Should breast surgery be considered for patients with de novo metastatic inflammatory breast cancer?

INTRODUCTION

We aimed to identify factors predicting surgery for de novo stage IV inflammatory breast cancer (IBC) and determine the association of surgery with overall survival (OS).

METHODS

Female patients with unilateral AJCC clinical stage IV IBC treated 2010-2018 in the NCDB were identified. Logistic regression and multivariable proportional Cox hazards regressions determined factors associated with treatment and OS.

RESULTS

Of 1049 patients, 29.1% underwent breast surgery (BS) and 70.9% had no surgery (NS). Increasing age and more recent treatment year were significantly associated with NS. 2-Year OS was superior in BS patients (71% vs 38% NS). Single-site and bone-only metastasis had no association with treatment type or OS.

CONCLUSION

Contrary to guidelines, 1/3 of de novo stage IV IBC patients underwent BS, and had an independent OS benefit irrespective of extent or site of metastasis. Further research is needed to determine which patients with stage IV IBC should undergo BS.

Using MammaPrint on core needle biopsy to guide the need for axillary staging during breast surgery

BACKGROUND

At present, the only opportunity to omit axillary staging is with Choosing Wisely criteria for women ages >70 y with cT1 2N0 estrogen receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. However, many women are diagnosed when pathologic node status-negative, raising the question of additional opportunities to omit sentinel lymph node biopsy. We sought to investigate the association between MammaPrint, a genomic test that estimates estrogen receptor-positive breast cancer recurrence risk, and pathologic node status, with the aim that low-risk MammaPrint could be considered for omission of sentinel lymph node biopsy if associated with pathologic node status-negative.

METHODS

A single-institution database was queried for all women with cT1 2N0 estrogen receptor-positive/human epidermal growth factor receptor 2-negative invasive breast cancer with breast surgery as their first treatment and MammaPrint performed from 2020 to 2021. Patient and tumor factors, including MammaPrint score, were compared with axillary node status for correlation.

RESULTS

A total of 668 women met inclusion criteria, with a median age of 66 y. MammaPrint was low-risk luminal A in 481 (72%) and high-risk luminal B in 187 (28%). At the time of breast surgery, 588 (88%) had sentinel lymph node biopsy, 27 (4%) had axillary lymph node dissection, and 53 (7.9%) had no axillary staging. Most women in both the pathologic node status-negative and pathologic node status-positive cohorts had low-risk MammaPrint (355 [73.3%] pathologic node status-negative vs 91 [69.5%] pathologic node status-positive), and women with low-risk MammaPrint did not have a significantly lower risk of pathologic node status-positive (P = .377).

CONCLUSION

Low-risk MammaPrint does not predict lower risk of pathologic node status-positive breast cancer. Based on our results, genomic testing does not appear to provide additional personalization for the ability to omit sentinel lymph node biopsy for patients outside of the Choosing Wisely guidelines.

Validation of the PREDICT Prognostication Tool in US Patients With Breast Cancer

BACKGROUND

PREDICT is an online prognostication tool derived from breast cancer registry information on approximately 6,000 women treated in the United Kingdom that estimates the postsurgical treatment benefit of surgery alone, chemotherapy, trastuzumab, endocrine therapy, and/or adjuvant bisphosphonates in early-stage breast cancer. Our aim was to validate the PREDICT algorithm in predicting 5- and 10-year overall survival (OS) probabilities using real-world outcomes among US patients with breast cancer.

METHODS

A retrospective study was performed including women diagnosed with unilateral breast cancer in 2004 through 2012. Women with primary unilateral invasive breast cancer were included. Patients with bilateral or metastatic breast cancer, no breast surgery, or missing critical clinical information were excluded. Prognostic scores from PREDICT were calculated and external validity was approached by assessing statistical discrimination through area under time-dependent receiver-operator curves (AUC) and comparing the predicted survival to the observed OS in relevant subgroups.

