Radioactive seed localization is a safe and effective tool for breast cancer surgery: an evaluation of over 25,000 cases

Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center's RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient's radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.

The Presence of Extensive Lymphovascular Invasion (LVI) is Associated with Higher Risk of Recurrence in Curatively Treated Breast Cancer Patients

PURPOSE/OBJECTIVE(S)

Lymphovascular invasion (LVI) is a pathological feature seen in breast cancer that may be an important step in cancer metastasis. Multiple datasets have demonstrated a correlation between LVI and local-regional recurrence (LRR). Whether the extent of LVI is an incremental determinant of LRR risk is unknown. We describe clinical outcomes in women with invasive breast cancer stratified by: 1) absence of LVI (neg), 2) LVI focal or suspicious (FS-LVI), 3) usual (non-extensive) LVI (LVI) and 4) extensive LVI (E-LVI).

MATERIALS/METHODS

Between December 2009 and August 2021, there were 8,837 patients with early-stage breast cancer (T1-2 and N0-2a) were treated with curative intent and were evaluable. Clinical-pathological details were abstracted by retrospective review. The description of LVI was abstracted from pathology reports. Recurrence and survival outcomes were compared based on the extent of LVI.

RESULTS

Of the 8837 patients studied, 5584 were neg, 461 had FS-LVI, 2315 had LVI, and 477 had E-LVI. The E-LVI cohort had baseline characteristics suggestive of higher risk such as younger median age, higher proportion of grade 3, more nodal positivity, more mastectomy (67% vs 48%), and higher use of chemotherapy compared to LVI. The cumulative incidence of LRR and DM was highest in the E-LVI group. Using LVI as the reference, the presence of E-LVI, age, tumor size, ER status, grade, mastectomy, and close/positive margins were independent variables for LRR on Cox multivariable regression (Table 1). To assess the effect with an alternate statistical method, we created propensity matched cohorts (matched for age, size, receptors, grade, surgery type, margins and chemotherapy/RT use); a statistical difference in OS was noted between groups with LVI vs E-LVI (HR 1.44 (CI 1.06-1.96, p = 0.018), but not in LRR (HR 1.31 (CI 0.87-1.97, p = 0.2) or DM (HR 1.16 (CI 0.88-1.53, p = 0.3).

CONCLUSION

Our work suggests that patients with E-LVI are at a higher risk for LRR compared to patients with usual LVI, despite maximal standard of care treatment. This is important because E-LVI can be determined from breast specimens, and may help define indications for RNI/PMRT when nodal information is not available.

Oncotype Recurrence Score (RS) at the Extremes of Tumor Size: Which Drives Clinical Outcomes?

PURPOSE/OBJECTIVE(S)

Tumor size is an established and independent risk factor for local-regional recurrence (LRR) and distant recurrence (DM). More recently, the recurrence score calculated from a 21-gene expression assay (Oncotype DXTM, Exact Sciences) has also been correlated with LRR and DM. We sought to determine the impact of the interaction between tumor size and Oncotype RS, particularly when the variables are in discrepancy with each other. More specifically, we evaluated clinical outcomes in patients with small tumors (≤1 cm) and high RS (≥26) and, separately, in patients with large tumors (>5 cm) with low RS.

MATERIALS/METHODS

Between 2008 and 2020, 310 patients were identified retrospectively as having been treated for early-stage, hormone-receptor positive, Her2-negative breast cancers with tumor size ≤1 cm that were node-negative and had RS ≥ 26 at our institution. In addition, 64 patients were identified with tumor size >5 cm and RS < 26 (irrespective of nodal status). Locoregional recurrence rates (LRR) and invasive recurrence rates (composite of LRR and distant recurrence) were estimated using the Kaplan-Meier method.

RESULTS

Patient characteristics are shown in Table 1. In the group of patients with small tumors and high RS, the 5- and 10-year invasive recurrence rates with 95% CI were 8% (4.2-12) and 17% (8.2-26). The 5- and 10-year locoregional recurrence rates with 95% CI were 5.8% (2.7-8.8) and 15% (6.2-23). In the group of patients with large tumors and low RS, 10-year rates could not be estimated with the available data. The 5- and 8-year invasive recurrence rates with 95% CI were 3.2% (0-7.5) and 3.2% (0-7.5). The 5- and 8-year locoregional recurrence rates with 95% CI were 1.6% (0-4.7) and 1.6% (0-4.7).

CONCLUSION

Our findings suggest that patients with small tumors and high RS are at a higher risk for LRR compared to the average ≤1 cm node-negative breast cancer based on published data on the effect of tumor size on LRR and DM. Similarly, tumors larger than 5 cm with low RS appear to behave indolently and in a manner consistent with more favorable risk (despite their large size). These findings may have important implications for the tailoring of local-regional treatment strategies.

Discovery of over 200 new and expanded genetic conditions using GeneMatcher

GeneMatcher is a platform through which various stakeholders can connect with others interested in candidate gene findings. GeneDx, a diagnostic laboratory, has utilized GeneMatcher over the last seven years to successfully facilitate connections between clinicians and researchers, generating fruitful research collaborations. Our ultimate goal in reporting candidate gene findings is to amass sufficient evidence to establish novel disease–gene relationships (DGRs), thus providing diagnostic answers to families and clinicians. Our database of over 300,000 clinical exomes has been a major driver of DGR discovery. Our laboratory accounts for over 20% of total GeneMatcher submissions. Largely fueled by GeneMatcher matches, we have published over 200 articles involving new DGRs or expanded phenotypes for known disease‐causing genes in the past three years. These endeavors require commitments to sharing data and dedicating resources to investigate potential matches. Ultimately, GeneMatcher enables collaboration on a broad scale: we are grateful to the clinicians, researchers, patients, and caregivers who have partnered with us to accelerate the pace of DGR discovery. GeneMatcher opens the door to new partnerships, new discoveries, and families finding answers that otherwise may not have been possible.

Use of bilateral prophylactic nipple-sparing mastectomy in patients with high risk of breast cancer

BACKGROUND

Nipple-sparing mastectomy (NSM) is being performed increasingly for risk reduction in high-risk groups. There are limited data regarding complications and oncological outcomes in women undergoing bilateral prophylactic NSM. This study reviewed institutional experience with prophylactic NSM, and examined the indications, rates of postoperative complications, incidence of occult malignant disease and subsequent breast cancer diagnosis.

METHODS

Women who had bilateral prophylactic NSM between 2000 and 2016 were identified from a prospectively maintained database. Rates of postoperative complications, incidental breast cancer, recurrence and overall survival were evaluated.

RESULTS

A total of 192 women underwent 384 prophylactic NSMs. Indications included BRCA1 or BRCA2 mutations in 117 patients (60·9 per cent), family history of breast cancer in 35 (18·2 per cent), lobular carcinoma in situ in 29 (15·1 per cent) and other reasons in 11 (5·7 per cent). Immediate breast reconstruction was performed in 191 patients. Of 384 NSMs, 116 breasts (30·2 per cent) had some evidence of skin necrosis at follow-up, which resolved spontaneously in most; only 24 breasts (6·3 per cent) required debridement. Overall, there was at least one complication in 129 breasts (33·6 per cent); 3·6 and 1·6 per cent had incidental findings of ductal carcinoma in situ and invasive breast cancer respectively. The nipple-areola complex was preserved entirely in 378 mastectomies. After a median follow-up of 36·8 months, there had been no deaths and no new breast cancer diagnoses.

