Abstract SP012: Convergent evolution of resistance pathways during early stage breast cancer treatment with combination cell cycle (CDK) and endocrine signaling inhibitors

Combining cyclin-dependent kinase (CDK) inhibitors with endocrine therapy improves outcomes for metastatic estrogen receptor positive (ER+), HER2 negative, breast cancer patients. However, the value of this combination in potentially curable earlier stage patients is not clear. Using single cell transcriptomic profiling, we examined the evolutionary trajectories of early stage breast cancer tumors using serial tumor biopsies from a clinical trial of preoperative endocrine therapy alone (letrozole) or in combination with the cell cycle inhibitor ribociclib. Applying hierarchical regression and Gaussian process mathematical modelling, we classified each tumor by whether it shrinks or persists with therapy and determined cancer phenotypes related to evolution of resistance and cell cycle transcriptional rewiring. We found that all patients’ tumors undergo subclonal evolution during therapy, irrespective of the clinical response. However, tumors subjected to endocrine therapy alone showed reduced diversity over time, those facing combination therapy exhibited increased diversity. Despite different diversity, single nuclei RNA sequencing uncovered common phenotypic changes in tumor cells that persist following treatment. In these tumors, accelerated loss of estrogen signaling is convergent with up-regulation of the JNK pathway, while persistent tumors that maintain estrogen signaling during therapy show potentiation of CDK4/6 activation consistent with ERBB4 and ERK signaling up-regulation. Cell cycle reconstruction identified that these tumors can rebound during combination therapy treatment, indicating stronger selection and promotion of a proliferative state. These results indicate that combination therapy in early stage ER+ breast cancers with ER and CDK inhibition drives rapid evolution of resistance via a shift from estrogen signaling to alternative growth factor receptor mediated proliferation and JNK signaling activation, concordant with a bypass in the G1 checkpoint.

Citation Format: JI Griffiths, J Chen, PA Cosgrove, A O'Dea, P Sharma, CX Ma, M Trivedi, K Kalinsky, KB Wisinski, R O'Reagan, I Makhoul, LM Spring, A Bardia, FR Adler, AL Cohen, JT Chang, QJ Khan, AH Bild. Convergent evolution of resistance pathways during early stage breast cancer treatment with combination cell cycle (CDK) and endocrine signaling inhibitors [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 SP012.

Abstract P2-14-01: The impact of local therapy on locoregional recurrence in women with high risk breast cancer in the neoadjuvant I-SPY2 TRIAL

Background: In women with breast cancer receiving neoadjuvant chemotherapy, residual cancer burden (RCB) predicts distant recurrence and survival. In those with high risk tumors, locoregional recurrence (LRR) remains a concern, and has been associated with type of local therapy received. We evaluated the impact of local therapy on LRR in the ISPY-2 TRIAL.

Methods: Data were analyzed in Stata 14.2, using Chi2 test, log rank test, and a Cox proportional hazards model. RCB was considered a categorical variable (0/1 versus 2/3), as described in prior publications. Breast surgery categories were lumpectomy +/- radiotherapy, or mastectomy +/- radiotherapy. Axillary surgery was defined as sentinel lymph node (SLN) surgery (≤6 nodes removed) or axillary dissection (>6 nodes).

Results: Follow up data from the I-SPY2 TRIAL were available for 630 patients (median follow up 2.76 yrs, range 0.4-7.2). Type of local therapy was significantly associated with clinical stage at presentation, with stage III patients most frequently undergoing mastectomy + radiation (p<0.001). Women with higher RCB were more likely to undergo mastectomy than those with lower RCB (61.3% vs 48.8% mastectomy rate, p=0.002), and more likely to receive adjuvant radiotherapy (62.0% vs 53.9%, p=0.048). There was no association between clinical stage, type of surgery, or radiotherapy and LRR (Table). Higher RCB was significantly associated with LRR, with 3 year locoregional recurrence free rate of 95.1% in RCB 0/1 versus 89.9% in RCB 2/3 (p=0.003).

In a Cox model adjusting for clinical stage, tumor subtype, surgical therapy, RCB status, nodal radiation, and age, significant predictors for LRR were tumor subtype and RCB status. Hazard ratio (HR) for LRR in those with RCB 0/1 was 0.39 compared to those with RCB 2/3 (95% CI 0.17-0.87, p=0.021). There was no difference in LRR between breast conservation and mastectomy; within the breast conservation group, those who had lumpectomy alone had higher hazard of LRR compared to those having lumpectomy + radiation (HR 3.1, 95% CI 1.1-9.2, p=0.043).

Conclusions: Extent of surgical therapy was not associated with local tumor control, regardless of advanced tumor stage at presentation. Rather, tumor biology and response to therapy were the best predictors of LRR. These data highlight the opportunity to minimize the morbidity of extensive surgical therapy for patients with excellent response to systemic therapy.

LRR rates by clinical features and treatment status FrequencyLRR RateP valueClinical Stage  0.5I240 (47.5%)5.8% II185 (36.6%)8.7% III80 (15.8%)6.3% Tumor Subtype  0.014ER+PR+Her2-161 (26.4%)3.1% ER+PR-Her2-56 (9.2%)3.6% Her2+176 (28.9%)6.3% Triple negative216 (35.5%)11.1% Local therapy  0.169Lumpectomy85 (13.5%)11.8% Lumpectomy with radiation198 (31.4%)5.6% Mastectomy173 (27.5%)5.2% Mastectomy with radiation174 (27.6%)8.6% Axillary surgery  0.23None5 (0.8%)20% SLN329 (52.2%)5.8% ALND296 (47%)8.5% Axillary radiation  0.535Yes42 (6.7%)9.5% No588 (93.3%)7.0% Axillary management  0.2No surgery or radiation5 (0.8%)20.0% SLN312 (50%)5.3% SLN+Axillary radiation17 (2.7%)8.3% ALND271 (43%)10.3% ALND+Axillary radiation25 (4%)5.4% RCB  0.0020/1293 (50.1%)3.8% 2/3292 (49.9%)10.3% 

Citation Format: Silverstein J, Suleiman L, Yau C, Price ER, Singhrao R, Yee D, DeMichele A, Isaacs C, Albain KS, Chien AJ, Forero-Torres A, Wallace AM, Pusztai L, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Leyland-Jones B, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, I-SPY 2 TRIAL Consortium, Berry DA, Asare SM, Esserman LJ, Boughey JC, Mukhtar RA. The impact of local therapy on locoregional recurrence in women with high risk breast cancer in the neoadjuvant I-SPY2 TRIAL [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 P2-14-01.

