Boughey, JC

Abstract Purpose: Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype with substantial risks of disease recurrence. While cytotoxic chemotherapy is commonly administered and reduces recurrence, disease outcomes vary considerably and few prognostic tools are available for risk stratification for TNBC patients. We constructed and validated clinical calculators for invasive-disease free survival (IDFS) and overall survival (OS) for TNBC and compared their performance against AJCC-based models which include only tumor size and nodal status. Methods: From a surgical cohort of 9,982 patients who underwent breast cancer surgery at Mayo Clinic between January 1985 and December 2012, 605 centrally reviewed TNBC patients were identified and used to construct Cox models for IDFS and OS. Patients treated with neoadjuvant chemotherapy were excluded. Variables considered included age, menopausal status, tumor size, nodal status, Nottingham grade, type of breast surgery (mastectomy vs. lumpectomy), adjuvant radiation therapy, adjuvant chemotherapy, Ki67, stromal tumor infiltrating lymphocytes (sTILs), and neutrophil-to-lymphocyte ratio (NLR). Missing values were imputed using single imputation with all variables (including outcomes) included in the imputation model. Backward step-down procedure was used for model selections. The final models were internally validated for calibration and discrimination using bootstrapping methods and compared with AJCC-based models. Results: For both IDFS and OS, higher sTIL's, less extensive nodal involvement, use of adjuvant chemotherapy, and lower NLR were significant predictors of improved clinical outcomes. Premenopausal status and younger age were additionally predictive of improved IDFS and OS, respectively. Models for IDFS and OS have good calibration and are associated with bias-corrected C-indices of 0.68 and 0.71, respectively, as compared with C-indices of 0.59 and 0.62 for AJCC-based models. Conclusions: Our data indicate that a clinical calculator that includes sTIL's, NLR, menopausal status, age, nodal involvement as well as chemotherapy use can provide significantly greater prediction of clinical risk than tumor size and nodal status alone. These tools may be used to identify TNBC patients at elevated risk of disease relapse and to aid physician's communication with patients regarding their long-term disease outlook and planning treatment strategies. External validation is required to further evaluate broader applicability of this tool, which was developed utilizing a single-institutional experience. Citation Format: Polley M-YC, Leon-Ferre RA, Liu H, Gilbert J, Cafourek V, Hillman DW, Negron V, Boughey JC, Liu MC, Ingle JN, Kalari K, Couch F, Visscher DW, Goetz MP. Mayo clinic TNBC outcome calculator: A clinical calculator to predict disease relapse and survival in women with triple-negative breast cancer [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 P1-06-07.

Abstract Background: Pathological complete response (pCR) is accepted by FDA as a surrogate endpoint for accelerated approval of targeted agents in combination with chemotherapy based on better long-term outcomes compared to residual disease (Cortazar 2014). Methods: The multi-center, adaptively-randomized I-SPY2 platform trial uses pCR as the primary endpoint to identify investigational agents that will improve outcomes in women with stage 2/3 breast cancer with high risk of early recurrence, across all signatures, based on hormone receptor (HR), HER2, and 70-gene (MammaPrint) status. For patients with HR+ HER2- tumors, only 70-gene (Mammaprint) high-risk patients are enrolled. To date, 1200+ patients have been randomized to one of 14 arms: control (paclitaxel followed by AC); veliparib/carboplatin; neratinib; MK2206; trebananib; trastuzumab/pertuzumab; ado-trastuzumab emtansine/pertuzumab; pembrolizumabx4; ganitumab/metformin; ganetespib; PLX-3397. 