Pockaj, Barbara A.

Abstract Background: Contrast-enhanced mammography (CEM) is an emerging breast imaging technique utilizing iodinated contrast to highlight areas of neovascularity. The role of CEM in patients with breast implants has not yet been characterized. We report our clinical experience of CEM in patients with breast augmentation surgery to better understand the potential diagnostic utility and limitations of CEM in the setting of breast implants. Materials and Methods: A HIPPA compliant, IRB exempt single-institution review of prospective CEM cases who had “breast implants” in their report between 01/2015 and 03/2020. Medical records were reviewed to supplement database information. Results: Forty-six patients were included with a mean age of 52 years (range 33-72). Clinical indications included: high risk research screen 3 (6%), diagnostic evaluation for abnormal imaging 24 (52%), further evaluation of newly diagnosed breast cancer 12 (26%) or assessment of neoadjuvant treatment response 7 (15%). Thirty patients had malignant lesions. Histology was invasive ductal carcinoma (90%), invasive lobular carcinoma (7%), and ductal carcinoma in situ (3%). CEM identified the index cancer and extent of disease in 28/30 (93%) of malignant cases. In two patients (7%), the malignant lesion was not included in the field-of-view due to its location. One of these lesions was a far medial mass within the breast which was detected by ultrasound alone. The other false negative CEM was a palpable axillary mass negative on both mammogram (MG) and MRI but seen by ultrasound. Twenty-three (50%) underwent additional breast MRI of which 20 had an already diagnosed cancer. the findings on CEM were concordant with MR imaging for the index lesion in 19/20 (95%) cases (kappa=0.86; p <0.001). Six additional lesions were found by CEM and confirmed by MRI. Of these lesions, 33% were found to be malignant and changed the surgical procedure. Four were only seen on CEM (no MRI comparison was available) and 75% were found to be malignant. One was only seen on MRI and was benign. One additional lesion was only seen as an asymmetry on MG without CEM or MRI correlate. This was benign on both the biopsy and surgical pathology. Conclusions: CEM appears to be a valuable breast imaging modality for diagnostic evaluations and surgical staging, including patients with breast implants. Due to technical artifacts and positioning limitations for posterior lesions, we recommend performing CEM with implant displaced views. Breast centers that use CEM, should be aware of field of view as a potential limitation when evaluating extent of disease in patients with breast augmentation. Citation Format: Molly Carnahan, Barbara Pockaj, Victor Pizzitola, Marina Giurescu, Roxanne Lorans, William Eversman, Richard Sharpe, Patricia Cronin, Donald Northfelt, Karen Anderson, Brenda Ernst, Bhavika Patel. Experience of contrast-enhanced mammography in patients with breast augmentation surgery [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 PS3-23.

Abstract Objective and Rationale: To investigate the utility of screening Contrast Enhanced Mammography (CEM) imaging as a supplemental screening tool in women at elevated risk for breast cancer. Materials and Methods: This prospective, single institution, IRB approved observational study was conducted in asymptomatic women 35 years of age or older who were deemed at elevated risk of breast cancer, defined as IBIS v.8.0 lifetime risk of breast cancer score >15% or a prior personal history of breast cancer. Enrollment started in January 2019 and is on-going. An interim data analysis was performed. Women were invited to undergo supplemental CEM screening within 180 days of negative (BI-RADS 1 or 2) conventional 2D/3D screening mammography (MG). Patients with prior screening MBI, ultrasound or MR imaging within 12 months were excluded from study participation. Outcome measures were supplemental cancer detection