RESULTS

We included 708,652 women, with a median age of 58 years. Most patients were White (85.4%), non-Hispanic (88.4%), and diagnosed with estrogen receptor-positive breast cancer (79.6%). Approximately 50% of patients received adjuvant chemotherapy, 67% received adjuvant endocrine therapy, 60% underwent a partial mastectomy, and 59% had 1 to 5 axillary sentinel nodes removed. Median follow-up time was 97.7 months. The population's 5- and 10-year OS were 89.7% and 78.7%, respectively. Estimated 5- and 10-year median survival with PREDICT were 88.3% and 73.8%, and an AUC of 0.77 and 0.76, respectively. PREDICT performed most poorly in patients with high Charlson-Deyo comorbidity scores (2-3), where PREDICT overestimated OS. Sensitivity analysis by year of diagnosis and HER2 status showed similar results.

CONCLUSIONS

In this prognostic study utilizing the National Cancer Database, the PREDICT tool accurately predicted 5- and 10-year OS in a contemporary and diverse population of US patients with nonmetastatic breast cancer.

Summary: Appropriate Use Criteria for Lymphoscintigraphy in Sentinel Node Mapping and Lymphedema/Lipedema

Expert representatives from 11 professional societies, as part of an autonomous work group, researched and developed appropriate use criteria (AUC) for lymphoscintigraphy in sentinel lymph node mapping and lymphedema. The complete findings and discussions of the work group, including example clinical scenarios, were published on October 8, 2022, and are available at https://www.snmmi.org/ClinicalPractice/ content.aspx?ItemNumber=42021. The complete AUC document includes clinical scenarios for scintigraphy in patients with breast, cutaneous, and other cancers, as well as for mapping lymphatic flow in lymphedema. Pediatric considerations are addressed. These AUC are intended to assist health care practitioners considering lymphoscintigraphy. Presented here is a brief overview of the AUC, including the rationale and methodology behind development of the document. For detailed findings of the work group, the reader should refer to the complete AUC document online.

Racial-ethnic variations in phyllodes tumors among a multicenter United States cohort

BACKGROUND AND OBJECTIVES

Previous studies have identified racial-ethnic differences in the diagnostic patterns and recurrence outcomes of women with phyllodes tumors (PT). However, these studies are generally limited in size and generalizability. We therefore sought to explore racial-ethnic differences in age, tumor size, subtype, and recurrence in a large US cohort of women with PT.

METHODS

We performed an 11-institution retrospective review of women with PT from 2007 to 2017. Differences in age at diagnosis, tumor size and subtype, and recurrence-free survival according to race-ethnicity.

RESULTS

Women of non-White race or Hispanic ethnicity were younger at the time of diagnosis with phyllodes tumor. Non-Hispanic Other women had a larger proportion of malignant PT. There were no differences in recurrence-free survival in our cohort.

CONCLUSIONS

Differences in age, tumor size, and subtype were small. Therefore, the workup of young women with breast masses and the treatment of women with PT should not differ according to race-ethnicity. These conclusions are supported by our finding that there were no differences in recurrence-free survival.

Abstract P2-14-05: Patient rather than tumor factors predict contralateral prophylactic mastectomy for inflammatory breast cancer