Abstract P2-07-03: Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden

Background: Patients achieving a pathologic complete response (pCR) following neoadjuvant therapy have significantly improved event-free survival relative to those who do not; and pCR is an FDA-accepted endpoint to support accelerated approval of novel agents/combinations in the neoadjuvant treatment of high risk early stage breast cancer. Previous studies have shown that recurrence risk increased with increasing burden of residual disease (as assessed by the RCB index). As well, these studies suggest that patients with minimum residual disease (RCB-I class) also have favorable outcomes (comparable to those achieving a pCR) within high risk tumor subtypes. In this study, we assess whether integrating RCB with MRI functional tumor volume (FTV), which in itself is prognostic, can improve prediction of distant recurrence free survival (DRFS); and identify a subset of patients with minimal residual disease with comparable DRFS as those who achieved a pCR. Imaging tools can then be used to identify the subset that will do well early and guide the timing of surgical therapy.

Method: We performed a pooled analysis of 596 patients from the I-SPY2 TRIAL with RCB, pre-surgical MRI FTV data and known follow-up (median 2.5 years). We first assessed whether FTV predicts residual disease (pCR or pCR/RCB-I) using ROC analysis. We applied a power transformation to normalize the pre-surgical FTV distribution; and assessed its association with DRFS using a bi-variate Cox proportional hazard model adjusting for HR/HER2 subtype. We also fitted a bivariate Cox model of RCB index adjusting for subtype; and assessed whether adding pre-surgical FTV to this model further improves association with DRFS using a likelihood ratio (LR) test. For the Cox modeling, penalized splines approximation of the transformed FTV and RCB index with 2 degrees of freedom was used to allow for non-linear effects of FTV and RCB on DRFS.

Result: Pre-surgical MRI FTV is significantly associated with DRFS (Wald p<0.00001), and more effective at predicting pCR/RCB-I than predicting pCR alone (AUC: 0.72 vs. 0.65). Larger pre-surgical FTV remains associated with worse DRFS adjusting for subtype (Wald p <0.00001). The RCB index is also significantly associated with DRFS adjusting for subtype (Wald p<0.00001). Adding FTV to a model containing RCB and subtype further improves association with DRFS (LR p=0.0007). RCB-I patients have excellent DRFS (94% at 3 years compared to 95% in the pCR group). Efforts are underway to identify an optimal threshold for dichotomizing pre-surgical FTV and FTV change measures for use in combination with pCR/RCB-I class to generate integrated RCB (iRCB) groups as a composite predictor of DRFS.

Conclusion: Pre-surgical MRI FTV is effective at predicting minimal residual disease (RCB0/I) in the I-SPY 2 TRIAL. Despite the association between FTV and RCB, FTV appears to provide independent added prognostic value (to RCB and subtype), suggesting that integrating MRI volume measures and RCB into a composite predictor may improve DRFS prediction.

Citation Format: Hylton NM, Symmans WF, Yau C, Li W, Hatzis C, Isaacs C, Albain KS, Chen Y-Y, Krings G, Wei S, Harada S, Datnow B, Fadare O, Klein M, Pambuccian S, Chen B, Adamson K, Sams S, Mhawech-Fauceglia P, Magliocco A, Feldman M, Rendi M, Sattar H, Zeck J, Ocal I, Tawfik O, Grasso LeBeau L, Sahoo S, Vinh T, Yang S, Adams A, Chien AJ, Ferero-Torres A, Stringer-Reasor E, Wallace A, Boughey JC, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, Haugen PK, van't Veer LJ, Perlmutter J, Melisko ME, Wilson A, Peterson G, Asare AL, Buxton MB, Paoloni M, Clennell JL, Hirst GL, Singhrao R, Steeg K, Matthews JB, Sanil A, Berry SM, Abe H, Wolverton D, Crane EP, Ward KA, Nelson M, Niell BL, Oh K, Brandt KR, Bang DH, Ojeda-Fournier H, Eghtedari M, Sheth PA, Bernreuter WK, Umphrey H, Rosen MA, Dogan B, Yang W, Joe B, I-SPY 2 TRIAL Consortium, Yee D, Pusztai L, DeMichele A, Asare SM, Berry DA, Esserman LJ. Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden [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 P2-07-03.

Abstract P4-10-06: Influence of older age on triple negative breast cancer (TNBC) clinical-pathological characteristics and outcomes

Background: The impact of age at diagnosis on clinical presentation and treatment delivery for triple negative breast cancer (TNBC) is unclear. Utilizing data from a prospective registry, the aim of this study was to further elucidate the age-dependent correlation between TNBC clinical-pathological features, and the implications of age-bias on treatment delivery and prognosis.

Methods: 480 subjects with stage I-III TNBC were enrolled in an IRB approved multisite prospective registry between 2011 and 2016. Clinical, demographic, treatment information was collected and patients were followed for recurrence and survival. Patients were categorized as older (>60 years) or younger groups (<60 years). Recurrence free survival (RFS) and overall survival (OS) were estimated according to the Kaplan-Meier method and compared among groups by log-rank test.

Results: 145 (30%) of 480 TNBC patients were older (> 60 years) at time of diagnosis. Compared to younger patients, older patients were more likely to present with screen detected vs symptomatic cancer (47% vs 25% p=<0.001), more likely to have node negative cancer (71% vs 61% p=0.030), stage I disease (42% vs 28% p=0.003), and low level (1-10%) ER or PR positivity (19% vs 12% p=0.046). Compared to the younger patients, older patients were less likely to have a BRCA1/2 mutation (6% vs 23% p=0.0002) but more likely to have a prior history of hormone positive breast cancer (7% vs 1% p=0.0002). Compared to younger counterparts, older patients were less likely to receive neo/adjuvant chemotherapy (93% vs 99% p=0.0006), and less likely to receive > 4 cycles of neo/adjuvant chemotherapy (61% vs 78%, p=0.0003). Three year RFS for the entire cohort was 80% and was identical for older and younger patients at 80%. Three year OS for the entire cohort was 87% and was similar for older and younger patients. On multivariable analysis only tumor size and nodal status significantly impacted RFS.

Conclusions: A significant fraction (30%) of TNBC patients are older (> 60 years) at time of diagnosis. Despite presenting a with more favorable disease stage, older TNBC patients did not demonstrate better outcomes compared to the higher risk younger patients. The underlying reasons for this observation may be tumor biology differences between older and younger TNBC patients or perhaps could be related to underutilization of appropriate systemic chemotherapy (39% of older patients received < 4 cycles of chemotherapy). Further studies are warranted on this subject.

Citation Format: Mina A, Lehn C, Wang YY, Klemp JR, O'Dea AP, Elia M, Hoffmann M, Crane G, Sheehan M, Madhusudhana S, Jensen RA, Godwin AK, Khan QJ, Kimler BF, Sharma P. Influence of older age on triple negative breast cancer (TNBC) clinical-pathological characteristics and outcomes [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 P4-10-06.

