Abstract P1-08-10: Integration of next generation sequencing (NGS) and patient derived xenografts (PDX) to identify novel markers of paclitaxel (T) response in the breast cancer genome guided therapy study (BEAUTY)
Abstract Background: Based upon the association between pathologic response and disease free survival, the neoadjuvant setting is increasingly being used for drug development. NGS has identified unique and recurrent genetic alterations in breast cancer (BC) that are potentially targetable; however, the clinical implications are mostly unknown. We developed a prospective neoadjuvant study (BEAUTY) in high risk BC patients (pts) using weekly T followed by anthracycline-based chemo wherein percutaneous tumor biopsies (PTB) are obtained before/during/after chemo for NGS and PDX. Our goal is to identify novel biomarkers/pathways and develop PDX to test new therapeutic approaches. Methods: Pts underwent PTB at baseline and after 12 wks of T. Response to T was defined based upon 12 week Ki-67: responder (<15%) vs non-responder (≥15%). Pts with histologic response and absence of invasive BC at 12 wks were classified as responders. NGS was performed using PTB/blood DNA (exome) and PTB (RNA seq). MRI response was classified using RECIST criteria. NGS data were used to identify somatic copy number variants (cnvs) and expressed single nucleotide variants (eSNVs). Non-SCID mice (estrogen supplemented) were implanted ≤ 30 minutes with PTB samples. Results: Of the first 78 pts, 44 have completed T. Here we focus on 18 pts with either triple negative or luminal B BC. Clinical characteristics according to Ki-67 response are shown in Table 1. Comparison of genomic alterations in BEAUTY pts with TCGA identified a greater overlap with copy number gains (73%) compared to deletions (40%), along with similar observations of mutations in TP53, PTEN, RYR2, and AKT1 genes. Association analysis of CNVs and eSNVs between responders/non-responders identified 33 genes (predominantly located in chromosomes 1, 8, 13) and 580 eSNVs (corresponding to 497 genes) with a p < 0.05. Differential gene expression (DGE) analysis of responders/non-responders identified 198 genes with a p-value < 0.05. Integrated analysis of 539 genes (CNVs, eSNVs and DGE) identified pathways such as TGF-beta, Jak-Stat, WNT and NOTCH signalling. PDX take rate was 44% [triple negative (6/10); Luminal B (2/8)]. PDX growth rate was significantly associated with clinical baseline Ki-67 (p = 0.00014). Conclusion: This is the first prospective study to demonstrate the feasibility of using PTB to obtain both NGS data and PDX in the neoadjuvant setting. PDX take rate is associated with BC subtype and baseline Ki-67. Studies are ongoing to 1) validate genes/pathways associated with treatment response in subsequent BEAUTY pts; 2) genomically characterize and assess PDX in vivo response to T and 3) Use NGS data to prioritize new drugs/drug combinations in PDX. Funded by Mayo Clinic Center for Individualized Medicine and MC Cancer Center. Clinical CharacteristicsOverallResponders: 12 week Ki-67 < 15% (n = 9)Non-Responders: 12 week Ki-67 ≥ 15% (n = 9)Median Age495345T stage T2/T314 (78%)7 (78%)7 (78%)Node Positive8 (44%)4 (44%)4 (44%)Triple negative10 (56%)6 (67%)4 (44%)Luminal B8 (44%)3 (33%)5 (56%)Ki-67 after 12 Weeks of T Median 5% (0-11%)Median 35% (17-60%)Complete/Partial MRI Response after T 6 (67%)2 (22%) Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-10.
P5-15-05: Impact of Breast Specialized Physician Consultation on Surgical Decision Making for Breast Cancer and Decision Conflict in Women with Hereditary Breast Cancer Risk.