CONCLUSION

These findings support the use of prophylactic NSM in high-risk patients. The nipples could be preserved in the majority of patients, postoperative complication rates were low, and, with limited follow-up, there were no new breast cancers.

Breast cancer in young black women

BACKGROUND

Young age at breast cancer diagnosis is associated with negative prognostic outcomes, and breast cancer in black women often manifests at a young age. This study evaluated the effect of age on breast cancer management and outcomes in black women.

METHODS

This was a retrospective cohort study of all black women treated for invasive breast cancer between 2005 and 2010 at a specialized tertiary-care cancer centre. Clinical and treatment characteristics were compared by age. Kaplan-Meier methodology was used to estimate overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 666 black women were identified. Median BMI was 30 (range 17-56) kg/m² and median tumour size was 16 (1-155) mm. Most tumours were oestrogen receptor-positive (66·4 per cent). Women were stratified by age: less than 40 years (74, 11·1 per cent) versus 40 years or more (592, 88·9 per cent). Younger women were significantly more likely to have a mastectomy, axillary lymph node dissection and to receive chemotherapy, and were more likely to have lymphovascular invasion and positive lymph nodes, than older women. The 5-year OS rate was 88·0 (95 per cent c.i. 86·0 to 91·0) per cent and the 5-year DFS rate was 82·0 (79·0 to 85·0) per cent. There was no statistically significant difference in OS by age (P = 0·236). Although DFS was inferior in younger women on univariable analysis (71 versus 88 per cent; P < 0·001), no association was found with age on multivariable analysis.

CONCLUSION

Young black women with breast cancer had more adverse pathological factors, received more aggressive treatment, and had worse DFS on univariable analysis. Young age at diagnosis was, however, not an independent predictor of outcome.

Applying the Care Group model to tuberculosis control: findings from a community-based project in Mozambique

BACKGROUND

We describe the effectiveness of an innovative community-based social mobilization approach called Care Groups to improve the effectiveness of the national tuberculosis (TB) program by increasing TB testing and improving treatment outcomes in six districts of rural Mozambique.

METHODS

The Care Group approach, which was implemented in a population of 218 191, enabled a facilitator to meet every 6 months with 10-12 community health volunteers (forming a Care Group) to share key TB messages and then for them to convey these messages over the subsequent 6 months to 10-12 households. Three household surveys were performed over 5 years to measure population-level changes in knowledge and behaviors. Data from village TB, laboratory, and district registers were also used to monitor activities and outcomes.

RESULTS

There were substantial improvements in TB-related knowledge and behaviors in the number of patients initiating treatment, in the percentage of patients receiving directly observed treatment, in treatment success, and in TB-related mortality.

CONCLUSION

Care Groups are uniquely suited to address some of the challenges of TB control. This project sheds light on a new strategy for engaging communities to address not only TB, but other health priorities as well.

Abstract P6-13-07: Chemotherapy with and without trastuzumab or no treatment in elderly patients with HER2 amplified breast cancer at a single center

Introduction

Trastuzumab with systemic chemotherapy has shown an improvement in outcomes for patients (pts) with HER2 amplified/overexpressed (HER2+) breast cancer. Pts enrolled onto trials were young with a minority of pts at ≥65 years (yrs) of age. Herein, we report the administration of systemic treatment (ST) (chemotherapy and/or trastuzumab) verus no treatment in elderly pts at a single center.

Methods

Patients ≥65 yrs with stage I-III HER2+ (defined as IHC 3+ or FISH &gt;2.0) breast cancer, treated at Memorial Sloan Kettering Cancer Center between 2000-2012, were retrospectively identified from our database.

Clinicopathologic features were retrieved and co-morbidity indexes (CI) were calculated. Pts were divided by hormone receptor (HR) (defined as ER &gt;10% and/or PR &gt;10%) status into HER2+HR- and HER2+HR+. Each group was further divided by use of ST into: chemotherapy and trastuzumab (CT+T), chemotherapy alone (CT) or no systemic treatment (No Rx). Patients receiving neoadjuvant ST or trastuzumab only as ST were excluded from the KM analysis. Primary objective was to identify patterns of treatment recommendation in the elderly population. We explored disease-free survival (DFS) as estimated using the Kaplan-Meier (KM) method.

Results

We identified 300 pts ≥65 yrs with HER2+ tumors. 128 (42.7%) were HER2+HR- and 172 (57.3%) were HER2+HR+. The median follow-up for all patients was 6.1 years (range, 0.07-16.7).

In the HER2+HR- group, 63 (49.2%) patients received CT+T, 25 (19.5%) CT alone, and 40 (31.3%) had no Rx. Anthracycline based chemotherapy was administered to 57/88 (65%) of patients on CT. Women receiving chemotherapy with or without trastuzumab were younger (65-70 vs &gt;70 years of age) (p=.002) and had more advanced tumor stages (p=.003). Their respective 5-yr DFS KM estimates were 0.84, 0.80, and 0.61 (logrank p=0.06).

In the HER2+HR+ group, 77 (44.8%) patients received CT+T, 22 (12.8%) CT alone, and 73 (42.2%) had no Rx. Anthracycline based chemotherapy was administered to 51/99 (51%) of patients on CT. Endocrine therapy was given to 153/172 (89%) of the total cohort. Women receiving chemotherapy with or without trastuzumab were younger (p&lt;.001), and had higher nuclear grade (NG) (p=.04), more lymphovascular invasion (&lt;.001) and more advanced tumor stages (p=.002). Their respective 5-yr DFS KM estimates were 0.84, 1.00, and 0.83 (log rank p=0.02).

Conclusions

At a single center, in the elderly populations at ≥65 years of age with HER2+ HR- and HER2+HR+ breast cancer, pts who received systemic treatment were younger and had higher stage of disease than those who received no treatment. In an exploratory analysis, there appeared to be a benefit of systemic treatment in pts in the HER+HR- group.

Citation Format: Muhsen S, Dang C, Plitas G, Seier K, Stempel M, Patil S, Morrow M, El-Tamer M. Chemotherapy with and without trastuzumab or no treatment in elderly patients with HER2 amplified breast cancer at a single center [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-13-07.

Abstract P6-13-05: Frequency of delivery of systemic chemotherapy in elderly versus younger patients with triple negative breast cancer

Introduction

Chemotherapy (CT) is the standard of care for most triple negative breast cancer (TNBC). Chemotherapy is less commonly recommended in older than younger patients. We aim to explore the frequency of CT delivered in elderly patients when compared to young patients.