rates, sensitivity, specificity, positive predictive value, and negative predictive value of CEM, along with their 95% confidence intervals, as well as the biologic profiles of MG-occult, CEM detected cancers. Results: A total of 351 women were enrolled in this prospective study over a 20-month period. To date, we have 1 year follow up on 106 cases with negative follow-up MG. Average age of the participants was 56 years ± 9.44 (standard deviation); 11 patients had screening 2D MG, 333 had combined 3-D and 2-D screening MG; 309 dense and 37 non-dense breasts based on ACR BI-RADS categories. CEM depicted 8 additional breast cancers (table 1), which were otherwise MG occult, for an overall supplemental cancer detection rate of 22.7 per 1000 patients, 95% CI (9.9, 44.3). 1 false negative cancer on CEM imaging which was further detected on MR imaging only. Biopsy revealed 16 benign changes (16/28=57%), 4 high-risk lesions (4/28=14%), and 8 breast cancers (8/28=29%) (table 2). CEM imaging screening offered high specificity (0.942, 95% CI (0.917, 0.967), high NPV 0.997, 95% CI (0.991, 1.000) and moderate PPV (0.286, 95% CI (0.118, 0.453) and sensitivity (0.889, 95% CI (0.684, 1.000)). Size of CEM detected cancers ranged from 7 to 57 mm. Conclusion: This pilot trial demonstrates a supplemental cancer detection rate of 22.7 per 1000 during prevalence round of CEM screening in women at an elevated risk for breast cancer. These initial results are comparable to results reported for high-risk surveillance MR imaging. Larger, multi-institutional high-risk CEM trials are needed for those patients who are not otherwise undergoing regular supplemental surveillance MR imaging. Citation Format: Bhavika K. Patel, Victor Pizzitola, Donald Northfelt, Karen Anderson, Marina Giurescu, Gina Mazza, Roxanne Lorans, William Eversman, Richard Sharpe, Juliana Kling, Denise Millstine, Ernst Brenda, Patricia Cronin, Heidi Apsey, Jennifer Palmieri, Barbara Pockaj, Michele Halyard. Supplemental contrast enhanced mammography screening of women with elevated risk of breast cancer [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 PS2-41.

Background Same-day discharge after mastectomy is a recently described treatment approach. Limited data exist investigating whether same-day discharge can be successfully implemented in patients undergoing mastectomy with immediate implant-based breast reconstruction (IBR). Methods Patients having mastectomy with IBR from 2013 to 2019 were reviewed. Enhanced recovery with same-day discharge was implemented in 2017. Patient characteristics, oncologic treatments, surgical techniques, and 90-day postoperative complications and reoperations were analyzed comparing enhanced recovery patients with historical controls. Results A total of 363 patients underwent nipple-sparing (214, 59%) or skin-sparing (149, 41%) mastectomy with 1-stage (270, 74%) or tissue expander (93, 26%) IBR. Enhanced recovery was used for 151 patients, with 79 of these patients (52%) discharged same-day. Overall, enhanced recovery patients experienced a significantly lower rate of 90-day complications (21% vs 41%, P < 0.001 ), including hematoma (3% vs 11%, P = 0.002), mastectomy flap necrosis (7% vs 15%, P = 0.02), seroma (1% vs 9%, P < 0.001), and wound breakdown (3% vs 9%, P = 0.05). Postoperative complication rates did not significantly differ among enhanced recovery patients discharged same day. Postoperative admissions significantly decreased after enhanced recovery implementation (100% to 48%, P < 0.001), and admitted enhanced recovery patients experienced a lower length of stay (1.2 vs 1.8, P < 0.001 ). Enhanced recovery patients experienced a lower incidence of ≥1 unplanned reoperation (22% vs 33%, P = 0.01); overall average unplanned and total reoperations did not significantly differ between groups. Conclusions In conjunction with enhanced recovery practices, same-day discharge after mastectomy with IBR is a safe and feasible treatment approach.

