Current Landscape of Breast Cancer Imaging and Potential Quantitative Imaging Markers of Response in ER-Positive Breast Cancers Treated with Neoadjuvant Therapy

In recent years, neoadjuvant treatment trials have shown that breast cancer subtypes identified on the basis of genomic and/or molecular signatures exhibit different response rates and recurrence outcomes, with the implication that subtype-specific treatment approaches are needed. Estrogen receptor-positive (ER+) breast cancers present a unique set of challenges for determining optimal neoadjuvant treatment approaches. There is increased recognition that not all ER+ breast cancers benefit from chemotherapy, and that there may be a subset of ER+ breast cancers that can be treated effectively using endocrine therapies alone. With this uncertainty, there is a need to improve the assessment and to optimize the treatment of ER+ breast cancers. While pathology-based markers offer a snapshot of tumor response to neoadjuvant therapy, non-invasive imaging of the ER disease in response to treatment would provide broader insights into tumor heterogeneity, ER biology, and the timing of surrogate endpoint measurements. In this review, we provide an overview of the current landscape of breast imaging in neoadjuvant studies and highlight the technological advances in each imaging modality. We then further examine some potential imaging markers for neoadjuvant treatment response in ER+ breast cancers.

Accuracy of sentinel lymph node biopsy in invasive lobular carcinoma of the breast

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Background: The safety of the sentinel lymph node biopsy procedure (SLNB) in the surgical management of breast cancer relies upon a false negative rate (FNR) being less than 10%. The accuracy of SLNB in invasive lobular carcinoma (ILC), the second most common type of breast cancer, has not been evaluated. Because of high rates of false negative imaging and the diffuse growth pattern in ILC, less accurate pre-operative staging and a potentially unreliable lymphatic drainage pattern may impact the accuracy of SLNB in this tumor type. We therefore sought to characterize the accuracy of SLNB in a cohort of patients with ILC. Methods: We queried an institutional database of 707 patients with ILC and identified 196 patients who underwent SLN mapping with excision of both sentinel and non-sentinel nodes. A false negative was defined as having negative sentinel lymph nodes and a positive non-sentinel node. We calculated the FNR and sensitivity of SLNB and evaluated clinicopathologic variables. Results: Of 196 cases, 183 were clinically node-negative, 9 were clinically node-positive, and 4 had unknown clinical node status. Of the 183 clinically node-negative patients, 69 (37.7%) patients had node-positive disease at surgery. Overall, 7 of 196 cases had false negative SLNB, yielding an FNR of 8.97%. The sensitivity of SLNB was 91%. Patients with a false negative SLNB were significantly older than patients without (mean age 63 versus 54.7 years, p = 0.041). Significantly fewer sentinel and non-sentinel nodes were removed in women aged 50 years or older compared to those under 50 (1.9 vs. 2.5 sentinel nodes, p = 0.0158; 4.7 vs. 7.9 non-sentinel nodes, p = 0.0077). There were no differences in tumor receptor subtype, grade, stage, presence of lymphovascular invasion, or receipt of neoadjuvant therapy in those with a false negative SLNB compared to those without. Conclusions: The high rate of nodal positivity in clinically node negative patients highlights the challenges of clinical nodal assessment in ILC. Despite this, the SLNB procedure had a FNR that fell within the acceptable range, supporting its use in ILC. The relationship between number of sentinel nodes removed and FNR deserves further study, particularly in older women where extent of nodal surgery continues to decline.

Mitotic score and pleomorphic histology in invasive lobular carcinoma of the breast: impact on disease-free survival

PURPOSE

Pleomorphic invasive lobular carcinoma (ILC) has long been thought to have worse outcomes than classic ILC and is therefore often treated with chemotherapy. However, recent data question the utility of the pleomorphic designation, as the poor outcomes seen may be related to other associated high-risk features. Importantly, mitotic count may better define a subset of ILC with high risk of recurrence. We sought to determine the impact of pleomorphic histology versus mitotic count on disease-free survival (DFS) in pure ILC. Additionally, we evaluated whether pleomorphic histology was associated with receipt of chemotherapy when adjusting for other factors.

METHODS

We analyzed a cohort of 475 patients with stage I-III pure ILC. We used Kaplan-Meier estimates, and Cox proportional hazards and logistic regression for multivariate analyses. Pleomorphic histology was confirmed by central pathology review.

RESULTS

In a multivariate model, pleomorphic histology was not associated with reduced DFS. Only mitotic score, receptor subtype, and pathologic stage were independently and significantly associated with DFS. Patients with pleomorphic ILC were significantly more likely to receive chemotherapy than patients with classic ILC (adjusted odds ratio 2.96, p = 0.026).

CONCLUSIONS

The pleomorphic designation in ILC does not have clinical utility and should not be used to determine therapy. Rather, mitotic count identified clear prognostic groups in this cohort of pure ILC.

Abstract P4-13-01: Trends in primary management of invasive lobular carcinoma: An analysis of the National Cancer Database (NCDB)

Background: Invasive lobular carcinoma (ILC) is typically strongly hormone receptor (HR) positive, with unique characteristics. It has been shown to have poor response to neoadjuvant chemotherapy (NAC) and recent studies describe the benefits of neoadjuvant endocrine therapy (NET).

We sought to determine how the primary management strategy in ILC has changed over time, and the impact of ILC tumor biology on its management. Specifically, we hypothesized that use of NAC has decreased, while NET use increased. Additionally, we investigated whether NET is associated with higher rates of breast conservation surgery (BCS) than other primary management strategies.

Methods: We queried the NCDB from 2010-2016 and identified all women with ILC who underwent surgical therapy. Patients with stage IV disease were excluded. First course of treatment was classified as: NAC (chemotherapy starting 31-365 days before surgery), NET (short course defined as 7-30 days before surgery; long course defined as 31-365 days before surgery), and primary surgery. Tumors were considered HR+ if they were estrogen receptor and/or progesterone receptor positive. Trends over time in first treatment strategy were compared using Cochrane-Armitage tests. The association between first treatment strategy and use of BCS was assessed using multivariable logistic regression.

Results: Among 79,709 women with ILC, 94.0% were HR+/HER2-, 4.7% were HER2+, and 1.3% were triple negative. The most common primary treatment strategy was surgery (92.3%), but the percent undergoing systemic treatment before surgery increased from 7.1% in 2010 to 8.8% in 2016 (p<0.001). The use of NAC increased significantly over the study period in patients with triple negative (12.1% in 2010 to 23.7% in 2016, p=0.007) and HER2+ (12.2% in 2010 to 29.1% in 2016, p<0.001) ILC tumors. Among patients with HR+/HER2- tumors, however, the use of NAC decreased from 4.7% in 2010 to 4.2% in 2016, p=0.007, and the use of long course NET increased significantly, from 1.6% in 2010 to 2.7% in 2016, p<0.001. The use of short course NET in HR+/HER2- patients remained very low over the study period (0.4% in 2010 to 0.5% in 2016, p=0.14).

