Takahiro Kogawa

The Role of Inflammation in Inflammatory Breast Cancer

Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. Despite extensive study, whether inflammation contributes to the tumorigenicity or aggressiveness of IBC remains largely unknown. In this chapter, we will review the potential role played by inflammation in IBC based on the results of in vitro, in vivo, and patient studies. Current evidence suggests that several major inflammatory signaling pathways are constitutively active in IBC and breast cancer. Among them, the NF-κB, COX-2, and JAK/STAT signaling systems seem to play a major role in the tumorigenesis of IBC. Inflammatory molecules such as interleukin-6, tumor necrosis factor alpha (TNF-α), and gamma interferon have been shown to contribute to malignant transformation in preclinical studies of IBC, while transforming growth factor-β, interleukins 8 and 1β, as well as TNF-α appear to play a role in proliferation, survival, epithelial-mesenchymal transition, invasion, and metastasis. In this chapter, we also describe work thus far involving inhibitors of inflammation in the development of prevention and treatment strategies for IBC.

Comparison of molecular subtype distribution in triple-negative inflammatory and non-inflammatory breast cancers

IntroductionBecause of its high rate of metastasis, inflammatory breast cancer (IBC) has a poor prognosis compared with non-inflammatory types of breast cancer (non-IBC). In a recent study, Lehmann and colleagues identified seven subtypes of triple-negative breast cancer (TNBC). We hypothesized that the distribution of TNBC subtypes differs between TN-IBC and TN-non-IBC. We determined the subtypes and compared clinical outcomes by subtype in TN-IBC and TN-non-IBC patients.MethodsWe determined TNBC subtypes in a TNBC cohort from the World IBC Consortium for which IBC status was known (39 cases of TN-IBC; 49 cases of TN-non-IBC). We then determined the associations between TNBC subtypes and IBC status and compared clinical outcomes between TNBC subtypes.ResultsWe found the seven subtypes exist in both TN-IBC and TN-non-IBC. We found no association between TNBC subtype and IBC status (P = 0.47). TNBC subtype did not predict recurrence-free survival. IBC status was not a significant predictor of recurrence-free or overall survival in the TNBC cohort.ConclusionsOur data show that, like TN-non-IBC, TN-IBC is a heterogeneous disease. Although clinical characteristics differ significantly between IBC and non-IBC, no unique IBC-specific TNBC subtypes were identified by mRNA gene-expression profiles of the tumor. Studies are needed to identify the subtle molecular or microenvironmental differences that contribute to the differing clinical behaviors between TN-IBC and TN-non-IBC.

c-Jun N-terminal kinase promotes stem cell phenotype in triple-negative breast cancer through upregulation of Notch1 via activation of c-Jun

c-Jun N-terminal kinase (JNK) plays a vital role in malignant transformation of different cancers, and JNK is highly activated in basal-like triple-negative breast cancer (TNBC). However, the roles of JNK in regulating cancer stem-like cell (CSC) phenotype and tumorigenesis in TNBC are not well defined. JNK is known to mediate many cellular events via activating c-Jun. Here, we found that JNK regulated c-Jun activation in TNBC cells and that JNK activation correlated with c-Jun activation in TNBC tumors. Furthermore, the expression level of c-Jun was significantly higher in TNBC tumors than in non-TNBC tumors, and high c-Jun mRNA level was associated with shorter disease-free survival of patients with TNBC. Thus, we hypothesized that the JNK/c-Jun signaling pathway contributes to TNBC tumorigenesis. We found that knockdown of JNK1 or JNK2 or treatment with JNK-IN-8, an adenosine triphosphate-competitive irreversible pan-JNK inhibitor, significantly reduced cell proliferation, the ALDH1+ and CD44+/CD24− CSC subpopulations, and mammosphere formation, indicating that JNK promotes CSC self-renewal and maintenance in TNBC. We further demonstrated that both JNK1 and JNK2 regulated Notch1 transcription via activation of c-Jun and that the JNK/c-Jun signaling pathway promoted CSC phenotype through Notch1 signaling in TNBC. In a TNBC xenograft mouse model, JNK-IN-8 significantly suppressed tumor growth in a dose-dependent manner by inhibiting acquisition of the CSC phenotype. Taken together, our data demonstrate that JNK regulates TNBC tumorigenesis by promoting CSC phenotype through Notch1 signaling via activation of c-Jun and indicate that JNK/c-Jun/Notch1 signaling is a potential therapeutic target for TNBC.