Methods

Patients ≤50yrs and ≥70 yrs with stage I-III TNBC defined as ER &lt;10% PR &lt; 10% HER2 IHC &lt; 3+ or FISH &lt; 2.0 and treated at our institution from 2000-2011 were identified from our institutional breast cancer database. Clinicopathologic features were retrieved and co-morbidity indexes (CI) were calculated. Patients were grouped by age and CT use, and features were compared between groups using chi-square tests. Cause of death was reported as dead of disease (DOD) or dead of other causes (DOC) when available; otherwise, it was recorded as dead of unknown causes (DUC). OS survival was estimated using the Kaplan-Meier (KM) methods. Cumulative incidence functions for competing risks were calculated and compared between groups using Gray's test. Competing risks regression was performed for multivariate analysis.

Results

We identified 901 pts with TNBC; 664 (73.7%) were ≤50yrs and 237 (26.3%) were ≥70 yrs. Median followup is 7 yrs (range, 0-16.8yrs).

Younger women diagnosed with TNBC were more likely to have stronger family history of breast cancer (p&lt;.001), to present with palpable masses (p&lt;.001), higher nuclear grade (NG) (p&lt;.001), larger tumors (p=.04), more involved nodes (p=.01), advanced tumor stage (p=.02) and to receive systemic chemotherapy (&lt;.001). Anthracycline-based chemotherapy was administered to 486 (80.3%) in women ≤50yrs and only to 42 (36.5%) in the ≥70 yrs cohort (p&lt;0.001). Chemotherapy data was missing on 2 pts in ≤50 yrs and 4 pts ≥70 for a total cohort of 662 patients ≤50 yrs and 233 pts ≥70 yrs.

The 5 year rates of DOD were similar between both groups at 10.6% (range, 8.3-13.2) for pts ≤50yrs and 10.8% (range, 7.0-15.4) (p=0.52) for the older group; meanwhile, the 5 year OS rates were significantly different between both groups at 87.5% (range, 84.7-90.0) for pts ≤50yrs and 74.3% (range, 68.2-80.0) (p&lt;.001) for the older group since older women die at higher rates from causes other than disease.

CT was given to 115 (49%) patients of the ≥70 yrs cohort with a selection biased by larger tumors (p&lt;.001) and more advanced stages (p&lt;.001). There was no significant difference however, between tumor size (p=0.47) and stage (p=0.98) when comparing the 609 (92%) pts ≤50 yrs and the 115 (49%) of ≥70 yrs patients who received CT.

When categorized based on age and receipt of CT, in the 662 pts ≤ 50 yrs, 609 (92%) and 53 (8%) received CT vs no CT respectively; in the 233 pts ≥70 yrs, 115 (49%) and 118 (50%) received CT vs no CT; the cumulative incidence curves for DOD were not statistically different for the four groups (p=0.85) at 5 years.

Conclusions

In our series, CT was given to 92% of patients ≤ 50 yrs of age. In the elderly pts ≥ 70 yrs of age, CT was limited to 50% of patients, namely those with worse clinicopathologic features.

Citation Format: Muhsen S, Dang C, Plitas G, Knezevic A, Stempel M, Patil S, Morrow M, El-Tamer M. Frequency of delivery of systemic chemotherapy in elderly versus younger patients 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 P6-13-05.

Abstract ES7-1: Challenges in the management of locoregional recurrence

The increasing trend toward tailoring treatment of the primary breast cancer with limited surgery of both the breast and axilla has increased the challenge of managing locoregional recurrence (LRR). In the era when patients uniformly had axillary dissection, the appropriateness of repeat sentinel node biopsy was not a question. Similarly, the dogma that all ipsilateral breast tumor recurrences must be treated with mastectomy if the breast has been previously irradiated is also being challenged. LRR events are infrequent with modern multi-modality therapy, and there are no randomized trials to address these questions.

Re-operative sentinel node (SN) biopsy after breast conserving surgery therapy (BCT) has been shown to be feasible, with the likelihood of identifying additional SNs related to the number of nodes excised at the time of initial SN biopsy. The accuracy of SN biopsy after mastectomy is less clear. However, the impact of identification of nodal disease on management of LRR is controversial. In a study of 12 patients with isolated chest wall recurrence post mastectomy, 10/12 had successful mapping and 7/10 had an axillary SN. The absence of nodal metastases was an indication to avoid supraclavicular RT (Johnson J. Ann Surg Oncol 2016;23:715). In a study of 83 patients with in breast (n=79) or chest wall recurrence who were clinically node negative, 47 had axillary surgery and 36 did not. At a median of 4.2 years after LR, rates of axillary and non-axillary local recurrence, distant metastases, and death did not differ significantly between groups (Ugras S. Ann Surg Oncol 2016). With the findings of the CALOR trial that systemic chemotherapy is beneficial in the management of LRR, the finding of axillary metastases is less likely to influence systemic therapy than in the past and repeat axillary staging could potentially be avoided.

In the untreated breast, drainage to the contralateral axilla is very rare and contralateral axillary metastases classify a patient as Stage IV. After initial axillary dissection, between 4% and 33% of patients with local recurrence will have contralateral axillary drainage. In a systemic review of 48 cases of contralateral nodal recurrence without other distant metastatic disease, at a mean follow-up of 50.3 months disease free survival was 65% and overall survival 83% after treatment that included both local and systemic therapy (Moossdorff M. Eur J Surg Oncol 2015;41:1128). These findings raise the possibility that in the setting of LR, contralateral axillary metastases should be treated aggressively for cure after excluding distant metastases.

Citation Format: Morrow M. Challenges in the management of locoregional recurrence [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 ES7-1.

Abstract P2-12-03: Impact of the SSO-ASTRO consensus guidelines on invasive margins on the re-excision rate among patients undergoing breast conserving surgery (BCS)

Background: BCS has been historically associated with a high re-excision rate, driven in part by lack of consensus on what constitutes an adequate negative margin. The SSO-ASTRO consensus guideline on invasive margins defined a negative margin as no ink on tumor based on evidence suggesting that more widely clear margins do not further decrease the risk of recurrence, potentially reducing the need for re-excision. In a large nationwide cohort of breast cancer patients undergoing BCS for invasive breast cancer we evaluate the rates of re-excision following BCS before and after the SSO-ASTRO consensus guidelines were disseminated.

Methods: Breast cancer patients undergoing BCS for invasive breast cancer between January 2012 and December 2015 were identified among female beneficiaries in the MarketScan database. Patients receiving chemotherapy before surgery were excluded. Based upon presentation of the guideline recommendations in October 2013, the pre-guideline period was defined from January 2012 to September 2013. On-line publication of the guideline in February 2014 led to definition of the post-guideline period from March 2014 onwards. The peri-guideline period was defined as the time between the pre and post-guideline intervals. Any re-excision or mastectomy within 3 months of initial BCS was identified using ICD-9 or CPT codes. Overall re-excision rates and 95% CI were calculated; groups were compared using X2test. We used a regression model to evaluate the association between pre-peri-post guideline period and re-excision while adjusting for important covariates. Results are expressed as risk ratios (RRs) and 95%CI.