Abstract Background: Women with hereditary breast cancer risk, who develop breast cancer, face complex surgical decisions related to their breast cancer and risk to their contralateral breast. The aim of this study was to prospectively evaluate the factors influencing decision making in these women and degree of decision conflict before and after consultation with breast specialized physicians (BSP). Methods: Women with hereditary breast cancer risk and recently diagnosed with unilateral breast cancer were enrolled in a prospective decision making questionnaire study. Questionnaires were completed prior to their initial breast clinic visit and after consultation with a breast clinic physician, nurse educator and a breast surgeon. Results: 68 women completed both questionnaires. Mean age was 52 (range 27–84). Prior to meeting with BSP, 10 (15%) women reported having made a decision for the cancer side and 18 (26%) reported being close to deciding. Of the 20 who expressed a surgical preference prior to consultation, 5 (25%) changed their decision after meeting with the BSP [1 to mastectomy (MTX), 4 to breast conservation (BC)]. After consultation with BSP, 65 (96%) reported having made a decision (BC in 29 (45%), MTX in 35 (54%), unspecified in one). The most commonly cited reasons influencing surgical choice were doctor's advice (79%), family history of breast cancer (74%) and worrisome findings on biopsy (50%). Prior to meeting with BSP, 9 (13%) women reported having made a decision regarding screening and/or risk-reducing options for the contralateral breast and another 11 (16%) reported being close to a decision. The choices in these 20 women were screening only in 10 (50%), contralateral prophylactic MTX (CPM) in 3 (15%), CPM and oophorectomy in 2 (10%), other combinations of options in 4, and unspecified in 1. After meeting with the BSP, 49 (72%) reported having made a decision regarding the contralateral breast; this decision was for screening only in 21 (43%), CPM only in 9 (18%), screening plus tamoxifen in 7 (14%), CPM and oophorectomy in 2 (4%), other combinations of options in 8, and unspecified in 2. The most commonly cited reasons for choices on the contralateral side were: family history (81%), doctor's advice (78%), and worrisome findings on biopsy (43%); only 25% cited psychological or emotional reasons. For both the cancer and contralateral sides, decisional conflict was significantly lower after meeting with BSP than prior to meeting with BSP. Decision-conflict scale total scores (possible range 0–100; higher scores indicate more decisional conflict) summarized for each side and compared between timepoints Conclusion: The BSP consult and family history have the greatest influence on decision making among women with hereditary risk diagnosed with breast cancer. After consultation most women felt they had made decisions for both the cancer and contralateral sides and reported significantly lower decision conflict compared to prior to the consultation. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-15-05.
Abstract PD06-08: Size Matters: Incorporation of Sentinel Lymph Node (SLN) Metastasis Size into a Nomogram Predicting NonSLN Involvement in SLN Positive Breast Cancer Patients
Abstract Purpose: Emerging data from cooperative group trials suggests that not all patients with a positive SLN require completion axillary lymph node dissection (ALND). The controversy regarding who will benefit from additional nodal clearance continues, suggesting a need for improved tools to predict non-SLN involvement. We hypothesized that the size of a SLN metastasis evaluated as a continuous variable would be an important predictor of non-SLN involvement. The goal of this study was to determine clinicopathologic factors including SLN metastasis size that predicted non-SLN involvement and to use these factors to construct an improved predictive nomogram. Methods: Using a prospective database, we identified 509 patients with invasive breast cancer from 1996 - 2007 with a positive SLN who underwent ALND. Patients receiving neoadjuvant therapy were excluded. Clinicopathologic data including age, primary tumor size, presence of multifocal disease, histology (invasive ductal vs. invasive lobular vs. mixed invasive), tumor grade, estrogen receptor, progesterone receptor, and HER2/neu status, presence of lymphovascular invasion (LVI), the number of SLNs identified, number of positive SLNs, the maximum SLN metastasis size and the presence of extranodal extension were recorded. For SLNs described only as containing isolated tumor cells, size was recorded as 0.1 mm. Univariate and multivariate logistic regression analyses were performed to identify factors predictive of positive non-SLNs. Using these variables, a nomogram was constructed and subsequently validated using an external cohort of 464 patients. Results: On univariate analysis, the following factors were predictive of positive non-SLNs: number of SLN identified (p<.001), number of positive SLN (p<.001), maximum SLN metastasis size (p<.001), extranodal extension (p<.001), primary tumor size (p=.001), LVI (p=.019) and histology (p=.034). On multivariate analysis, all factors remained significant at the 5% level except LVI. A nomogram was created using these variables. When applied to an external cohort, the nomogram was accurate and discriminating with an area under the receiver operating characteristic curve of .73 (95% CI: .68 - .77). Conclusions: SLN metastasis size is predictive for identifying additional disease in the axilla. These data have been incorporated into a nomogram that accurately predicts the likelihood of having additional, non-SLN metastasis suggesting that routine reporting of the SLN metastasis size would assist with clinical decision making regarding the need to perform a completion ALND. Figures available in online version. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD06-08.