Effectiveness of an Adjuvant Chemotherapy Regimen for Early-Stage Breast Cancer: A Systematic Review and Network Meta-analysis

IMPORTANCE Different adjuvant chemotherapy regimens are available for early-stage breast cancer. Because conventional meta-analysis does not allow comparing all regimens, we performed a network meta-analysis to identify the most effective adjuvant chemotherapy regimen. OBJECTIVE To find the most effective adjuvant therapy regimen for early-stage breast cancer. DATA SOURCES We searched MEDLINE, Embase, and the Cochrane Library for articles published before June 2015; the American Society of Clinical Oncology annual meeting abstracts from January 1983 through December 2014; and the American Association for Cancer Research annual meeting abstracts from January 1916 through December 2014. Additionally, we manually searched bibliographies for related references. STUDY SELECTION We included randomized clinical trials of adjuvant treatments for early-stage breast cancer that compared 2 or more of the following: no adjuvant chemotherapy; sequential anthracycline-cyclophosphamide and taxane (AC-T); concurrent anthracycline-cyclophosphamide and taxane (ACT); anthracycline-cyclophosphamide without taxane (AC); docetaxel and cyclophosphamide (TC); cyclophosphamide, methotrexate, and fluorouracil (CMF); and platinum-containing regimens. DATA EXTRACTION AND SYNTHESIS We followed the PRISMA guidelines. Two investigators independently selected the articles and extracted information. Disagreements were resolved by discussion with another author. Quality was assessed by Cochrane risk-of-bias method. Data were pooled using random-effects models. MAIN OUTCOMES AND MEASURES We used network meta-analysis to test the most effective adjuvant therapy regimen in terms of overall survival (OS) by comparing regimens listed in the National Comprehensive Cancer Network guidelines and platinum-containing regimens. RESULTS We identified 24 trials. The TC and platinum-containing regimens had OS benefit similar to that of sequential AC-T (TC hazard ratio [HR], 0.93; 95% CI, 0.62-1.40; and platinum HR, 0.93; 95% CI, 0.66-1.31). Patients treated with CMF or AC had significantly worse OS than those treated with sequential AC-T (CMF HR, 1.56; 95% CI, 1.32-1.85; and AC HR, 1.22; 95% CI, 1.10-1.37). Platinum-containing regimens tended to be more toxic than sequential AC-T. The toxicity of TC was similar to or less than that of sequential AC-T. Meta-regression analysis showed that hormone receptor status did not impact the HRs for OS for any regimen. CONCLUSIONS AND RELEVANCE Sequential AC-T is likely to be the most effective adjuvant therapy regimen for early-stage breast cancer regardless of hormone receptor status.

Revisiting the definition of estrogen receptor positivity in HER2-negative primary breast cancer

Background Although 1% has been used as cut-off for estrogen receptor (ER) positivity, several studies have reported that tumors with ER < 1% have characteristics similar to those with 1% ≤ ER < 10%. We hypothesized that in patients with human epidermal growth factor 2 (HER2)-negative breast cancer, a cut-off of 10% is more useful than one of 1% in discriminating for both a better pathological complete response (pCR) rate to neoadjuvant chemotherapy and a better long-term outcome with adjuvant hormonal therapy. Our objectives were to identify a percentage of ER expression below which pCR was likely and to determine whether this cut-off value can identify patients who would benefit from adjuvant hormonal therapy. Patients and methods Patients with stage II or III HER2-negative primary breast cancer who received neoadjuvant chemotherapy followed by definitive surgery between June 1982 and June 2013 were included. Logistic regression models were used to assess the association between each variable and pCR. Cox models were used to analyze time to recurrence and overall survival. The recursive partitioning and regression trees method was used to calculate the cut-off value of ER expression. Results A total of 3055 patients were analyzed. Low percentage of ER was significantly associated with high pCR rate (OR = 0.99, 95% CI = 0.986-0.994, P < 0.001). The recommended cut-off of ER expression below which pCR was likely was 9.5%. Among patients with ER ≥ 10% tumors, but not those with 1%≤ER < 10% tumors, adjuvant hormonal therapy was significantly associated with long time to recurrence (HR = 0.24, 95% CI = 0.16-0.36, P < 0.001) and overall survival (HR = 0.32, 95% CI = 0.2-0.5, P < 0.001). Conclusion Stage II or III HER2-negative primary breast cancer with ER < 10% behaves clinically like triple-negative breast cancer in terms of pCR and survival outcomes and patients with such tumors may have a limited benefit from adjuvant hormonal therapy. It may be more clinically relevant to define triple-negative breast cancer as HER2-negative breast cancer with <10%, rather than <1%, of ER and/or progesterone receptor expression.