Abstract P6-12-11: Feasibility and biomarker modulation due to high levels of moderate to vigorous physical activity as part of a weight loss intervention in older, sedentary, obese breast cancer survivors

We sought to demonstrate that older, sedentary, obese breast cancer survivors could achieve > 200 minutes per week of moderate to vigorous physical activity (MVI PA) as part of a weight loss intervention; and to assess modulation of risk biomarkers. This level of PA in combination with moderate calorie restriction is associated with weight losses of >10% in women without cancer, which in turn is associated with significant modulation of cancer risk biomarkers.

Eleven participants with BMI > 30 kg/m2 enrolled in a 12-week program that consisted of moderate caloric restriction, weekly phone group behavioral sessions, and individualized exercise plans based on measured heart rate reserve. Women were provided an accelerometer with heart rate monitor linked to GarminConnect, membership to a YMCA, twice weekly supervised exercise sessions with a personal trainer, and weekly feedback regarding weight and physical activity progress. The goal was to increase MVI PA (≥45% heart rate reserve) gradually from <60 to >200 minutes per week.

The median age was 61, 5/11 women had received prior chemotherapy, and 7/11 were currently taking aromatase inhibitors. Median values of baseline anthropomorphic measures acquired by dual energy x-ray absorptiometry (GE Lunar iDXA) included BMI, 37.3 kg/m2; total mass, 97.5 kg; fat mass, 47.6 kg; visceral fat, 1.7 kg (range 1.4-3.0); and fat mass index, 17.6 kg/m2. The majority had a baseline VO2 peak in the poor range for their age. All 11 participants completed the intervention, with no reported serious adverse events. Median MVI PA achieved over weeks 5-12 was 161 minutes/week (range 48-320). VO2 peak was increased in 10/11 with a median relative change of 12% from baseline. All but one lost weight with an overall median of 8% total mass loss, which was associated with 13% total fat mass loss and 21% visceral fat mass loss. For those with MVI PA above the median, values were 11%, 17%, and 40%, respectively. Visceral fat mass loss was linearly correlated with minutes per week of MVI PA (p=0.032); these parameters in turn were associated with changes in a number of serum biomarkers, including adiponectin-leptin ratio, TNF-alpha, as well as circulating adipose stromal cells, a potential marker for metastasis. Insulin and hs-CRP were favorably modulated in almost all participants but change was not linearly correlated with activity or mass loss parameters; thus these may not be ideal biomarkers to document a dose response to level of MVI PA.

Conclusion: These results demonstrate that older, sedentary, obese breast cancer survivors can safely achieve a high level of MVI PA when provided a structured program that includes an exercise trainer. It is feasible to design a clinical trial for such breast cancer survivors to examine biomarker modulation as a function of level of physical activity.

Citation Format: Fabian CJ, Klemp JR, Burns JM, Vidoni ED, Nydegger JL, Kreutzjans AL, Phillips TL, Baker HA, Hendry B, John C, Amin AL, Khan QJ, Mitchell MP, O'Dea AP, Sharma P, Wagner JL, Hursting SD, Kimler BF. Feasibility and biomarker modulation due to high levels of moderate to vigorous physical activity as part of a weight loss intervention in older, sedentary, obese breast cancer survivors [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 P6-12-11.

A randomized adaptive phase II/III study of buparlisib, a pan-class I PI3K inhibitor, combined with paclitaxel for the treatment of HER2- advanced breast cancer (BELLE-4)

Background

Phosphatidylinositol 3-kinase (PI3K) pathway activation in preclinical models of breast cancer is associated with tumor growth and resistance to anticancer therapies, including paclitaxel. Effects of the pan-Class I PI3K inhibitor buparlisib (BKM120) appear synergistic with paclitaxel in preclinical and clinical models.

Patients and methods

BELLE-4 was a 1:1 randomized, double-blind, placebo-controlled, adaptive phase II/III study investigating the combination of buparlisib or placebo with paclitaxel in women with human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer with no prior chemotherapy for advanced disease. Patients were stratified by PI3K pathway activation and hormone receptor status. The primary endpoint was progression-free survival (PFS) in the full and PI3K pathway-activated populations. An adaptive interim analysis was planned following the phase II part of the study, after ≥125 PFS events had occurred in the full population, to decide whether the study would enter phase III (in the full or PI3K pathway-activated population) or be stopped for futility.

Results

As of August 2014, 416 patients were randomized to receive buparlisib (207) or placebo (209) with paclitaxel. At adaptive interim analysis, there was no improvement in PFS with buparlisib versus placebo in the full (median PFS 8.0 versus 9.2 months, hazard ratio [HR] 1.18), or PI3K pathway-activated population (median PFS 9.1 versus 9.2 months, HR 1.17). The study met protocol-specified criteria for futility in both populations, and phase III was not initiated. Median duration of study treatment exposure was 3.5 months in the buparlisib arm versus 4.6 months in the placebo arm. The most frequent adverse events with buparlisib plus paclitaxel (≥40% of patients) were diarrhea, alopecia, rash, nausea, and hyperglycemia.

Conclusions

Addition of buparlisib to paclitaxel did not improve PFS in the full or PI3K pathway-activated study population. Consequently, the trial was stopped for futility at the end of phase II.

Abstract P6-11-08: Safety and efficacy results from phase I study of BYL 719 plus nab-paclitaxel in HER 2 negative metastatic breast cancer

Introduction

Mutations/deregulations in the phosphatidylinositol-3-kinase (PI3K) pathway are common in breast cancer, Inhibition of the PI3K pathway is recognized as a promising target for the treatment of breast cancer. Although taxanes are effective early on in advanced stage breast cancer, resistance often develops. It has been demonstrated that activation of the PI3K/AKT pathway confers resistance to paclitaxel, and in preclinical models, concomitant inhibition of the PI3K pathway enhances the efficacy of taxanes. BYL719 is a potent oral, class I PI3K inhibitor which strongly inhibits the PI3K alpha isoforms and is significantly less active against the other class I isoforms. Targeting the alpha isoform of PI3K is expected to improve the therapeutic window over inhibitors with less isoform specificity. Nab-Paclitaxel is a solvent-free, nanoparticle, albumin-based paclitaxel which takes advantage of the antitumor activity of paclitaxel while decreasing the toxicities typically associated with the solvent (Cremophor) used to administer the most common formulation of paclitaxel.

Methods

A 3+3 dose-escalation design evaluated three dose levels of BYL719 (250mg, 300mg, and 350mg) administered PO once daily (D1-28) with nab-Paclitaxel (100 mg/m2 intravenously D 1, 8, 15) every 28 days in patients with metastatic HER 2 negative breast cancer. The aims of the study were to 1) determine the recommended phase II dose (RPTD) of BYL719 + nab-Paclitaxel, 2) assess pharmacokinetics of BYL and nab-paclitaxel, and 3) assess preliminary efficacy.

