Hounsfield Units Predict Survival of Patients With Estrogen Receptor-Positive and Human Epithelial Growth Factor Receptor 2-Negative Breast Cancer

BACKGROUNDS

Tumor vascularity plays a fundamental role in cancer progression, including breast cancer. This study aimed to elucidate tumor vascularity and its impact on patient survival in the context of breast cancer subtypes using Hounsfield units (HU) on contrast-enhanced computed tomography (CT).

MATERIALS AND METHODS

Patients with early-stage breast cancer who completed planned treatment between 2003 and 2013 were retrospectively assessed.

RESULTS

The final cohort comprised 440 patients. Of the 440 patients, 262 had estrogen receptor (ER)-positive disease and 119 had human epidermal growth factor receptor 2 (HER2)-overexpressing disease. The tumor-to-aorta ratio of Hounsfield units (TAR) was related to significantly worse recurrence-free interval (RFI) (P < .001) and overall survival (OS) (P < .001) in patients with TAR > 0.33 for RFI and > 0.35 for OS than their counterparts. In the subgroup analysis, the survival disadvantage was limited only to patients with ER-positive and HER2-negative disease (P < .001 for both RFI and OS).

CONCLUSION

This study showed that TAR, which reflects tumor vascularity, was significantly related to patients' RFI and OS, suggesting its capacity as a feasible biomarker. This study also showed that TAR was associated with the survival in patients with ER-positive and HER2-negative disease.

Abstract P3-05-51: Patients with low expression of BCL 2 experience more late recurrence than patients who do not, which neutralized the protective effect of low BCL2 expression in patients with estrogen receptor positive breast cancer

Background) BCL2 is a key factor for the regulation of cellular apoptosis and its overexpression inhibits apoptotic cell death and activates cellular proliferation, resulting tumor progression. Although BCL2 are expected to be associated with an adverse prognosis in breast cancer, previous studies have reported inconsistent results and some reported even favorable features. The aim of this study is to investigate what characteristics of BCL2 yield this discrepant result in patients with breast cancer. Materials and methods) Female patients with breast cancer who completed primary treatment against breast cancer between 2003 and 2018 at Wonju Severance Hospital, Korea, were included. Clinocopathological characteristics including BCL2 expression were collected. Patients were categorized into two groups, BCL2 expression in more or less than 10% of tumor cells. Kaplan-Meier curves were generated to compare recurrence-free interval (RFI) and overall survival (OS). Result) The final cohort included 616 patients with a mean age of 54.79±11.2 (25-86) years. Patients with estrogen receptor positive breast cancer were more frequent in patients with tumor in which BCL2 was expressed in less than 10% of tumor cells (70.7% vs. 57.7%). Patients with tumor in which BCL2 was expressed in less than 10% of tumor cells showed better survival than their counterpart. Subgroup analysis according to the estrogen receptor and HER2 overexpression status was done. In patients with tumor in which HER2 was not overexpressed, patients with tumors in which BCL2 expressed less than 10% of tumor cells showed better survival(p=0.007). Survival difference maintained in patients with triple negative disease(p=0.010). However, in patients with estrogen receptor positive breast cancer, survival of two groups of patients with high and low BCL2 expression become not significant over time as late recurrence occurred (p=0.227). In contrast, patients with HER2 positive disease breast cancer showed worse prognosis than their counterpart when their tumor showed BCL2 expression in less than 10% of tumor cells. Conclusion) BCL2 overexpression showed different contribution to the patients’ survival according to the subtypes. Patients with HER2 overexpression showed better survival when BCL2 was overexpressed and patients with HER2 negative disease does not. First, similar survival was resulted from late recurrence in patients with estrogen receptor positive disease. Second, apoptotic capacity of tumor cells may not be major survival factor if tumor cells are exactly targeted.

Citation Format: Hyang Suk Choi, Hany Hany Noh, In-Jeong Cho In-Jeong Cho, Seung Taek Lim, Jong-In Lee, Airi Han. Patients with low expression of BCL 2 experience more late recurrence than patients who do not, which neutralized the protective effect of low BCL2 expression in patients with estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-51.

Abstract P2-11-30: Performance of tumor vascularity as a biomarker is correlated with the change of tumor vascularity after preoperative systemic treatment in patients with breast cancer

Background) Breast cancer is a leading cause of death worldwide. Tumor vascularity is a hallmark of cancer including breast cancer. However, targeting tumor vascularity did not show consistent benefit when applied in clinic. This study aimed to investigate in which group of patients can tumor vascularity be a prognostic factor and how does change of tumor vascularity play in this situation. Materials and methods) Female patients with breast cancer who received preoperative chemotherapy due to breast cancer between 2003 and 2018 at Wonju Severance Hospital, Korea, were included. Clinocopathological characteristics were collected. Hounsfield units(HU) on contrast-enhanced computed tomography(CT) was used as a marker indicating tumor vascularity. Tumor to aortic arch ratio(TAR) of HU on contrast enhanced CT was applied to enhance objectivity of measurement. Patients were categorized according to the cut-off values retrieved from the receiver operating characteristic curve. Kaplan-Meier curves were generated to compare recurrence-free interval (RFI) and overall survival (OS). Results) The final cohort included 162 patients with a mean age of 48.63±7.9 (30-69) years. Initial TAR was 0.38±0.103 (range, 0.184-0.946) and TAR after completion of preoperative systemic treatment was 0.29 0.094(0.677-0.298). Difference between TAR of immediate before surgery and first clinical presentation was -0.0860.094(-0.386 – 0.176). TAR was decreased in 122 (75.3%) patients. Initial TAR was significantly correlated with recurrence free survival(RFS)(p=0.002). However, TAR after preoperative systemic treatment (p=0.221) or delta TAR (area under receiver operating characteristics = 0.498) were not significant. Interestingly, initial TAR was significant only in patients with decreased TAR after preoperative systemic treatment(p=0.005). Conclusion) Tumor vascularity represented with HU was significantly related with patients’ survival only when tumor vascularity was decreased in response to systemic treatment. Considering no antiangiogenic agents were applied as preoperative systemic treatment and still capacity of tumor vascularity as a biomarker was influenced by the change of itself, antiangiogenic agents could be used as a complimentary agent for the other agents which also impact tumor vascularity.

Citation Format: Hyang Suk Choi, Eun Ju Son, Hany Hany Noh, In-Jeong Cho In-Jeong Cho, Seung Taek Lim, Jong-In Lee, Airi Han. Performance of tumor vascularity as a biomarker is correlated with the change of tumor vascularity after preoperative systemic treatment in patients with breast cancer. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-11-30.

