development during pregnancy. Moreover, tumor development also occurred in female post parous GANP-heterodeficient mice. GANP has a significant role in the suppression of DNA damage caused by estrogen in human breast cancer cell lines. These results indicated that the GANP protein is associated with breast cancer resistance.

Prediction of sentinel lymph node status using single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging of breast cancer.

PURPOSE: Single-photon emission computed tomography (SPECT)/computed tomography (CT) improves the anatomical identification of sentinel lymph nodes (SNs). We aimed to evaluate the possibility of predicting the SN status using SPECT/CT. METHODS: SN mapping using a SPECT/CT system was performed in 381 cases of clinically node-negative, operable invasive breast cancer. We evaluated and compared the values of SN mapping on SPECT/CT, the findings of other modalities and clinicopathological factors in predicting the SN status. RESULTS: Patients with SNs located in the Level I area were evaluated. Of the 355 lesions (94.8 %) assessed, six cases (1.6 %) were not detected using any imaging method. According to the final histological diagnosis, 298 lesions (78.2 %) were node negative and 83 lesions (21.7 %) were node positive. The univariate analysis showed that SN status was significantly correlated with the number of SNs detected on SPECT/CT in the Level I area (P = 0.0048), total number of SNs detected on SPECT/CT (P = 0.011), findings of planar lymphoscintigraphy (P = 0.011) and findings of a handheld gamma probe during surgery (P = 0.012). According to the multivariate analysis, the detection of multiple SNs on SPECT/CT imaging helped to predict SN metastasis. CONCLUSIONS: The number of SNs located in the Level I area detected using the SPECT/CT system may be a predictive factor for SN metastasis.

Prognostic role of PIK3CA mutations of cell-free DNA in early-stage triple negative breast cancer.

PIK3CA is an oncogene that encodes the p110α component of phosphatidylinositol 3-kinase (PI3K); it is the second most frequently mutated gene following the TP53 gene. In the clinical setting, PIK3CA mutations may have favorable prognostic value for hormone receptor-positive breast cancer patients and, during the past few years, PIK3CA mutations of cell-free DNA (cfDNA) have attracted attention as a potential noninvasive biomarker of cancer. However, there are few reports on the clinical implications of PIK3CA mutations for TNBC patients. We investigated the PIK3CA major mutation status of cfDNA as a noninvasive biomarker of cancer using droplet digital polymerase chain reaction (ddPCR), which has high level sensitivity and specificity for cancer mutation, in early-stage 49 triple negative breast cancer (TNBC) patients. A total of 12 (24.4%) of 49 patients had PIK3CA mutations of cfDNA. In a median follow up of 54.4 months, the presence of PIK3CA mutations of cfDNA had significant impacts on relapse-free survival (RFS; P = 0.0072) and breast cancer-specific survival (BCSS; P = 0.016), according to the log-lank test. In a Cox proportional hazards model, the presence of PIK3CA mutations of cfDNA had significant prognostic value in the univariate and multivariate analysis. Additionally, the presence of PIK3CA mutations of cfDNA was significantly correlated with positive androgen receptor phosphorylated form depending on PI3K signaling pathway (pAR) which is independent favorable prognostic factors of TNBC. We demonstrated that the presence of PIK3CA major mutations of cfDNA could be a discriminatory predictor of RFS and BCSS in early-stage TNBC patients and it was associated with PI3K pathway-dependent AR phosphorylation.

Targeted therapies for ER+/HER2- metastatic breast cancer.

The majority of breast cancers present with estrogen receptor (ER)-positive and human epidermal growth factor receptor (HER2)-negative features and might benefit from endocrine therapy. Although endocrine therapy has notably evolved during the last decades, the invariable appearance of endocrine resistance, either primary or secondary, remains an important issue in this type of tumor. The improvement of our understanding of the cancer genome has identified some promising targets that might be responsible or linked to endocrine resistance, including alterations affecting main signaling pathways like PI3K/Akt/mTOR and CCND1/CDK4-6 as well as the identification of new ESR1 somatic mutations, leading to an array of new targeted therapies that might circumvent or prevent endocrine resistance. In this review, we have summarized the main targeted therapies that are currently being tested in ER+ breast cancer, the rationale behind them, and the new agents and combinational treatments to come.