Results: A total of 38,573 patients were included (20,159 in the pre-guideline, 4,607 peri-guideline and 13,807 post-guideline). The overall re-excision rate was 23.9% (95%CI 23.4-24.3). The pre-guideline re-excision rate was 25.3% (95%CI 24.7-29.9) compared to 21.6% (95%CI 20.9-22.3] in the post-guideline period. (p&lt;0.001). The rate of mastectomy as the final surgical procedure was 20.2% in the pre-guideline period and 19.1% in the post-guideline (p=0.15). We observed significant geographic variability by state in the decrease of the re-excision rates. No change in re-excision rates was seen in Mississippi, Vermont, Georgia, Oregon, West Virginia, Arkansas, Oklahoma and Tennessee. An absolute decrease greater than 10% in the re-excision rate was observed in Indiana, Nebraska, Alabama, Maine and Nevada. In the multivariable analysis, patients undergoing BCS in the post-guideline period had a statistically significant decrease in the risk of re-excision compared to patients undergoing surgery in the pre-guideline period (RR=0.87; 95%CI 0.84-0.91; p&lt;0.001).

Conclusions: There has been a statistically significant decrease in the re-excision rate after BCS associated with the time of the dissemination of the SSO-ASTRO consensus guideline on invasive margins. The wide geographical variation observed suggests differences in the adoption rates. Our study confirms the impact that guidelines have modifying patterns of practice, reducing the frequency of unnecessary surgical interventions.

Citation Format: Chavez-MacGregor M, Lei X, Morrow M, Giordano SH. Impact of the SSO-ASTRO consensus guidelines on invasive margins on the re-excision rate among patients undergoing breast conserving surgery (BCS) [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 P2-12-03.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

Abstract P2-02-06: Genetic counseling, germline genetic testing, and impact of results in patients with newly diagnosed breast cancer

The surge in BRCA1/2 and multiple-gene panel testing after a diagnosis of breast cancer has fueled concerns about how genetic testing results will be integrated into patient management. However, there is virtually no research about the timing or extent of genetic counseling before or after testing or the impact of genetic results on bilateral mastectomy (BLM) use since the advent of more widespread testing.

Methods: A population-based sample of 3600 patients newly diagnosed with breast cancer identified by two SEER registries (Georgia and Los Angeles County) were sent surveys two months after surgery (Dx dates 2014-15) about their genetic testing and treatment experiences. Survey information was merged with SEER data. We examined patterns and correlates of counseling and genetic testing and the impact of results on patient preferences for BLM and receipt of BLM.

Results: Among 2388 patients with unilateral breast cancer (response 70%), 697 (29.2%) had elevated pre-test risk of a germline mutation (based on age, family cancer history, ancestry, and tumor subtype). One-quarter of these higher risk patients (25.6%) did not discuss whether to have testing with any provider, 26.1% discussed it with clinicians only, and 48.3% had a visit with a genetic counselor. Half of patients with elevated pre-test risk (51.2%) were tested: 6.6% before diagnosis, 65.4% after diagnosis but before surgery and 28.0% after surgery. Higher risk patients who underwent testing were younger (p&lt;.001) and had higher income (p=.029) but rates did not differ significantly by race, education, insurance, marital status, cancer stage, comorbidities, or geographic site after controlling for all covariates. There was wide variation in the type of professional who discussed test results with patients: discussed with surgeon only (17.8%), medical oncologist only (19.7%), both physicians but no counselor (4.8%), or genetic counselors (56.8%). Among all testers in the total sample (n=667), 54 (9.4%) reported a pathogenic mutation (12.1% of higher risk patients vs 5.7% of low risk patients) and 59 (10.0%) reported a variant of unknown significance (VUS) (10.2% of higher risk patients vs 9.9% of lower risk patients), p=.027 for differences between groups. Two-thirds (60.4%) of patients with pathogenic mutations reported that the test made them more interested in BLM vs 8.8% of those with a VUS, and 11.4% of those with negative tests, p&lt;.001. Two-thirds (69.2%) of those with pathogenic mutations received BLM vs 21.9% of those with VUS and 27.9% of those with negative tests, p&lt;.001.

Conclusions: Many patients newly diagnosed with breast cancer at higher risk of carrying a pathogenic mutation do not receive pre-test counseling or genetic testing and disparities are observed. There is wide variability in the timing of genetic testing after diagnosis and with which clinician the findings are discussed. Taken together, these results suggest that germline genetic testing after a diagnosis of breast cancer is poorly integrated into practice. However, the impact of genetic test results on patient attitudes and receipt of bilateral mastectomy suggests that genetic testing does help target prevention to a patient's future risk for a new primary breast cancer.

Citation Format: Katz SJ, Morrow M, Jagsi R, Kurian A. Genetic counseling, germline genetic testing, and impact of results in patients with newly diagnosed breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-02-06.

Abstract PD5-05: Metabolic obesity, adipose inflammation and aromatase: Potential drivers of breast cancer risk in women with normal body mass index

Background: Elevated body mass index (BMI) is associated with increased risk of postmenopausal breast cancer, which may be partly attributable to an inflammation-aromatase axis. Most individuals with elevated BMI harbor white adipose tissue inflammation (WATi), defined by the presence of crown-like structures in the breast (CLS-B). CLS-B are composed of a dead/dying adipocyte surrounded by CD68+ macrophages. This inflammation is associated with activation of NF-κB and elevated expression of aromatase, which could contribute to tumor development. Additionally, WATi correlates with several circulating changes, including hyperinsulinemia, which increase breast cancer risk. Although breast WATi correlates with rising BMI, it is also present in some normal BMI individuals. Beyond inherited germline syndromes, the etiology of breast cancer in individuals with normal BMI is not well understood. Here we examined the impact of breast WATi on breast aromatase expression and circulating factors in women with normal BMI.

Methods: Non-tumorous breast tissue and fasting blood were collected from 72 women with BMI &lt; 25 kg/m2 undergoing mastectomy at MSKCC. Breast inflammation was detected by the presence of CLS-B using CD68 immunohistochemistry. The primary objective was to determine if breast WATi in normal BMI individuals correlates with elevated aromatase levels in the breast, measured by qPCR, western blotting, immunofluorescence and enzyme activity. Secondary objectives included assessment of breast adipocyte size and circulating metabolic and inflammatory factors.

Results: Breast inflammation was present in 39% of women. Median BMI was 23.0 (range 18.4 to 24.9) in women with breast WATi versus 21.8 (range 17.3 to 24.6) in those without inflammation (P=0.04). Aromatase mRNA expression was positively correlated with WATi (CLS-B/cm2; P=0.002). Those with severe WATi had highest aromatase mRNA levels, compared to those with no or mild WATi (P=0.005). Aromatase protein, assessed by measuring adipose stromal cell-specific immunofluorescence or western blotting, and activity were also higher in CLS-B+ cases compared to CLS-B- (P&lt;0.001). Breast WATi correlated with larger adipocytes (P=0.01) and higher circulating levels of C-reactive protein, leptin, insulin, and triglycerides (P&lt;0.05). Insulin resistance, characterized by the homeostasis model (HOMA2-IR), correlated with breast WATi (P=0.004). Finally, leptin, a known inducer of aromatase and driver of cancer growth, correlated with higher breast aromatase levels (P=0.02) and larger adipocytes (P&lt;0.01).