Usefulness of Hounsfield Units and the Serum Neutrophil-to-Lymphocyte Ratio as Prognostic Factors in Patients with Breast Cancer

Breast cancer is a leading cause of death worldwide. Tumor vascularity and immune disturbances are hallmarks of cancer. This study aimed to investigate the reciprocal effect of tumor vascularity, assessed by the tumor-to-aorta ratio (TAR) of Hounsfield units (HU) on computed tomography (CT), and host immunity, represented by the serum neutrophil-to-lymphocyte ratio (NLR) from peripheral, complete blood cell counts and its impact on patient survival. Female patients with breast cancer who received primary treatment between 2003 and 2018 at Wonju Severance Hospital, Korea, were included. The final cohort included 740 patients with a mean age of 54.3 ± 11.3 (22−89) years. The TAR was 0.347 ± 0.108 (range, 0.062−1.114) and the NLR was 2.29 ± 1.53 (0.61−10.47). The cut-off value for the TAR and NLR were 0.27 and 1.61, respectively. The patients with a TAR > 0.27 showed a poor recurrence free-interval (RFI) only when their NLR was larger than 1.61, and vice versa. The patients showed worse RFI when they had both high TAR and NLR. Our results suggest a dynamic reciprocal communication between tumor vascularity and systemic immunity.

Transcriptional reprogramming differentiates active from inactive ESR1 fusions in endocrine therapy-refractory metastatic breast cancer

Genomic analysis has recently identified multiple ESR1 gene translocations in estrogen receptor-alpha positive (ERα+) metastatic breast cancer (MBC) that encode chimeric proteins whereby the ESR1 ligand binding domain (LBD) is replaced by C-terminal sequences from many different gene partners. Here we functionally screened 15 ESR1 fusions and identified 10 that promoted estradiol-independent cell growth, motility, invasion, EMT and resistance to fulvestrant. RNA sequencing identified a gene expression pattern specific to functionally active ESR1 gene fusions that was subsequently reduced to a diagnostic 24-gene signature. This signature was further examined in 20 ERα+ patient-derived xenografts (PDXs) and in 55 ERα+ MBC samples. The 24-gene signature successfully identified cases harboring ESR1 gene fusions and also accurately diagnosed the presence of activating ESR1 LBD point mutations. Therefore, the 24-gene signature represents an efficient approach to screening samples for the presence of diverse somatic ESR1 mutations and translocations that drive endocrine treatment failure in MBC.

Neutrophil to Lymphocyte Ratio after Treatment Completion as a Potential Predictor of Survival in Patients with Triple-Negative Breast Cancer

Purpose

Triple-negative breast cancer (TNBC) has been associated with worse prognosis, and biomarkers are needed to identify high-risk patients who may benefit from clinical trials or escalated treatment after completion of standard treatment. We aimed to assess whether the post-treatment neutrophil-to-lymphocyte ratio (NLR) can reflect patient prognosis and determine the follow-up period that can provide the most feasible data.

Methods

In this retrospective analysis involving patients with TNBC, clinicopathological data, including those on peripheral complete blood cell count, were collected. The prognostic powers of serial NLRs obtained at baseline and after treatment completion were compared. Kaplan-Meier curves were generated to compare the overall survival (OS) and distant disease-free survival (DDFS).

Results

In total, 210 patients were enrolled. Forty-three (20.5%) events were detected. Two-thirds of the events (29/43) were related to breast cancer. Most recurrent breast cancer-related diseases (27/29) were detected within 5 years of the initial diagnosis. In contrast, half of the events due to secondary malignancies or non-breast-related diseases (7/14) occurred 5 years after the initial diagnosis. Comparison of the prognostic performance of NLRs at baseline and at 6, 12, and 24 months after treatment completion revealed the strongest prognostic performance at 6 months after treatment completion (area under the curve = 0.745). The high NLR group (NLR >2.47) showed worse OS (p = 0.006) and DDFS (p < 0.001) than low NLR group.

Conclusion

Elevated post-treatment NLR was significantly associated with worse survival in patients with TNBC. We believe that it can be a useful surrogate marker for identifying high-risk patients with TNBC.

Increasing Mortality in Korean Patients With Breast Cancer: High Mortality Rate in Elderly Breast Cancer Population Due to Suboptimal Treatment and Other Diseases

Background

The incidence of breast cancer in Asia, including Korea, has rapidly increased. Each country has shown different clinical features. This study presents a comprehensive understanding of breast cancer in different age groups in Korea and determines potential measures for improving patient survival.

Methods

Patients diagnosed with invasive breast cancer stages I to III with available clinicopathologic and follow-up data were included in the study. Kaplan–Meier survival graphs were generated for each group and compared using log-rank test. The hazard ratio for each risk factor was calculated using the Cox regression model and the 95% confidence interval.

Results

The final cohort included 833 patients with a mean age of 51.3±11.3 years (range, 22–89 years), and 191 (22.9%) of them were aged >60 years. Patients aged ≥60 years had worse overall survival (OS) and distant disease-free survival than those aged <60 years. Although no difference was observed in the tumor biology, elderly patients showed significant differences in practice patterns: they tended to undergo mastectomy (40.2% vs 62.8%, P<0.001), did not receive the standard chemotherapy (88.4% vs 69.3%, P < 0.001), and had a higher risk of developing second primary cancer or diseases other than breast cancer (1.2% vs 6.8%, P < 0.001), which significantly correlated with poor survival in elderly patients.

Conclusion

Less-than-the-standard treatment of care or development of a second primary disease resulted in poor prognosis in elderly patients in Korea. A multi-institutional and multinational study is warranted to elucidate the clinical features of breast cancer in Asian patients.

Abstract PS8-36: Why is neoadjuvant treatment for patients with triple negative breast cancer of T1cN0 required ?

Background) Patients with early stage triple negative breast cancer(TNBC) are typically treated with surgery and chemotherapy, and sometimes radiotherapy. Despite effective neoadjuvant and adjuvant chemotherapies, the relapse rate is high and up to 50% of patients will experience disease recurrence including 10% of patients with stage I disease, and pCR is useful surrogate marker for patients with neoadjuvant treatment. Currently Neoadjuvant treatment is recommended for patients with TNBC of 2cm or larger at diagnosis. However, patients with T1 disease at diagnosis are mostly recommended with upfront surgery because uncertain clinical meaning of pCR and potential escalation of treatment for patients with non-pCR in this group. The aim of this study is to see whether patients with T1c of TNBC has different prognosis from T1a /b of same or different subtype and the potential benefit of neoadjuvant treatment exist or not. Material and methods) From 2000 to 2015, female patients treated with upfront surgery for stage I-III breast cancer were included. Patients of estrogen receptor positive disease and TNBC were further stratified according to the tumor size. The primary objective of this study was to see the different incidence of disease recurrence, for which chi-square test or Fisher’s exact tests were used. The secondary objective was recurrence free survival and distant disease free survival, for which Kaplan-Meier(K-M) graphs were generated and compared with log-rank test. Results) None of the TNBC patients experienced disease recurrence when they have T1a/b disease. However, patients with T1c disease showed similar incidence of disease recurrence with patients with T2 or T3 stage (89% vs. 86%), suggesting conventional T staging might not reflect real characteristics of TNBC. On the other hands, patients with ER positive disease less affected by tumor size, showing incidence of recurrent disease of T1a/b, T1c and T2 or over as 96.7%, 93.1% and 91.5% respectively. K-M graphs were generated and log-rank test showed worse survival of patients with T1c of TNBC than T1a/b and rather similar prognosis with patients with T2 or over. Conclusion) Effective adjuvant treatment, such as capecitabine had been proposed for patients with non-pCR. However, mixed results are reported, suggesting appropriate selection of patients is critical. While we need to define TNBC better, patients also need appropriate biomarker to decide whether they need escalated treatment after completion of neoadjuvant treatment. Given the dismal prognosis of T1c of TNBC, we propose this group of patients might benefit from preoperative systemic treatment with using pathologic result as surrogate marker.