Analyzing the HR+/HER2- subset, 48.4% (295/609) of patients undergoing long course NET with a cT2 tumor underwent BCS compared to 35.3% for primary surgery, 27.3% for NAC, and 24.8% for short course NET (p<0.001). Long course NET was also associated with a higher BCS rate in cT3/cT4 tumors: 22.6% BCS for long course NET, 8.3% BCS for primary surgery, 9.6% BCS for NAC, 7.8% BCS for short course NET (p<0.001). In multivariable analysis including a clinical T category by treatment interaction, long course NET was the only treatment that was associated with higher rates of BCS compared to primary surgery in cT2 (OR 1.51, 95% CI: 1.27-1.79) tumors, while both long course NET (OR 2.52, 95% CI: 1.97-3.22) and NAC (OR 1.54, 95% CI: 1.27-1.88) were associated with increased use of BCS in cT3/cT4 tumors, see Table.

Conclusions: The primary management of ILC is slowly evolving over time with a decrease in primary surgery. NAC use has increased appropriately in tumor subtypes with greatest potential benefit (i.e., triple negative or HER2 positive). In HR+/HER2- disease, NAC use has decreased, however NET use has increased and in cT2+ tumors NET was associated with higher rates of BCS.

Variable1Odds ratio for BCS (95% CI)p-valueAge, per 1 year increase1.04 (1.03-1.04)<0.001Charlson-Deyo comorbidity score<0.0011 vs 00.86 (0.82-0.90)2+ vs 00.72 (0.66-0.79)Grade2<0.001Moderately/Poorly vsWell Differentiated0.91 (0.88-0.95)Clinical N category2<0.001cN1 vs cN00.49 (0.46-0.52)cN2/cN3 vs cN00.41 (0.35-0.47)Multicentric<0.001Yes vs No0.36 (0.34-0.38)Primary treatment by clinical T category2<0.001For cT1 tumorsLong course NET vs primary surgery0.65 (0.51-0.83)NAC vs Primary surgery0.31 (0.24-0.41)Short course NET vs primary surgery0.85 (0.58-1.24)For cT2 tumorsLong course NET vs primary surgery1.51 (1.27-1.79)NAC vs primary surgery1.04 (0.90-1.20)Short course NET vs primary surgery0.53 (0.33-0.85)For cT3/cT4 tumorsLong course NET vs primary surgery2.52 (1.97-3.22)NAC vs primary surgery1.54 (1.27-1.88)Short course NET vs primary surgery0.79 (0.31-2.02)1Model additionally adjusted for year of diagnosis, race, ethnicity, and insurance status.2Unknown level included in the model but not reported

Citation Format: Rita A Mukhtar, Tanya L. Hoskin, Elizabeth B. Habermann, Judy C. Boughey. Trends in primary management of invasive lobular carcinoma: An analysis of the National Cancer Database (NCDB) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-13-01.

Abstract OT3-09-01: Use of Oncotype DX DCIS for disease management in a prospective DCIS registry

Background: Ductal carcinoma in situ (DCIS) now represents nearly a quarter of newly diagnosed breast cancers in the United States. Standard-of-care treatment for DCIS is aggressive local therapy consisting of either mastectomy or breast conserving surgery with radiation. However, DCIS mortality is low regardless of initial treatment, suggesting opportunities to explore a spectrum of treatment options. With these treatment options, there is the potential to create risk-adapted treatment plans, but the question of how to assess risk remains. Molecular tests can help to personalize treatment by stratifying disease sub-types and providing prognosis. One such tool is the Oncotype DX® Breast DCIS Score, a risk measure which was validated in a meta-analysis of 773 patients from the E5194 and Ontario DCIS Cohort studies. Along with calculating a Breast DCIS Score™ from the expression levels of 12 genes, the test provides a predicted 10-year risk of local recurrence from the score result, age, and tumor size for patients who receive breast conserving surgery alone. Understanding how such a tool might impact decision-making will inform its implementation.

Eligibility & trial design: The ATHENA Breast Health Network is a consortium of the five University of California Medical centers. Through ATHENA, patients with histologically confirmed DCIS and no concurrent invasive cancer are approached to participate in the Athena DCIS Registry. Patients in the registry facing an active management decision are eligible to participate in the Oncotype DX® DCIS prospective study.

Specific aims: The primary aim of the study is to determine whether the additional diagnostic information (i.e. the DCIS Score™) impacts patient treatment decisions and physician recommendation. Additional goals are to correlate the DCIS Score™ with mammographic findings, pathological variables, and treatment recommendations, and to estimate risk within each DCIS Score™ group. Participants and their physicians answer survey questions both before and after receiving the score to evaluate the impact of the DCIS Score™ on treatment recommendations and decisions.

Statistical methods: The study will assess the percentage of patients who thought the DCIS risk score influenced their treatment decision. The study will also assess whether a significant proportion of physicians changed their recommendations after considering the DCIS Score™ using the chi-square test. Similarly, the patients’ preferred treatment option pre- and post- test surveys will be evaluated. In addition, the concordance between physicians’ and patients’ choices will be assessed by the Kappa statistic before and after the score. The patients’ and physicians’ confidence levels in their treatment recommendation and decision pre- and post- test will be compared using a Wilcoxon signed-rank test, as well as the percentage of patients and physicians who are glad they used the test. In addition, the study will assess whether the DCIS test influences a patient’s perception of their recurrence risk by comparing the self-reported 10-year breast cancer recurrence risk in their pre- and post- test questionnaires using a Wilcoxon signed-rank test.

Current and target accrual: The current accrual across all sites in the Oncotype study is 94 patients. The target accrual for the initial pilot phase data is defined as the first 100 patients accrued.

If interested in learning more about the study, please contact Rita Mukhtar, MD (Rita.Mukhtar@ucsf.edu).

Citation Format: Jane M Wei, Paul Kim, Cheryl Ewing, Jasmine Wong, Laura J Esserman, Michael D Alvarado, Abimbola O Olusanya, Skye Stewart, Ashley Tydon, Parima Daroui, Jeffrey V Kuo, Hannah L Park, Karen T Lane, Eliza Jeong, Kelsey Brown, Ava Hosseini, Barbara A Parker, Sarah L Blair, Athena Breast Health Network Investigators, Frederick Baehner, Olivier Harismendy, Antonia Petruse, Carlie K Thompson, Helena R Chang, Alexander D Borowsky, Christina Yau, Gillian L Hirst, Richard J Bold, Rita A Mukhtar. Use of Oncotype DX DCIS for disease management in a prospective DCIS registry [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-09-01.

Abstract P6-16-06: Improved early stratification of invasive cancer risk using MRI in a ductal carcinoma in-situ short-term active surveillance cohort treated with neoadjuvant endocrine therapy

Purpose

Standard treatment for ductal carcinoma in situ (DCIS) involves surgical excision and radiation treatment, and often adjuvant endocrine therapy (ET). However, this may constitute overtreatment for some women. The purpose of this neoadjuvant ET study in patients with biopsy-proven DCIS was to evaluate the relationship between the primary outcome of upstaging at surgery (invasive disease) and changes in the pre- and post-ET MRI appearances of both (1) lesion and (2) background parenchymal enhancement (BPE), with the goal to better inform de-escalated therapy.