Clinical significance of CYLD downregulation in breast cancer.

Cylindromatosis (CYLD) is a tumor suppressor gene that is mutated in familial cylindromatosis, a rare autosomal dominant disorder associated with numerous benign skin adnexal tumors. CYLD is now known to regulate various signaling pathways, including transforming growth factor-ß signaling, Wnt/ß-catenin signaling, and NF-κB signaling by deubiquitinating upstream regulatory factors. Downregulation of CYLD has been reported in several malignancies; however, the clinical significance of CYLD expression in many malignancies, including breast cancer, remains to be elucidated. This study investigated the clinical significance of CYLD in breast cancer and its roles in tumor progression. We evaluated CYLD expression in matched normal breast tissue samples and tumor breast tissue samples from 26 patients with breast cancer and in a series of breast cancer cell lines. In addition, by means of immunohistochemistry, we investigated CYLD protein expression and its clinical significance in 244 breast cancer cases. We also analyzed the effects of CYLD repression or overexpression on breast cancer cell viability, cell migration, and NF-κB activity with or without receptor activator of NF-κB ligand (RANKL) stimulation. Breast cancer tissues demonstrated significantly reduced CYLD mRNA expression compared with normal breast tissues. Downregulation of CYLD promoted cell survival and migratory activities through NF-κB activation, whereas CYLD overexpression inhibited those activities in MDA-MB-231 cells. As an important finding, CYLD overexpression also inhibited RANKL-induced NF-κB activation. Our immunohistochemical analysis revealed that reduced CYLD protein expression was significantly correlated with estrogen receptor negativity, high Ki-67 index, high nuclear grade, decreased disease-free survival, and reduced breast cancer-specific survival in primary breast cancer. Moreover, reduced CYLD expression was an independent factor for poor prognosis in breast cancer. CYLD downregulation may promote breast cancer metastasis via NF-κB activation, including RANKL signaling.

[Efficacy and safety of TS-1 monotherapy for advanced/metastatic breast cancer - an observational study by the Kumamoto Breast Cancer Cooperative Group(KBCCG)].

TS-1, an oral fluoropyrimidine, is known to be effective for the treatment of various carcinomas including advanced/metastatic breast cancer.The Kumamoto Breast Cancer Cooperative Group(KBCCG)conducted an observational study, wherein, the efficacy and safety of TS-1 monotherapy was analyzed in 35 patients with recurrent or metastatic breast cancer.The median time to cancer progression was 3.7 months, overall response rate was 12%, and clinical benefit rate was 32%. Adverse events were observed in 27 patients(77%), and adverse events of Grade >3 were observed in 7 patients(20%). The rate of treatment-related Grade 3 and 4 adverse events increased, and was associated with poor levels of creatinine clearance(Ccr)ie <60mL/min.This study suggests that TS-1 monotherapy can potentially be used as a salvage treatment for advanced/metastatic breast cancer owing to its safety and efficacy.Measuring the level of Ccr before TS-1 therapy should be considered to avoid severe adverse events.

Comparison of prognostic values between combined immunohistochemical score of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67 and the corresponding gene expression score in breast cancer.