Background The purpose of this study is to evaluate how prior breast augmentation impacts rates of complications and risk for reoperation after mastectomy with concurrent breast reconstruction. Methods Patients undergoing nipple-sparing, skin-sparing, or simple mastectomy with implant-based reconstruction from 2008 to 2018 were identified in a prospective database. Postoperative complications and reoperations were then analyzed comparing patients with prior augmentation to patients without history of previous breast surgery. Results A total of 468 patients were identified with a median follow-up of 4 years. Of these, 72 had prior augmentation mammoplasty. These patients underwent nipple-sparing (52, 72%), skin-sparing (15, 21%), or simple (5, 7%) mastectomy with immediate direct-to-implant (46, 61%) or tissue expander (26, 35%) reconstruction. On univariate analysis, this cohort had a lower body mass index (23.3 vs 25.3, P = 0.003), a higher rate of nipple-sparing mastectomy (72% vs 54%, P = 0.01), and a higher prevalence of stage I disease (44% vs 33%, P = 0.04). Differences in age, comorbidities, reconstructive techniques, tumor size, and neoadjuvant/adjuvant therapies were not significant. Overall complication rate between patients with or without prior augmentation did not significantly differ (51% vs 50%, P = 0.83); no significant differences in rates of surgical site infection, hematoma, mastectomy skin flap/wound necrosis, nipple complications, implant loss, or capsular contracture were found. Analysis of reoperations between patients with and without prior augmentation revealed no significant differences in average number of subsequent planned, unplanned, or total reoperations. On multivariate analysis, prior breast augmentation was found to be associated with significantly increased risk for undergoing ≥1 unplanned reoperation (odds ratio, 2.28; 95% confidence interval, 1.28–4.05, P = 0.005). Conclusions Prior augmentation mammoplasty does not significantly affect rates of postoperative complications after mastectomy with concurrent reconstruction. Although prior augmentation does not affect number of subsequent reoperations on average, it does increase the risk of experiencing 1 or more unplanned reoperation after mastectomy with reconstruction.

BackgroundThe goal of this study was to assess the impact of trastuzumab on locoregional failure.METHODSThe analysis included 2763 patients with HER2‐positive (HER2+) breast cancer who were randomly assigned to adjuvant doxorubicin (A), cyclophosphamide (C), paclitaxel (T) and trastuzumab (H) (arm A, AC→T [n = 922]; arm B, AC→T→H [n = 988]; arm C, AC→T+H→H [n = 853]). Radiotherapy was given after AC→T concurrently with H. Radiotherapy was given after lumpectomy (L) or after mastectomy (M) with ≥4 positive lymph nodes but was optional for 1 to 3 positive lymph nodes. Locoregional failures at 10 years (LFR10) as first events were compared using competing risk analysis.ResultsThe median follow‐up was 13.0 years. The first site of failure was local‐only in 96 cases, locoregional in 16 cases, regional in 32 cases, and not specified in 2 cases; LFR10 was 4.8% (95% CI 4.1%‐5.7%). LFR10 was 5.5% (95% CI 4.3%‐7.2%), 4.9% (95% CI 3.7%‐6.4%), and 2.8% (95% CI 1.9%‐4.1%) in arms A, B, and C (B vs A: hazard ratio [HR] 0.91, P = .62; C vs A: HR 0.72, P = .12). For estrogen receptor–positive patients, LFR10 was 3.7% (95% CI 2.8%‐4.8%) and for estrogen receptor–negative patients, it was 6.1% (95% CI 5.0%‐7.4%; HR 0.61, P = .004). Local treatment included L+RT (n = 1044 [38%]), M+RT (n = 1025 [37%]), and M (n = 694 [25%]). LFR10 was 6.% (95% CI 5.0%‐7.8%), 3.0% (95% CI 2.1%‐4.3%), and 5.5% (95% CI 4.0%‐7.4%) for L+RT, M+RT, and M, respectively (M+RT vs L+RT: HR 0.43, P < .001; M vs L+RT: HR 0.88, P = .57). For 1 to 3 positive lymph nodes, LFR10 was 6.5% (95% CI 4.8%‐8.9%), 4.1% (95% CI 2.4%‐7.0%), and 4.3% (95% CI 2.9%‐6.5%) in L+RT, M+RT, and M, respectively (M vs L+RT: HR 0.68, P = .14; M vs M+RT: HR 1.2, P = .6).ConclusionLow 10‐year LFRs were seen regardless of trastuzumab use. Differences in local therapy in patients with 1 to 3 positive lymph nodes did not appear to improve local control. Local therapy studies for HER2+ and other tumor characteristics are important as the role of local therapies continues to evolve.