Results

10 patients were enrolled at 3 dose levels of BYL719 and 3 patients were enrolled in expansion cohort at the RPTD of BYL719 of 350 mg PO daily plus nab-paclitaxel 100mg/m2 (D 1, 8, 15). Median age was 61years; 54% (7/13) of patients were hormone receptor positive and 46% (6/13) triple negative. 85% (11/13) had visceral disease, 69% (9/13) had received prior chemotherapy for metastatic disease and 85% (11/13) had received prior taxane in adjuvant/metastatic setting. There were no DLTs in the three cohorts and the MTD of BYL was not reached. Hyperglycemia (G3:31%, G4:0%) and neutropenia (G3:15%, G4:8%), were the most common grade 3/4 adverse events. There were no Grade 3/4 diarrhea or rash. Best overall response for 12 patients was 58% (7/12) (complete response=1, partial response=6), and an additional 33% (4/12) demonstrated stable disease. Objective responses were noted in both hormone positive and triple negative disease. Median duration of response is 6.5 months (range 2-14 months). No pharmacokinetic interactions were detected when BYL and nab-paclitaxel were co-administered.

Discussion:

This phase I study demonstrates that combination of BYL719 and nab-paclitaxel was well tolerated and shows encouraging efficacy in metastatic HER2 negative breast cancer. Enrollment in the phase II portion of the trial at the RPTD (BYL719 350mg PO daily plus nab-paclitaxel 100mg/m2 D1,8,15 every 28 days) continues. Ongoing analysis of PI3K pathway alterations in tumor and cfDNA will be correlated with clinical response.

Citation Format: Sharma P, Abramson VG, O'Dea A, Lewis S, Scott JN, Ward J, De Jong JA, Lehn C, Brown AR, Williamson SK, Perez RP, Komiya T, Godwin AK, Reed GA, Khan QJ. Safety and efficacy results from phase I study of BYL 719 plus nab-paclitaxel in HER 2 negative metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-11-08.

Abstract P5-16-02: Pathological complete response is associated with excellent outcomes in BRCA mutation associated triple negative breast cancer

Introduction: Pathological complete response (pCR) in unselected triple negative breast cancer (TNBC) is associated with excellent long-term survival. However, controversy remains as to whether pCR in BRCA mutation associated (BRCA[+]) TNBC is predictive of improved long-term outcome. A recent study suggests that pCR was not a surrogate for outcomes in BRCA1 associated TNBC. All of the patients in this study harbored an Ashkenazi Jewish founder BRCA1 mutation and the majority of mutation carriers underwent lumpectomy. Impact of pCR as it relates to BRCA status in a larger, heterogeneous TNBC cohort treated in a contemporary time frame is not known.

Aim: Evaluate and compare the prognostic impact of pCR as it relates to the BRCA mutation status in patients enrolled in a prospective multisite TNBC registry.

Methods: 453 patients with stage I-III TNBC were enrolled within a multisite registry between 2011- 2015, out of which 173 received neoadjuvant chemotherapy (NAC) and also underwent germline BRCA testing. pCR in the breast and axilla was evaluated and patients were followed for reoccurrence and survival. Recurrence free survival (RFS) was estimated according to the Kaplan-Meier method and compared among groups with log-rank statistic.

Results: For the 173 eligible patients the median age was 49 years; African-American:14%; median tumor size:3 cm; 42%:Lymph node positive; and 18% (32/173) demonstrated BRCA mutation (BRCA1=28, BRCA2=4). All patients received anthracycline and/or taxane based NAC. pCR rates for BRCA[+] and wild type (BRCA[-]) patients was 72% and 46% respectively (p=0.01). 97% of BRCA[+] and 42% of BRCA[-] patients underwent bilateral mastectomy (p=0.001). The three year RFS was 92% and 81% in BRCA[+] and BRCA[-] patients, respectively (p=0.18). Attainment of pCR was associated with excellent 3 year RFS of 95% and 97% in BRCA[+] and BRCA[-] patients, respectively (p=0.85). Among BRCA[-] patients lack of pCR was associated with significantly worse 3 year RFS (70% RFS in patients without pCR, compared to 97% in patients with pCR; p=0.001). Among BRCA[+] patients lack of pCR was associated with numerically lower but not statistically significant worse 3 year RFS (83% RFS in patients without pCR, compared to 95% in patients with pCR; p=0.41). On multivariable Cox regression analysis, only stage III disease was associated with higher risk of relapse (p<0.001).

Conclusions: Our observation of higher pCR in BRCA-carriers compared to wild-type TNBC patients is consistent with previously published literature. In this contemporary cohort of TNBC patients for whom the majority of BRCA[+] patients underwent bilateral mastectomy, attainment of pCR carried an excellent prognosis in both BRCA[+] and BRCA[-] patients. On the other hand, BRCA[+] patients who do not attain pCR may have better outcomes compared to BRCA[-] patients without pCR. Further research to explore the underlying biological mechanisms involved in tumor response and relapse in BRCA[+] and BRCA[-] TNBC patients is needed. Furthermore, given these observations, germline BRCA mutation status should be used as a stratification variable in studies evaluating pCR and long term outcomes with investigational therapies in TNBC.

Citation Format: Prochaska LH, Godwin AK, Kimler BF, Lehn C, Klemp JR, O'Dea A, Elia M, Hoffmann MS, Crane G, McKittrick R, Sheehan M, Graff SL, Madhusudhana S, Khan QJ, Jensen RA, Sharma P. Pathological complete response is associated with excellent outcomes in BRCA mutation associated triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-02.

Abstract OT3-02-06: Femara plus ribociclib or placebo as neo-adjuvant endocrine therapy for women with ER+, HER2-negative early breast cancer - The Feline trial

Background:

In early ER+ breast cancer, neo-adjuvant (NA) endocrine therapy (ET) may identify a subset of patients with endocrine sensitive disease with excellent outcomes without chemotherapy. In patients receiving a NA aromatase inhibitor, on- therapy, short term (day 14) Ki-67 of <10% and post NA pre-operative endocrine prognostic index (PEPI) 0 at surgery are associated with low relapse rates without chemotherapy. Ribociclib, a novel CDK4/6 inhibitor is active in ER+ metastatic breast cancer. We hypothesize that ribociclib+letrozole as NA ET for stage II-III breast cancer will increase the number of women with a PEPI 0 at surgery.

Trial Design:

Randomized, placebo-controlled, multi-center, phase II, investigator initiated trial of NA letrozole +/- ribociclib in postmenopausal women with ER+, HER2-, breast cancer. Subjects will be randomized 1:1:1 to letrozole 2.5 mg daily + placebo, letrozole 2.5mg daily + ribociclib 600mg daily on D1-21 of a 28 day cycle (intermittent dosing), or letrozole 2.5mg daily + ribociclib 400mg daily (continuous dosing). Treatment will be continued for 6 months followed by surgery. Research core biopsies and blood will be collected at baseline, at day 14, and at surgery. A Ki67 >10% at day 14 will result in discontinuation of the subject from the protocol as this may be an early indicator of resistance to endocrine therapy. An MRI will be done after 2 months of therapy to assess response/progression. Primary endpoint is a PEPI score of 0 at surgery.