Conclusions: A metabolically unhealthy state occurs in women with inflamed breast adipose despite having a normal BMI. This subclinical inflammatory state is characterized by elevated aromatase in the breast, insulin resistance, and dysplipidemia. The presence of enlarged adipocytes in the breasts of normal BMI women with inflammation suggests a state of hyperadiposity which could not be predicted based on BMI alone. These findings indicate that normal BMI metabolic obesity may be associated with increased cancer risk. Our results suggest that objective measurements of adiposity rather than BMI may help to identify individuals at increased risk for disease.

Citation Format: Iyengar NM, Brown KA, Zhou XK, Subbaramaiah K, Giri DD, Gucalp A, Howe LR, Zahid H, Bhardwaj P, Wendel NK, Falcone DJ, Morrow M, Wang H, Williams S, Pollak M, Hudis CA, Dannenberg AJ. Metabolic obesity, adipose inflammation and aromatase: Potential drivers of breast cancer risk in women with normal body mass index [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 PD5-05.

Abstract P1-09-14: Breast carcinoma with 21-gene recurrence score lower than 18: Rate of distant metastases in a large series with clinical follow-up

Background: The 21-gene recurrence score (RS) estimates the likelihood of distant recurrence and the benefit from chemotherapy in patients with early-stage node-negative, estrogen receptor (ER)-positive, HER2-negative breast carcinoma. The use of the assay resulted in a substantial reduction in adjuvant chemotherapy usage. In this study, we reviewed the outcome of patients with node-negative, ER+/HER2- breast cancer and low recurrence score treated at our center to further verify the prognostic value of the assay.

Design: We identified breast cancer patients treated at our center between 09/2008 and 08/2013 with ER-positive, HER2-negative breast cancer and known RS. We reviewed clinicopathological characteristics, RS, treatment and outcome data. The Institutional Review Board approved the study.

Results: We identified 1406 consecutive patients with early stage node negative ER+/HER2- breast cancer and low RS [RS 0-10: 510 (36%), RS 11-17: 896 (64%)] in the study period. The median age at breast cancer diagnosis was 56 years (range 22-90). Sixty-three (4%) patients were &lt;40 years old at breast cancer diagnosis. A total of 1362 (97%) patients received endocrine therapy, and 170 (12%) received chemotherapy. The median follow up time was 46 months (range 1-85). Six (0.4%) of the 1406 patients developed biopsy proven distant metastases within 5 years of breast cancer diagnosis, 5 of which were in the RS 11-17 group (Table 1). Three of the 5 patients with RS 11-17 and distant metastases were younger than 40 years old at breast cancer diagnosis. In the RS 11-17 group, the absolute incidence of distant metastases among patients with breast cancer diagnosed at age younger than 40 years old is 7.1% (3/42), whereas the absolute incidence of distant metastases among patients ≥40 years is 0.2% (2/854).

Conclusion: Our results suggest that young age (&lt;40 years old) might be a negative prognostic factor even in patients with low RS. Analysis of data from other studies is necessary to further validate this observation.

Table 1. Clinicopathologic characteristics of the 6 patients with ER-positive, HER2-negative, node-negative breast carcinoma of recurrence score &lt;18 who developed distant metastasisPatients#1#2#3#4#5#6Age at diagnosis (years)505437713839Family history of breast/ ovarian cancerNoYesNoNoNoYesPersonal history of breast carcinomaNoIpsilateral DCISNoIpsilateral DCISNoNoTumor typeILCIDCIDCIDCIDCIDCTumor size (cm)2.11.32.72.31.62.1Tumor Grade222223LVINoNoNoNoYesNoER (%)909595959595PR (%)30585757595Oncotype DX RS51212131417SurgeryBTMTMBTMBCSBCSBTMRadiationNoNoNoYesYesNoEndocrine therapyYesYesYesYesNoYesChemoNoNoCMFNoNoNoTime interval to metastasis (months)584125204812Site of metastasisBoneMultipleLungMultipleMultipleBoneFollow-up (months)725359647142SurvivalAWDAWDAWDDODAWDAWDAbbreviations: RS, recurrence score; ILC, invasive lobular carcinoma; IDC, invasive ductal carcinoma; LVI, lymphovascular invasion; BTM, bilateral total mastectomy; TM, total mastectomy; BCS, breast conserving surgery; CMF, cyclofosphamide, metotrexate and 5-fluorouracil. AWD, alive with disease; DOD, died of disease.

Citation Format: Wen HY, Krystel-¬Whittemore M, Patil S, Pareja F, Bowser ZL, Dickler M, Norton L, Morrow M, Hudis C, Brogi E. Breast carcinoma with 21-gene recurrence score lower than 18: Rate of distant metastases in a large series with clinical follow-up [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 P1-09-14.

Abstract BL2: Changing paradigms in the local therapy of breast cancer: Making less more

The ability of surgery to cure breast cancer has not changed over time. What has changed is that the cancers seen in the screening era are smaller and have fewer nodal metastases, making them more amenable to surgical cure. Only 25% of patients enrolled in the landmark NSABP B-06 trial had cT1N0 disease compared to 80% of those enrolled in NSABP B32, which began 15 years later. At the same time, improved systemic therapy options and a better understanding of tumor biology have led to greater success in treating micrometastatic disease. Systemic therapy is now widespread for early-stage breast cancers and often for longer durations with anti-HER2 therapy given for 12 months and endocrine therapy for 5-10 years. The progressive addition of therapies has increased the burden of treatment for patients at the same time it has improved outcomes. The beneficial effect of systemic therapy on local control and the lower disease burden seen today offer the opportunity to decrease the morbidity of surgery without compromising outcomes. The ACOSOG Z011 trial, now with follow-up of 10 years, demonstrated no difference in locoregional recurrence or survival among patients with metastases in 1–2 sentinel nodes after sentinel node biopsy alone or axillary dissection (ALND) when treated with breast-conserving surgery (BCS) and whole breast irradiation (RT). In 9/2010 we began prospectively utilizing Z11 eligibility criteria in patients with cT1-2 N0 cancers undergoing breast conservation with ALND reserved for those with &gt;2 nodal metastases or gross extracapsular extension. Of the initial 723 consecutive, unselected patients, ALND was avoided in 84%. At a mean follow-up of 33 months (12–68), there were no isolated axillary recurrences. The 5-year Kaplan Meier rate of any nodal recurrence was 98% (95% CI 96–99). In the 251 patients considered “high risk” based on triple negative, HER2+, or age &lt;50 years or a combination of these factors, ALND was required in 15.5% vs 15.9% of postmenopausal, ER+ patients (p=.89). The same principles led us to address the issue of what constitutes an optimal negative margin in women with invasive breast cancer undergoing BCS and RT. After a metaanalysis and review of other relevant literature, an SSO-ASTRO sponsored consensus committee concluded that evidence did not support routinely obtaining margins more widely clear than no ink on tumor, and that adherence to this recommendation, disseminated in late 2013 and published 2/14, had the potential to significantly reduce the use of re-excision. Since that time, the proportion of surgeons in a population-based sample endorsing no ink on tumor as an adequate margin rose to over 60%, compared to 11% in a similar survey conducted in 2006–7. This change in attitude has translated into a reduction in the use of additional surgery, both re-excision and mastectomy after initial lumpectomy. In a SEER sample from 2013–15, this resulted in a 9% absolute increase in the use of BCS during the study period. The use of neoadjuvant therapy offers further opportunities to decrease the morbidity of surgery and individualize local therapy in the future.