7 agents graduated in at least one signature (> 85% probability of success in a 300-patient phase III confirmatory trial); 2 did not graduate; 1 stopped for toxicity, and 3 are enrolling (patritumab/trastuzumab, talazoparib/irinotecan, pembrolizumabx8). Local pathologists were centrally trained using the Residual Cancer Burden (RCB) assessment to ensure uniform evaluation and response classification; RCB 0 = pCR. Results: We evaluated the relationship between pCR and event free (EFS) and distant disease free survival (DDFS) in the first 522 pts (median follow-up:2.5 years). 180 pts achieved pCR (36%) while 338 did not (RCB=1-3). There were 82 EFS and 65 DRFS events. Over the entire group (including all arms), pCR was highly associated with 3-year EFS (p<0.001 for both). Pts achieving pCR had a 3% recurrence risk (RR) at 3 years; those with non-pCR had 24% RR over this time period. For distant recurrence, the 3-year RR with pCR was 2%, compared to 20% in pts with non-pCR. As expected, pCR rates varied by breast cancer subtype (HR+/HER2: 18% (35/196), HR+/HER2+: 40% (33/82), HR-/HER2+:68% (34/50), HR-/HER2-:41% (76/188)). The relationship between pCR and EFS was significant and clinically impactful within each subtype. 3-year survival (pCR group)Hazard Ratio OverallOverallHR+/HER2-HER2+TNBCEFS97%0.08 (0.03-0.23)0.14 (0.02-1.04)0 (NA)0.11 (0.03-0.37)DDFS98%0.08 (0.03-0.26)0.17 (0.01-1.23)0 (NA)0.09 (0.02-0.40) Conclusions: The first long-term efficacy results from the I-SPY2 TRIAL demonstrate that achieving pCR is a very strong surrogate endpoint for improved EFS and DDFS in a high-risk population, across all treatment arms, regardless of subtype. I-SPY2 shows substantially lower estimated EFS hazards for patients achieving pCR, compared to the 5 yr EFS hazard ratio for pCR vs not in Cortazar (hazard ratio 0.49), demonstrating important differences between a metaanalysis compared to a platform trial with uniform high-risk eligibility, standardized pathology assessment, and multiple targeted therapies. Our data support the use of pCR as a primary endpoint for accelerated approval of new drugs if EFS is evaluated in the same population. Based on these findings, the I-SPY2 TRIAL will test whether therapy can be deescalated or escalated for individual patients with the goal of achieving pCR for all. Citation Format: Yee D, DeMichele A, Isaacs C, Symmans F, Yau C, Albain KS, Hylton NM, Forero-Torres A, van't Veer LJ, Perlmutter J, Rugo HS, Melisko M, Chen Y-Y, Balassanian R, Krings G, Datnow B, Hasteh F, Tipps A, Weidner N, Zhang H, Tickman R, Thornton S, Ritter J, Amin K, Klein M, Chen B, Keeney G, Ocal T, Feldman M, Klipfel N, Sattar H, Mueller J, Gwin K, Baker G, Kallakury B, Zeck J, Duan X, Ersahin C, Gamez R, Troxell M, Mansoor A, Grasso LeBeau L, Sams S, Wisell J, Wei S, Harada S, Vinh T, Stamatakos MD, Tawfik O, Fan F, Adams A, Rendi M, Minton S, Magliocco A, Sahoo S, Fang Y, Hirst G, Singhrao R, Asare SM, Wallace AM, Chien AJ, Ellis ED, Han HS, Clark AS, Boughey JC, Elias AD, Nanda R, Korde L, Murthy R, Lang J, Northfelt D, Khan Q, Edmiston KK, Viscusi R, Haley B, Kemmer K, Zelnak A, Berry DA, Esserman LJ. Pathological complete response predicts event-free and distant disease-free survival in the I-SPY2 TRIAL [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 GS3-08.