High HER2/Centromeric Probe for Chromosome 17 Fluorescence In Situ Hybridization Ratio Predicts Pathologic Complete Response and Survival Outcome in Patients Receiving Neoadjuvant Systemic Therapy With Trastuzumab for HER2-Overexpressing Locally Advanced Breast Cancer

BACKGROUND The present study was performed to determine whether the human epidermal growth factor receptor-related 2 (HER2)/centromeric probe for chromosome 17 fluorescence in situ hybridization (FISH) ratio is a predictor of a pathologic complete response (pCR), recurrence-free survival (RFS), and/or overall survival (OS) in patients receiving neoadjuvant systemic treatment (NST) with trastuzumab (NST-T) for HER2+ locally advanced breast cancer (LABC). PATIENTS AND METHODS The present retrospective study included 555 patients with HER2+ LABC who had undergone NST and definitive surgery (1999-2012); 373 had concurrently received trastuzumab. HER2-positivity was considered present with an immunohistochemical score of 3+ and/or HER2 FISH ratio of ≥2.0. We used logistic regression analysis and Cox proportional hazard modeling to determine whether a high HER2 FISH ratio, either as a continuous variable or with a cutoff of ≥7.0, would predict for pCR (no invasive disease in the breast and no tumor in the ipsilateral axillary lymph nodes), RFS, and/or OS. RESULTS The pCR groups median HER2 FISH ratio was significantly higher than that of the non-pCR group (6.4 vs. 5.2; p = .003). The logistic regression model demonstrated that the independent predictors of pCR included a high HER2 FISH ratio as a continuous variable (p = .04). The multicovariate Cox proportional hazard model showed that a high HER2 FISH ratio (with a cutoff of ≥7.0 or as a continuous variable) was a significant prognostic indicator of longer RFS time (p = .047 and p = .04, respectively). Similarly, a high HER2 FISH ratio of ≥7.0 was associated with longer OS (p = .06). CONCLUSION A high HER2 FISH ratio is a predictor of pCR in patients with HER2+ LABC who receive NST-T. IMPLICATIONS FOR PRACTICE This study demonstrated the optimal predictive and prognostic value of a HER2/centromeric probe for chromosome 17 FISH ratio for primary HER2+ breast cancer treated with trastuzumab combined with neoadjuvant systemic treatment (NST-T). This suggests that a high HER2 FISH ratio is a potential indicator for a high pathologic complete response rate and a better prognosis when patients are treated with NST-T.

Nomogram to predict pathologic complete response in HER2-positive breast cancer treated with neoadjuvant systemic therapy.

Background:Pathologic complete response (pCR) is associated with improved survival outcomes in patients with HER2-positive primary breast cancer. We developed a nomogram to predict the probability of pCR rates by using oestrogen receptor (ER) expression, progesterone receptor (PR) expression and HER2/CEP17 ratio as continuous variables.Methods:We retrospectively reviewed patients with stages I–III HER2-positive invasive breast cancer who had definitive surgery in 1999–2015 and received neoadjuvant systemic therapy (NST). Multivariate logistic regression models were applied to assess the effect of variables on pCR. A nomogram was built to estimate the probability of pCR. The discriminative ability was estimated by the concordance index (C-index). The accuracy was assessed graphically with a calibration curve.Results:A total of 793 patients were included in the analysis. Low ER expression (P<0.001), high HER2/CEP12 ratio (P=0.03), and non-inflammatory breast cancer subtype (P=0.003) were associated with increased pCR rates. Regimens containing trastuzumab or trastuzumab and pertuzumab were associated with higher pCR rates than cytotoxic agents alone (P<0.001 and P<0.001, respectively). The C-index was 0.69. The calibration curve showed good agreement.Conclusions:Our nomogram predicted the pCR rate after NST among patients with HER2-positive primary breast cancer using clinicopathologic factors.