Citation Format: Hyang Suk Choi, In-Jeong Cho, Hany Noh, Kwang-Min Kim, Kyoung Tae Nam, Airi Han. Why is neoadjuvant treatment for patients with triple negative breast cancer of T1cN0 required ? [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS8-36.

Dissecting the Role of VicK Phosphatase in Aggregation and Biofilm Formation of Streptococcus mutans

VicRK (WalRK or YycFG) is a conserved 2-component regulatory system (TCS) that regulates cell division, cell wall biosynthesis, and homeostasis in low-GC Gram-positive bacteria. VicRK is also associated with biofilm formation of Streptococcus mutans on the tooth surface as it directly regulates the extracellular polysaccharide (EPS) synthesis. Of the 2 components, VicK possesses both autokinase and phosphatase activities, which regulate the phosphorylation and dephosphorylation of the regulator VicR in response to environmental cues. However, the dual mechanism of VicK as the autokinase/phosphatase in regulating S. mutans' responses is not well elucidated. Previously, it has been shown that the phosphatase activity depends on the PAS domain and residues in the DHp domain of VicK in S. mutans. Specifically, mutating proline at 222 in the PAS domain inhibits VicK phosphatase activity. We generated a VicK^P222A mutant to determine the level of VicR-P in the cytoplasm by Phos-tag sodium dodecyl sulfate polyacrylamide gel electrophoresis. We show that in VicK^P222A phosphatase, attenuation increased phosphorylated VicR (VicR-P) that downregulated glucosyltransferases, gtfBC, thereby reducing the synthesis of water-insoluble polysaccharides (WIS-EPS) in the biofilm. In addition, VicK^P222A presented as long-rod cells, reduced growth, and displayed asymmetrical division. A major adhesin of S. mutans, SpaP was downregulated in VicK^P222A, making it unable to agglutinate in saliva. In summary, we have confirmed that VicK phosphatase activity is critical to maintain optimal phosphorylation status of VicR in S. mutans, which is important for cell growth, cell division, EPS synthesis, and bacterial agglutination in saliva. Hence, VicK phosphatase activity may represent a promising target to modulate S. mutans' pathogenicity.

Changes in neutrophil to lymphocyte ratio (NLR) during neoadjuvant treatment correlated with patients' survival

INTRODUCTION

Neoadjuvant treatment has been widely used for patients with advanced breast cancer, and pathological complete response (pCR) has been proposed as a surrogate marker. However, more than 50% of patients will not achieve pCR and an appropriate, practical prognostic marker is required for these patients.

MATERIALS AND METHODS

A retrospective analysis of patients treated with neoadjuvant treatment for stage I-III disease was performed. Clinicopathological data including the neutrophil-to-lymphocyte ratio (NLR) were collected. NLRs were collected serially according to the treatment schedule. Changes in NLRs were calculated, of which the performance capacity as a prognostic factor was evaluated, and a Kaplan-Meier plot was developed and compared with the log rank test RESULTS: Changes in NLRs of each time points of 148 patients were used to assess performance capacity as a prognostic factor for invasive disease-free survival (IDFS), overall survival (OS) and distant disease-free survival (DDFS), and that of shortly prior to the third cycle treatment showed statistical significance. With a cut off value of 0.1258, patients could be divided into high- and low-risk of invasive disease recurrence. Kaplan-Meier curves were developed and the log rank test showed that patients in high-risk group after 2 cycles of neoadjuvant treatment were significantly correlated with worse survival outcomes than those in low-risk group.

CONCLUSION

Changes in NLRs after neoadjuvant treatment showed statistically significant correlation with patient survival and could categorize patients into high- and low-risk groups. Larger, prospectively designed clinical trials are required to substantiate findings of this study.

Abstract P3-08-72: Poor prognosis in elderly patients with breast cancer resulted from under-treatment in patients with triple negative breast cancer and mortality from other than breast cancer

Background: Breast cancer is the leading cause of malignant disease in Korean women nest to thyroid cancer. Age is one of the significant risk factor and Korean population is aging rapidly, almost 1.5 times older than a half century ago, from 52.4 years in 1960 to 78.5years at 2005. While it is uncertain the proportional incidence is also increasing, absolute number of elderly patients is increasing and unmet clinical needs and unanswered questions are remained in the clinical practice for elderly patients. The aim of this study is to outline breast cancer in elderly patients and examine survivals by clinicopathologic factors such as age, stage and disease subtype.

Material and Methods: Patients who were diagnosed and completed their primary treatment for breast cancer from 2000 to 2013 were included. Clinicopathologic data was collected with retrospective data review and survival data and risk factors, if the survival was statistically significant, were obtained.

Results: 1103 patients with invasive breast cancer were included. Mean age was 52.71±11.478(22-89). Subjects were divided into three group, &lt;40 (n=147, 35.9±3.704), 40-60 (n=680,49±5.131), &gt;60(n=276,68.6±5.62). Patients over 60 had statistically worse overall survival(p=0.011) and distant disease free survival(p=0.012) with Kaplan-Meier method with log rank test and hazard ratio(HR) of elderly was 2.206 with 1.046-4.658 96% Confidence Interval(CI). For the worse prognosis of elderly, triple negative breast cancer who got less than standard systemic treatment (HR=4.836, 95% CI, 1.514-15.452) and mortality from other than breast(HR=2.395, 95% CI,1.106-5.188) cancer were significantly correlated with higher mortality in elderly patients.

Conclusion: Elderly patients with breast cancer experience significant worse survival when they got less than standard systemic treatment or second primary disease other than breast cancer in their follow up period.

Citation Format: Gilseong Moon, Ji wool Ko, Hany Noh, In-Jeong Cho, Jong-in Lee, Airi Han. Poor prognosis in elderly patients with breast cancer resulted from under-treatment in patients with triple negative breast cancer and mortality from other than breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-72.