Methods

Outcomes of patients with DCIS who were prospectively enrolled in a neoadjuvant ET trial between 2002 and 2009 were retrospectively analyzed with IRB approval. All patients had dynamic contrast-enhanced breast MRI prior to and following an average of 3.1 months of ET (range 1.9 – 5 months), followed by surgical excision within one year of the second MRI. Pathology reports were used to confirm initial biopsy results and to determine the nature and extent of disease postoperatively. Surgeon and radiologist’s reports were used to assess improvement of lesion after ET based on 1) less prominently enhancing pattern or 2) reduction in size of DCIS lesion after treatment. BPE response to ET on imaging was assessed by two radiologists specialized in breast imaging who compared pre- and post-ET MRI’s, blinded to all imaging reports. The change in BPE of the ipsilateral breast with treatment was scored subjectively as increased, decreased, or unchanged. Readers reached a consensus on discordant classifications of the change in BPE. The correlation between imaging change (of lesion and BPE) and incidence of invasive ductal carcinoma (IDC) at surgery was determined using Fisher’s exact test.

Results: Of 34 patients evaluated, six (18%) had IDC at surgery. The prevalence of IDC in each group is shown in Table 2. Those with improvement of lesion on MRI had a lower likelihood of IDC at surgery compared to patients with no imaging improvement (Table 2, p= 0.048). Addition of change in BPE to the evaluation of lesion improvement significantly increased the chance of identifying specific patients who were much more likely to have an underlying invasive cancer at surgery (Table 2, p= 0.032). The risk of having IDC at surgery was considerably higher in the group whose lesion was assessed as not improved and who had decreased BPE scores on MRI (Table 2, p= 0.018).

Conclusion: In our unique population of patients with mostly ER+ DCIS receiving pre-operative endocrine therapy, the combination of lack of lesion improvement and reduction in BPE score in blinded reads was significantly associated with the finding of invasive disease at surgical excision. This result may reflect the unmasking of a more aggressive lesion in those with underlying IDC and help identify patients with a higher likelihood of the presence of IDC at surgery. Although this study is small, it suggests that risk-stratifying patients with DCIS based on lesion and parenchymal imaging features associated with treatment response may aid in tailoring therapy for DCIS. We are testing this prospectively in an active surveillance cohort.

Table 1. Incidence of IDC at surgery depending on image features (n= 34)Improvement of lesion in MRINo Improvement of lesion in MRIP-value (Fisher’s Exact Test)& No Reduction in BPE& Reduction in BPE& No Reduction in BPE& Reduction in BPEIncidence of IDC at surgery (n)0204Incidence of Not IDC at surgery (n)121024%IDC at surgery when assessing lesion only (%)9.1%40%0.048*%IDC at surgery when assessing lesion AND BPE (%)0%16.7%0%50%0.032*%IDC at surgery when assessing lesion AND BPE (%)8.3%50%0.018*

Citation Format: Paul Kim, Heather I. Greenwood, Rita I. Freimanis, Gillian L Hirst, Megan Fischer-Colbrie, Jessica Gibbs, Nola M Hylton, Christina Yau, Eun-Sil Shelley Hwang, Laura J. Esserman, Rita A Mukhtar. Improved early stratification of invasive cancer risk using MRI in a ductal carcinoma in-situ short-term active surveillance cohort treated with neoadjuvant endocrine therapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-16-06.

Abstract P3-08-16: The impact of residual ductal carcinoma in situ on breast cancer recurrence in the neoadjuvant I-SPY2 TRIAL

Background: Patients who achieve a pathological complete response (pCR- defined as no invasive cancer) after neoadjuvant chemotherapy (NAC) for breast cancer (BC) have improved outcomes, but there is still controversy about the significance of residual ductal carcinoma in situ (DCIS) on local recurrence rate (LRR). The I-SPY 2 TRIAL is an adaptive neoadjuvant platform trial evaluating novel experimental regimens in comparison to standard chemotherapy in women with high-risk breast cancer. The purpose of this study is to determine if residual DCIS after NAC in early BC affects LRR in patients with or without residual invasive disease in the I-SPY 2 TRIAL.

Methods: 933 I-SPY 2 patients with residual cancer burden (RCB) and follow-up data were included in this analysis. Residual DCIS was defined as any carcinoma in situ > 0% on RCB evaluation. Local recurrence was defined as recurrence in breast, chest wall or locoregional nodes and/or skin and subcutaneous tissue. We stratified our cohort into four groups: those without residual invasive disease (defined as RCB0) ± residual DCIS, and those with residual invasive disease (RCB>0) ± residual DCIS. We estimated LRR within each group using the Kaplan Meier method; and used Cox proportional hazards models to assess LRR differences between groups, with: patients with no residual disease (invasive or in situ) as reference group.

Results: Among 933 patients assessed, median follow up time was 3.9 years. RCB 0 status was achieved in 337 patients (36%). Of these, 267 (29%) had no residual DCIS, which represents our reference group, and 70 (7%) had residual DCIS. Among 596 (64%) patients who had RCB>0, 296 (32%) had residual DCIS. For patients with RCB0 without DCIS and RCB0 with DCIS, the LRR at 3 years were similar: 2% vs 3% respectively (Hazard ratio: 1.29 [0.26-6.39]). Results were also similar in the RCB>0 group, with a LRR of 10% at 3 years in those without residual DCIS, and 11% in those with residual DCIS. Both RCB>0 groups had significantly higher LRR when compared to the patients with RCB0 without DCIS (Hazard ratio: 5.25 [2.20-12.5]) and HR 5.85 [2.47-13.9] respectively).

Conclusion: There was no association between residual DCIS and LRR after neoadjuvant chemotherapy, regardless of resolution of invasive disease. Further work is needed to determine whether residual DCIS should drive locoregional therapy decisions after neoadjuvant chemotherapy for invasive breast cancer.

Citation Format: Marie Osdoit, Christina Yau, W. Fraser Symmans, Judy C. Boughey, Smita M. Asare, Ron Balassanian, Jodi M. Carter, Yunn-Yi Chen, Kimberly Cole, Laila Khazai, Molly Klein, Dina Kokh, Gregor Krings, Sunati Sahoo, Gretchen Ahrendt, Akiko Chiba, Cheryl Ewing, Constantine Godellas, Nora Jaskowiak, Brigid Killelea, Helen Krontiras, Rachael Lancaster, Julie Lang, M. Catherine Lee, Arpana Naik, Roshni Rao, Julia Tchou, Shannon Tierney, Eleni Tousimis, Tod Tuttle, Anne Wallace, I-SPY 2 TRIAL Consortium, Bev Parker, Laura J. Esserman, Rita A. Mukhtar. The impact of residual ductal carcinoma in situ on breast cancer recurrence in the neoadjuvant I-SPY2 TRIAL [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-16.