In the clinical diagnosis of breast cancer, immunohistochemistry panels with estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2) and Ki-67 are routinely used, and they have been proposed for the classification of breast tumors into distinct subtypes. Gene expression analysis with formalin-fixed paraffin-embedded material have also become widely available recently, but the prognostic values of corresponding gene panels compared with these four immunohistochemical panels had never tested. We independently evaluated the 5-year relapse risk-estimation scores using semiquantitative data of four immunohistochemical panels (Ku-IHC4 score) and compared these with the results of four-gene expression profiling of formalin-fixed paraffin-embedded specimens (Ku-FFPE4 score) in a consecutive series of 235 primary invasive breast cancer patients. Ku-IHC4 score was revealed to be an independent predictor of recurrence other than Ku-FFPE4 score in a multivariate model analyzed by classical clinical parameters (Ku-IHC4 score vs Ku-FFPE4 score; χ(2): 14.2 vs 2.5, P: 0.0002 vs 0.11). When patients were trichotomized into high-, intermediate- and low-risk groups using the thresholds determined from the approximately calculated 5-year relapse rate, Kaplan-Meier analyses showed a significant difference among the three groups in Ku-IHC4 score (log-rank, P<0.0001), but not in Ku-FFPE4 score. The high-risk group according to Ku-FFPE4 score showed contradictory low recurrence rates (Ku-IHC4 score vs Ku-FFPE4 score, 53.1 vs 24.8%), which might be caused by risk-dependently extended error ranges. We show that the Ku-IHC4 score, consisted with semiquantitative measures of immunohistochemistry, provides better prognostic information than the corresponding quantitative RNA measurements. Prognostication tools such as the Ku-IHC4 score may be potentially useful in screening which patients had better be assessed by further testing using other genes rather than ER, PgR, HER2 and Ki-67 to determine critical aspects of therapeutic decision making.

A comprehensive analysis of Aurora A; transcript levels are the most reliable in association with proliferation and prognosis in breast cancer.

BACKGROUND: Aurora A kinase, a centrosomal serine/threonine kinase which plays an essential role in chromosome segregation during cell division, is commonly amplified and/or over expressed in human malignancies. Aurora A is suggested to be one of the proliferation parameters which is an independent prognostic factor for early invasive breast cancer patients; however the individual clinical or prognostic relevance of this gene has been a matter of debate. METHODS: A comprehensive analysis of Aurora A at the levels of gene expression, gene copy number and protein expression was performed for 278 primary invasive breast cancer patients; and the correlation with clinical outcomes were investigated. RESULTS: Aurora A gene expression level not only correlated with gene amplification, but was also significantly associated with several clinicopathological parameters and patient prognosis. Patients with higher nuclear grade, negative progesterone receptor status and higher Ki67 expressed higher levels of Aurora A mRNA, which was associated not only with poor relapse-free survival (RFS) but was also found to be a significant multivariate parameter for RFS. Aurora A protein expression was also significantly associated with clinicopathological characteristics; lymph node status, nuclear grade, estrogen receptor status and Ki67, but not with prognosis. By contrast, Aurora A gene amplification correlated with tumor size, nuclear grade and Ki67, and had no prognostic value. CONCLUSION: Our data indicate that Aurora A gene expression is an effective tool, which defines both tumor proliferation potency and patient prognosis.

Randomized controlled trial of toremifene 120 mg compared with exemestane 25 mg after prior treatment with a non-steroidal aromatase inhibitor in postmenopausal women with hormone receptor-positive metastatic breast cancer.

BACKGROUND: After the failure of a non-steroidal aromatase inhibitor (nsAI) for postmenopausal patients with metastatic breast cancer (mBC), it is unclear which of various kinds of endocrine therapy is the most appropriate. A randomized controlled trial was performed to compare the efficacy and safety of daily toremifene 120 mg (TOR120), a selective estrogen receptor modulator, and exemestane 25 mg (EXE), a steroidal aromatase inhibitor. The primary end point was the clinical benefit rate (CBR). The secondary end points were objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and toxicity. METHODS: Initially, a total of 91 women was registered in the study and randomly assigned to either TOR120 (n = 46) or EXE (n = 45) from October 2008 to November 2011. Three of the 46 patients in the TOR120 arm were not received treatment, 2 patients having withdrawn from the trial by their preference and one having been dropped due to administration of another SERM. RESULTS: When analyzed after a median observation period of 16.9 months, the intention-to-treat analysis showed that there were no statistical difference between TOR120 (N = 46) and EXE (n = 45) in terms of CBR (41.3% vs. 26.7%; P = 0.14), ORR (10.8% vs. 2.2%; P = 0.083), and OS (Hazard ratio, 0.60; P = 0.22). The PFS of TOR120 was longer than that of EXE, the difference being statistically significant (Hazard ratio, 0.61, P = 0.045). The results in treatment-received cohort (N = 88) were similar to those in ITT cohort. Both treatments were well-tolerated with no severe adverse events, although the treatment of 3 of 43 women administered TOR120 was stopped after a few days because of nausea, general fatigue, hot flush and night sweating. CONCLUSIONS: TOR120, as a subsequent endocrine therapy for mBC patients who failed non-steroidal AI treatment, could potentially be more beneficial than EXE. TRIAL REGISTRATION NUMBER: UMIN000001841.