Key Eligibility Criteria:

Postmenopausal (natural or surgical) women with stage II/III ER+, HER2- breast cancer. Must have a palpable breast mass of at least 2 cm. Multicentric/contralateral invasive disease not allowed. Ipsilateral/contralateral DCIS is allowed. Inflammatory breast cancer is excluded.

Specific Aims:

Primary objective: To determine if ribociclib+letrozole as a 24 week NA ET increases rate of PEPI score of 0 at surgery compared to letrozole. Secondary objectives: To determine if ribociclib+letrozole as a 24 week NA ET increases the proportion of tumors with complete cell cycle arrest compared to letrozole; to determine if ribociclib in combination with letrozole for 24 weeks results in improved 5 year RFS compared to letrozole; to examine differences in response rates between the two ribociclib containing arms vs letrozole.

Statistical Methods:

The two ribocilib containing arms (n=80) will be combined for analysis against placebo + letrozole (n=40). Assuming that addition of ribociclib will increase the rate of PEPI 0 by 20%, and setting Type I error rate at 10% and Type II error rates at 20% in the final analysis, a sample size of 80 women in the treatment arms (40 in each arm) and 40 women in the control arm are needed to show significance.

Patient accrual and target accrual:

Participating sites include The Univ of Kansas Med Ctr, City of Hope National Med Ctr, Massachusetts General Hospital, University of Miami Sylvester Comprehensive Cancer Ctr, University of Arkansas for Medical Sciences, and University of Wisconsin. The trial has accrued 16 patients with a target accrual of 120 patients. Accrual should be complete in 2/2017.

Contact information: Qamar Khan, MD (qkhan@kumc.edu).

Citation Format: Khan QJ, Prochaska LH, Mohammad J, Yuan Y, O'Dea A, Bardia A, Wisinski K, Hard M, Baccaray S, Makhoul I, Wagner J, Laura S, Ma C, Sharma P. Femara plus ribociclib or placebo as neo-adjuvant endocrine therapy for women with ER+, HER2-negative early breast cancer - The Feline trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-02-06.

Abstract P5-13-03: Fulvestrant plus anastrozole as neoadjuvant therapy in postmenopausal women with hormone receptor positive early breast cancer

Background: Aromatase inhibitors (AIs) are effective in reducing the risk of recurrence from breast cancer (BC) but 20% of patients (pts) with early BC still recur despite adjuvant AIs. Thus more effective endocrine therapies (HTs) are needed. In metastatic BC (MBC), combination of lower dose fulvestrant plus anastrozole improves survival compared to anastrozole alone. The 21-gene Recurrence Score® (RS; Oncotype DX®) has been validated to predict benefit from adding chemotherapy (CT) to HT where pts with a low score have little benefit from CT and derive a large benefit from HT. Ki-67 response to neo-adjuvant HT may predict adjuvant outcomes to HT. Postoperative Endocrine Prognostic Index (PEPI) and modified PEPI may further identify a subset of HT sensitive cancers that do not require adjuvant CT (PEPI 0 category). We conducted a single arm phase II trial to assess the efficacy of fulvestrant plus anastrozole as neoadjuvant HT in pts with operable BC.

Methods: Postmenopausal pts with stage II and III, ER/PR+, HER2 (-) BC with a RS<25 (performed on initial core bx) were included. Duration of neo-adjuvant HT was 4 months. Pts received anastrozole 1mg (PO) daily continuously from day 1 until surgery + fulvestrant (IM) 500mg on day 1, 14 and 28 of cycle 1, and on the last day of three subsequent 28 day cycles (total 6 doses of fulvestrant). At week 4, an optional core bx was repeated to assess change in Ki-67. Response assessments were made clinically every 4 wks. All pts had breast/axillary surgery after the 6th dose of fulvestrant. Ki-67, histologic grade, ER/PR status, and RS were assessed at baseline, core bx at 4 wks, and at definitive surgery. Primary end points were pathologic complete response (pCR) rate and change in Ki-67. Adjuvant CT was left to the discretion of treating physician.

Results: 42 pts were enrolled 7/2009 to 11/2014. Median age was 62. 32 (76%) patients had stage IIA, 7 (17%) had stage IIB and 3 (7%) had stage III disease. 14% had clinically node positive disease. The median RS was 12 (0-24). Median tumor size was 3.5cm. 21%, 74%, and 5% had grade 1, 2 and 3 tumors respectively. Mean ER expression was 95%. 16 (38%) pts had a clinical complete response (cCR), 13 (31%) had a clinical partial response (cPR) and 12 (29%) had stable disease. One pt had progression on therapy. There were no pCRs. Median baseline Ki-67 was 5% (1-36%). 94% of pts had decrease in Ki-67 from baseline to 4-week bx and 97% of pts had decrease in Ki-67 from baseline to surgery. Modified PEPI score at surgery was 0 in 53% of patients. 78% of pts did not receive adjuvant CT. At median follow up of 38 mos only 1 pt had a recurrence with 98% free of a recurrence. There were no grade 3 or grade 4 toxicities.

Conclusions: The neoadjuvant combination of anastrozole and fulvestrant in pts with RS<25 markedly improves Ki-67 response with more than half of pts achieving a modified PEPI score of 0 at surgery. At a relatively short median follow up, recurrence rate is very low. Given the efficacy and tolerability of anastrozole plus fulvestrant in MBC and now in the neo-adjuvant setting, an adjuvant trial of this combination is warranted in pts with ER+ BC.

Citation Format: Khan QJ, Barr JA, Britt AS, Kimler BF, Connor CS, McGinness M, Mammen JMV, Wagner JL, Amin A, Springer M, Baccaray S, Fabian CJ, Sing AP, Sharma P. Fulvestrant plus anastrozole as neoadjuvant therapy in postmenopausal women with hormone receptor positive early breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-13-03.

Abstract OT3-01-12: Phase II trial of lapatinib and everolimus for HER2 positive metastatic breast cancer

Background:

Although the treatment of HER2 positive metastatic breast cancer (MBC) has improved with anti-HER2 agents and chemotherapy, most patients will eventually develop resistance to these agents. Preclinical studies have shown that mTOR inhibition may reverse trastuzumab resistance. We hypothesize that combining mTOR inhibitor everolimus with lapatinib will be an effective strategy for patients who have progressed on prior anti-HER2 therapies.