Abstract PD9-08: Accuracy of ultrasound in evaluating response to neoadjuvant therapy in invasive lobular carcinoma of the breast

Background: Evaluating the size of invasive lobular carcinoma of the breast (ILC) poses a challenge due to higher rates of false negatives compared to invasive ductal carcinoma. Magnetic resonance imaging (MRI) is often considered the best imaging modality for ILC, but requires additional cost, time, and the use of intravenous contrast, unlike ultrasonography (U/S). We sought to determine whether U/S might provide sufficient information to evaluate response to therapy, thus enabling the use of U/S for surgical planning after NAT in ILC.

Methods: We queried a database of 685 ILC cases at UCSF between 1981 and 2018, identifying all cases receiving NAT. We reviewed MRI and U/S reports and collected longest tumor diameter and imaging features. We used t-test, chi-squared test, and Pearson’s correlation to compare U/S and MRI longest diameter to true size on pathology. Data were evaluated in Stata 14.2.

Results: 148 patients treated with NAT were identified. Of these, 84 (56.8%) received neoadjuvant chemotherapy and 64 (43.2%) received neoadjuvant endocrine therapy. Compared to the endocrine therapy group, those receiving chemotherapy were significantly younger (mean age 53.3 years vs. 62.8 years, p=0.0002), more likely to have tumors of the ER-PR-HER2- or HER2+ subtypes (p=0.016), and of higher pathologic stage (p=0.024). Among 43 cases with evaluable data, longest tumor diameter on post-treatment U/S strongly correlated with longest diameter on post-treatment MRI (r=0.93, p<0.0001). Post-treatment U/S longest diameter was significantly correlated with true size on pathology (r=0.56, p=0.0008). This correlation held true whether the patient had endocrine therapy (r=0.47, p=0.02) or chemotherapy (r=0.75, p=0.03). Finally, we sought to determine whether tumor phenotype on pre-treatment MRI was associated with accuracy of post-treatment U/S. For patients who had no non-mass enhancement (NME) on pre-treatment MRI, post-treatment U/S was significantly correlated with true tumor size on pathology (r=0.65, p=0.0013). However, if NME was present on pre-treatment MRI, there was no correlation between post-treatment U/S and true tumor size (p=0.48). In our cohort, 82 patients (55.8%) had no NME on pre-treatment MRI.

Conclusions: Post-treatment MRI longest diameter and post-treatment U/S longest diameter were strongly correlated. The presence of NME on pre-treatment MRI meant that post-treatment U/S was no longer a useful predictor of true tumor size, but when NME was not present, post treatment U/S longest diameter was significantly correlated with true size. Therefore, for ILC patients with no NME on pre- treatment MRI, these findings suggest that treatment response evaluation of tumor size can be done with U/S only. Future work will explore the ability of U/S to determine nodal response compared to MRI. Additionally, MRI features such as functional tumor volume may provide additional response information beyond longest diameter, and ongoing research is needed.

Table 1: Characteristics of study population.Neoadjuvant chemotherapy (n=84)Neoadjuvant endocrine therapy (n=64)P-valueMean age, range53.3 (29-81)62.8 (41-89)0.0002Biomarker and receptor status0.016ER+PR+HER2-41 (54.7%)35 (62.5%)ER+PR-HER2-19 (25.33%)20 (35.7%)ER-PR-HER2-4 (5.33%)0HER2+11 (14.7%)1 (1.8%)Grade0.11122 (27.9%)24 (37.5%)250 (63.3%)29 (60.9%)37 (8.9%)1 (1.56%)Pathologic stage0.024I30 (35.7%)34 (53.1%)II36 (42.9%)14 (21.9%)III18 (21.4%)16 (25.0%)Mean follow-up time (years, 95% confidence interval)5.9 (4.9-6.9)5.1 (4.2-6.1)0.15

Citation Format: Kelly Fahrner-Scott, Jasmine M Wong, Merisa Piper, Cheryl Ewing, Michael Alvarado, Laura J Esserman, Nola Hylton, Rita A Mukhtar MD. Accuracy of ultrasound in evaluating response to neoadjuvant therapy in invasive lobular carcinoma of the breast [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD9-08.

Abdominal Imaging of Pancreatic Cysts and Cyst-Associated Pancreatic Cancer in BRCA1/2 Mutation Carriers: A Retrospective Cross-Sectional Study

BACKGROUND

Direct-to-consumer BRCA testing will increase BRCA diagnoses and subsequent abdominal imaging. It is unclear whether BRCA carriers are at higher risk of developing pancreatic cysts (PCs) or cyst-associated pancreatic ductal adenocarcinoma (PDAC). We investigated the prevalence of PCs in BRCA-tested patients, and whether BRCA-carriers have higher rates of PDAC when PCs are found.

STUDY DESIGN

This is a retrospective cross-sectional study of patients with BRCA testing and abdominal imaging between 1996 and 2018. Pancreatic cysts were identified on original imaging reports. Prevalence and risk characteristics of PCs, as well as incidence of PDAC, were compared between BRCA+, BRCA-, and BRCA-untested patients.

RESULTS

Pancreatic cysts were identified in 4,045 patients among 128,164 unique patients with abdominal imaging, including 33 patients with PCs in 1,113 BRCA-tested patients. There was no difference in PC prevalence between BRCA+, BRCA-, and untested patients (3.6%, 2.6%, 3.2%, respectively; p = 0.64). Pancreatic cysts were diagnosed in BRCA+ patients at a younger age (57.1 vs 65.3 years, p < 0.001); however, there was no difference in risk stratification compared with BRCA- or untested patients by consensus criteria. Across the population of imaged patients, patients with PCs had significantly higher rates of PDAC compared with those without PCs (18.2% vs 2.4%, p < 0.001). Incidence of cyst-associated PDAC was similar in BRCA+ and BRCA- patients (13.3% vs 22.2%, p = 0.84).

CONCLUSIONS

BRCA+ patients have similar rates of PCs, high-risk features in their cysts, and PDAC as BRCA- and untested patients. BRCA+ patients likely do not require dedicated abdominal imaging to evaluate for PCs and should follow management guidelines similar to those as the untested general population if an incidental PC is identified.