Breast cancers with high DSS1 expression that potentially maintains BRCA2 stability have poor prognosis in the relapse-free survival.

BACKGROUND: Genetic BRCA2 insufficiency is associated with breast cancer development; however, in sporadic breast cancer cases, high BRCA2 expression is paradoxically correlated with poor prognosis. Because DSS1, a mammalian component of the transcription/RNA export complex, is known to stabilize BRCA2, we investigated how the expression of DSS1 is associated with clinical parameters in breast cancers. METHODS: DSS1 mRNA and p53 protein were examined by RT-PCR and immunohistochemical staining of breast cancer specimens to classify DSS1(high) and DSS1(low) or p53(high) and p53(low) groups. Patient survival was compared using Kaplan-Meier method. DSS1(high) or DSS1(low) breast cancer cells were prepared by retroviral cDNA transfection or DSS1 siRNA on proliferation, cell cycle progression, and survival by flow cytometric analyses with or without anti-cancer drugs. RESULTS: In comparison to patients with low levels of DSS1, high-DSS1 patients showed a poorer prognosis, with respect to relapse-free survival period. The effect of DSS1 was examined in breast cancer cells in vitro. DSS1 high-expression reduces the susceptibility of MCF7 cells to DNA-damaging drugs, as observed in cell cycle and apoptosis analyses. DSS1 knockdown, however, increased the susceptibility to the DNA-damaging drugs camptothecin and etoposide and caused early apoptosis in p53 wild type MCF7 and p53-insufficient MDA-MB-231 cells. DSS1 knockdown suppresses the proliferation of drug-resistant MDA-MB-231 breast cancer cells, particularly effectively in combination with DNA-damaging agents. CONCLUSION: Breast cancers with high DSS1 expression have worse prognosis and shorter relapse-free survival times. DSS1 is necessary to rescue cells from DNA damage, but high DSS1 expression increases drug resistance. We suggest that DSS1 expression could be a useful marker for drug resistance in breast cancers, and DSS1 knockdown can induce tumor apoptosis when used in combination with DNA-damaging drugs.

Predictive and prognostic significance of BRCAness in HER2-negative breast cancer.

BACKGROUND: BRCAness is characterized as the phenotypes shared between some sporadic tumors and BRCA1/2 mutation cancers resulting in defective homologous recombination. The predictive or prognostic value of BRCAness in HER2-negative breast cancer patients who have received neoadjuvant chemotherapy (NAC) is not fully elucidated. METHODS: We retrospectively selected 101 high-risk HER2-negative patients diagnosed with stage I-III breast cancer who underwent NAC treatment and evaluated BRCA1-like phenotype using multiplex ligation-dependent probe amplification assay. In an analysis of BRCAness, 95 out of 101 patients were analyzed. RESULTS: In total, 70 (74%) patients had sporadic-type tumors and 25 (26%) had BRCA1-like tumors according to pre-treatment samples. The BRCA1-like phenotype was not associated with pathological complete response (pCR) rate in the entire cohort. In survival analysis, pre-treatment BRCA1-like phenotype was not associated with survival. On the other hand, post-treatment BRCA1-like patients apparently showed shorter relapse-free survival (log-rank P = 0.016) and breast cancer-specific survival (P < 0.001) compared with sporadic features. In multivariate analysis, only the post-treatment BRCA1-phenotype was significant prognostic factors (HR 5.67, 95% CI 1.19-29.3). Furthermore, we found phenotype change between BRCA1-like and sporadic type through NAC in 19% of non-pCR patients. Post-treatment Ki67 significantly decreased in the persistent sporadic tumors during treatment or sporadic tumors changed after NAC (P < 0.0001, P = 0.0078, respectively). CONCLUSIONS: BRCAness may be useful biomarkers to predict prognosis for HER2-negative breast cancer refractory to standard chemotherapy. Our results pave the way for identifying patients who require alternative therapies.