Abstract Introduction: The 21-gene Recurrence Score (RS) assay has been shown in retrospective studies to predict benefit of adjuvant chemotherapy (AC) in node positive (N+) breast cancer (BC) patients (pts). This study evaluates the trends and patterns of use of RS assay in N+, ER+/HER2-breast cancer and the impact of RS on decision to use AC in a real-world multi-institutional database. Methods: Pts with T1-T4c, N1mi-N3, ER+/HER2- BC diagnosed between 2010 and 2013, included in the National Cancer Data Base were analyzed. Pts who received neo-AC were excluded. Analyses included Cochrane-Armitage tests for trends and multivariable logistic regression assessing factors influencing RS testing and AC recommendations based on RS. Results: Among 73,049 pts, RS was obtained in 20.6%, increasing from 14.9% in 2010 to 24.4% in 2013 (p<0.001). RS testing was most common in N1mi (43.6%) and N1 (22.0%) and rare in N2/N3 (3.3%) BC. Of the 12,540 BC with quantitative RS results, 61.1% were low RS, 32.3% intermediate RS and 6.6% high RS. AC recommendation was less frequent in pts with RS testing compared to pts not tested (50.4% recommended AC vs 80.9%, p<0.001). In pts with N1mi/N1 BC, recommendation rates for AC were higher with higher RS (see table), however in N2/N3 BC, AC was recommended in the majority (71-88%) regardless of RS. Most pts (>85%) with RS 26-30 or high risk RS were recommended AC regardless of N stage. For pts with low risk RS, recommendation for AC increased significantly with increasing N stage (see table). On multivariable analysis, in pts with low risk RS, AC was more likely to be recommended in those with N1/N2+ stage (OR 2.3 and 9.1 vs N1mi), T2 and T3/T4 tumors (OR 1.3 and 2.2 vs T1 tumors), poorly differentiated tumors (OR 1.6) and younger age (OR 3.4 and 1.7, respectively, for <40 and 40-49 vs 50-59) (all p<0.001). Among pts with RS 18-25, AC was more likely to be recommended in those with higher tumor grade, younger age but the effect of N stage was less pronounced. Histology (IDC vs ILC) did not influence AC recommendation in any RS subset. Path N StageRS Risk GroupLow RiskIntermediate RiskHigh RiskRS<18RS 18-25RS 26-30RS>30N1mi AC No1,854 (75.9%)389 (36.9%)36 (14.6%)16 (7.0%)N1mi AC Yes590 (24.1%)666 (63.1%)210 (85.4%)212 (93.0%)N1 AC No3,000 (60.6%)699 (33.0%)75 (14.8%)33 (6.0%)N1 AC Yes1,954 (39.4%)1,422 (67.0%)431 (85.2%)518 (94.0%)N2/N3 AC No76 (29.0%)17 (16.7%)3 (12.5%)7 (14.9%)N2/N3 AC Yes186 (71.0%)85 (83.3%)21 (87.5%)40 (85.1%)p-value<0.001<0.0010.880.16 Conclusions: RS was obtained in about one fifth of pts with N+ ER+/HER2- BC, predominantly for N1mi and N1 disease. Overall, RS testing decreased frequency of recommendation of AC in N+ BC pts. The RS influenced use of AC particularly in N1mi and N1 pts, likely avoiding overtreatment of those with low risk RS and RS 18-25. Prospective data regarding RS to direct AC in N+ BC are awaited. Citation Format: Peethambaram PP, Hoskin TL, Heins CN, Habermann EB, Boughey JC. How 21-gene recurrence score assay is being used to individualize adjuvant chemotherapy recommendations in ER+/HER2 -node positive breast cancer -A national cancer data base study [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 PD7-05.

Abstract Background: I-SPY 2 is a multicenter, phase 2 trial using response-adaptive randomization within biomarker subtypes to evaluate novel agents when added to standard neoadjuvant therapy for women with high-risk stage II/III breast cancer - investigational agent(I) +paclitaxel(T) qwk, doxorubicin & cyclophosphamide(AC) q2-3 wk x 4 vs. T/AC (control arm). The primary endpoint is pathologic complete response (pCR) at surgery. The goal is to identify/graduate regimens that have ≥85% Bayesian predictive probability of success (statistical significance) in a 300-patient phase 3 neoadjuvant trial defined by hormone-receptor (HR) & HER2 status & MammaPrint (MP). Regimens may also leave the trial for futility (< 10% probability of success) or following accrual of maximum sample size (10%< probability of success <85%). We report the results for experimental arm Ganitumab, a type I insulin-like growth factor receptor (IGF1R) inhibitor. IGF1R inhibitors are known to induce insulin resistance and all patients assigned to Ganitumab received metformin. Methods: Women with tumors ≥2.5cm were