Introduction: Inflammatory breast cancer (IBC) is an aggressive form of breast cancer with best outcomes result-ing from trimodality therapy: neoadjuvant chemotherapy (NAC), modified radical mastectomy (MRM), and radiation (PMRT). Contralateral prophylactic mastectomy (CPM) is generally discour-aged at the time of MRM due to poor prognosis. Our aim was to identify factors associated with CPM for IBC and determine its relationship with overall survival (OS). Methods: The National Cancer Database was used to identify female patients with AJCC stage IIIC unilateral IBC (cT4d and inflammatory histology code) treated 2004-2018. Patients were stratified by mastec-tomy type: unilateral mastectomy (UM) was defined as MRM or simple mastectomy, and CPM was defined as UM + CPM. Logistic regression identified factors associated with mastectomy type, and multivariable proportional Cox hazards regression identified factors associated with OS. A subset analysis of patients receiving NAC compared complete pathologic response (pCR) between mastec-tomy groups. Results: Of the 2,837 patients with non-metastatic IBC, 2,013 (70.2%) underwent UM and 855 (29.8%) had CPM. The CPM group was significantly younger than the UM group (mean age 52 vs. 56.6 years, p=0.028), more frequently identified as Non-Hispanic White (79.7% vs. 70.1%, p< 0.001), and had private insurance (66.9% vs. 55.6%, p< 0.001). Nearly all patients received chemotherapy and over 80% were treated with NAC. Receipt of PMRT did not differ by mastectomy type (80% for UM and CPM). On multivariable logistic regression, patients age < 40 were more likely to undergo CPM than UM (OR 3.7, 95% CI 1.61-8.5, p< 0.002). Patients with age >70, Hispanic ethnicity, and public insur-ance were significantly less likely to receive CPM (all p≤0.002). On multivariable Cox regression ad-justed for patient, tumor, and treatment factors, CPM was not associated with OS benefit (HR 0.86, 95% CI 0.73-1.02, p=0.08). Higher histologic grade, node-positive disease, and greater co-morbidity were associated with poorer OS, while receipt of chemotherapy and PMRT improved OS. In the subset of NAC patients, overall pCR did not differ significantly by mastectomy type (CPM 22.3%, UM 19.4%, p=0.26). When included in multivariable models, pCR rates were not predictive of CPM de-spite being associated with improved OS. Conclusion: Nearly 30% of IBC patients undergo CPM despite discouragement by guidelines. Demographic char-acteristics – particularly age < 40 – predicted CPM, suggesting patient preferences and access to care affect surgical decisions. As expected, trimodality therapy and favorable NAC response im-proved oncologic outcomes, but CPM had no association with OS. While CPM may be chosen for risk reduction and symmetry, patients should be counseled that it does not improve survival for IBC.

Citation Format: Lauren M. Drapalik, Amanda L. Amin, Ashley Simpson, Lisa Rock, Mary Freyvogel, Robert Shenk, Megan E. Miller. Patient rather than tumor factors predict contralateral prophylactic mastectomy for inflammatory breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-14-05.

Modeling the COVID Pandemic: Do Delays in Surgery Justify Using Stereotactic Radiation to Treat Low-Risk Early Stage Non-Small Cell Lung Cancer?

INTRODUCTION

It was suggested that stereotactic radiation (SBRT) is an "alternative if no surgical capacity is available" for non-small cell lung cancer (NSCLC) care during the COVID-19 pandemic. The purpose of this study was to compare the oncologic outcomes of delayed surgical resection and early SBRT among operable patients with early stage lung cancer.

METHODS

The National Cancer Database was queried for patients with cT1aN0M0 NSCLC who underwent surgery or SBRT (2010-2016) with no comorbidity. Patients with any comorbidities or age >80 were excluded. The outcome of interest was overall survival. Delays in surgical care were modeled using different times from diagnosis to surgery. A 1:1 propensity match was performed and survival was analyzed using multivariable Cox regression.

RESULTS

Of 6720 healthy cT1aN0M0 NSCLC patients, 6008 (89.4%) received surgery and 712 (10.6%) received SBRT. Among surgery patients, time to surgery >30 d was associated with inferior survival (HR > 1.4, P ≤ 0.013) compared with patients receiving surgery ≤14 d. Relative to SBRT, surgery demonstrated superior survival at all time points evaluated: 0-30 d, 31-60 d, 61-90 d, and >90 d (all P < 0.001). Among a propensity-matched cohort of 256 pairs of patients, delayed surgery (>90 d) remained association with better overall survival relative to early SBRT (5-year survival 76.9% versus 32.3%, HR = 0.266, P < 0.001).