Overall survival and post-progression survival are potent endpoint in phase III trials of second/third-line chemotherapy for advanced or recurrent epithelial ovarian cancer

Purpose: A growing number of treatment options and active compounds in treatments have led to better outcomes for patients with advanced or recurrent epithelial ovarian cancer. We examined the association between progression-free survival (PFS), post-progression survival (PPS) and overall survival (OS) in phase III trials of second- and third-line chemotherapy for advanced or recurrent epithelial ovarian cancer. We aim to determine whether PFS or PPS is a surrogate of OS so that we can decide progress of disease is optimal endpoint for ovarian cancer. Methods: We identified 22 trials conducted between January 1, 2000 through December 31, 2014 by literature search. We divided OS into PFS and PPS, and assessed the association between OS and PFS/PPS. We also examined whether the year of trial enrollment completion was associated with any variables. Results: The median PPS was slightly longer in recent trials compared to older trials (10.0 vs. 8.8 months). While PPS was strongly associated with OS (r = 0.88) in all trials, PFS was moderately correlated with OS (r = 0.72). The correlation between OS and PPS in recent trials (r = 0.93) was stronger than in older trials (r = 0.84). Conclusions: Our findings indicate that PPS is highly associated with OS in second/third-line chemotherapy for advanced or recurrent epithelial ovarian cancer, while the association between PFS and OS is moderate. We recommend using OS as primary endpoint for clinical trial of ovarian cancer, however PFS is still an optional endpoint.

Histone Deacetylase Inhibitor Enhances the Efficacy of MEK Inhibitor through NOXA-Mediated MCL1 Degradation in Triple-Negative and Inflammatory Breast Cancer.

Purpose: Inflammatory breast cancer (IBC), diagnosed clinically, and triple-negative breast cancer (TNBC), diagnosed by molecular receptor status, are the two most aggressive forms of breast cancer, and both lack effective targeted therapies. We previously demonstrated involvement of histone deacetylase (HDAC) inhibitor entinostat in regulating apoptosis in IBC and TNBC cells; here, we aimed to identify novel combination therapy candidates. Experimental Design: Potential therapeutic targets were identified by mRNA expression profiling of TNBC and IBC cells treated with entinostat. Drug action and synergism were assessed by in vitro proliferation assays, tumor growth in vivo, and proteomic analyses. Gain/loss-of-expression studies were utilized to functionally validate the role of identified targets in sensitivity of TNBC and IBC cells to combination therapy. Results: Entinostat induced activity of the oncogenic ERK pathway and expression of proapoptotic NOXA. These are known to stabilize and degrade, respectively, MCL1, an antiapoptotic Bcl-2 protein. In breast cancer patients, high-MCL1/low-NOXA tumor expression correlated significantly with poor survival outcomes. Combination treatment of entinostat with MEK inhibitor pimasertib reduced the growth of TNBC and IBC cells in vitro and inhibited tumor growth in vivo. The synergistic action of combination therapy was observed in TNBC and IBC cell lines in which NOXA expression was induced following entinostat treatment. The therapeutic activity depended on induction of mitochondrial cell death pathways initiated by NOXA-mediated MCL1 degradation. Conclusions: Our preclinical findings provide a rationale for the clinical testing of combination HDAC and MEK pathway inhibition for TNBC and IBC that exhibit elevated baseline tumor MCL1 expression. Clin Cancer Res; 23(16); 4780–92. ©2017 AACR.

Reverse phase protein array identification of triple-negative breast cancer subtypes and comparison with mRNA molecular subtypes

Background Reverse phase protein array (RPPA) analysis, allows investigation of potential targets at the functional protein level,. We identified TNBC subtypes at the protein level using RPPA and compared them with mRNA molecular subtypes (TNBCtype, TNBCtype-4, and PAM50) that is unique in its availability of both RPPA and mRNA analyses. Methods We classified the samples from 80 TNBC patients using both k-means and hierarchical consensus clustering analysis and performed Ingenuity Pathway Analysis. We also investigated whether we could reproduce the mRNA molecular subtypes using the RPPA dataset. Results Both clustering methods divided all samples into 2 clusters that were biologically the same. The top canonical pathways included inflammation, hormonal receptors, and MAPK signaling pathways for the first cluster [“inflammation and hormonal-related (I/H) subtype”] and the GADD45, DNA damage, and p53 signaling pathways for the second cluster [“DNA damage (DD)-related subtype”]. Further k-means cluster analysis identified 5 TNBC clusters. Comparison between sample classification using the 5 RPPA-based k-means cluster subtypes and 6 gene-expression-based TNBCtype molecular subtypes showed significant association between the 2 classifications (p = 0.017). Conclusions The I/H and DD subtypes identified by RPPA advance our understanding of TNBC’s heterogeneity from the functional proteomic perspective.