eligible for screening. MP low/HR+ and HER2+ tumors were ineligible for randomization. Hemoglobin A1C≥ 8.0% were ineligible. MRI scans (baseline, 3 cycles after start of therapy, at completion of weekly T and prior to surgery) were used in a longitudinal statistical model to improve the efficiency of adaptive randomization. Ganitumab was given at 12mg/kg q2 weeks and metformin at 850mg PO BID, while receiving ganitumab. Analysis was intention to treat with patients who switched to non-protocol therapy counted as non-pCRs. Ganitumab/metformin was open only to HER2- patients, and eligible for graduation in 3 of 10 pre-defined signatures: HER2-, HR+HER2- and HR-HER2-. Results: Ganitumab/metformin did not meet the criteria for graduation in the 3 signatures tested. When the maximum sample size was reached, accrual to this arm stopped. Ganitumab/metformin was assigned to 106 patients; there were 128 controls. We report probabilities of superiority for Ganitumab/metformin over control and Bayesian predictive probabilities of success in a neoadjuvant phase 3 trial equally randomized between Ganitumab/metformin and control, for each of the 3 biomarker signatures, using the final pathological response data from all patients. Safety data will be presented. SignatureEstimated pCR Rate (95% probability interval)Probability Ganitumab/ Metformin Is Superior to ControlPredictive Probability of Success in Phase 3 Ganitumab/ Metformin N = 106Control N = 128 All HER2-22% (13%-31%)16% (10%-23%)89%33%HR+/HER2-14% (4%-24%)12% (4%-19%)66%21%HR-/HER2-32% (17%-46%)21% (11%-32%)91%51% Conclusion: The I-SPY 2 adaptive randomization study estimates the probability that investigational regimens will be successful in a phase 3 neoadjuvant trial. The value of I-SPY 2 is to give insight about the performance of an investigational agent's likelihood of achieving pCR. For Ganitumab/metformin, no subtype came close to the efficacy threshold of 85% likelihood of success in phase 3, and this regimen does not appear to impact upfront reduction of tumor burden. Our data do not support its continued development for the neoadjuvant treatment of breast cancer. Citation Format: Yee D, Paoloni M, van't Veer L, Sanil A, Yau C, Forero A, Chien AJ, Wallace AM, Moulder S, Albain KS, Kaplan HG, Elias AD, Haley BB, Boughey JC, Kemmer KA, Korde LA, Isaacs C, Minton S, Nanda R, DeMichele A, Lang JE, Buxton MB, Hylton NM, Symmans WF, Lyandres J, Hogarth M, Perlmutter J, Esserman LJ, Berry DA. The evaluation of ganitumab/metformin plus standard neoadjuvant therapy in high-risk breast cancer: Results from the I-SPY 2 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 P6-11-04.

Abstract Background:Pathologic complete response(pCR) after neoadjuvant therapy is an established prognostic biomarker for high-risk breast cancer(BC). Improving pCR rates may identify new therapies that improve survival. I-SPY 2 uses response-adaptive randomization within biomarker subtypes to evaluate novel agents when added to standard neoadjuvant therapy for women with high-risk stage II/III breast cancer; the goal is to identify regimens that have ≥85% Bayesian predictive probability of success (statistical significance) in a 300-patient phase 3 neoadjuvant trial defined by hormone-receptor (HR), HER2 status and MammaPrint (MP). We report the results for Ganetespib, a selective inhibitor of Hsp90 that induces the degradation/deactivation of key drivers of tumor initiation, progression, angiogenesis, and metastasis.Ganetespib + taxanes previously have resulted in a superior therapeutic response compared to monotherapy in multiple solid tumor models including BC. Methods:Women with tumors ≥2.5cm were eligible for screening and participation. MP low/HR+ tumors were ineligible for randomization. QTcF >470msec and HbA1C >8.0% were ineligible. MRI scans (baseline, +3 cycles, following weekly paclitaxel, T, and pre-surgery) were used in a longitudinal statistical model to improve the efficiency of adaptive randomization. Ganetespib was given with weekly T at 150 mg/m2 IV weekly (3 weeks on, 1 off). Patients were premedicated (dexamethasone 10mg and diphenhydramine HCl 25-50 mg, or therapeutic equivalents). Analysis was intention to treat with patients who switched to non-protocol therapy counted as non-pCRs. The Ganetespib regimen was open only