Abstract Background: Amplification of chromosome 9p24.1 targeting PD-L1, PD-L2, and JAK2 (PDJ amplicon) is present in ~15% of TNBCs and is associated with activation of the JAK/STAT pathway and poor clinical outcomes. In preclinical studies, PD-L1 expression is markedly and rapidly inducible by low-dose IFN-γ in a PDJ amplicon copy-number dependent manner, mimicking an in situ inflammatory response. This suggests PDJ amplification could identify those TNBCs that would respond to ICIs and/or JAK2 targeted-therapies. The goals in this study were to determine the PDJ status of a well annotated cohort of TNBC PDXs with a 3 color FISH assay and to further define the genomes and transcriptomes of PDJ+ and PDJ- TNBCs. Methods: Tissue microarrays (TMAs) of 49 cores from 27 breast cancer PDX samples, including 21 TNBCs were obtained from the Baylor College of Medicine. The TMAs were interrogated with a 3 color FISH assay consisting of three probes that simultaneously target the PDJ amplicon, 9q22, and 9q34.1. The ratios of PDJ to 9q22 and PDJ to 9q34.1 were calculated to distinguish PDJ amplification from polyploidy. In each case, 50 cells were scored. Samples with PDJ signal &gt;4.0, PDJ/9q22 ≥2 and/or PDJ/9q34.1 ≥2 were called positive by FISH. A subset of PDJ+ PDXs was then flow sorted by DNA content and interrogated with 400k whole genome CNV arrays. These results were integrated with existing clinical, exome, and transcriptome data for the TMAs (pdxportal.research.bcm.edu). Results: PDJ amplification was identified in 6/27 PDX samples including 3/21 (14%) TNBCs. Notably the number of PDJ+ cells in each sample ranged from 2-18. Single cells with ≥10 copies were observed in each PDJ+ sample as well as two PDJ- TNBCs. PDJ+ samples had increased expression of PD-L1 and JAK2 in their RNAseq data. Whole genome CNV analysis of flow sorted PDJ+ samples confirmed the presence of the PDJ amplicon and identified co-occurring amplifications and deletions. A similar pattern of PDJ amplicon heterogeneity was seen in a Mayo Clinic Arizona cohort of 70 surgically resected TNBCs. Previous whole genome CNV analysis of flow sorted samples identified 13/70 (18%) PDJ+ cases. FISH analysis of 14 TNBCs from this cohort (PDJ+ and PDJ- cases) validated these results and identified PDJ+ tumors with cells containing &gt;20 copies of the amplicon. Conclusion: Our multicolor FISH assay of PDX and primary resected samples confirms a prevalence of ~15% PDJ+ TNBCs. Previous studies have reported an enrichment of JAK2 amplification in neoadjuvant treated TNBCs. Given the heterogeneous FISH patterns in both PDJ+ and PDJ- samples in our cohorts, we hypothesize that neoadjuvant therapy could enrich the presence of PDJ+ cells and thereby sensitize TNBCs to ICIs and JAK2 targeted therapies. Future work will explore the role of PDJ amplification and the presence of PDJ+ cells in TNBCs in response to neoadjuvant therapy. Citation Format: Alexander S. Roesler, Smriti Malasi, Elizabeth Lenkiewicz, Barbara A. Pockaj, Michael T. Lewis, Lacey E. Dobrolecki, Lori Koslosky, Peter Hartmayer, Karen S. Anderson, Michael T. Barrett. PDJ amplicon heterogeneity in triple negative breast cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1790.