Abstract 850: Evaluating preclinical efficacy of anti-HER2 drug combinations using ER+/HER2 mutant models

Targeting HER2 is one of the greatest successes in oncology, and has resulted in the generation of a wide array of HER2-targeting agents. Our genomic approaches are revealing other mechanisms of HER2 activation, such as our discovery of activating HER2 mutations in different cancer types. From initial breast cancer and SUMMIT trial data, the pan-HER drug neratinib as monotherapy showed initial clinical response in ER+ breast cancer, but with frequent early relapse. This study investigates the preclinical efficacy of anti HER2 agents alone or in combination with endocrine therapy agents or in combination with CDK4/6 inhibitors using ER+/HER2 mutant cell lines and ex vivo HER2 mutant patient derived xenograft (PDX) model. ER+ breast cancer cell lines (T47D and MCF7) stably expressing HER2V777L, and ER+/HER2 mutant PDX model (HER2G778_P780 dup) were used to examine HER2 signaling. We found that MCF7/T47D cells expressing HER2V777L and HER2G778_P780 dup PDX tumors showed strongly activated autophosphorylation of HER2 and increased expression of CDK4, CDK6, phospho-Rb, and cyclin D1 as compared to MCF7/T47D cells expressing HER2WT or ER+/non-HER2mut PDX model, suggesting that HER2 mutations preferentially depend on CDK4/6 signaling for cell growth. Additionally, we showed that activating MCF7 HER2V777L cause resistance to endocrine therapy treatment (fulvestrant IC50 &gt;5μM). Further, we show that neratinib alone is effective at higher concentrations (IC50 &lt; 2μM) in MCF7/HER2V777L cells. Next we showed that abemaciclib alone exhibited moderate activity against MCF7 HER2V777L cells (IC50 &lt; 0.4μM) and additional activity in combination with neratinib (IC50 &lt; 0.06μM) was seen. Moreover, ex vivo HER2G778_P780 dup cells are relatively resistant to fulvestrant alone (IC50 &lt; 0.2μM), neratinib alone (IC50 &lt; 0.006μM), abemaciclib alone (IC50 &lt; 0.04μM), and neratinib in combination with abemaciclib (IC50 &lt; 0.005μM), suggesting that patients harboring ER+/HER2-mutant tumors may benefit from neratinib in combination with abemaciclib. Therefore, we propose that simultaneous targeting of both HER2 and the CDK4/6 axis is required for maximal inhibition of ER+ breast cancers harboring HER2 activating mutations.

Citation Format: Vaishnavi Devarakonda, LaTerrica Williams, Sinem Seker, Jonathan T. Lei, Purba Singh, Airi Han, Meenakshi Anurag, Kimberly R. Holloway, Alana L. Welm, Matthew J. Ellis, Shyam M. Kavuri. Evaluating preclinical efficacy of anti-HER2 drug combinations using ER+/HER2 mutant models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 850.

Abstract P6-17-15: Evaluating preclinical efficacy of anti-HER2 drug combinations using ER+/HER2 mutant models

Background

Until recently, HER2 gene amplification was the only mechanism of HER2 activation recognized. However, activating HER2 mutations have been noted in different cancer types. A trials of HER2 mutant breast cancer and the subsequent SUMMIT trial data have shown that monotherapy with the pan-HER drug neratinib as showed clinical efficacy, but with poor response durability. This study therefore investigates the preclinical efficacy of anti HER2 agents alone or in combination with endocrine therapy agents or in combination with CDK4/6 inhibitors using ER+/HER2 mutant cell lines and ex vivo HER2 mutant patient derived xenograft (PDX) model to define a more effective treatment approach.

Methods

ER+ breast cancer cell lines (T47D and MCF7) stably expressing HER2V777L, and ER+/HER2 mutant PDX model (HER2G778_P780 dup) were used to examine HER2 signaling and drug responses. Signaling downstream mutant HER2 was examined by immunoblot analysis. Effects of neratinib alone, neratinib + fulvestrant, and neratinib + abemaciclib on cell growth were examined in ER+/HER2 mutant cell lines and in an ex vivo HER2G778_P780 dup.

Results

We found that MCF7/T47D cells expressing HER2V777L and HER2G778_P780 dup PDX tumors showed strongly activated autophosphorylation of HER2 and increased expression of CDK4, CDK6, phospho-Rb, and cyclin D1 as compared to MCF7/T47D cells expressing HER2WT or ER+/non-HER2mut PDX modes, suggesting that HER2 mutations preferentially depend on CDK4/6 signaling for cell growth. Additionally, we showed that activating MCF7 HER2 V777L cause resistance to endocrine therapy treatment (fulvestrant IC50 &gt;5μM). Further, we show that neratinib alone is effective at higher concentrations (IC50 &lt; 2μM) in MCF7/HER2 V777L cells. We also demonstrate that abemaciclib alone exhibited moderate activity against MCF7 HER2 V777L cells (IC50 &lt; 0.4μM) and additional activity in combination with neratinib (IC50 &lt; 0.06μM) was seen. Moreover, ex vivo HER2 G778_P780 dup cells are relatively resistant to fulvestrant alone (IC50 &lt; 0.2μM), neratinib alone (IC50 &lt; 0.006μM), abemaciclib alone (IC50 &lt; 0.04μM), and neratinib in combination with abemaciclib (IC50 &lt; 0.005μM), suggesting that patients harboring ER+/HER2-mutant tumors may benefit from neratinib in combination with abemaciclib.

Conclusion

These preclinical data suggest that neratinib monotherapy may not be effective to treat ER+/HER2 mutant patients and we propose that simultaneous targeting of both HER2 and the CDK4/6 axis will be required for effective treatment of ER+ breast cancers harboring HER2 activating mutations.

Citation Format: Kavuri SM, Devarakonda V, Williams LC, Seker S, Lei JT, Singh P, Han A, Anurag M, Holloway KR, Welm AL, Ellis MJ. Evaluating preclinical efficacy of anti-HER2 drug combinations using ER+/HER2 mutant models [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-15.

Abstract P5-08-01: DPYSL3 modulates mitosis, migration and epithelial to mesenchymal transition in claudin-low breast cancer

Proteogenomics is the field of integrating data from mass spectrometry-based shotgun proteomics, and phosphoproteomics into next-generation RNA and DNA sequencing data analysis pipelines that promises new insights into cancer biology and therapeutic targeting. As well as analyses of clinical samples for disease phenotype association analysis, the application of proteogenomics to model systems also has considerable potential. A Clinical Proteomic Tumor Analysis Consortium (CPTAC) proteogenomic analysis prioritized dihydropyrimidinase-like-3 (DPYSL3) as a multi-level (RNA/Protein/Phosphoprotein) expression outlier specific to the Claudin-Low (CLOW) subset of triple negative breast cancers. A Pubmed informatics tool indicated a paucity of data in the context of breast cancer which further prioritized DPYSL3 for study.