to HER2- patients, and eligible for graduation in 3 of 10 pre-defined signatures: HER2-, HR+/HER2- and HR-/HER2-. Results:Ganetespib did not meet the criteria for graduation in the 3 signatures tested. When the maximum sample size was reached, accrual stopped. Ganetespib was assigned to 93 patients; there were 140 controls. We report probabilities of superiority for Ganetespib over control and Bayesian predictive probabilities of success in a neoadjuvant phase 3 trial equally randomized between Ganetespib and control, for the 3 biomarker signatures, using the final pCR data from all patients. Safety data will be presented. SignatureEstimated pCR Rate (95% probability interval)Probability Ganetespib Is Superior to ControlPredictive Probability of Ganetespib Success in a Phase 3 Trial Ganetespib N = 93Control N = 140 All HER2-26% (16%-37%)18% (8%-28%)91%47%HR+/HER2-15% (4%-27%)14% (4%-24%)60%19%HR-/HER2-38% (23%-53%)22% (9%-35%)96%72% Conclusion:The I-SPY 2 adaptive randomization model efficiently evaluates investigational agents in the setting of neoadjuvant BC. The value of I-SPY 2 is that it provides insight as to the regimen's likelihood of success in a phase 3 neoadjuvant study. Although no signature reached the efficacy threshold of 85% likelihood of success in phase 3, we observed the most impact in HR-/HER2- patients, with a 16% improvement in pCR rate. While our data do not support the continued development of Ganetespib alone for neoadjuvant BC, combinations with Ganetespib, which could potentiate its effect, may be worth pursuing in I-SPY 2 or similar trials. Citation Format: Forero A, Yee D, Buxton MB, Symmans WF, Chien AJ, Boughey JC, Elias AD, DeMichele A, Moulder S, Minton S, Kaplan HG, Albain KS, Wallace AM, Haley BB, Isaacs C, Korde LA, Nanda R, Lang JE, Kemmer KA, Hylton NM, Paoloni M, van't Veer L, Lyandres J, Perlmutter J, Hogarth M, Yau C, Sanil A, Berry DA, Esserman LJ. Efficacy of Hsp90 inhibitor ganetespib plus standard neoadjuvant therapy in high-risk breast cancer: Results from the I-SPY 2 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 P6-11-02.

Abstract Background: Locoregional recurrence (LRR) is a concern after neoadjuvant chemotherapy. Absolute risk of LRR and risk factors associated with LRR among women with node positive breast cancer treated with neoadjuvant chemotherapy on ACOSOG Z1071 were examined. Methods: ACOSOG Z1071 (Alliance for Clinical Trials in Oncology) enrolled cT1-3, N1-2 breast cancer patients treated with neoadjuvant chemotherapy from 2009-2011. All patients underwent axillary dissection. Data was analyzed for locoregional recurrence-free survival (LR-RFS) and multivariable analysis performed to identify factors impacting locoregional recurrence. Results: Of 756 women enrolled, 701 patients were eligible. Median follow-up was 4.0 years (range 0.03–6.2). 39 pts (5.6%) experienced LRR (32 LRR alone and 7 LRR concurrent with metastatic disease) and 96 patients (13.7%) died. LR-RFS was lowest in patients with triple negative tumors (TNBC) (87.6% at 3 years), followed by HER2-positive tumors (94.1%) compared with Hormone Receptor (HR) positive/HER2-negative tumors (96.9%). Residual in-breast disease was present in 57% of patients undergoing BCT and 73% of patients undergoing mastectomy (p<0.0001). LRR was higher in BCT compared to mastectomy (p=0.018), however when evaluated by subtype there was no significant difference in LRR by BCT vs mastectomy. There was no difference in LRR by clinical T stage at presentation or pathologic N stage, however LRR increased with higher pathologic T stage (p=0.006). Overall LRR was lower in patients who achieved a pathologic complete response (pCR) across all tumor subtypes (0% in HR positive/HER2-negative, 2.1% in TNBC, 4% in HER2-positive at 3 years) than in non-pCR patients (HR=0.37, p=0.04). By tumor subtype, pCR was associated with a lower LRR in patients with TNBC (HR=0.17, p=0.019), but was not significantly different by pCR in HER2-positive (HR=0.50, p=0.31) or HR-positive/HER2-negative tumors (HR=inestimable). In the multivariable model, factors associated with increased LRR risk were tumor subtype (TNBC and HER2-positive tumors, p<0.0001), lack of pCR in the breast (p=0.013), breast conservation surgery (p=0.018) and omission of adjuvant radiation therapy (p=0.010). Predictors