Abstract P5-14-10: Risk Factors Associated with Surgical Site Infection after Breast Operations
Abstract INTRODUCTION: Surgical site infection (SSI) is a problematic cause of morbidity following breast/axillary surgery. The breast/axilla has a higher rate of SSI than expected for clean wounds. We evaluated risk factors associated with SSI after breast/axillary operations. Methods: A retrospective review of breast/axillary procedures from July 2004 to July 2006 was performed. SSI was defined using Centers for Disease Control and Prevention criteria, including cases with cellulitis as the only criterion of infection. Data collected included patient demographics, BMI, surgical procedure, ASA class, antibiotic use, drains, and prior radiation (RT). RESULTS: We identified 389 patients who underwent 678 procedures. Thirty-seven SSI (5.5% of procedures) were identified, of which 24 (65%) had only cellulitis. Median time from surgery to SSI diagnosis was 9 days (range 2-112), with 81% occurring in the first 30 days. Univariate analysis identified prior RT, BMI, type of procedure, operative time, use of drain, and postoperative seroma to be associated with SSI (all P<0.05). With multivariate analysis, procedure type remained significant overall (p=0.04). Specifically, mastectomy with sentinel lymph node biopsy (SLNB) and modified radical mastectomy remained significantly associated with higher risk of SSI, with hazard ratios (HR) of 6.3 and 13.5 fold respectively compared to SLNB alone. Seroma (HR 9.0, 95% CI 2.7-29.3), prior RT (HR 3.4, 1.2-9.9), and BMI >=30 (HR 3.1, 1.6-6.2) also remained significantly associated with SSI. CONCLUSION(S): SSI are more frequent after breast/axillary operations than other clean wounds and are associated with prior RT, obesity, more extensive and longer procedures, and postoperative seroma. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-14-10.
Abstract P4-10-02: Young Age Is Associated with Increased Risk of Local Recurrence Following Breast Conservation Surgery
Abstract Background Local recurrence after breast conservation surgery (BCS) varies with clinical risk factors. The aim of this study was to evaluate how local recurrence rates vary by patient age at time of BCS. Methods With IRB approval, all patients undergoing BCS for primary breast cancer between 1988 and 2001 at Mayo Clinic, Rochester were identified. Patients receiving neoadjuvant chemotherapy were excluded. Local recurrence-free survival rates were estimated using the Kaplan-Meier method. Associations with local recurrence-free survival were evaluated using log-rank tests and Cox proportional hazards regression models. Results 3,075 patients underwent 3,143 BCS between 1988 and 2001. Mean age at BCS was 61 years (range 21-98). There were 177 (5.6%) patients aged <40, 496 (15.8%) 40-49, 763 (24.3%) 50-59, 803 (25.6%) 60-69, and 904 (28.8%) who were 70+ years old at time of surgery. At last follow-up, 214 patients (6.9%) experienced a local recurrence at a median of 3.4 years following BCS (range 0.1-14.4). Median follow-up for patients who did not experience a local recurrence was 8.7 years (range 0.0-20.2). The 5-year local recurrence-free survival rate was 95.0%. The frequency of local recurrences by age group were as follows: age <40 — 11.9%; age 40-49 — 5.9%; age 50-59 — 5.9%; age 60-69 — 7.6%; age 70 and older — 6.4%. The 5-year local recurrence-free survival rates for these age groups were 90.0%, 95.4%, 95.6%, 95.4%, and 94.7%, respectively (p=0.041; log-rank test). On univariate analysis, patients <40 years old were nearly twice as likely to experience a local recurrence following BCS compared with patients DCIS was associated with an increased risk of local recurrence compared with T1, T2, T3, or T4 disease (HR 2.25; P<0.001). Factors associated with a decreased risk of local recurrence on univariate analysis included ER positivity (HR 0.46; P<0.001), PR positivity (HR 0.60; p=0.001), adjuvant radiation (HR 0.48; p=0.007) and endocrine therapy (HR 0.65; p=0.012). Multivariate analysis of patients with complete data (n=2126) demonstrated that age <40 and node positivity were associated with an increased risk of local recurrence, while ER positivity, adjuvant radiation and endocrine therapy were associated with a decreased risk of local recurrence. Multivariable analysis of local recurrence after BCS Conclusion Risk factors for local recurrence after BCS include young age, node positivity, ER and PR negativity and absence of adjuvant radiation and endocrine therapy. Patients under age 40 are at increased risk of local recurrence following BCS for breast cancer. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-10-02.