Trial Design:

We are conducting an open-label phase II pilot study of the combination of everolimus and lapatinib for pts with HER-2 positive MBC. Eligible pts must have histologically documented locally advanced (inoperable) or metastatic HER-2 positive breast cancer that have progressed on at least one HER-2 based regimen in the metastatic or locally advanced setting. Pts with disease progression during or within 12 mos of the completion of adjuvant trastuzumab are eligible. Pts with untreated asymptomatic brain metastases are allowed. Pts with symptomatic brain metastases are allowed to enroll after they have completed radiation and are off steroids. Eligible pts are started on everolimus 5 mg PO daily and lapatinib 1250 mg PO daily without interruption. Among subjects progressing on lapatinib, lapatinib is continued and everolimus initiated. Pts will continue to receive treatment until there is evidence of progressive disease (PD), unacceptable toxicity, or withdrawal of consent. Pts will have radiological evaluation every 8 weeks with CT, bone scan, and MRI brain (for pts with known brain metastasis at baseline).

Specific Aims:

Primary objective is to assess the effectiveness of the combination of RAD-001 and lapatinib as measured by the six-month Overall Response Rate in women with MBC who have progressed on trastuzumab and/or lapatinib based therapies. Secondary objectives are six-month PFS, safety and tolerability of the combination, six-month objective CNS response rate, six-month clinical benefit rate of systemic disease, and six-month clinical benefit rate in CNS.

Statistical methods:

The response rate of lapatinib monotherapy in heavily pre-treated patients is estimated to be 7% (Blackwell 2009). For an expected ORR of 17%, a sample size of 45 subjects will provide 79% power to detect the difference at 0.10 Type I error rate according to 1-sided exact binomial test.

Present accrual and target accrual:

The trial has accrued 20 patients with a target accrual of 45 patients.

Citation Format: Barr JA, Sharma P, Fabian CJ, Yeh H, Baccaray S, Springer M, Khan QJ. Phase II trial of lapatinib and everolimus for HER2 positive metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-01-12.

Abstract PD09-02: BRCA1 insufficiency is predictive of superior survival in patients with triple negative breast cancer treated with platinum based chemotherapy

Introduction: Triple negative breast cancer (TNBC) and BRCA1-associated breast cancers share many histopathologic and molecular features. BRCA1 plays a crucial role in HR-dependent DNA repair and BRCA1-deficient cells are particularly susceptible to the DNA damaging agents like platinums. Increasing evidence suggests that in addition to germline BRCA defects, other mechanisms (like epigenetic BRCA1 silencing) can lead to BRCA1 insufficiency in TNBC. However, the impact of BRCA1 insufficiency on the efficacy of DNA damaging agents in TNBC is not known.

Aim: To investigate the impact of BRCA1 insufficiency on relapse-free survival (RFS) and overall survival (OS) in patients with stage II-III TNBC treated with neoadjuvant platinum-based chemotherapy. BRCA1 insufficiency (BRCA1insuf) state was defined as presence of germline BRCA1/2 mutation or BRCA1 promoter methylation (PM) and/or low BRCA1 expression (lowest quartile).

Methods: Thirty patients with stage II/III TNBC received neoadjuvant chemotherapy (6 cycles of Carboplatin AUC 6, Docetaxel 75mg/m2 and Erlotinib 150 mg PO) on a phase II trial between 8/2007–6/2010. All but one patient underwent comprehensive BRCA analysis (Myriad Genetic Laboratories). Pre-treatment tumor specimens were used for evaluation of BRCA1 PM and expression. Genomic DNA was isolated from FFPE samples, bisulfite converted and then subjected to methylation-specific PCR (MSP). RNA was isolated, reverse transcribed to cDNA and assayed by quantitative real-time PCR (qRT-PCR) for determination of BRCA1 mRNA transcript levels. RFS and OS were estimated according to the Kaplan-Meier method and compared among groups with log-rank statistic. Cox proportional hazards models were fit to determine the association of BRCA1insuf with the risk of death after adjustment for other characteristics.

Results: Median age: 51yrs, African American: 20%, Median tumor size: 3.3 cm, LN positive: 40%. Six of 30 patients (20%) harbored germline BRCA mutation (4 BRCA1, 2 BRCA2). Baseline tumor specimen was available for 26/30 patients. BRCA1 MSP was successful in 92% and BRCA1 qRT-PCR was successful in 84% of specimens. BRCA1 PM and low BRCA1 expression was present in 30% and 15% of subjects, respectively. There was evidence of BRCA1insuf in 53% (16/30) of subjects. At a median time from diagnosis of 42 months (range, 23–59 months) there have been 9(30%) recurrences and 7(23%) deaths. On univariate analysis node negativity, lower stage and presence of BRCA1insuf were associated with better OS. At the median follow up, RFS is 81% for patients with BRCA1insuf versus 54% for patients without BRCA1insuf (p = 0.16); OS is 83% for patients with BRCA1insuf versus 46% for patients without BRCA1insuf (p = 0.021). After adjustment for clinical variables patients with BRCA1insuf had a significantly better OS compared to patients without BRCA1insuf (p = 0.036).

Conclusions: Germline BRCA testing plus tissue BRCA1 PM/expression can be used to identify a BRCA1insuf sub-population within TNBC demonstrating a favorable outcome with platinum treatment. This BRCA1insuf criteria can be easily used to select TNBC patients likely to benefit from DNA damaging agents like platinums and PARP inhibitors.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD09-02.

Evaluation of Ki-67 measured in benign breast tissue acquired from premenopausal women treated with a flaxseed derivative

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Background: The lignans enterolactone and enterodiol are derived from the action of gut bacteria on ingested secoisolariciresinol diglycoside (SDG) which is commonly found in flaxseed. Enterolactone and enterodiol are thought to impair mammary carcinogenesis via reduction in aromatase activity and the mid-cycle surge of luteinizing hormone. We assessed the modulatory activity of 1 year of SDG on a number of risk biomarkers for breast cancer in a prospective phase II pilot study. We report the effect of SDG on the primary endpoint, proliferation in benign breast tissue as measured by Ki-67 immunocytochemistry, in the first 35 women completing study. Methods: Premenopausal women age 21 to 55 at increased risk for breast cancer underwent a baseline random periareolar fine needle aspiration (RPFNA) between the first and tenth days of their menstrual cycle. Those with RPFNA evidence of hyperplasia and Ki-67 greater than or equal to 2% were invited to participate. Women taking flaxseed or oral contraceptives were ineligible. All women took one Brevail (lignan research) capsule containing 50 mg of SDG daily. Ki-67 staining was performed with DAKO M7240 antibody on hematoxylin counterstained slides and the number of cells staining positive in 500 cells within hyperplastic clusters was counted. Results: Forty-nine women were enrolled on study between February 2006 and June 2008. Of these, four stopped prematurely, 10 women have not completed, and 35 have completed study and undergone follow-up RPFNA. Baseline characteristics of the 35 women completing study are as follows: median age 44 (range 29–50), median baseline 5-year Gail model risk 1.6% (range 0.1%-5.7%), median Ki-67 4.2% (range 2.0%-16.8%). Thirty seven percent had hyperplasia without atypia, and 63% had atypia. At repeat RPFNA, Ki-67 expression was reduced (median value of 2.0%, range 0%-15.2%); with 29 of the 35 women demonstrating a decrease (median relative reduction of 0.70). Conclusions: Based upon reduction in Ki-67 expression in hyperplastic benign breast tissue after 12 months, 50 mg of SDG administered daily as Brevail appears promising as a preventive. Supported in part by grant R21 CA117847 from the National Cancer Institute.