of locoregional recurrence UnivariableMultivariableVariableHR (95% CI)p-valueHR (95% CI)p-valueClinical T stageT0-T2REF0.34REF0.087T3-T41.38 (0.72-2.65) 1.87 (0.91-3.84) Tumor BiologyHR+/Her2-REF0.002REF<0.0001Her2+1.49 (0.65-3.45) 2.11 (0.89-5.00) Triple negative3.59 (1.68-7.68) 5.53 (2.53-12.13) Path CR breastNoREF0.019REF0.013Yes0.35 (0.15-0.84) 0.27 (0.09-0.76) Path CR breastNoREF0.064REF0.81Yes0.51 (0.25-1.04) 0.67 (0.29-1.59) SurgeryBCTREF0.067REF0.018Mastectomy0.55 (0.29-1.04) 0.43 (0.22-0.87) RadiationYesREF0.033REF0.010No2.18 (1.06-4.48) 2.60 (1.26-5.39) Conclusion: In patients with node-positive breast cancer treated with neoadjuvant chemotherapy, early LRR is higher in TNBC and HER2-positive tumors. In TNBC patients pCR is associated with lower LRR than residual disease. In this contemporary cohort of node-positive, HER2-positive tumors treated with anti-HER2 therapy, patients achieving a pCR had low LRR rate. Adjuvant radiation appears to be important for locoregional control regardless of pCR. Citation Format: Boughey JC, Ballman KV, McCall LM, Mittendorf EA, Hunt KK. Predictors of locoregional recurrence after neoadjuvant chemotherapy and surgery for node positive breast cancer: Results from ACOSOG Z1071 (Alliance) [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 P6-09-01.

Abstract Background: Negative margins are important in decreasing risk of local recurrence after breast conservation surgery. Further, positive margins on final pathology require a second operation, burdening patients and increasing costs. We identified factors predicting positive margins at lumpectomy prompting intraoperative re-excision in a large referral center. Methods With IRB approval we reviewed all breast cancer lumpectomy cases from January 2012 to December 2013. Associations between rates of positive margin (defined as tumor at ink) and patient and tumor factors were assessed using chi square tests and univariate and adjusted multivariable logistic regression, overall and stratified by DCIS or invasive cancer. Results 385 patients (105 DCIS and 280 invasive disease) were identified. Overall positive margin rate at lumpectomy requiring intraoperative re-excision was 62.3% and was higher in DCIS than in invasive disease (78.1% vs 56.4%, OR=2.78, p=0.001). Positive margin rates did not vary by surgeon, patient age, ER, PR or HER2 status of the tumor. On univariate analysis higher tumor grade was associated with a higher margin positive rate (grade 3 vs grade 1, OR=1.71, p=0.049). Within the 105 DCIS cases, no factors had statistically significantly different odds of positive margins on univariate or multivariable analysis. Within the 280 cases of invasive breast cancer, factors independently associated with lower odds of margin positivity were neoadjuvant chemotherapy (OR 0.30, p=0.037, relative to no neoadjuvant therapy) and seed localized excision (OR 0.24, p=0.03, relative to no localization). Multivariable Logistic Regression* Modeling DCISInvasive DiseaseVariableOdds RatioP-valueOdds RatioP-valueAge 50+ vs Age <502.860.111.590.23Grade 2 vs Grade 10.940.921.500.21Grade 3 vs Grade 13.250.121.580.37Estrogen Receptor Positive vs Negative3.950.221.640.42Progesterone Receptor Positive vs Negative0.840.871.110.84Her2 Positive vs Negative 1.270.68Stage T2 vs T1 2.540.45Stage T3 vs T1 2.180.69Ki67 <15% vs 15%+ 0.570.09Neoadjuvant Chemotherapy vs None 0.300.04Seed Localization vs No Localization 0.240.03Wire Localization vs No Localization 0.330.13Intraoperative Ultrasound vs No Localization 0.670.53*adjusted for individual surgeons (all p >0.05) Conclusion DCIS was associated with higher rate of positive margins at lumpectomy than invasive breast cancer. Within invasive disease, neoadjuvant chemotherapy and seed localization were associated with lower rates of margin positivity. Strategies to decrease positive margins would be best employed in cases of lumpectomy for DCIS and for invasive disease treated without neoadjuvant chemotherapy. Seed localization may be one strategy to lower positive margin rates. Citation Format: Boughey JC, Keeney MG, Glasgow AE, Keeney GL, Habermann EB. Tumor and procedural factors associated with positive margins at lumpectomy in women undergoing breast conservation surgery [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 P1-11-08.