Citation Format: Morrow M. Changing paradigms in the local therapy of breast cancer: Making less more [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 BL2.

Abstract P3-13-07: Are there patients with T1-T2, node-negative breast cancer who are high-risk for locoregional recurrence?

Background: Indications for post-mastectomy radiotherapy (PMRT) in T1-T2, node negative (N0) breast cancer patients with “high-risk” features are controversial based on lack of consensus as to what constitutes “high-risk”, and variable results of small retrospective studies. The EORTC 22922 and MA20 trials reporting improved 10-year disease-free survival with nodal irradiation included high-risk N0 patients but these patients were not analyzed separately and did not receive modern systemic therapy. We sought to evaluate long-term locoregional control in T1-T2N0 patients with high-risk features undergoing mastectomy in the contemporary era.

Methods: We retrospectively identified patients with T1-T2N0 breast cancer with ≥1 high-risk feature treated with mastectomy from 1/2006-12/2011. High-risk features were defined as age &lt;40 years, multifocal/multicentric disease, lymphovascular invasion (LVI), medial or central tumor location, and high nuclear grade. The primary outcome of interest was rate of LRR.

Results: Among 672 patients meeting inclusion criteria, 187 (28%) had 1 risk factor: 21 (3%) were age &lt;40 years, 132 (20%) were multifocal/multicentric, and 34 (5%) had LVI; 449 (67%) patients had ≥2 high-risk features, and 36 patients with unknown grade were excluded from risk analysis. PMRT was received by only 15 (2%) patients. Clinicopathologic characteristics of the 657 patients treated without PMRT are shown in Table 1.

Table 1: Clinicopathologic characteristics, n = 657 Median (Range)Age, years49 (24-89)Tumor size, cm1.4 (&lt;0.1-5.0) n (%)Ductal histology566 (86%)High nuclear grade*266 (40%)LVI232 (35%)Multifocal/multicentric447 (68%)Medial/central tumor226 (34%)Receptor status** ER+/HER2-438 (67%)HER2+123 (19%)ER-/HER2-70 (11%) n (%)Rate of LRR# of risk factors*  1183 (28%)3.8%2265 (40%)5.3%3143 (22%)4.9%4 or 532 (5%)9.4%*Unknown grade in 34 cases, excluded from risk analysis **Unknown receptor status in 26 cases

Sentinel node biopsy alone was performed in 98% of these patients. A median of 4 lymph nodes were retrieved (range 1-15). Adjuvant systemic therapy was received by 86% of patients. At median 5.6 years of follow-up, overall LRR rate was 4.7% (n = 31), with the majority (55%) of events involving the chest wall. Increasing tumor size was associated with LRR (HR 1.70, 95% CI 1.26–2.29, p = 0.006), while age, histology, grade, subtype, LVI, multifocality/multicentricity, and tumor location were not (all p &gt; 0.05). Although rate of LRR increased from 3.8% to 9.4% with 1 vs. ≥4 high-risk features, a comparison of 1 vs. 2 vs. 3 vs. ≥4 risk factors was not significant by Kaplan-Meier estimation (p = 0.54).

Conclusions: A low LRR rate of 4.7% was seen in this large unselected cohort of T1-T2N0 cancers with "high-risk" features treated by mastectomy and systemic therapy without PMRT. While increasing tumor size was predictive, other features did not confer a higher risk of LRR either independently or together, and do not by themselves mandate the use of PMRT in this population.

Citation Format: Mamtani A, Patil S, Stempel M, Morrow M. Are there patients with T1-T2, node-negative breast cancer who are high-risk for locoregional recurrence? [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 P3-13-07.

Abstract P4-04-11: Preferential expression of the chemokine receptor 8 (CCR8) on regulatory T cells (Treg) infiltrating human breast cancers represents a novel immunotherapeutic target

Treg cells are identified by the expression of the transcription factor FoxP3 and preserve immune homeostasis by the establishment and maintenance of peripheral tolerance. This suppressive function however, limits anti-tumor immune responses and represents a critical obstacle to immunotherapy. Safely targeting Treg cells will require selective elimination of tumor infiltrating Treg cells, as systemic depletion will lead to immune related adverse events. We hypothesize that differential gene expression analysis of Treg cells isolated from human breast tumors and peripheral blood will identify a tumor specific means to target Treg cells for the immunotherapy of breast cancer.

Methods: Tumor infiltrating lymphocytes were isolated from fresh operative specimens of patients undergoing surgery for primary invasive breast carcinoma. Lymphocytes were also isolated from normal breast tissue and peripheral blood buffy coat. T cell subsets including Treg cells were isolated by fluorescent activated cell sorting and analyzed by RNAseq. Mixed bone marrow chimeric mice were generated by reconstituting irradiated immunodeficient mice with a mixture of CCR8-/- + FoxP3-/- or CCR8+/+ + FoxP3-/- bone marrow, thus creating mice with Treg cells lacking CCR8 and controls.

Results: We found that Treg cells are more prevalent in breast tumors as opposed to normal breast tissue regardless of the biologic subtype of breast cancer (p&lt;0.05). Gene expression profiling of Treg cells and CD4 T cells isolated from tumor or blood revealed a distinct tumor Treg cell gene signature. This signature was enriched for cytokine binding and chemokine receptor GO categories (FDR&lt;0.005). Specifically, we identified CCR8 to be differentially and robustly expressed on tumor infiltrating Treg cells. This was validated by flow cytometry on over 50 primary breast cancers where the mean florescence intensity of CCR8 on Treg cells was at least twice that observed on conventional CD4 T cells (p&lt;0.05). CCR8 expression on Treg cells also significantly correlated with higher-grade cancers (p&lt;0.05). Using a data set generated by the Cancer Genome Atlas, we found that a high CCR8/FOXP3 gene expression ratio is strongly associated with worse disease free and overall survival of breast cancer (p&lt;0.001) patients while FOXP3 gene expression level alone does not predict disease outcome. To investigate the role of CCR8 expression on Treg cells in a preclinical murine model of mammary carcinogenesis, we implanted syngeneic polyoma middle-T antigen-driven breast cancer cells in the mammary fat pads of mixed bone marrow chimeric mice in which Treg cells lack CCR8 expression. CCR8 deficiency in Treg cells significantly decreased primary tumor progression and distant metastases without any overt immunopathology (p&lt;0.05).