Estimation of Risk of Recurrence of Early Stage Estrogen Receptor Positive Breast Carcinoma by Surgical and Medical Oncologists and Pathologists Compared to the Oncotype Dx® Recurrence Score.
Abstract Background: The decision to use adjuvant chemotherapy in patients with early stage breast cancer is based in part on the estimation of risk of tumor recurrence by physicians, which traditionally relies heavily on tumor size, nodal status and a set of biologic tumor characteristics such as hormone receptor and HER2 expression. The Oncotype DX® assay is a 21-gene expression profile aiming to improve risk stratification, recurrence prediction and optimize selection of patients for adjuvant chemotherapy.Methods: We selected 154 consecutive patients with early stage estrogen receptor (ER) positive breast cancer and available Oncotype Dx® recurrence score (RS) for the study. Clinicopathologic data, including patient age, menopausal status, tumor size, histologic type, grade, mitotic activity, presence of lymphatic invasion (LVI), nodal status, hormone receptor and HER2 status on all patients were provided to four surgical oncologists, four medical oncologists and three pathologists, specializing in breast cancer diagnosis and management. Participants were asked to estimate the risk of recurrence of tumors based on available clinicopathologic data and to provide the three most important tumor features their risk estimates were based on. Risk estimates of participants were compared with RS results.Results: Based on the Oncotype Dx® results, 95 (61.7%), 45 (29.2%) and 14 (9.1%) tumors were of low (RS <18), intermediate (RS 18-30) and high (RS ≥31) risk, respectively. RS values showed a highly significant correlation with tumor grade, mitotic activity, LVI, hormone receptor and HER2 status, while no correlation with patient age, menopausal status, tumor size and histologic type was found. Participants' risk estimates agreed with those of the Oncotype Dx® assay in 54.2 ± 2.3 % (mean ± SEM, range 41.6 - 63.0%) of cases, while the risk of recurrence was over- and underestimated compared to RS results in 31.8 ± 3.1% (16.2 - 43.5%) and 14.1 ± 1.4% (7.1 - 22.7%), respectively. The rates of overestimation were significantly higher than those of underestimation (p = 0.0003). Although medical oncologists tended to overestimate the risk more frequently (38.1 ± 2.0%) compared to surgeons (28.7 ± 5.9%) and pathologists (27.5 ± 7.8%), the difference did not reach statistical significance. Estimation of the agreement of participants' risk assessment with RS results showed a mean kappa value of 0.2955 (range 0.1506 - 0.4123). No statistically significant difference in overall concurrence with RS results was found between surgeons, medical oncologists and pathologists. Participants ranked tumor stage/nodal status, hormone receptor status and tumor size to be the most important features when estimating recurrence risk.Conclusions: Based on traditional clinicopathologic features alone, surgeons, medical oncologists and pathologists tend to overestimate the risk of tumor recurrence as compared to Oncotype Dx® assay results. The RS may provide additional information regarding the intrinsic biological features of ER positive breast cancers and help tailoring treatment recommendations. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4061.