Abstract Purpose/Objectives: The optimal clinical target volume (CTV) for internal mammary node irradiation (IMNI) is uncertain in an era of increasingly conformal volume-based treatment planning for breast cancer. We mapped the location of gross internal mammary lymph node (IMN) metastases in order to identify areas at highest risk for harboring occult disease. Methods and Materials: Patients with axial imaging of IMN disease, including fluorodeoxyglucose F-18 (FDG18) positron emission tomography (PET-CT) and magnetic resonance imaging (MRI), were identified from a breast cancer registry. The IMN location was transferred by a radiation oncologist and breast radiologist onto the corresponding anatomic position on representative axial CT images of a patient in the treatment position. Distribution of lymph nodes, and their location was compared with consensus group guidelines of IMN target delineation. Results: Sixty-seven patients with 130 IMN metastases were mapped. The location was in the first three intercostal spaces in 102 of 130 (78%) nodal metastases. Eighteen of 130 (14%) IMN were located caudal to the third intercostal space, while 10 of 130 (8%) IMN were located cranial to the first intercostal space, including 3 patients with isolated IMN metastases at that location in the absence of distant disease. Of the 102 nodal metastases within the first three intercostal spaces, 54 (53%) were located within the RTOG consensus volume. Relative to the internal mammary (IM) vessels, 19 (19%) nodal metastases were located medially with a mean distance of 2.2 mm (SD 2.9 mm), while 29 (28%) were located laterally with a mean distance of 3.6 mm (SD 2.5 mm). Ninety and ninety-five percent of lymph nodes within the first three intercostal spaces would have been encompassed within a 4 mm and 6 mm medial and lateral expansion on the IM vessels, respectively. Conclusions: For women with indications for elective IMNI, a 4 mm medial and lateral expansion on the IM vessels within the first 3 intercostal spaces may be appropriate. In women with known IMN involvement, cranial extension to the confluence of the IM vein with the brachiocephalic vein +/- caudal extension to the 4th or 5th interspace with a 6 mm medial and lateral expansion may be considered, provided that normal tissue constraints are met. Citation Format: Jethwa KR, Kahila MM, Hunt KN, Brown LC, Corbin KS, Park SS, Yan ES, Boughey JC, Mutter RW. Delineation of internal mammary nodal target volumes in breast cancer radiotherapy [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 P1-10-09.