Conclusions: Treg cells infiltrate human breast cancers and suppress anti-tumor immune responses. Our results demonstrate that CCR8 is selectively expressed by human breast cancer infiltrating Treg cells. Targeting CCR8 represents a promising immunotherapeutic approach for the treatment of patients with breast cancer. Depleting CCR8 antibodies are currently in development for additional preclinical and human studies.

Citation Format: Plitas G, Konopacki C, Wu K, Paula B, Morrow M, Rudensky A. Preferential expression of the chemokine receptor 8 (CCR8) on regulatory T cells (Treg) infiltrating human breast cancers represents a novel immunotherapeutic target. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-04-11.

Nipple-sparing mastectomy in patients with BRCA1/2 mutations and variants of uncertain significance

BACKGROUND

Nipple-sparing mastectomy (NSM) is associated with improved cosmesis and is being performed increasingly. Its role in BRCA mutation carriers has not been well described. This was a study of the indications for, and outcomes of, NSM in BRCA mutation carriers.

METHODS

BRCA mutation carriers who underwent NSM were identified. Details of patient demographics, surgical procedures, complications, and relevant disease stage and follow-up were recorded.

RESULTS

A total of 177 NSMs were performed in 89 BRCA mutation carriers between September 2005 and December 2013. Twenty-six patients of median age 41 years had NSM for early-stage breast cancer and a contralateral prophylactic mastectomy. Mean tumour size was 1·4 (range 0·1-3·5) cm. Sixty-three patients of median age 39 years had prophylactic NSM, eight of whom had an incidental diagnosis of ductal carcinoma in situ. There were no local or regional recurrences in the 26 patients with breast cancer at a median follow-up of 28 (i.q.r. 15-43) months. There were no newly diagnosed breast cancers in the 63 patients undergoing prophylactic NSM at a median follow-up of 26 (11-42) months. All patients had immediate breast reconstruction. Five patients (6 per cent) required subsequent excision of the nipple-areola complex for oncological or other reasons. Skin desquamation occurred in 68 (38·4 per cent) of the 177 breasts, and most resolved without intervention. Debridement was required in 13 (7·3 per cent) of the 177 breasts, and tissue-expander or implant removal was necessary in six instances (3·4 per cent).

CONCLUSION

NSM is an acceptable choice for patients with BRCA mutations, with no evidence of compromise to oncological safety at short-term follow-up. Complication rates were acceptable, and subsequent excision of the nipple-areola complex was rarely required.

Abstract P2-03-03: Feasibility of evaluation of breast tissue using confocal microscopy with strip mosaicing

Background: Confocal microscopic strip mosaicing (CSM) provides noninvasive optical sectioning and high resolution, which allows for imaging of nuclear and morphological detail in freshly excised tissue. CSM can image large areas of tissue at micron-level resolution in minutes, which may offer an advantage over standard histology that requires days. We have conducted a preliminary investigation of the feasibility of this technology for the evaluation of breast tissue from surgical excision specimens.

Design: In a prospective study, 80 fresh human breast tissue samples from surgical excision specimens of 24 patients were imaged using a prototype confocal strip scanner. Fresh tissue specimens were immersed in Acridine Orange (AO) for 45 seconds to stain the nuclei, then pressed against the glass imaging window and imaged with a 30X, 0.75 numerical aperture (measured) objective lens and a 488 nm laser. Images were acquired in two modes of contrast: in fluorescence (with AO), showing nuclear morphology, and in reflectance (endogenous), showing stroma. The use of fluorescence for nuclear staining mimics the use of hematoxylin in pathology, and the use of reflectance eosin. Use of two contrast modes allows the fluorescence image to be colorized purple and the reflectance image pink, producing confocal strip mosaics that mimic H&E histology in appearance. Specimens were subsequently fixed in formalin and routinely processed to obtain H&E stained sections. H&E and confocal images were compared by the study pathologist (M.M.)

Results: Freshly excised breast tissue samples as large as 2 cm x 2 cm were imaged in less than five minutes, with 1-micron resolution and measured optical sectioning of 6 microns. We compared the CSM images against standard histopathology images. In our series we evaluated the following histologies: 12 invasive carcinoma (11 ductal, 1 lobular), 3 ductal carcinoma in-situ, 3 lobular carcinoma in situ, 1 atypical lobular hyperplasia, 1 atypical ductal hyperplasia and various benign lesions such as fat necrosis, fibrocystic changes, and ductal hyperplasia. In confocal images invasive and in situ carcinoma as well as benign ducts and lobules were distinguished from surrounding stromal tissue. Limitations that are typically encountered in standard histology, such as distinguishing low grade ductal carcinoma in situ (DCIS) from lobular carcinoma in situ (LCIS) or atypical proliferations were encountered in the grayscale confocal images as well.

Conclusion: In this initial feasibility study, CSM produced images that could be diagnosed as benign or neoplastic by the study pathologist. Further study is needed to build an image library of breast histology and compare reproducibility of histologic diagnoses between CSM (grayscale and colorized images) and traditional optical microscopy, and assess interobserver reproducibility in diagnosis. CSM potentially provides rapid and noninvasive evaluation of breast parenchyma, and has a potential application for intraoperative margin assessment of resected breast specimens.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-03-03.

Abstract AL-2: William L. McGuire memorial lecture – Local therapy in the molecular era: Relevant or relic?

Surgery has always been driven by disease burden; initially, to determine operability, and recently, to select patients for BCT. Systemic therapy also initially relied on disease burden (axillary nodes, tumor size), but gene profiles and molecular targets now predominate in selecting systemic therapy.

Reliance on disease burden as a determinant of the intensity of local therapy is problematic as advanced imaging modalities and molecular pathology allow detection of increasingly smaller tumors. The application of management strategies proven beneficial for macroscopic tumor to subclinical disease has the potential for overtreatment as evidenced by increased mastectomy rates in patients undergoing preoperative MRI, and use of ALND and chemotherapy for sentinel node micrometastases. It is an appropriate time to ask how recognition of molecular subtypes and improvements in systemic therapy can be leveraged to improve local therapy outcomes and decrease the burden of therapy.

Recognition that systemic therapy results in a major decrease in the rate of IBTR was the major impetus for SSO and ASTRO to commission a systemic review on margins for BCT in stage I and II breast cancer as the evidence base for a consensus conference. We concluded that evidence that margins more widely clear than no ink on tumor significantly improve local control was lacking and the routine practice of obtaining more widely clear margins is not indicated. Adoption of this approach has the potential to spare many women unnecessary surgery. The morbidity of ALND can also be avoided in many patients. The ACOSOG Z0011 trial showed no benefit to ALND for patients with 1 or 2 sentinel node metastases receiving WBRT and systemic therapy. There were many criticisms of this study, but 3 other prospective randomized trials (NSABP B04, NSABP B32, IBCSG 2013) demonstrate that residual axillary nodal disease does not translate to regional recurrence or a decrease in survival in a 1:1 ratio, and that systemic therapy greatly reduces the incidence of regional recurrence. In a prospective study of the applicability of Z0011 findings to an unselected population of women meeting study eligibility criteria, we found that only 16% of 287 consecutive patients had metastases in ≥3 sentinel nodes or matted nodes identified intraoperatively, sparing 84% ALND. These examples represent initial steps in reducing the morbidity of local therapy. Moving forward, it is appropriate to ask whether patients with favorable molecular profiles (luminal A), require the same local therapy as those with other molecular subtypes. More controversially, the success of HER2 blockade in improving survival raises the question of whether effective targeted therapy could allow a reduction in local therapy intensity. A major barrier to progress is the belief of many clinicians and patients that bigger surgery is better surgery. The full realization of multidisciplinary care will occur when improvements in outcomes with one modality result in studies examining the elimination of other treatments which may no longer be beneficial to patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr AL-2.