No significant financial relationships to disclose.

Vitamin D levels during and after high-dose vitamin D supplementation in women with early-stage breast cancer

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Background: Experts define vitamin D deficiency as a 25-hydroxyvitamin D (25OHD) level of < 20 ng/ml; a level < 32 ng/ml is considered insufficient for bone health and > 40 ng/ml may be associated with optimum musculoskeletal function and reduced risk for breast cancer. We conducted a study to determine the effect of high dose vitamin D3 at 50,000 IU/wk (HD vitD) on musculoskeletal symptoms from adjuvant letrozole in breast cancer patients. We present here the effectiveness of HD vitD in achieving optimum 25OHD levels and the rate of decline of 25OHD levels after 12 weeks of HD vitD. Methods: The cohort included post-menopausal women with early stage hormone receptor positive breast cancer initiating letrozole treatment. Women with baseline 25OHD levels < 40 ng/ml received 12 weeks of HD vitD. 25OHD levels were assessed at 6 and 12 weeks during HD vitD supplementation and at 3 and 6 months after completing HD vitD but while taking maintenance dose of 600–1000 IU of vitamin D3 daily. Results: 40 women that received HD vitD completed the follow-up phase of the study and are included in this analysis. At entry on study, median 25OHD level was 23 ng/ml; 38% of the women had vitD deficiency, 75% had insufficiency, and 93% had 25OHD levels < 40 ng/ml. Six weeks of HD vitD increased median 25OHD level to 60 ng/ml and another 6 weeks increased it further to 66 ng/ml. With only 6 weeks of HD vitD supplementation, 98% of the women achieved a 25OHD level of > 40 ng/ml. Median 25OHD levels 3 and 6 months after completion of HD vitD were 49 and 40 ng/ml, respectively. The median rate of decrease in vitD levels per month was 6.8% of the level at completion of supplementation. Using linear regression analysis, projected changes in 25OHD levels were calculated for each subject. Median extrapolated time to drop to a 25OHD level of < 40 ng/ml was 6.0 months, to <32 ng/ml was 7.8 months, and to <20 ng /ml was 10.6 months. Conclusions: Supplementation with vitD3 at 50,000 IU/week for 6 weeks is sufficient to achieve a 25OHD level of >40 ng/ml in 98% of postmenopausal women with breast cancer on an AI. After 12 weeks of HD vitD, there is a steady decline in 25OHD levels at a rate of about 7% per month despite continuing on 600 to 1000 IU of D3 daily. Thus, standard doses of D3 are not adequate to maintain 25OHD levels achieved by HD vitD.

No significant financial relationships to disclose.

BRCA1 and BRCA2 germline mutation carriers have a lower breast density compared to high risk women without such mutations

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Background: High mammographic breast density, a known risk factor for breast cancer is influenced by both genetic and non genetic factors. It is not clear if there are differences in breast densities between BRCA1/2 mutation carriers and high-risk non carriers. The aim of this study was to compare breast density in high-risk women with and without BRCA1/2 mutation. Methods: Women at high risk for development of breast cancer (based on family history, prior precancerous disease or prior breast cancer) who underwent genetic testing at the University of Kansas Breast Cancer Prevention Center between 1998 and 2005 were identified under an IRB approved protocol. BRCA1/2 full sequencing was performed at Myriad Genetic Laboratories. The earliest digitized mammogram of these subjects was identified from a preexisting mammogram database. All mammograms had to be prior to/at least one year from any chemoprevention intervention. For subjects with prior breast cancer, mammogram of the uninvolved breast was used. Breast density was assessed on the left craniocaudal mammographic view by computer assisted method, Cumulus. Frequencies of categorical variables were assessed using chi-square analysis. Continuous variables were assessed using Mann-Whitney non parametric test. Multiple regression analysis was used to investigate whether differences are due to variables other than mutation status. Results: The study population consisted of 284 high-risk women who underwent BRCA1/2 testing and for whom a mammogram was available. 30 (11%) had BRCA1 and/or 2 deleterious mutation. There was no difference between mutation carriers and non-carriers for BMI, 5 year Gail risk, parity, menopausal status and HRT use. Mutation carriers were younger (median age 42 vs. 46, p=0.020) and more likely to have a positive family history (100% vs. 85%, p=0.020). Older age (p<0.001), higher BMI (p<0.001) and having a BRCA1/2 mutation (p=0.025) were significantly associated with a lower breast density. Conclusion: Among high risk women, possession of a deleterious BRCA1/2 mutation is associated with lower breast density after adjusting for factors known to affect breast density. This suggests that breast density may be governed by genetic factors other than BRCA1/2 mutation status.

No significant financial relationships to disclose.

Integrated FDG-PET/CT for initial staging of breast cancer

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Background: Integrated FDG-PET/CT improves the diagnostic accuracy of staging of some cancers. The value of FDG-PET/CT in initial staging of breast cancer for detection of distant metastases has not been defined. Methods: Retrospective analysis of 83 consecutive women at the University of Kansas Medical Center who had a FDG-PET/CT from Jan 2005 to July 2006, at the time of initial diagnosis of invasive breast cancer. Women with symptoms suspicious for metastatic disease were excluded. Radiographic reports and patient charts were reviewed. All suspicious CT scans were re-read by a single radiologist who was blinded to the PET results. All suspicious scans were confirmed either by a biopsy or follow-up scans according to the discretion of the treating physician. Results: Median age was 52. 23 (28%) cancers were stage I, 44 (53%) stage II and 16 (19%) were stage III. 15/83 (18%) women had a suspicious FDG-PET/CT. Only 2 of these 15 women were confirmed to have metastatic disease, while 13 (16 %) had a false positive (FP) scan. In 5 women where both CT and PET were suspicious, 2 were true positives (TP) whereas 3 were FP. All 3 women who had suspicious PET but a non-suspicious CT were FP. All 7 women who had a non-suspicious PET and a suspicious CT were FP. PET influenced the CT classification by the radiologist in 5 (6%) women. 71/83 (86%) women had a negative or a non-suspicious CT. 3 women had lesions classified as non-suspicious with the help of a negative PET, two had lesions classified as suspicious with the help of a positive PET and seven had suspicious lesions on CT regardless of the PET. FDG-PET/CT resulted in unnecessary follow-up scans in eleven women, and unnecessary biopsies in two. One TP had metastatic bone disease. The other TP had a solitary liver metastasis detected by FDG-PET/CT which was resected and she has no evidence of disease after two years of follow-up. Conclusions: Given the high false positive rate and overall low incidence of metastases, routine use of FDG- PET/CT in asymptomatic women diagnosed with invasive breast cancer cannot be recommended.