DPYSL3 was identified as a protein that is regulated during neuronal differentiation in the cerebral cortex and in neuronal cell lines and plays a role in regulating neurite outgrowth somehow through an association with vesicles in the growth cone. In addition, DPYSL3 expression has been observed in several malignant tumors, including prostate cancer, pancreatic cancer, gastric cancer and neuroblastoma. DPYSL3 is reported to play a role in cell migration and metastasis suppression in prostate cancer. However, in pancreatic cancer, DPYSL3 is positively associated with liver metastasis and poor outcome.

DPYSL3 knock-down in DPYSL3 (+) CLOW cell lines demonstrated reduced proliferation, yet enhanced motility and increased expression of Epithelial to Mesenchymal Transition (EMT) markers suggesting that DPYSL3 is a multi-functional signaling modulator. Slower proliferation in DPYSL3 (-) CLOW cells was associated with accumulation of multi-nucleated cells indicating a mitotic defect that was associated with a collapse of the vimentin (VIM) microfilament networkinduced by VIM hyperphosphorylation. On the other hand, DPYSL3 suppressed the expression of EMT regulators TWIST and SNAIL and opposed p21 activated kinase 2 (PAK2) dependent migration, but these EMT regulators in turn induced DPYSL3 expression, suggesting DPYSL3 participates in negative feedback in EMT. Cell migration in DPYSL3 (-) cells correlated with increased phosphorylation of PAK2 on Ser20 and was sensitive to PAK2 siRNA and pharmacological PAK inhibition.Immunoprecipitation and mass spectrometry-based proteomics or western blotting strongly suggests that PAKs interact such that DPYSL3 may function as a direct negative regulator of PAK family kinases. Thus, a PAK inhibitor could potentially mitigate increase migration as an adverse effect of DPYSL3 suppression.

In conclusion, DPYSL3 is a remarkable multifunctional signaling scaffold that should be examined further to provide insights into the stem cell-like state of claudin-low breast cancers, particularly in terms of their cell cycle dependencies, migratory activity and capacity for EMT.

Citation Format: Matsunuma R, Chan DW, Kim B-J, Singh P, Han A, Saltzman A, Cheng C, Lei JT, Sahin E, Leng M, Fan C, Perou CM, Malovannaya A, Ellis MJ. DPYSL3 modulates mitosis, migration and epithelial to mesenchymal transition in claudin-low breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-08-01.

Macromolecular crowding tunes 3D collagen architecture and cell morphogenesis

Collagen I is the primary extracellular matrix component of most solid tumors and influences metastatic progression. Collagen matrix engineering techniques are useful for understanding how this complex biomaterial regulates cancer cell behavior and for improving in vitro cancer models. Here, we establish an approach to tune collagen fibril architecture using PEG as an inert molecular crowding agent during gelation and cell embedding. We find that crowding produces matrices with tighter fibril networks that are less susceptible to proteinase mediated degradation, but does not significantly alter matrix stiffness. The resulting matrices have the effect of preventing cell spreading, confining cells, and reducing cell contractility. Matrix degradability and fibril length are identified as strong predictors of cell confinement. Further, the degree of confinement predicts whether breast cancer cells will ultimately undergo individual or collective behaviors. Highly confined breast cancer cells undergo morphogenesis to form either invasive networks reminiscent of aggressive tumors or gland and lobule structures reminiscent of normal breast epithelia. This morphological transition is accompanied by expression of cell-cell adhesion genes, including PECAM1 and ICAM1. Our study suggests that cell confinement, mediated by matrix architecture, is a design feature that tunes the transcriptional and morphogenic state of breast cancer cells.

Analysis of Two Quantitative Ultrasound Approaches

There are two well-known ultrasonic approaches to extract sets of quantitative parameters: Lizzi-Feleppa (LF) parameters: slope, intercept, and midband; and quantitative ultrasound (QUS)-derived parameters: effective scatterer diameter (ESD) and effective acoustic concentration (EAC). In this study, the relation between the LF and QUS-derived parameters is studied theoretically and experimentally on ex vivo mouse livers. As expected from the theory, LF slope is correlated to ESD ([Formula: see text]), and from experimental data, LF midband is correlated to EAC ([Formula: see text]). However, LF intercept is not correlated to ESD ([Formula: see text]) nor EAC ([Formula: see text]). The unexpected correlation observed between LF slope and EAC ([Formula: see text]) results likely from the high correlation between ESD and EAC due to the inversion process. For a liver fat percentage estimation, an important potential medical application, the parameters presenting the better correlation are EAC ([Formula: see text]) and LF midband ([Formula: see text]).

Abstract P5-06-01: Proteomic analysis of conserved kinases between PDX tumors and corresponding PDX-derived cell lines

(Background) Patient-derived xenograft (PDX)s are valuable models for precision oncology as they are thought to recapitulate the biological and genomic characteristics of the human tumors they were derived from. Even though this model is widely used, it is still difficult to manipulate genes in this system and it is not as convenient as in vitro cell culture for drug sensitivity screening. On the other hand in vitro cell cultures have a highly artificial microenvironment and also have undergone selection which might generate misleading data. To address these issues cell lines from PDX tumors with different intrinsic subtypes were characterized by kinobead precipitation/mass spectrometry analysis (KiP/MS) to profile each PDX line in vivo and ex vivo for therapeutic targets.

(Materials and Methods)Washington University Human in Mice (WHIM) tumors and Hutsman Cancer Institute (HCI) tumors were transplanted into mammary fat pads of female severe combined immunodeficiency/beige (SCID/beige) mice. PDXs tumors were harvested when they reached 1˜1.5cm. PDX tumor-derived ex vivo cells/organoids were routinely cultured with Rock inhibitor support. Estradiol was applied only for the tumors originating from E2 supplementation in vivo. Cells and tumors were harvested and lysed by sonication. Kinases in soluble lysates are enriched with drug-bound beads (kinobead) and digested with trypsin. Digested peptides are analyzed by mass spectrometry.

(Results) 5 of WHIM tumors and 4 of HCI tumors were successfully dissociated and cultured ex vivo for further analysis and experiments. Hierarchical clustering of tumors and corresponding cells showed ex vivo cultured cells cluster together with their original PDX tumors. Tumors/ex vivo cultured cells clustered by intrinsic subtype and enrichment analysis identified specific kinases for each PDX tumor/cell line. The WHIM 4 tumor-cell pair showed high level of PIM kinase and EGFR and other PDX tumors such as WHIM18, WHIM 20 (Luminal subtypes), WHIM 35(HER2 enriched subtype) also showed model unique intrinsic kinases, such as JAK2 for WHIM18, EPHB4 for WHIM20.