Exosomal miRNA profiles of triple-negative breast cancer in neoadjuvant treatment.

Triple-negative breast cancer (TNBC) is characterized by aggressive clinicopathological features and is associated with a poor prognosis. Identifying patients that are non-responsive to chemotherapy remains a critical goal for effective personalized therapies. In the present study, the predictive value of exosomal microRNAs (miRNAs) was investigated in patients with TNBC. Exosomes were isolated from patients with TNBC undergoing neoadjuvant chemotherapy. Microarray-based miRNA profiles were compared between patients with pathological complete response (pCR; n=12) and non-pCR (n=12). Furthermore, the miRNA profiles of non-pCR patients with breast cancer recurrence were compared with those with no recurrence. A total of 16 differentially expressed exosomal miRNAs were identified between the patients with pCR and non-pCR by microarray analysis. Of these, a combined signature of four miRNAs (miR-4448, miR-2392, miR-2467-3p and miR-4800-3p) could be used to discriminate between pCR and non-pCR patients with TNBC with an area under the curve value of 0.7652. Furthermore, this study found 43 differentially expressed miRNAs between the patients with non-pCR and recurrence and non-pCR patients without recurrence. In network analysis, 'pathway in cancer', 'focal adhesion' and 'cell cycle' were identified as the crucial pathways in patients with non-pCR who also developed recurrence. Several exosomal miRNAs may be useful biomarkers to predict treatment efficacy for TNBC. The present study identified patients who were resistant to standard chemotherapy and therefore more likely to develop breast cancer recurrence.

Neoadjuvant endocrine therapy for estrogen receptor-positive primary breast cancer.

Neoadjuvant endocrine treatment (NAE) for estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative primary breast cancer improves the surgical outcome, and its therapeutic response is useful for predicting prognosis. The indication for NAE is patients who have highly hormone-sensitive breast cancer. The optimal treatment duration depends on the required endpoint. In the case of tumor reduction or introduction to breast-conserving surgery (BCS), a treatment period of at least 6 months is required. Several clinical trials are underway to develop treatment strategies based on shortterm responsiveness to NAE to improve the prognosis of hormone receptor (HR)-positive/HER2-negative breast cancer. This article outlines the current status of NAE and new treatment strategies based on the responsiveness during NAE or clinical and biological feature on residual tumor after NAE.

BRCAness as an Important Prognostic Marker in Patients with Triple-Negative Breast Cancer Treated with Neoadjuvant Chemotherapy: A Multicenter Retrospective Study.

Triple-negative breast cancer (TNBC) has several subtypes. The identification of markers associated with recurrence and poor prognosis in patients with TNBC is urgently needed. BRCAness is a set of traits in which BRCA1 dysfunction, arising from gene mutation, methylation, or deletion, results in DNA repair deficiency. In the current study, we evaluated the clinical significance and prognosis of BRCAness in a multicenter retrospective study. Ninety-four patients with TNBC treated with neoadjuvant chemotherapy were enrolled from three university hospitals for this retrospective study. BRCAness was evaluated in 94 core needle biopsy (CNB) specimens prior to neoadjuvant chemotherapy and 49 surgical specimens without pathological complete response (pCR). The samples were assessed using multiplex ligation-dependent probe amplification, and the amplicons were scored. Of the 94 patients, 51 had BRCAness in CNB specimens. There were no significant differences in pCR rates or recurrence between the BRCAness and non-BRCAness groups. Among surgical specimens, the BRCAness group had a significantly shorter recurrence-free survival and overall survival compared with the non-BRCAness group. The BRCAness of surgical specimens was found to be an important marker to predict prognosis in patients with TNBC after neoadjuvant chemotherapy. A clinical trial to assess the clinical impact of carboplatin with BRCAness is planned.