CONCLUSIONS

Although longer time to surgery is associated with inferior survival among surgery patients, delayed surgery is superior to early SBRT. Surgical resection should remain the standard of care to treat operable early stage lung cancer despite delays imposed by the COVID-19 pandemic.

Abstract P6-01-02: Using MammaPrint on Core Needle Biopsy to Guide Neoadjuvant Chemotherapy for Invasive Breast Carcinoma

Introduction: MammaPrint, a 70-gene assay used to predict breast cancer recurrence, is typically obtained on the surgical specimen to guide the use of adjuvant chemotherapy. However, MammaPrint results obtained at the time of diagnosis on core biopsy specimen could allow consideration of neoadjuvant chemotherapy (NAC), particularly for tumors that may not traditionally be considered for NAC such as invasive lobular carcinoma (ILC). We hypothesized that MammaPrint scores correlate with pathologic complete response (pCR) and can predict NAC response independent of histology type.

Methods: The National Cancer Database was used to identify patients with AJCC Stage I-III unilateral HR+/HER2- breast cancer with MammaPrint scores treated 2010-2018. Patients were stratified by histology: invasive ductal carcinoma (IDC) and ILC; and by MammaPrint score for 5-year breast cancer recurrence: Low Risk (1%) and High Risk (12%). Descriptive statistics identified clinical and treatment differences between groups. Logistic regression was used to identify factors associated with chemotherapy receipt and sequence. A subset analysis of patients receiving NAC compared pCR rates by MammaPrint score and histology type.

Results: Of 10,999 patients, 9,351 (85%) were diagnosed with IDC and 1,648 (15%) with ILC. ILC were larger at presentation: 40% of ILC were cT2 or greater vs. 29% of IDC (p&lt; 0.001). However, 90% of patients in both groups had cN0 disease. The majority of ILC were grade II (67% ILC vs. 52% IDC, p&lt; 0.001). High Risk MammaPrint scores were significantly more common in IDC tumors: 44% IDC vs 25% ILC (p&lt; 0.001). Mastectomy and axillary lymph node dissection (ALND) were performed more often for ILC than IDC (unilateral mastectomy 32% vs. 21%, bilateral mastectomy 17% vs. 12%, ALND 29% vs. 24%; all p&lt; 0.001). Conversely, chemotherapy (38% vs. 30%, p&lt; 0.001) and radiation (69% vs. 64%, p&lt; 0.001) were more frequently used to treat IDC than ILC. In the subset analysis of patients who received NAC (n = 715), tumors with High Risk MammaPrint scores had more favorable in-breast and axillary responses than those with Low Risk scores for both ILC and IDC (Table 1). Furthermore, only tumors with High Risk Mammaprint scores achieved an overall pCR: 7% IDC and 5% ILC. There were no significant differences in pCR rates by histology type. On multivariable logistic regression, High Risk MammaPrint score was positively associated with the receipt of NAC (OR 4.3, p&lt; 0.001) and adjuvant chemotherapy (OR 24.8, p&lt; 0.001). NAC, adjuvant chemotherapy, and any chemotherapy were also strongly associated with node-positive disease and tumor size &gt;2cm, but not IDC vs. ILC histology.

Conclusions: Superior response to NAC was observed in tumors with High Risk MammaPrint score regardless of histology type, indicating a correlation between pCR rates and genomic assay results. Greater use of NAC guided by High Risk Mammaprint score obtained on core needle biopsy may allow patients with invasive breast cancer to undergo less extensive breast and axillary surgery. Further prospective studies using MammaPrint testing on core biopsy specimens could validate these findings in clinical practice.