Success rates of re-excision after positive margins for invasive lobular carcinoma of the breast

Rates of positive margins after surgical resection of invasive lobular carcinoma (ILC) are high (ranging from 18 to 60%), yet the efficacy of re-excision lumpReceptor subtypeectomy for clearing positive margins is unknown. Concerns about the diffuse nature of ILC may drive increased rates of completion mastectomy to treat positive margins, thus lowering breast conservation rates. We therefore determined the success rate of re-excision lumpectomy in women with ILC and positive margins after surgical resection. We identified 314 cases of stage I-III ILC treated with breast conserving surgery (BCS) at the University of California, San Francisco. Surgical procedures, pathology reports, and outcomes were analyzed using univariate and multivariate statistics and Cox-proportional hazards models. We evaluated outcomes before and after the year 2014, when new margin management consensus guidelines were published. Positive initial margins occurred in 118 (37.6%) cases. Of these, 62 (52.5%) underwent re-excision lumpectomy, which cleared the margin in 74.2%. On multivariate analysis, node negativity was significantly associated with successful re-excision (odds ratio [OR] 3.99, 95% CI 1.15-13.81, p = 0.029). After 2014, we saw fewer initial positive margins (42.7% versus 25.5%, p = 0.009), second surgeries (54.6% versus 20.2%, p < 0.001), and completion mastectomies (27.7% versus 4.5%, p < 0.001). In this large cohort of women with ILC, re-excision lumpectomy was highly successful at clearing positive margins. Additionally, positive margins and completion mastectomy rates significantly decreased over time. These findings highlight improvements in management of ILC, and suggest that completion mastectomy may not be required for those with positive margins after initial BCS.

Initial experience of dedicated breast PET imaging of ER+ breast cancers using [F-18]fluoroestradiol

Dedicated breast positron emission tomography (dbPET) is an emerging technology with high sensitivity and spatial resolution that enables detection of sub-centimeter lesions and depiction of intratumoral heterogeneity. In this study, we report our initial experience with dbPET using [F-18]fluoroestradiol (FES) in assessing ER+ primary breast cancers. Six patients with >90% ER+ and HER2- breast cancers were imaged with dbPET and breast MRI. Two patients had ILC, three had IDC, and one had an unknown primary tumor. One ILC patient was treated with letrozole, and another patient with IDC was treated with neoadjuvant chemotherapy without endocrine treatment. In this small cohort, we observed FES uptake in ER+ primary breast tumors with specificity to ER demonstrated in a case with tamoxifen blockade. FES uptake in ILC had a diffused pattern compared to the distinct circumscribed pattern in IDC. In evaluating treatment response, the reduction of SUVmax was observed with residual disease in an ILC patient treated with letrozole, and an IDC patient treated with chemotherapy. Future study is critical to understand the change in FES SUVmax after endocrine therapy and to consider other tracer uptake metrics with SUVmax to describe ER-rich breast cancer. Limitations include variations of FES uptake in different ER+ breast cancer diseases and exclusion of posterior tissues and axillary regions. However, FES-dbPET has a high potential for clinical utility, especially in measuring response to neoadjuvant endocrine treatment. Further development to improve the field of view and studies with a larger cohort of ER+ breast cancer patients are warranted.

Changes in mammographic density following bariatric surgery

BACKGROUND

Obesity and high breast density both increase breast cancer risk but paradoxically are inversely related. Bariatric surgery decreases breast cancer risk, but its impact on mammographic breast density is not well understood.

OBJECTIVES

We investigated how mammographic density changes after bariatric surgery and whether this change is related to weight loss.

SETTING

University of California, San Francisco Medical Center.

METHODS

We reviewed records from 349 prospectively collected patients who underwent bariatric surgery between 2013 and 2015 and identified 42 women with pre- and postoperative screening mammograms within 1.5 years of surgery. We recorded body mass index (BMI), height and Breast Imaging Reporting and Data System density and calculated BMI loss and total weight loss. Data were analyzed in Stata 14.2.

RESULTS

Average age was 54.2 years, mean preoperative BMI was 43.8 kg/m², mean BMI lost was 30.9%, and total weight loss was 31.1% at 1.3 years. Over one-third had a change in mammographic breast density, which increased 93.3% of the time (P < .001). Amount of weight loss was not associated with a density change. Patients with the lowest mammographic density preoperatively were most likely to have a density change (P = .02).

CONCLUSIONS

Most women with a mammographic change had an increase in breast density, despite bariatric surgery being associated with reduced breast cancer risk. Baseline breast density was associated with a density change, but amount of weight loss was not. These findings suggest the metabolic effects of bariatric surgery have an effect on breast parenchyma independent of absolute BMI reduction or weight loss.

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 (&gt;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&lt;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 P1-15-15: Accuracy of MRI after neoadjuvant therapy for invasive lobular carcinoma of the breast

Background: Invasive lobular carcinoma of the breast (ILC) has higher rates of false negative imaging than invasive ductal carcinoma, and lower rates of neoadjuvant therapy (NAT) use. We evaluated the accuracy of Breast Imaging Reporting And Data System (BIRADS) findings on magnetic resonance imaging (MRI) after either neoadjuvant chemotherapy or endocrine therapy, and determined whether imaging change correlates with disease free survival.

Methods: We queried a database of 674 ILC cases treated at UCSF from 1981-2017 and identified all patients treated with NAT. We reviewed MRI reports and recorded BIRADS descriptors of findings, maximal tumor diameter for mass or non-mass enhancement (NME), and subjective radiologist comments on progression or improvement. We used the t-test, chi-squared test, Pearson's correlation, and Kaplan Meier survival estimates to evaluate the accuracy of MRI after NAT compared to true tumor size on pathology, and the relationship between imaging change and disease free interval in Stata 14.2.

Results: Of 136 patients with ILC treated with NAT, we included 101 women who had a post-treatment breast MRI report available. Of these, 58.4% received neoadjuvant chemotherapy, and 41.6% neoadjuvant endocrine therapy. After NAT, MRI findings were mass only in 43%, both mass/NME in 33%, NME only in 18%, and neither in 5%. Maximal diameter of mass on post-treatment MRI underestimated true size by a mean of 3.3 cm (range -3.6 to 15.3 cm). NME size on post-treatment MRI underestimated true size by a mean of 1.87 cm (range -7.2 to 9.7 cm). Mass size on MRI underestimated true size by ≥1 cm in 61.5% of cases; this size discrepancy was associated with increased positive margins (46.4% versus 20%, p=0.011). NME size on MRI underestimated true size by at ≥1 cm in 65.6%. The correlation coefficient between mass size on MRI and true size was 0.34 (p=0.0041), which increased to 0.67 (p&lt;0.0001) when excluding those with associated NME. The correlation coefficient between NME size on MRI and true size was 0.28 (p=0.1239). Subjective progression on post-treatment MRI was associated with increased recurrence rates (80% versus 18.3%, p=0.001). In those with subjective improvement on MRI, there was a trend towards longer disease free interval (89% versus 73% disease free at 4 years, p=0.13).

Table 1.Patient and tumor characteristics. Neoadjuvant chemotherapy (n=59)Neoadjuvant endocrine therapy (n=42)P valueMean age (yrs, 95% CI)53.6 (50.9-56.3)61.3 (58.4-64.1)0.0002Subtype  0.105ER+ PR+ HER2-29 (53.7%)23 (62.16%) ER+ PR- HER2-14 (25.9%)13 (35.14%) ER- PR- HER2-1 (1.85%)0 HER2+10 (18.5%)1 (2.7%) Grade  0.076114 (25%)16 (38.1%) 237 (66.1%)26 (61.9%) 35 (8.93%)0 Surgical stage  &lt;0.001I17 (28.81%)28 (66.67%) II26 (44.07%)6 (14.29%) III16 (27.12%)8 (19.1%) Mean follow-up time (yrs, 95% CI)5.6 (4.53-6.75)5.1 (3.84-6.27)0.48

Conclusions: Maximal tumor diameter on MRI after NAT in ILC vastly underestimates true tumor size. While these findings suggest using caution when using an MRI for surgical planning in patients with ILC, particularly if there is associated NME, the trend towards improved disease free survival in those with a subjective improvement is intriguing and suggests that MRI changes could become an early predictor of outcomes.