Abstract Background: DNA methylation is a promising prognostic and predictive biomarker of response to treatment in advanced breast cancer (Fackler MJ. Can Res 2014). We evaluated whether baseline and change in tissue and serum methylation would predict pathological complete response (pCR) in patients with HER2-negative early breast cancer treated with PST. Methods: TBCRC008 was a multicenter placebo-controlled trial that investigated pCR (no invasive cancer in breast/axilla) following 12 weeks of preoperative carboplatin and albumin-bound paclitaxel with or without the histone deacetylase (HDAC) inhibitor vorinostat in 62 patients with HER2-negative breast cancer. We performed an exploratory planned biomarker study correlating baseline and change (D15) in tumor tissue and serum methylation with pCR. Methylation was measured using cumulative methylation index (CMI) in quantitative multiplexed methylation-specific polymerase chain reaction (QM-MSP) assays; cMethDNA assay for serum (Fackler MJ. Can Res 2014) and QM-MSP for tissue (Fackler MJ. Can Res 2004). The analysis population included all patients with available methylation and pCR data. Association between CMI level (log transformed baseline, D15, change) and pCR was evaluated using univariate as well as multivariable logistic regression models controlling for treatment arm and estrogen receptor (ER) status. Additional subgroup analyses assessed association of CMI level with pCR stratified by ER status and treatment arms, respectively. Spearman's correlation coefficient was performed to evaluate the correlation between tissue and serum CMI. Results: pCR data were available for 61 of 62 patients. One patient with unknown response was treated as a non-responder. The pCR rate was similar in both arms (vorinostat 25.8%, placebo 29%). Both tissue and serum CMI data were available in 55 (baseline), 50 (D15) and 46 (change) patients. Elevated serum methylation based on a predefined threshold (6.9 units) was identified in 23/59 (39%) patients. In univariate analysis, one log unit increase in tissue CMI levels at D15 was associated with a 40% lower chance of obtaining a pCR (odds ratio, OR=0.60, 95% CI 0.37-0.97; p=0.037). The multivariable analysis did not show a statistically significant association of tissue or serum CMI with pCR, although a similar trend in magnitude towards association with pCR was observed for D15 and change in tumor tissue CMI (OR 0.67 and 0.57, p=0.129 and 0.147 respectively). Subgroup analyses suggested a significant association between tissue CMI levels at D15 and pCR in the group treated with vorinostat [tissue OR: 0.44 (0.20, 0.93), p=0.03; serum OR 0.37 (0.13, 1.07), p=0.07] but not in the placebo group. No significant correlation was observed between tissue and serum CMI. Conclusion: This is the first study to evaluate the predictive role of tissue and serum methylation (CMI) in patients with early breast cancer treated with PST ± an HDAC inhibitor. Methylation was detected more frequently in tissue than serum. Tissue CMI levels at D15 may predict poor response to this regimen. Further evaluation of the predictive role of methylation in early breast cancer is warranted. Citation Format: Connolly RM, Fackler MJ, Zhang Z, Zhou XC, Goetz MP, Boughey JC, Walsh B, Carpenter J, Storniolo AM, Watkins S, Barielson E, Sukumar S, Stearns V. Tumor and serum DNA methylation in women receiving preoperative chemotherapy (PST) with or without vorinostat in primary operable HER2-negative breast cancer in TBCRC008 [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 P1-09-15.

240 Background: Contralateral prophylactic mastectomy (CPM) is increasingly chosen by patients with breast cancer. Satisfaction after CPM is high. However, decreased satisfaction has been associated with reoperation after reconstruction. This study’s aim was to examine the adverse aspects patients attribute to reconstruction and the subsequent effect on psychosocial consequences and satisfaction with CPM. Methods: 487 unilateral breast cancer patients with a family history of breast cancer who underwent CPM between 1960 and 1993 were mailed a questionnaire evaluating QOL and satisfaction with CPM. Results: Of 269 respondents, 210 (78%) underwent reconstruction and 59 (22%) did not. Mean age at CPM was 46 and 50 years respectively (p=0.01). Mean follow-up was 20.2 years. Reconstruction was immediate in 96%, 98% with implants and 2% with tissue flap. Reconstruction was associated with lower satisfaction with CPM (p=0.03), but still only 7% (vs 2% in those without reconstruction) said they were dissatisfied. Most (83%) of those with reconstruction said they would choose reconstruction again while 7% were unsure and 10% said they would not. In those who did not undergo reconstruction, 18% said they would choose reconstruction if able to make the choice again while 5% were unsure and 77% said they still would not. 95 patients (45%) of those that underwent reconstruction required one or more reoperations for complications. Those with reoperation reported poorer responses for satisfaction with CPM (p=0.04), choice to have CPM again (p=0.008), and choice to have reconstruction again (p=0.004) when compared to patients with reconstruction and no reoperation. Those with and without reconstruction did not differ significantly with respect to femininity, sexual relationships or emotional stability, but those without reconstruction reported significantly poorer effects related to self esteem (p=0.04) and body appearance (p=0.002). Conclusions: In patients who undergo CPM, many years after surgery satisfaction with CPM is higher in those choosing not to have reconstruction than those with reconstruction although it was high in both groups. Reoperation is common after reconstruction and is associated with lower satisfaction.