Table 1. Response to neoadjuvant chemotherapy by MammaPrint score for patients with Invasive breast carcinoma, NCDB 2010–2018

Citation Format: Lauren M. Drapalik, Rashi Singh, Ashley Simpson, Lisa Rock, Robert Shenk, Amanda L. Amin, Megan E. Miller. Using MammaPrint on Core Needle Biopsy to Guide Neoadjuvant Chemotherapy for Invasive Breast Carcinoma [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-02.

Detection of SARS-CoV-2 RNA in wastewater and comparison to COVID-19 cases in two sewersheds, North Carolina, USA

Wastewater surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be useful for monitoring population-wide coronavirus disease 2019 (COVID-19) infections, especially given asymptomatic infections and limitations in diagnostic testing. We aimed to detect SARS-CoV-2 RNA in wastewater and compare viral concentrations to COVID-19 case numbers in the respective counties and sewersheds. Influent 24-hour composite wastewater samples were collected from July to December 2020 from two municipal wastewater treatment plants serving different population sizes in Orange and Chatham Counties in North Carolina. After a concentration step via HA filtration, SARS-CoV-2 RNA was detected and quantified by reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) and quantitative PCR (RT-qPCR), targeting the N1 and N2 nucleocapsid genes. SARS-CoV-2 RNA was detected by RT-ddPCR in 100 % (24/24) and 79 % (19/24) of influent wastewater samples from the larger and smaller plants, respectively. In comparison, viral RNA was detected by RT-qPCR in 41.7 % (10/24) and 8.3 % (2/24) of samples from the larger and smaller plants, respectively. Positivity rates and method agreement further increased for the RT-qPCR assay when samples with positive signals below the limit of detection were counted as positive. The wastewater data from the larger plant generally correlated (⍴ ~0.5, p < 0.05) with, and even anticipated, the trends in reported COVID-19 cases, with a notable spike in measured viral RNA preceding a spike in cases when students returned to a college campus in the Orange County sewershed. Correlations were generally higher when using estimates of sewershed-level case data rather than county-level data. This work supports use of wastewater surveillance for tracking COVID-19 disease trends, especially in identifying spikes in cases. Wastewater-based epidemiology can be a valuable resource for tracking disease trends, allocating resources, and evaluating policy in the fight against current and future pandemics.

Trends in surgery and survival for T1-T2 male breast cancer: A study from the National Cancer Database

BACKGROUND

Despite evidence that early-stage male breast cancer (MBC) can be treated the same as in females, we hypothesized that men undergo more extensive surgery.

METHODS

Patients with clinical T1-2 breast cancer were identified in the National Cancer Database 2004-2016. Trends in surgery type and overall survival were compared between sexes.

RESULTS

Of 9,782 males and 1,078,105 females, most were cN0 with AJCC stage I/II disease. Unilateral mastectomy was most common in men (67.1% vs. 24.1%, p < 0.001) and partial mastectomy in women (64.7% vs. 26.4%, p < 0.001), with no significant change over time. Over 1/3 of men received ALND in 2016. While overall survival was superior in females (HR 0.83, 95% CI 0.73-0.94, p = 0.003), partial mastectomy was associated with a 42% reduction in mortality risk for males (HR 0.58, 95% CI 0.4-0.8, p = 0.003).

CONCLUSIONS

De-escalation of surgery could be considered for MBC to improve survival and align with current standards of care.

Guideline-Consistent Treatment for Inflammatory Breast Cancer Provides Associated Survival Benefit Independent of Age

BACKGROUND

Guideline-consistent treatment (GCT) for inflammatory breast cancer (IBC) includes neoadjuvant chemotherapy (NAC), modified radical mastectomy (MRM), and radiation. We hypothesized that younger patients more frequently receive GCT, resulting in survival differences.

METHODS

Using the National Cancer Database (2004-2018), female patients with unilateral IBC (by histology code and clinical stage T4d) were stratified by age (< 50, 50-65, > 65 years). Factors associated with NAC, MRM, radiation, and "GCT" (defined as all three treatments) were identified using multivariable logistic regression. Multivariable Cox proportional hazards regression identified predictors of overall survival.