(Conclusion) PDX tumor-derived ex vivo lines could be routinely cultured with Rock inhibitor support. Each PDX tumor and cell line pair were cluster together in hierarchical clustering and categorized into the same intrinsic subtype based on kinome profiling, suggesting these cells maintain their tumor specific intrinsic kinase signaling. A subset of kinases exhibit activity/expression that is conserved after ex vivo culture, we hypothesize these are intrinsic kinases might be promising target for treatment, because they are tumor intrinsic, i.e. their high expression is maintained despite the strong contrast in the microenvironment of in vitro versus in vitro growth. Ongoing studies with drugs and knock down reagents are examining whether the in vivo/ex vivo comparative KIP analysis indeed identifies therapeutic targets, which will be presented at the meeting more in detail.

Citation Format: Han A, Kim B-J, Chan DW, Matsunuma R, Singh P, Ellis MJ. Proteomic analysis of conserved kinases between PDX tumors and corresponding PDX-derived cell lines [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-06-01.

3D collagen architecture induces a conserved migratory and transcriptional response linked to vasculogenic mimicry

The topographical organization of collagen within the tumor microenvironment has been implicated in modulating cancer cell migration and independently predicts progression to metastasis. Here, we show that collagen matrices with small pores and short fibers, but not Matrigel, trigger a conserved transcriptional response and subsequent motility switch in cancer cells resulting in the formation of multicellular network structures. The response is not mediated by hypoxia, matrix stiffness, or bulk matrix density, but rather by matrix architecture-induced β1-integrin upregulation. The transcriptional module associated with network formation is enriched for migration and vasculogenesis-associated genes that predict survival in patient data across nine distinct tumor types. Evidence of this gene module at the protein level is found in patient tumor slices displaying a vasculogenic mimicry (VM) phenotype. Our findings link a collagen-induced migration program to VM and suggest that this process may be broadly relevant to metastatic progression in solid human cancers.

Extracellular matrix plays a central role in driving cancer development. Here the authors using an in vitro approach show that confining collagen architectures induce fast and persistent cell migration and the formation of multicellular network structures linked to vascular mimicry observed in tumours from patients.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Impedance spectroscopy-based cell/particle position detection in microfluidic systems

An impedance spectroscopy-based cell/particle position detection method in microfluidic systems is presented. A single pair of non-parallel surface microelectrodes was utilized to detect the transverse positions of particles/cells flowing in a microchannel without the need for a multi-electrode multi-channel impedance detection. This method can be a simple solution for high-throughput and low-cost position detection in microfluidic sorting and separation applications.

Involved-field irradiation in definitive chemoradiotherapy for T4 squamous cell carcinoma of the esophagus

OBJECTIVES

Definitive concurrent chemoradiotherapy (ccrt) is currently a therapeutic option for locally advanced esophageal cancer. However, clinical practice differs with respect to the target volume for irradiation. The purpose of the present study was to analyze failure patterns and survival, and to determine the feasibility of using involved-field irradiation (ifi) with concurrent chemotherapy for T4 squamous cell carcinoma (scc) of the esophagus.

METHODS

Between January 2003 and January 2013, 56 patients with clinical T4M0 scc of the esophagus received ccrt using ifi. The radiation field included the primary tumour and clinically involved lymph nodes. Target volumes and sites of failure were analyzed, as were treatment-related toxicity and survival time.

RESULTS

In this 56-patient cohort, 13 patients (23.2%) achieved a complete response, and 21 (37.5%) achieved a partial response, for a total response rate of 60.7%. The major toxicities experienced were leucocytopenia and esophagitis, with 14 patients (25.0%) experiencing grade 3 toxicities. At a median follow-up of 34 months, 48 patients (85.7%) had experienced failure: 39 (69.6%) in-field, 7 (12.5%) elective nodal, and 19 (33.9%) distant. Only 1 patient (1.8%) experienced isolated elective nodal failure. The 1-, 2-, and 3-year survival rates were 39.3%, 21.4%, and 12.5% respectively.

CONCLUSIONS

For patients with T4M0 scc of the esophagus, definitive ccrt using ifi resulted in an acceptable rate of isolated elective nodal failure and an overall survival comparable to that achieved with elective nodal irradiation. A limited radiation therapy target volume, including only clinically involved lesions, would therefore be a feasible choice for this patient subgroup.

Abstract A47: Membrane translocation of GLUT1 induced by TP53 mutation is positively correlated with increased glucose uptake in patients with breast cancer

Background: High rate of glycolysis exhibited by cancer cells plays a crucial role in carcinogenesis and tumor progression. To uncover candidate contributing to increasing glucose uptake in breast cancer, we interrogated clinical transcriptome data set from 66 patients undergoing preoperative 18F-fluorodeoxy glucose positron emission tomography (FDG-PET). Also, we validated the candidate in other clinical data and confirm its role in glucose uptake through cell line works.

Methods: Clustered analysis by standardized uptake value (SUV) from FDG-PET and gene network analysis suggested that repression of p53 might be a key molecule associated with elevated SUV level. To validate p53 as a major determinant in an elevated glucose uptake, we used second cohort consisted of women with p53 gene sequencing analysis and FDG-PET. Mutational analysis of exons 5-9 of the p53 gene was carried out using polymerase chain reaction-denaturing high performance liquid chromatography. Of these women, to reduce bias and clearly estimate the influence of p53 mutation on SUV and survival, we identified 114 women by propensity-score matching method. Next, among the molecules associated glucose uptake, we compared the expression of GLUT1 using tissue-microarray (TMA). The TMA was constructed using achievable 73 tumors from second cohort with case-matching by P53 mutation status. Then, we validated the role of P53 in glucose uptake by mammary cell using the experiments with MCF-10A cell line. To compare the degree of glucose uptake between P53-mutated and P53-intact cells, we measured gamma activities of these cell lines after treated with 18F-FDG media. Simultaneously, different amount of glucose uptake is visualized using the PET camera.

Results: In case-matched cohort by P53 status, the mean SUV of p53-mutational group was significantly higher than that of wild-type p53-group (7.49 vs. 5.44, P=0.013). Compared with the group with intact p53, recurrence-free survival (RFS) was significantly reduced in the group with p53 mutation (P =0.017). In multivariate analysis, p53 mutational status carried prognostic significance (hazard ratio 3.73, 95% CI 1.15-12.07) independent of tumor size, nodal status, and estrogen receptor status. In immunohistochemical stain with GLUT1 using the TMA, we found that the expression of membraneous GLUT1 was significantly higher in P53-mutated tumors than in P53-intact tumor (P=0.022), in support of previous finding showing that P53 mutation promotes GLUT1 translocation to cell membrane. In experiments with MCF10A cell lines, we found that gamma activities and signal intensity by the absorption of18F-glucose were much higher in P53-mutated cell than in P53-intact cell. These experiments showed that the amount of glucose uptake in mammary cell increases followed by P53 mutation, supporting our clinical findings.