Citation Format: Fahrner-Scott KE, Wong JM, Piper M, Ewing C, Alvarado M, Esserman LJ, Hylton N, Mukhtar RA. Accuracy of MRI after neoadjuvant therapy for invasive lobular carcinoma of the breast [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 P1-15-15.

Abstract PD7-06: Molecular subtypes of invasive lobular breast cancer in the I-SPY2 TRIAL

Background: Invasive lobular carcinoma (ILC) of the breast has distinct histological and molecular variations compared to invasive ductal carcinoma (IDC), including absence of the adhesion protein E-cadherin. Recently, molecular subtypes within ILC have been described, with an analysis from The Cancer Genome Atlas (Ciriello et al) identifying three distinct groups within ILC based on gene expression—reactive-like, immune-related, and proliferative. In this study, we applied this 60-gene classifier to a locally advanced cohort of ILC and mixed ILC/IDC cases from patients screening for the I-SPY 2 neoadjuvant chemotherapy trial.

Methods: The I-SPY 2 TRIAL is open to women with more locally advanced, clinically/molecularly (as assessed by MammaPrint) high risk breast cancer. HR+HER2- MammaPrint Low risk patients ineligible for I-SPY 2 randomization are invited to join a MP Low risk registry. 131 ILC and mixed ILC/IDC tumors from these cohorts (I-SPY 2: n=80; low risk registry: n=51) with pre-treatment Agilent microarrays were available for analysis. We used the Classification to Nearest Centroid technique to assign TCGA subtype to our cohort. We assessed association between TCGA subtype, clinical covariates and response to therapy using a chi-square test. We also evaluated the Euclidean distance between each sample and the three subtype centroids. In an exploratory analysis, we used consensus clustering based on the 1000 most varying genes within the HR+HER2- I-SPY ILC cases to generate new unsupervised groupings, and assessed the concordance with the TCGA reactive-like, immune-related and proliferative subtype assignments.

Results: Of the 131 patients included, most (79%) were HR+HER2-, 11% were HR+HER2+, 2% were HR-HER2+ and 8% were HR-HER2- for a total of 10% HR-. 66 were pure ILC, while 65 were mixed ILC/IDC. Upon applying the TCGA 60-gene classifier, the distribution of ILC subtypes was as follows: 33 (25%) were classified as reactive-like, 50 (38%) were immune-related, and 48 (37%) were proliferative. 64% of triple negative cases were reactive-like; while the HR+HER2- and HER2+ cases were more likely to be in the proliferative or immune-related subtype (p=0.037). Among the 80 I-SPY 2 cases, the overall pathologic complete response rate was low (16%) but equivalent to the overall HR+HER2- I-SPY2 population (16%). This did not differ across the groups defined by the TCGA ILC subtypes (p=0.79).

Interestingly, a subset of cases assigned as reactive-like and immune-related were of similar distance to the proliferative subtype centroid as patients assigned to the proliferative subtype. When we used consensus clustering to identify new subsets within our locally advanced ILC cohort, our unsupervised groupings had only 32% concordance with the TCGA ILC subtype assignments.

Conclusion: The low concordance between our consensus cluster groupings and the TCGA subtype groupings may reflect underlying differences within a locally advanced cohort of ILC cases, like I-SPY, that may not be captured in the 60-gene classifier developed from the overall lower stage TCGA cohort. These findings suggest that considerable molecular heterogeneity exists in lobular cancers, which merits further investigation.

Citation Format: Zhu Z, Yau C, Chien AJ, Haddad T, Esserman LJ, van't Veer L, Mukhtar RA, I-SPY2 Consortium. Molecular subtypes of invasive lobular breast cancer in the 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 PD7-06.

Abstract P5-22-22: Breast tumor location in BRCA mutation carriers and implications for prevention

Introduction:

Close to 65% of BRCA mutation carriers do not choose prophylactic mastectomy, despite their high breast cancer risk. Breast reduction mammoplasty is a surgical technique shown to reduce breast cancer risk and can be modified to target specific areas of the breast. We wondered if a majority of tumors in BRCA mutation carriers would be confined to one quadrant, allowing for the use of targeted cosmetic mammoplasty as a novel method of risk reduction.

Methods:

We reviewed imaging reports on 103 consecutive patients with BRCA mutations and invasive breast cancer, and categorized tumor location by quadrant. Tumors spanning &gt;1 quadrant were classified as being in both. Bilateral cancers were counted separately. Categorical variables were compared with the chi-squaredtest.

Results:

Mean age at breast cancer diagnosis was 44 years with mean tumor size of 2.2 cm (0.1-7cm). 92% of tumors were invasive ductal carcinoma, 46% were hormone receptor positive, 10% Her2 positive, and 44% triple negative. 70% of the tumors were unicentric. Tumors were significantly more likely to be in the upper outer quadrant whether or not multicentric tumors were included in the analysis (p&lt;0.00001). Her2 positive tumors were more likely to be multicentric than other subtypes (p=0.021).

Conclusions:

More than half of breast cancers in BRCA mutation carriers form in the upper outer quadrant, suggesting that removing this quadrant through breast reduction mammoplasty could significantly reduce breast cancer risk. For women who are not ready for prophylactic mastectomy, this data supports an intermediate risk reduction step instead of only offering surveillance.

Citation Format: Hosseini A, Esserman LJ, Wallace AM, Au A, Mukhtar RA. Breast tumor location in BRCA mutation carriers and implications for prevention [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-22-22.

Abstract P4-10-19: Disparities in use of adjuvant radiotherapy following lumpectomy among California regions

Background

Women undergoing lumpectomy for invasive breast cancer typically receive radiotherapy (RT) to reduce risk of recurrence. Previous studies have reported disparities in the utilization of RT by race, socioeconomic status (SES), and age. In this study, we evaluate whether various sociodemographic factors are associated with use of RT in the different regions of California.

Methods

Utilizing data from the California Cancer Registry, the authors identified cases of women whose first primary invasive breast cancer was diagnosed between January 1, 2007 and December 31, 2012, whose primary surgery was breast conserving surgery, and for whom information was complete (n = 71,767). Multivariate logistic regression was used to determine whether demographic factors (SES, race, payer status, age) were significantly associated with use of RT following lumpectomy (p &lt; .05), adjusting for tumor characteristics (size, stage, grade, hormone receptor status, and nodal status).