9082 Background: Human tumors, including melanoma, are complex mixtures of individual, molecularly distinct subpopulations, or clones of cancer cells. Effective cancer therapy will likely require targeting of all tumor subsets within a given cancer. Understanding the tumor complexity and the ability to identify points of therapeutic vulnerability within the individual tumor subsets will be essential for development of effective personalized cancer therapies. Methods: We have developed an approach that combines identification of individual tumor subsets using a multiparameter nuclear flow cytometry coupled with a high-resolution genomic analysis using the array-based comparative genomic hybridization (aCGH). Melanoma nuclei were isolated from tumor tissues and subjected to flow cytomery using melanocyte-specific antibodies (to separate melanoma cells from stroma) and DNA content, to separate individual tumor subpopulations. DNA extracted from isolated nuclear subpopulations was extracted and analyzed by aCGH. This approach was adopted for both fresh-frozen and paraffin-embedded clinical specimens. Results: We initially demonstrate the feasibility of the outlined approach by successful separation of melanoma from stromal nuclei and separation of individual melanoma nuclear subpopulations by DNA content. aCGH analysis of the DNA derived from isolated tumor subpopulations allowed successful identification of potentially targetable molecular aberrations in individual subsets of tumor cells. Notably, such aberrations were often not detected in unsorted, bulk tumors analyzed by the same high-resolution aCGH approach. Conclusions: We demonstrate a feasible approach to in-depth molecular analysis of tumor subpopulations within a clinical cancer tissue. This approach allows identification of potentially targetable molecular aberrations within individual tumor subsets, thus opening a possibility for a broad tumor targeting through design of individually-tailored therapeutic approaches. No significant financial relationships to disclose.

623 Background: Neoadjuvant therapy plays an important role in breast cancer treatment. Unlike patients who undergo surgery followed by adjuvant therapy,there are no established guidelines for surgical management following neoadjuvant therapy. Methods: Surgical practice patterns from 50 patients in N0338 “Phase II trial of Docetaxel and Carboplatin administered every two weeks as induction therapy for Stage II and Stage III breast cancer” were reviewed. The protocol did not mandate surgical therapy leaving the decision to the treating surgeon and patient. Results: 66% of patients underwent mastectomy (M) and 33% underwent breast conservation therapy (BCT). Three (9%) had immediate reconstruction. Eight (24%) underwent contralateral prophylactic M. Residual tumor size did not always impact primary surgical therapy. In the M group 4 (12%) had no residual disease, 15 (45%) < 2cm and 14 (42%) > 2cm; whereas, in the BCT group 1 (6%) had no residual disease, 12 (70%) < 2cm and 4 (24%) > 2cm. Axillary lymph node (ALN) staging varied tremendously. Three (6%) patients presented with palpable lymphadenopathy and proceeded to complete axillary lymph node dissection (ALND) after chemotherapy (CT). Fine needle aspiration (8) or core needle biopsy (7) of the axilla was performed in 15 (30%) patients before CT; 1 was negative and went on to have sentinel lymph node biopsy (SLNB) after CT; 14 (94%) were positive with 13 (86%) going on to ALND and 1 SLNB after CT. Five (10%) underwent SLNB prior to CT. One (20%) was positive and went on to have ALND after CT; 4 (8%) were negative and had no further ALN staging. A total of 19 (39%) had SLNB after neoadjuvant therapy; 13 (68%) were positive and underwent ALND; 1 SLNB failed; 2 of 5 that were negative underwent ALND with 1 having a positive lymph node. Ten (20%) underwent ALND with no pre-operative staging with 8 being positive for ALN metastases. Conclusions: Review of study data from multiple institutions revealed no consistent criteria in selection of surgical intervention for the breast tumor or ALN staging. There remains a need for further research in this area to establish standard practice guidelines. Support from NIH, sanofi-aventis, Amgen, Breast Cancer Research Foundation. No significant financial relationships to disclose.