The Effect of Oncotype Dx® Recurrence Score on Treatment Recommendations for Patients with Early Stage Estrogen Receptor Positive Breast Cancer.
Abstract Background: Current guidelines recommend administration of chemotherapy for patients with breast carcinomas >1 cm in size, with consideration for patient age, comorbidities and tumor grade. However, it is unknown which patients actually benefit from therapy and overtreatment of a significant proportion of patients is a major concern. We investigated the impact of the Oncotype Dx® Recurrence Score (RS) on chemotherapy recommendations in early stage estrogen receptor (ER) positive breast cancer patients.Methods: We selected 154 patients with early stage ER positive breast cancer and available RS for the study. Clinicopathologic data, including age, menopausal status, tumor size, type, grade, mitotic activity, presence of lymphatic invasion, nodal status, hormone receptor and HER2 status on all patients were provided to four surgical oncologists, four medical oncologists and three pathologists, specializing in breast cancer diagnosis and management. Assuming that all patients were in good general health and would receive endocrine therapy, participants were asked whether they would also advovate adjuvant chemotherapy based on clinicopathologic data with and without knowledge of the RS, and to provide the three salient clinicopathologic features on which their recommendations were based. Changes in recommendations of participants following inclusion of RS data were compared.Results: Based on RS results, 95 (61.7%), 45 (29.2%) and 14 (9.1%) tumors were of low (RS <18), intermediate (RS 18-30) and high (RS ≥31) risk, respectively. The results are summarized in Table 1. Assuming that the hypothesis previously put forward that patients with low to intermediate risk RS are not likely to benefit from chemotherapy, 82.3 ± 1.3% (75.5 - 89.0%) and 69.0 ± 6.9% (5.9 - 85.7%) of patients for whom chemotherapy was recommended by the participants would be "overtreated" without and with the use of RS results (p = 0.0322). No statistically significant difference was found among surgeons, medical oncologists and pathologists. Participants ranked patient age/menopausal status, hormone receptor status and tumor stage/nodal status to be the most important features when recommending chemotherapy.Conclusions: Although current recommendations for adjuvant chemotherapy for early stage ER positive breast cancer patients are largely in line with published guidelines, inclusion of RS alters recommendations in about 25% of cases. While medical oncologists recommended chemotherapy more frequently compared to surgeons and pathologists, they were more likely to change recommendations in light of RS results.Table 1. Summary of results SurgeonsMedical oncologistsPathologistsp* Mean ± SEMRangeMean ± SEMRangeMean ± SEMRange Chemo without RS (%)29.2 ± 1.824.0 - 31.859.0 ± 5.046.8 - 70.846.8 ± 3.741.6 - 53.90.0156Chemo with RS (%)27.0 ± 5.611.0 - 36.438.6 ± 9.517.5 - 63.644.4 ± 5.833.8 - 53.90.1794No change (%)75.3 ± 7.054.5 - 85.766.7 ± 6.851.3 - 83.885.9 ± 6.478.6 - 98.70.3682Add chemo (%)11.2 ± 4.13.2 - 22.76.5 ± 1.93.2 - 11.75.8 ± 3.20.6 - 11.70.6882Avoid chemo (%)13.5 ± 3.94.5 - 22.726.8 ± 7.94.5 - 41.68.2 ± 4.50.6 - 16.20.2186*Kruskal-Wallis test Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4058.
Abstract Abstract #3103 Introduction: Lymphedema is well-known in the arm but can also occur in the breast. Diagnosis is currently non-standardized and based on clinical impression. We sought to determine if skin thickness could serve as a useful measure in the diagnosis of breast lymphedema (BLE).
 Methods: Patients undergoing unilateral non-mastectomy procedures were enrolled on this prospective clinical study preoperatively and evaluated for signs and symptoms of lymphedema in the operated breast in the postoperative period. Patients with established BLE were also studied. BLE diagnosis was independent of ultrasound findings and was based on a graded physical exam targeting clinical signs of edema and erythema. Skin thickness was measured with ultrasound at the 6 o'clock position of both breasts. Differences in skin thickness were assessed by the ratio of skin thickness in the operated and contralateral breasts, with comparison of means by two-sample t-test. Receiver operating characteristic curves were constructed to estimate the area under the curve (AUC) and to determine optimal cutpoints.