Results

In three out of eight regions in California, black race was associated with decreased odds of RT use (San Francisco, OR = 0.79, 95% CI = 0.68-0.92; Desert Sierra, OR = 0.72, 95% CI = 0.58-0.90; Los Angeles, OR = 0.78, 95% CI = 0.70-0.87). In Sacramento and Los Angeles regions, lower socioeconomic status was associated with declined odds of RT use. Age (70 years or older) was also associated with lower likelihood of RT use across all regions.

Conclusions

Even after accounting for payer status, racial and socioeconomic disparities persist in the use of RT. These disparities, previously documented in the time period of 2000-2007, have not disappeared. Hispanic race was not shown to be associated with decreased odds of RT use in Los Angeles, contrary to the results of a previous study. Women aged 70 years or older are less likely to receive RT.

Citation Format: Huang RJ, Mukhtar RA, Alvarado M. Disparities in use of adjuvant radiotherapy following lumpectomy among California regions [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 P4-10-19.

Abstract P5-12-04: The impact of bariatric surgery on mammographic breast density

Background:

Bariatric surgery decreases breast cancer risk, but its impact on mammographic findings is not well understood. Obesity and breast density both increase breast cancer risk, but paradoxically are inversely related. We investigated how mammographic density changes after bariatric surgery, and whether or not that change is related to amount of weight loss.

Methods:

We reviewed records for 349 prospectively collected patients who underwent bariatric surgery between 2013-2015, and identified 45 women with pre- and post-operative screening mammograms within 1.5 years of surgery. We recorded body mass index (BMI), Breast Imaging-Reporting and Data System density, and calculated excess BMI loss. Data were analyzed in Stata 14.2.

Results:

Average age was 54 years, mean pre-operative BMI was 44 (range 36-72), and mean percentage excess BMI lost was 73% at 1.3 years. One third had a change in mammographic breast density, which increased 93% of the time (p&lt;0.001). Amount of weight loss was not associated with density change; in fact, weight loss was lower in those with a density change than in those without a density change (68% versus 75% excess BMI lost).

Conclusions:

The majority of women with a mammographic change had an increase in breast density, despite bariatric surgery being associated with reduced breast cancer risk. Interestingly, the amount of weight loss was not associated with change in breast density. These findings suggest the metabolic effects of bariatric surgery have an effect on breast cancer risk independent of BMI reduction. Future work will include studying mammographic changes associated with non-surgical weight loss.

Citation Format: Hosseini A, Khoury AL, Carter J, Wong JM, Alvarado MD, Ewing C, Esserman LJ, Mukhtar RA. The impact of bariatric surgery on mammographic breast density [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-12-04.

The Novel Application of Genomic Profiling Assays to Shorten Inactive Status for Potential Kidney Transplant Recipients With Breast Cancer

The concern about cancer recurrence has traditionally resulted in delaying kidney transplantation for 2-5 years after a cancer diagnosis in patients who are otherwise eligible for transplant. This period of inactive status to observe the tumor biology can result in significant morbidity and decreased quality of life for patients with end-stage renal disease (ESRD). We reported the novel application of genomic profiling assays in breast cancer to identify low-risk cancers in two patients with ESRD who were able to have the mandatory inactive status eliminated prior to kidney transplantation.

The prognostic implications of macrophages expressing proliferating cell nuclear antigen in breast cancer depend on immune context

Tumor associated macrophages (TAMs) are recruited from the circulation to the tumor site, and can undergo a spectrum of phenotypic changes, with two contrasting activation states described in the literature: the M1 and M2 phenotypes. We previously identified a population of TAMs that express proliferating cell nuclear antigen (PCNA) and are associated with high grade, hormone receptor negative breast cancers and poor outcomes. In the present exploratory study we again found that high PCNA⁺ TAM counts in pre-treatment tumor biopsies (102 invasive breast cancer cases from the I-SPY 1 Trial, a prospective neoadjuvant trial with serial core biopsies and gene array data) were associated with high grade, hormone receptor negativity, and decreased recurrence free survival. We explored the association of these PCNA⁺ TAMs with the expression of M1 and M2 related genes and, contrary to expectation, observed that high PCNA⁺ TAM levels were associated with more M1- than M2-related genes. An immune gene signature, derived from cytotoxic T cell and MHC Class II genes (Tc/ClassII), was developed and we found that high PCNA⁺ TAM counts, in the context of a low Tc/ClassII signature score, were associated with significantly worse recurrence free survival in all cases and in hormone receptor negative only cases. We observed similar results using a gene signature-proxy for PCNA⁺ TAMs in a larger independent set of 425 neoadjuvant-treated breast cancer cases. The results of this exploratory study indicate that high numbers of PCNA⁺ TAMs, in the absence of an anti-tumor immune microenvironment (as indicated by a low Tc/ClassII signature score), are associated with poor outcomes in breast cancer patients treated with neoadjuvant chemotherapy. This, along with the observation that PCNA⁺ TAMs were associated predominantly with M1-related genes, may provide new insights into the role of the immune microenvironment in breast cancer.

Elevated levels of proliferating and recently migrated tumor-associated macrophages confer increased aggressiveness and worse outcomes in breast cancer

PURPOSE

Macrophages play a major role in inflammatory processes and have been associated with poor prognosis in a variety of cancers, including breast cancer. Previously, we investigated the relationship of a subset of tumor-associated macrophages (PCNA(+) TAMs) with clinicopathologic characteristics of breast cancer. We reported that high PCNA(+) TAM counts were associated with hormone receptor (HR)-negative, high-grade tumors and early recurrence. To further understand the significance of elevated PCNA(+) TAMs and the functionality of TAMs, we examined the expression of S100A8/S100A9 with the antibody Mac387. The heterodimeric S100A8/S100A9 complex plays a role in inflammation and is increased in several cancer types.

METHODS

We performed immunohistochemistry using the Mac387 antibody on 367 invasive human breast cancer cases. Results were compared to previous PCNA(+) TAM counts and were correlated with patient outcomes adjusting for HR status and histologic grade.

RESULTS

Like PCNA(+) TAMs, high Mac387 counts were associated with HR negativity, high tumor grade, younger age, and decreased recurrence-free survival. Mac387, however, appears to identify both a subset of macrophages and a subset of tumor cells. The concordance between Mac387 and PCNA(+) TAM counts was low and cases that had both high Mac387 and high PCNA(+) TAMs counts had a stronger association with early recurrence.

CONCLUSIONS

The presence of high numbers of PCNA(+) TAMs and Mac387-positive cells in breast cancers with poor outcomes may implicate a subset of TAMs in breast cancer pathogenesis, and may ultimately serve to develop potential cellular targets for therapeutic interventions.

PD02-05: MRI Phenotype and Tumor Subtype Affect Breast Conservation Eligibility and MRI Accuracy in the I-SPY 1 Trial

Background

Neoadjuvant chemotherapy (NAC) in breast cancer allows assessment of response to treatment and increases eligibility for breast conservation treatment (BCT). We previously reported that MRI tumor phenotype (based on loss of containment) predicted response to NAC and ability to achieve BCT. Since tumor subtype can affect MRI features, we sought to validate whether MRI phenotype and/or tumor subtype affected BCT eligibility in a prospective trial, I-SPY (CALGB 150007/ACRIN 6657). We also investigated the accuracy of post-NAC MRI in determining BCT eligibility, and the distribution of tumor subtypes within MRI phenotypes with the goal of identifying clinically useful factors associated with successful BCT.