Conclusion: We showed that TP53 mutation promotes GLUT1 translocation to membrane, which consequently induces glucose influx in patients with breast cancer. In terms of glucose metabolism, P53 mutation caused the increase of glucose uptake within tumor and adversely affect survival in breast cancer.

Citation Format: Sung Gwe Ahn, Hak Woo Lee, Airi Han, Jeong Joon. Membrane translocation of GLUT1 induced by TP53 mutation is positively correlated with increased glucose uptake in patients with breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A47.

Abstract A04: The role of surgical resection of primary tumor before the appearance of circulating tumor cells based on orthotopic allograft mouse model

Breast cancer causes death not because of the primary tumor in the breast but because of metastases in distant sites that gradually cause organ dysfunction. Circulating tumor cells (CTCs) are cells that have detached from the primary tumor or metastatic tumor site and entered the peripheral circulation. Using CTC-mouse model, we tested the hypothesis that curative resection prior to CTC appearance results in repression of tumor metastasis. In method, we implanted 1 x104 GFP expressing 4T1 cells in 4th or 5th mammary fat pad of 8 week-old BALB/cAnNCrl mice (n=69). Enumeration of CTCs was performed using a FACSCalibur flow cytometry system (Becton, Dickinson and Company, Cowley, U.K.). CTCs were considered positive if the number of counted cells is more than 5. First, to test the validity of our CTC count method using FACS, we conducted cell-spiking tests. Using phosphate-buffered saline (PBS) and human blood, 50, 200, 500, 1000 4T1/GFP tumor cells were spiked. The R2 between spiked tumor cells and counted cells were 0.930 for PBS and 0.975 for human blood, respectively. Next, we tested the correlation between CTC counts and tumor volume. In the results, tumor volume and the number of CTCs increased over time and tumor volume showed statistically significant correlation with CTCs (p&lt;0.001). In most cases, CTC-positive mouse died 6 weeks after orthotropic transplantation of 4T1 cell lines. Then, to evaluate the role of surgery in early breast cancer with no CTC, we removed transplanted tumor just before CTCs appeared in circulation (n=35). The smallest size of tumor with observable CTCs was 47.28mm3. After removal of the primary tumor, we evaluated the extent of surgical procedures. If there was any suspected residual tumor tissue in operation bed, the procedure was categorized as R1 resection. If operation bed was not suspected with residual tumor tissue, the resection was categorized as R0 resection. All the experimental animal showed CTCs after primary tumor appeared (n=69). The mice showed no CTCs during follow up period (16 weeks) if R0 resection was successfully conducted (n=25). However, we could detect CTCs during follow up period if incomplete resection (R1 resection) was done (n=10) (p&lt;0.001). Tumor progression was found in the mice with the re-occurrence of CTC, and these animals expired. In summary, we developed orthotopic allograft mouse model with breast cancer and circulating tumor cells, which is most similar with human breast cancer evolution. We provide evidence that R0 resection prior to CTC occurrence can inhibit tumor progression and metastasis. These results showed biologic rationale that the patients with no detectable CTC confirmed by an accurate CTC-count assay may not need any kinds of adjuvant treatment.

Citation Format: Hak Woo Lee, Airi Han, Ban Seok Yang, Jong Tae Park, Sung Gwe Ahn, Joon Jeong. The role of surgical resection of primary tumor before the appearance of circulating tumor cells based on orthotopic allograft mouse model. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A04.

Meeting highlights: the first korean breast cancer treatment consensus conference

The first Korean Breast Cancer Treatment Consensus Conference Expert Panel reviewed and endorsed new evidence on aspects of local and regional therapies and diagnostic procedures that support the conservative application of results from recent clinical trials. This conference clarified the barriers that limit the application of recent clinical trial results, such as questions about level of evidence, differences between the setting of clinical trials and that of daily clinical practice, and medical necessities and environment. Detailed decisions recommended for the treatment and diagnosis, according to the from the consensus conference, are recorded including details of the votes. These recommendations differed in the degree of support for clinical consideration of disease extent and host factors, medical necessities, and environment.

Biased signalling and proteinase-activated receptors (PARs): targeting inflammatory disease

Although it has been known since the 1960s that trypsin and chymotrypsin can mimic hormone action in tissues, it took until the 1990s to discover that serine proteinases can regulate cells by cleaving and activating a unique four-member family of GPCRs known as proteinase-activated receptors (PARs). PAR activation involves the proteolytic exposure of its N-terminal receptor sequence that folds back to function as a 'tethered' receptor-activating ligand (TL). A key N-terminal arginine in each of PARs 1 to 4 has been singled out as a target for cleavage by thrombin (PARs 1, 3 and 4), trypsin (PARs 2 and 4) or other proteases to unmask the TL that activates signalling via Gq , Gi or G12 /13 . Similarly, synthetic receptor-activating peptides, corresponding to the exposed 'TL sequences' (e.g. SFLLRN-, for PAR1 or SLIGRL- for PAR2) can, like proteinase activation, also drive signalling via Gq , Gi and G12 /13 , without requiring receptor cleavage. Recent data show, however, that distinct proteinase-revealed 'non-canonical' PAR tethered-ligand sequences and PAR-activating agonist and antagonist peptide analogues can induce 'biased' PAR signalling, for example, via G12 /13 -MAPKinase instead of Gq -calcium. This overview summarizes implications of this 'biased' signalling by PAR agonists and antagonists for the recognized roles the PARs play in inflammatory settings.

Pathway-selective antagonism of proteinase activated receptor 2

BACKGROUND AND PURPOSE

Proteinase activated receptor 2 (PAR2) is a GPCR associated with inflammation, metabolism and disease. Clues to understanding how to block PAR2 signalling associated with disease without inhibiting PAR2 activation in normal physiology could be provided by studies of biased signalling.

EXPERIMENTAL APPROACH

PAR2 ligand GB88 was profiled for PAR2 agonist and antagonist properties by several functional assays associated with intracellular G-protein-coupled signalling in vitro in three cell types and with PAR2-induced rat paw oedema in vivo.

KEY RESULTS

In HT29 cells, GB88 was a PAR2 antagonist in terms of Ca(2+) mobilization and PKC phosphorylation, but a PAR2 agonist in attenuating forskolin-induced cAMP accumulation, increasing ERK1/2 phosphorylation, RhoA activation, myosin phosphatase phosphorylation and actin filament rearrangement. In CHO-hPAR2 cells, GB88 inhibited Ca(2+) release, but activated G(i/o) and increased ERK1/2 phosphorylation. In human kidney tubule cells, GB88 inhibited cytokine secretion (IL6, IL8, GM-CSF, TNF-α) mediated by PAR2. A rat paw oedema induced by PAR2 agonists was also inhibited by orally administered GB88 and compared with effects of locally administered inhibitors of G-protein coupled pathways.