 Results: Ninety-seven women were studied; 85 were enrolled preoperatively and 12 postoperatively after a diagnosis of BLE. Median length of follow-up overall was 8 months. Of the 97 women, 46 had BLE at one or more follow-up visit with median time to first diagnosis of 3 months. Mean measured skin thickness was 2.3 ± 0.5mm in unaffected breasts and 3.2 ± 1.0 mm in operated breasts. Women with BLE had significantly greater skin thickness in the operated breast compared to the contralateral breast, with a mean skin thickness ratio of 1.83 ± 0.57 in patients with BLE compared to 1.18 ± 0.40 among those without BLE (p<0.0001). Skin thickness ratio provided excellent discrimination for BLE, with an area under the curve (AUC) of 0.86. At a ratio of 1.32 or greater (32% greater skin thickness in operated versus contralateral breast), sensitivity and specificity for diagnosing BLE were 81% and 82% respectively. A single measure of skin thickness in the operated breast also correlated well with diagnosis of BLE, with skin thickness of 3.2 mm or greater demonstrating sensitivity of 78% and specificity of 82%, AUC 0.82.
 Conclusions: Breast lymphedema results in skin edema and increased skin thickness that can be quantified with ultrasound. Measuring breast skin thickness- either as a single reading or as a ratio to the unaffected breast- may be useful in the diagnosis of breast lymphedema. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3103.
Assessment of the performance of the Stanford online calculator for the prediction of non-sentinel lymph node metastasis in sentinel node positive breast cancer patients.
Abstract Abstract #1005 Background: Several models for the prediction of non-sentinel lymph node metastasis (+NSLN) in sentinel lymph node positive (+SLN) breast cancer patients have been published. Multiple variables have been shown to be important in prediction of +NSLN. To this date, models that utilize 7-8 variables have been significantly more discriminatory than models using only 2-3 variables. In this study, we evaluate the performance of the newly created Stanford online calculator (SOC) to predict the likelihood of +NSLN. The SOC uses 3 variables: primary tumor size, sentinel lymph node metastasis size, and presence/absence of lymphovascular invasion.
 Methods: From 1997-2004, 465 breast cancer patients with clinically negative axillae were found to have a +SLN and underwent completion axillary lymph node dissection (ALND) at the Mayo Clinic. Using the SOC the probability of having +NSLN was determined for each patient. Complete variable data was available for 464 patients which make up the cohort reported here. A receiver-operating characteristic (ROC) curve was created and the area-under-the-curve (AUC) was calculated. Mean probabilities of patients with and without +NSLN were compared. Additionally, patients with a low Stanford probability were examined to determine the model's accuracy in discriminating patients who could potentially be spared ALND. These results were compared to the results of the Mayo Clinic and Memorial Sloan Kettering Cancer Center (MSKCC) nomograms which have been previously applied to this same cohort of patients.
 Results: The AUC of the Stanford model was 0.72 (95% CI 0.67-0.77). The mean Stanford probabilities for patients with and without NSLN disease were 0.75 (range 0.06 to 1.0) and 0.50 (range 0.05 to 1.0), respectively (p < 0.0001). Examining patients with a Stanford probability <= 10%, we found that 47 patients met this criterion; 6 had +NSLN and 41 did not, for a false negative (FN) prediction rate of 13%. There was only 1 patient with Stanford probability <= 5%, and this patient did not have +NSLN. The AUC of the MSKCC and Mayo nomograms in this same patient population was 0.74 and 0.77, respectively. The AUCs did not differ significantly (p = 0.13) among the 3 models.
 
 Conclusion: Despite using only three variables, the Stanford nomogram appears to perform as well as, but not better than the MSKCC and Mayo nomograms in our patient cohort. Further validation in other patient populations is needed prior to widespread utilization of this nomogram. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1005.