No significant financial relationships to disclose.

Correlation of mammographic breast density with Ki-67 expression in benign breast epithelial cells obtained by random periareolar fine needle aspiration of high risk women

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 >Background: Known risk factors for breast cancer development include elements incorporated into the Gail risk model, mammographic breast density and cytologic atypia detected by Random Periareolar Fine Needle Aspiration (RPFNA). Ki-67 expression is a possible risk biomarker and is currently being used as a response biomarker in chemoprevention trials. We have previously shown that Ki-67 expression is higher in RPFNA specimens of benign breast cells exhibiting cytologic atypia. It is not known whether there is a correlation between mammographic density and Ki-67 expression in benign breast ductal cells obtained by RPFNA. Methods: 344 women at high risk of developing breast cancer (based on personal or family history) seen at The University of Kansas Medical Center high risk breast clinic, who underwent RPFNA with cytomorphology and Ki-67 assessment, plus a mammogram were included in the study. Mammographic breast density was assessed using the Cumulus program. Categorical variables were analyzed by Chi-square test and continuous variables were analyzed by non-parametric test and linear regression. Results: 40% of women were premenopausal, 7% perimenopausal and 53% were postmenopausal. Median age was 49 years, median 5 year Gail Risk was 2.2%, and median Ki-67 was 1.9%. Median mammographic breast density was 37%. Ki-67 expression increased with cytologic abnormality and number of cells collected, but was unrelated to Gail risk (as observed previously). Breast density was higher in pre-menopausal women (p=0.001), those with lower BMI (p< 0.001), and lower 5-year Gail risk (p=0.012); Breast density showed no correlation with Ki-67 expression or cytomorphology. Conclusion: Given the lack of correlation of mammographic breast density with either cytomorphology or Ki-67 expression in RPFNA specimens, mammographic density and Ki-67 expression should be considered as potentially complementary response biomarkers for breast cancer chemoprevention trials.

No significant financial relationships to disclose.

Correlation of statin use with breast random periareolar fine needle aspiration (RPFNA) cytomorphology in high risk postmenopausal women

1031

Background: In vitro studies have demonstrated that statins (HMG CoA reductase inhibitors) suppress tumor growth and proliferation in breast cancer cell lines. Published clinical data on the chemoprotective role of statins in breast cancer are conflicting. Moreover, there are no published studies specifically examining the impact of statin use on breast cancer risk biomarkers in high risk women. We have previously demonstrated that cytologic atypia detected by RPFNA is associated with a 5 fold increase in short term risk of breast cancer in high risk women. The aim of this study was to explore the effect of statin use on breast RPFNA cytomorphology in postmenopausal women at high risk of developing breast cancer (based on personal and family history). Methods: Thehigh risk breast clinic database at the University of Kansas Medical Center was queried from April 2002 to September 2005 for statin use in postmenopausal women. We first identified postmenopausal women who underwent RPFNA while on a statin (cases). Postmenopausal women who underwent RPFNA while not on a statin (controls) were then identified and matched with statin users for known breast cancer risk factors (age, 5 year Gail risk and BMI). Frequencies of categorical variables were assessed using chi-square analysis. Continuous variables were assessed using Mann-Whitney non parametric test. Results: 504 postmenopausal women were identified. Thirty five of these 504 women underwent RPFNA while on statin therapy. For statin users (cases), the median age was 56 years, median 5 year Gail risk was 3.6%, median BMI was 28 and the median duration of statin use was 1.4 years (range 0.3 to 13 yrs). Sixty nine controls were identified. There was no difference between cases and controls with respect to HRT use (54% vs 40%, p=0.22), duration of HRT use (p=0.30) and visual breast density (p=0.80). RPFNA atypia was detected in 11% of cases and 26% of controls (p=0.13). Conclusion: Although prevalence of RPFNA atypia was less frequent among statin users, this difference was not statistically significant in this small cohort of high risk women with relatively short duration of statin use. Larger studies are warranted to investigate this further.

No significant financial relationships to disclose.

Effect of naproxen on the pharmacokinetic parameters of rifampicin

The effect of naproxen (500 mg) on the pharmacokinetics of rifampicin (450 mg) was evaluated in healthy human subjects (n = 10). Subjects participated in a two way crossover trial, the first dosing condition was rifampicin alone (control), and the second dosing condition was naproxen with rifampicin. The concentrations of rifampicin from the serum samples were determined by HPLC. The pharmacokinetic parameters indicated a significant (P < 0.05) increase in elimination rate constant (Ke), clearance (Cl), volume of distribution (Vd), while significant decrease in the mean residence time (MRT), and area under the concentration-time curve (AUC). Insignificant increase and decrease in absorption rate constant (Ka), and elimination half-life (t1/2), time for maximum concentration (Tmax), maximum drug concentration (Cmax) respectively was observed.

Hopf bifurcation in epidemic models with a time delay in vaccination

Two SIR models for the spread of infectious diseases which were originally suggested by Greenhalgh & Das (1995, Theor. Popul. Biol. 47, 129-179; 1995, Mathematical Population Dynamics: Analysis of Heterogeneity, pp. 79-101, Winnipeg: Wuerz Publishing) are considered but with a time delay in the vaccination term. This reflects the fact that real vaccines do not immediately confer permanent immunity. The population is divided into susceptible, infectious, and immune classes. The contact rate is constant in model I but it depends on the population size in model II. The death rate depends on the population size in both models. There is an additional mortality due to the disease, and susceptibles are vaccinated and may become permanently immune after a lapse of some time. Using the time delay as a bifurcation parameter, necessary and sufficient conditions for Hopf bifurcation to occur are derived. Numerical results indicate that that for diseases in human populations Hopf bifurcation is unlikely to occur at realistic parameter values if the death rate is a concave function of the population size.

Pharmacokinetic study about interaction of Naproxen and Isoniazid

Effect of Naproxen (500 mg) was studied on the pharmacokinetic characteristics of Isoniazid (300 mg) in ten healthy human volunteers in a complete crossover design. A high performance liquid chromatography (HPLC) method was used to analyze serum drug concentrations. Naproxen caused a highly significant (P<0.001) increase in AUC, significant (P<0.05) increase in elimination half life (t(1/2)) and time for the maximum drug concentration (tmax) while significant (P<0.05) decrease in elimination rate constant (Kc). Insignificant decrease and increase was observed in absorption rate constant (Ka) and maximum drug concentration (Cmax) respectively.