Abstract P2-19-01: Impact of breast reconstruction approach on patient-reported satisfaction with cosmetic outcomes after mastectomy with and without radiotherapy

Background: The optimal approach to combining breast reconstruction with post-mastectomy radiation (RT) remains hotly debated. We evaluated the comparative effectiveness of different approaches using patient-reported outcomes from a longitudinal survey of patients identified through population-based registries.

Methods: We conducted a multicenter cohort study of women diagnosed with stage 0-III breast cancer from 2005-07, as reported to the Los Angeles and Detroit SEER registries. We surveyed 2290 women approximately 9 months after diagnosis and again after 4 years (n = 1536). The primary dependent variable was a composite measure of satisfaction with the cosmetic outcomes of reconstruction derived from 5 items (range 1-5; Cronbach's alpha 0.91). A linear regression model evaluated the impact of reconstruction type and timing, as well as interaction with RT, controlling for age, education, and marital status, after selection from a variety of sociodemographic and clinical variables (race/ethnicity chemotherapy, contralateral mastectomy, cancer stage, comorbidities, smoking, body-mass index, bra cup size, and geographic site).

Results: Of the 1450 patients who responded to both surveys and had not recurred, 222 received mastectomy and reconstruction, of whom 201 had complete variable information. There were 53 patients who had RT (among whom 53% had autologous technique and 47% had delayed timing) and 148 who did not (among whom 23% had autologous technique and 29% had delayed timing). Patients who received autologous reconstruction vs implants reported higher cosmetic satisfaction. Receipt of RT was associated with lower satisfaction. The adjusted scaled satisfaction score was 4.39 for patients receiving autologous reconstruction without RT, 4.09 for patients receiving autologous reconstruction and RT, 3.86 for patients receiving implant reconstruction without RT, and 2.71 for patients receiving implant reconstruction and RT. Patients who received RT and implant-based reconstruction had significantly lower satisfaction than the other 3 groups. Timing of reconstruction was not significantly associated with satisfaction, nor was there a significant interaction between timing and RT.

Linear Regression Model of Satisfaction with Reconstruction Outcomes (n = 201)CharacteristicCoefficient95% CIpIntercept3.86(3.37,4.35)&lt;0.001Recon type & RT status  &lt;0.001Autologous, no RT0.53(0.06,1.00) Autologous with RT0.23(-0.30,0.75) Implant, no RT00 Implant with RT-1.15(-1.84,-0.47) Reconstruction timing  0.97Immediate0.009(-0.44,0.45) Delayed00 Age (centered on 60)-0.02(-0.05, -0.001)0.04Married/partnered  0.06Yes-0.40(-0.82,0.02) No00 Education  0.35HS or less-0.23(-0.70,0.24) Some college-0.32(-0.77,0.13) College or more00 

Conclusions: In patients undergoing post-mastectomy RT, use of autologous reconstruction may mitigate some of the deleterious impact on cosmetic outcomes, but this requires confirmation in a larger dataset. This study had limited power to evaluate whether delaying reconstruction preferentially benefits radiated patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-19-01.

Abstract P1-06-03: Validating the link between obesity and breast inflammation in women with breast cancer (BC)

Background: In post-menopausal women, obesity is a risk factor for the development of BC that expresses the estrogen and progesterone receptors (ER/PR). In mouse models of obesity, we previously described crown-like structures (CLS), consisting of macrophages surrounding dead adipocytes in white adipose tissue (WAT) of the mammary gland, which were associated with increased levels of proinflammatory mediators known to be involved in carcinogenesis. We translated these findings to women (n = 30), and provided the first evidence of CLS in the human breast (CLS-B). The presence and severity of CLS-B (CLS-B index) correlated with elevated body mass index (BMI), increased adipocyte size, activation of NF-κB, and increased levels of proinflammatory mediators (TNF-α, IL-1β, COX-2 and PGE2) and aromatase. We expanded our population to prospectively validate these preliminary findings.

Methods: We prospectively collected WAT from women undergoing breast and reconstructive surgery. WAT was subjected to immunohistochemistry for CD68, a macrophage marker, to detect CLS-B by light microscopy. Adipocyte diameter was measured on photomicrographs using the Canvas 11 Software. Endpoints were 1) CLS-B presence/absence and 2) CLS-B index (proportion of slides with CLS-B). Associations between CLS-B and clinicopathologic features were analyzed using logistic regression and Fisher's exact test.

Results: From 04/2010-02/2012, WAT (100 mastectomy and 5 abdominal reconstructions) was obtained from 101 women; median age 49 (range 26-80). CLS-B were found in 54 (53%) patients (pts). CLS-B were seen in 9/37 (24%) normal weight pts (BMI &lt;25), 23/39 (59%) overweight pts (BMI 25-29.9), and 22/25 (88%) obese pts (BMI ≥30). Pts with CLS-B had significantly larger average adipocyte diameter (106.5 +/- 11.5 microns) compared to those without CLS-B (91.5 +/- 16.1 microns; p&lt;0.001). Consistently, CLS-B index correlated with BMI (p&lt;0.001) and adipocyte size (p&lt;0.001). Breast inflammation was seen in pts with all tumor phenotypes: CLS-B were seen in 24/41 (59%) pts with ER/PR+, HER2- tumors; 7/16 (44%) pts with HER2+ tumors; and 3/10 (30%) pts with ER/PR/HER2- tumors. A higher CLS-B index was seen in WAT from ER+ tumors, but this was not statistically significant (p = 0.08). Regular use of nonsteroidal antiinflammatory drugs was protective against CLS-B (p = 0.17 for association with CLS-B, and p = 0.04 for association with CLS-B index in multivariable analyses). Among 25 pts with bilateral breast WAT, concordant CLS-B findings (+/-) were found in 20 (80%) pts. Among pts with paired breast and abdominal WAT, concordant findings were seen in 4/5 (80%) pts.

Conclusions: Findings from this prospective study, the largest reported to date, extend our previous observation that CLS-B are associated with BMI and adipocyte size. These results provide a plausible pathophysiological link between obesity and BC. Breast inflammation occurs in association with all BC phenotypes. Preliminary data suggest concordance between breasts and between abdominal and breast WAT. Hence, abdominal WAT may prove useful as a surrogate for breast WAT; biopsies of abdominal subcutaneous WAT are more easily done, which could prove useful in developing interventions to attenuate WAT inflammation.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-06-03.