Methods

We analyzed I-SPY 1 Trial data, a multi-center, prospective NAC trial with serial MRIs. Phenotypes 1 and 2 were well defined masses, while 3, 4, and 5 were more diffuse. Subjects were considered truly eligible for BCT if tumor diameter on surgical pathology was ≤ 4 cm (based on NSABP B-06 trial criteria). Post-NAC MRI and surgical pathology were considered discrepant if longest tumor diameter differed by &gt; 2 cm. Categorical variables were compared using the chi-squared test.

Results

Of the 221 subjects, 198 had pre and post-NAC MRIs, and surgical pathology available. Of these, 174 had a tumor diameter &gt; 4 cm prior to NAC, and were considered initially ineligible for BCT. After NAC, 141 (81%) patients became BCT eligible based on having ≤4 cm of residual tumor. In contrast, 46 (26%) had pathologic complete response (pCR, no invasive tumor). The rate of becoming BCT eligible differed by hormone receptor (HR)/Her2 status (p = 0.005) and MRI phenotype (p = 0.037), with higher rates of eligibility in Her2+ and triple negative tumors, and the well defined MRI phenotypes. Overall, 75 (38%) patients had a size discrepancy between tumor diameter on post-NAC MRI and size on surgical pathology. Subjects with diffuse MRI phenotypes had more size discrepancy than phenotypes 1 and 2 (p = 0.001). Subjects with HR+/Her2- tumors also had more size discrepancy than other subtypes (p = 0.004). The more diffuse MRI phenotypes were more commonly HR+/Her2- tumors, and less commonly HR−/Her2- (p = 0.006). There was no difference in actual receipt of BCT by HR/Her2 status. However, patients with a well-defined MRI phenotype were significantly more likely to actually receive BCT than those with a diffuse MRI phenotype (47% versus 27%, p = 0.023).

Conclusions

Patients with well defined patterns on MRI and with Her2+ or triple negative disease were more likely to become eligible for BCT after NAC. The same factors that predict pCR also predict BCT eligibility, but far more patients achieve BCT eligibility than pCR. MRI after NAC was less accurate in the diffuse phenotypes, which could reflect increased difficulty in measuring tumor size in this setting. Tumor phenotype and subtype can help predict likelihood of achieving eligibility for BCT, and can be useful in setting appropriate expectations for women at the start of NAC.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD02-05.

Elevated PCNA+ tumor-associated macrophages in breast cancer are associated with early recurrence and non-Caucasian ethnicity

African American and Hispanic women develop more triple negative breast cancer at younger ages than Caucasian women. The frequently observed association between race and socioeconomic status (SES) has confounded our understanding of the outcomes disparities seen in these groups. Given the association between inflammatory cells and high-grade, triple negative tumors, we sought to investigate whether differences in the presence of these cells varies by race. We evaluated breast tumor specimens for the presence PCNA+ tumor-associated macrophages (TAMs) in consecutive cases from a county hospital serving primarily un- or under-insured patients. All patients in this cohort had elevated PCNA + TAM levels. Higher PCNA + TAM counts were associated with hormone receptor (HR) negative tumors and non-Caucasian ethnicity. Hispanic women specifically had significantly higher PCNA + TAM counts than Caucasian patients and shorter disease-free survival. These findings implicate immune function in the development of aggressive breast cancer and suggest a possible link between SES and the inflammatory response.

Tumor-associated macrophages in breast cancer as potential biomarkers for new treatments and diagnostics

While several inflammatory cell types participate in cancer development, macrophages specifically play a key role in breast cancer, where they appear to be part of the pathogenesis of high-grade tumors. Tumor-associated macrophages (TAMs) produce factors that promote angiogenesis, remodel tissue and dampen the immune response to tumors. Specific macrophage types contribute to increased metastases in animal models, while human studies show an association between TAMs and tumors with poor prognostic features. Macrophages display a spectrum of phenotypic states, with the tumor microenvironment skewing TAMs towards a 'nonclassical' activation state, known as the M2, or wound healing/regulatory state. These TAMs are found in high-risk breast cancers, making them an important therapeutic target to explore. Improved techniques for identifying TAMs should translate into clinical applications for prognosis and treatment.

Benign thoracic disease in the elderly

The spectrum of benign thoracic disease in the elderly includes structural abnormalities, infectious disease and their complications, benign neoplastic growths, and autoimmune disease. Differences in physiologic reserve in this population make diagnosis difficult, as elderly patients may not present in the classic fashion, as well as complicate treatment. Benign thoracic disease in the elderly can pose a challenging clinical problem. Older patients with comorbid diseases may have poor tolerance of unnecessary surgical interventions. However, benign disorders of the chest associated with symptoms attributable to effusion or obstruction of airways can limit quality of life. Minimally invasive techniques (eg, video-assisted thoracoscopic surgery) can limit the morbidity associated with intervention. Additionally, prompt intervention may spare the patient more invasive treatments. For example, early effusions can be managed with simple drainage rather than thoracotomy and decortication. With respect to suspected benign thoracic lesions in the elderly, guiding principles for management include avoiding unnecessary interventions while not overlooking potential malignancies. Close surveillance of progressive symptoms, ensuring no radiographic change in the size of the lesion over 2 years, and use of positron-emission tomography remain the diagnostic keys to accurate management.

Long-term survival and renal transplantation in a monozygotic twin with cloacal dysgenesis sequence

Cloacal dysgenesis sequence (CDS) is a severe hindgut malformation occurring in 1:50,000 to 250,000 live births (Qureshi et al. Prenatal diagnosis of cloacal dysgenesis sequence: differential diagnosis from other forms of fetal obstructive uropathy. Fetal Diagn Ther 1998;13:69-74; Bargaje et al. Cloacal dysgenesis sequence. Ann Diagn Pathol 2008;12:62-66). It is characterized by a smooth perineum with no urethral, vaginal, or anal openings, and lack of labioscrotal development. Typically, the bladder, vagina, and colon each end blindly, although persistent cloaca without perineal orifice can be seen. With no egress for urine, infants have renal insufficiency and pulmonary hypoplasia, usually making CDS lethal (Sahinoglu Z et al. The prenatal diagnosis of cloacal dysgenesis in six cases: can the termination of pregnancy always be the first choice? Prenat Diagn 2004;24:10-16). Reported survivors have had a persistent urachus or have been spared the effects of oligohydramnios by the presence of a twin (Liang X. Cloacal dysgenesis sequence: observations in four patients, including three fetuses of second trimester gestation. Pediatr Dev Pathol 1998;1:281-288). We report a case of long-term survival, currently to 25 months of age, and renal transplantation in a monochorionic, diamniotic twin girl with CDS.