CONCLUSIONS AND IMPLICATIONS

GB88 is a biased antagonist of PAR2 that selectively inhibits PAR2/G(q/11)/Ca(2+)/PKC signalling, leading to anti-inflammatory activity in vivo, while being an agonist in activating three other PAR2-activated pathways (cAMP, ERK, Rho) in human cells. These findings highlight opportunities to design drugs to block specific PAR2-linked signalling pathways in disease, without blocking beneficial PAR2 signalling in normal physiology, and to dissect PAR2-associated mechanisms of disease in vivo.

Longer survival in patients with breast cancer with cyclin d1 over-expression after tumor recurrence: longer, but occupied with disease

Purpose

The effect of cyclin D1 overexpression on breast cancer outcomes and prognosis is controversial, even though amplification of the cyclin D1 gene, CCND1, has been shown to be associated with early relapse and poor prognosis. In this study, we examined the relationship between cyclin D1 overexpression and disease-specific survival (DSS). We also analyzed survival in patients who experienced recurrence.

Methods

We retrospectively analyzed data from patients diagnosed with ductal carcinoma between April 2005 and December 2010. We examined clinicopathologic factors associated with cyclin D1 overexpression and analyzed the influence of cyclin D1 on recurrence-free survival and DSS.

Results

We identified 236 patients diagnosed with primary breast cancer who completed all phases of their primary treatment. Cyclin D1 overexpression was significantly associated with longer DSS (5-year DSS, 89.9% in patients without cyclin D1 overexpression vs. 98.9% in patients with cyclin D1 overexpression; p=0.008). Multivariate analysis also found that patients with cyclin D1 overexpressing tumors had significantly longer disease-specific survival than patients whose tumors did not overexpress cyclin D1, with a hazard ratio for disease-specific mortality of 7.97 (1.17-54.22, p=0.034). However, in the group of patients who experienced recurrence, cyclin D1 overexpression was not significantly associated with recurrence-free survival. Cyclin D1 overexpression was significantly associated with increased survival after disease recurrence, indicating that cyclin D1 overexpression might be indicative of more indolent disease progression after metastasis.

Conclusion

Cyclin D1 overexpression is associated with longer DSS, but not recurrence-free survival, in patients with breast cancer. Longer postrecurrence survival could explain the apparent inconsistency between DSS and recurrence-free survival. Patients with cyclin D1-overexpressing tumors survive longer, but with metastatic disease after recurrence. This information should spark the urgent development of tailored therapies to cure these patients.

Abstract P6-06-25: Usefulness of pretreatment NLR as prognostic factor of late recurrence, 5-year after primary treatment

Background

Prognostic factor and predictive factors are well established in early-stage breast cancer, but less is known about recurrence, especially 5-year after primary treatment. While mortality of breast cancer is from organic dysfunction with metastatic disease, not from the diseased breast itself, still we do not have adequate information about metastatic disease as we do about primary breast cancer itself.

The aim of this study is to investigate of usefulness of pretreatment NLR(neutrophil to lymphocyte ratio) as prognostic factor that can tell risk of recurrence 5- year after primary treatment.

Patients and methods

A retrospective review of invasive breast cancer patients surgically resected between January 2001 and December 2007. Exclusion criteria were as followings: patients with recurrence or death within 5yrs.

Results

A total of 301 patients were included and 13 patients experienced with recurrence after 5 years.

Table 1. Patients' characteristics Total (n = 301) N (%)Age*48.8(±11.4)Age ≤3525(8.3)35&lt; ≤50165(54.8)50&lt;111(36.9)Histology Ductal270(89.7)Lobular7(2.3)Others24(8.0)Tumor size (cm)*2.73(±1.64)T stage T1126(41.9)T2158(52.5)T317(5.6)N stage N0199(66.1)N167(22.3)N220(6.6)N311(3.7)unknown4(1.3)Histologic grade I72(23.9)II110(36.5)III70 (23.3)unknown49(16.3)Estrogen receptor Negative111(36.9)Positive185(61.5)unknown5(1.6)Progesterone receptor Negative129(42.9)Positive167(55.5)Unknown5(1.6)HER-2 Negative196(65.1)Positive98(32.6)unknown7(2.3)Molecular subtype Luminal A136(45.2)Luminal B66(21.9)HER-2 enriched32(10.6)Triple negative60(20.0)unknown7(2.3)Late recur Yes13(4.3)No288(95.7)*mean±SD

Overall average of NLR value was 2.16, median value was 1.83. The average NLR were 2.80±1.68 in patients with recurrences occurred after 5 years and 2.13±1.15 in patients without recurrence. The NLR cutoff value of 1.83 was determined by median value.

In 1.83≤NLR group has a higher incidence of recurrence after 5 years compared with NLR&lt;1.83 group (8yr DFS 99.2% vs. 93.3%, p = 0.021). Especially in luminal A(ER (+) or PR (+), HER-2(-)), 1.83≤NLR group has a higher incidence of recurrence after 5 years compared with NLR&lt;1.83 group (8yr DFS 100% vs. 87.0%, p = 0.015).

Conclusion

We found that pretreatment NLR is associated with late recurrence that occurs after five years. And we suggest that NLR could be used as one of the prognostic factor that can tell about late recurrence, 5-year after primary treatment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-25.

Effects of maltitol and xylitol chewing-gums on parameters involved in dental caries development

AIM

The effects on plaque parameters of sugar free chewing-gums (CG) sweetened with either maltitol or xylitol were assessed to better understand the role polyols can play in dental caries prevention.

MATERIALS AND METHODS

A double-blind, parallel, randomised, controlled study was conducted in China. Subjects (N = 258, age = 13 to 15 years-old) were divided into 4 groups: 2 receiving polyols CG, containing respectively maltitol or xylitol, a group receiving gum base (placebo) and a negative control group not receiving any gum. CG were chewed for 30 days. This corresponds to a 10 g consumption of polyol per day. Plaque parameters (growth, pH, bacteria and insoluble glucans) were evaluated throughout the experimental period.

RESULTS

All parameters studied were significantly modified with gum base compared to no-gum: plaque pH increased; plaque growth, bacteria (S. mutans, S. sobrinus, A. viscosus and Lactobacillus) and insoluble glucans decreased. Maltitol and xylitol CG led similarly to a higher plaque pH (AUC, p⋜0.05) on short (at baseline after the first CG consumption) and long term (after 4 weeks of daily CG consumption), with or without saliva stimulation compared to both control and placebo groups. They led to a decrease in plaque growth (p=0.02) over the experimental period compared to controls. Moreover, they significantly reduced the concentration of 4 cariogenic bacteria species (p⋜0.05) in dental plaque compared to gum base.

CONCLUSION

Sugar free CG sweetened with either maltitol or xylitol can similarly reduce plaque acidogenicity compared to gum base through a decrease in oral bacteria presence. The use of a gum base placebo allowed to isolate effects on parameters involved in dental caries development specific to maltitol and xylitol, and to show these effects were similar.