RESULTS

Of 3278 IBC patients, 30% were younger than 50 years, 44% were 50-65 years of age, and 26% were older than 65 years. The youngest group comprised the greatest proportion of non-White patients ([35%] vs. [29%] age 50-65 years and [23%] age > 65 years, p < 0.001) and was most often treated at academic facilities ([33%] vs. [28%] age 50-65 years; and [23%] age > 65, p < 0.001). Patients older than 65 years received NAC, MRM, and radiation less frequently, and only 35% underwent GCT (vs. [57%] age 50-65 years and [52%] age < 50 years; p < 0.001). On multivariable logistic regression, age older than 65 years independently predicted omission of NAC (odds ratio [OR], 0.36), MRM (OR, 0.56), and radiation (OR, 0.56) (all p < 0.001), and patients older than 65 years also were less likely to undergo GCT than patients 50-65 years of age (OR, 0.65; p = 0.001). GCT was associated with superior overall survival in all three age groups ([hazard ratio {HR}, 0.61] age < 50 years, [HR, 0.62] age 50-65 years, [HR, 0.53] age > 65 years; all p < 0.001).

CONCLUSION

Advanced age alone should not limit receipt of GCT for IBC. Multimodal care should be performed for IBC patients of all ages to improve oncologic outcomes for this aggressive breast cancer subtype.

Abstract P3-18-02: Breast conservation plus radiotherapy provides superior survival benefit than mastectomy in triple negative breast cancer: A propensity matched national cancer database analysis

Background: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with a higher risk of locoregional and distance recurrence. Consequently, this population was considered poor candidate for breast conservation (BCT). Our study aim was to determine whether BCT plus radiotherapy (RT) was equivalent to mastectomy for TNBC after adjustment of selection bias of demographic and clinical characteristics. Methods: The National Cancer Database was queried for women diagnosed as primary unilateral invasive clinical T1-2N0-2 TNBC from 2004-2016. Patients who underwent mastectomy or breast conservation (partial mastectomy plus radiation) were included. A 1:1 propensity match with replacement was performed to compare breast conservation vs. mastectomy. Overall survival was analyzed using stratified multivariable Cox proportional hazard regression analysis.Results: Of 59,599 clinical T1-2N0-2 TNBC patients, 26,325 (44.2%) underwent mastectomy and 33,274 (55.8%) were treated with BCT. BCT patients were older (median age 59 vs. 54, p&lt;0.001), had smaller tumors (cT1 61.7% vs. 42.9%, p&lt;0.001) and node negative (cN0 85.8% vs. 73.7%, p&lt;0.001). Propensity matching reduced the bias between mastectomy and breast conservation groups and generated 30,980 pairs for analysis. Median follow-up times were 41 months (range 6.97-95.8) and 39 months (range, 0.62 -94.06) for BCT and mastectomy groups, respectively. After matching, BCT+RT was associated with significantly higher OS compared to mastectomy ( 86.8% vs. 79.7%, p&lt;0.001). The survival advantage was also present in multivariate cox regression after controlling age, race, insurance, facility type, clinical T and clinical N stage.Conclusions: Using both propensity matching and multivariate cox regression controlling for potential confounders, BCT+RT survival was superior to mastectomy in a retrospective analysis of a large cancer database.

Citation Format: Lifen Cao, Christopher W Towe, Megan E Miller, Alberto J Montero, Robert Shenk. Breast conservation plus radiotherapy provides superior survival benefit than mastectomy in triple negative breast cancer: A propensity matched national cancer database analysis [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-18-02.

Abstract PD7-08: Less is not necessarily more: A propensity matched national analysis on effect and outcome of sentinel lymph node biopsy omission

Background: Routine sentinel lymph node biopsy (SLNB) has been recommended against by Choosing Wisely© Foundation due to its low value in clinical node negative, hormone receptor positive breast cancer patients age≥70 years old. We used the National Cancer Database (NCDB) to examine the effect of SLNB omission and outcomes in this population. We hypothesized that SLNB would be beneficial in this population.Methods: The National Cancer Database was queried for women diagnosed with primary unilateral invasive clinical stage T1N0M0 hormone receptor positive, HER-2 negative breast cancer from 2012-2017. Patients age ≥ 70 years old with Charlson Score ≥1 who underwent partial mastectomy and received hormonal therapy were included in the study cohort. Patients received neoadjuvant therapy or underwent upfront axillary lymph node dissection (ALND) were excluded. A 1:3 propensity match with replacement was performed to compare SLNB omission vs. SLNB group controlling age, race, comorbidities, insurance and facility. Overall survival was analyzed using stratified multivariable Cox proportional hazard regression analysis.Results: Of 14,150 patients, 1,928 (13.6%) omitted SLNB and 12,222 (86.4%) underwent SLNB, including 1,545/12,222 (12.6%) who proceeded to ALND. Central portion tumor location (OR=1.77, P=0.001), clinical T1c (OR= 2.49, P&lt;0.001) and lymph-vascular invasion (OR=7.46, P&lt;0.001) were significant associated with positive pathological lymph node involvement in SLNB group. Among the 1,397 patients of positive nodal status with SLNB, 87.7% received radiation therapy and 19.3% received chemotherapy. Propensity matching reduced bias between the groups, generating 1,903 SLNB omission and 5,703 SLNB patients for analysis. After match, the SLNB omission group was less likely to receive chemotherapy (1.1% vs. 3.0%, p&lt;0.001) or radiation therapy (28.9% vs. 60.8%, p&lt;0.001). Omitting SLNB was associated with inferior overall survival (3-year 83.7% vs. 90.6%, 5-year 66.4% vs. 76.1%, p&lt;0.001). Omitting SLNB was also associated with inferior survival in multivariate cox regression (HR=1.64, p&lt;0.001). Chemotherapy (OR=0.51, p=0.020) and radiation therapy (OR=0.85, P=0.007) were associated with superior overall survival.Conclusions: SLNB remains to be of importance in cT1N0M0 HR+HER2- patients of age 70 years. Pathologic staging affects decisions on adjuvant treatment and SLNB omission is associated with inferior survival. In this population, SLNB might need to be re-implemented, especially in patients with high likelihood of nodal involvement.

Citation Format: Lifen Cao, Megan E Miller, Luke D Rothermel, Alberto J Montero, Christopher W Towe, Robert Shenk. Less is not necessarily more: A propensity matched national analysis on effect and outcome of sentinel lymph node biopsy omission [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD7-08.

Adjuvant trastuzumab with or without chemotherapy in stage 1 pT1N0 HER2+ breast cancer: a National Cancer Database analysis

PURPOSE

Approximately 20% of all breast cancers (BC) are HER2 amplified. In the APT trial, weekly paclitaxel/trastuzumab in node negative HER2+ BC with tumors < 3 cm was associated with a 7-year invasive disease-free survival of 93%. However, this was in the context of a non-randomized trial, and for pT1N0 HER2+ BC it remains unclear whether HER2 monotherapy would provide similar clinical outcomes to chemo-HER2 therapy. We hypothesized that adjuvant chemo-HER2 therapy would be associated with a modestly improved overall survival compared to HER2 monotherapy in patients with tumors < 2 cm.

METHODS

In the National Cancer Database (2004-2017), patients with a primary diagnosis of pT1N0M0 HER2+ BC, were separated into two groups: (i) HER2 monotherapy, i.e., trastuzumab, and (ii) chemo-HER2 therapy. A 3:1 propensity match was performed to balance patient selection bias between the two different cohorts. Long-term overall survival (OS) was compared between both groups.

RESULTS

A total of 23,281 patients met the criteria. 22,268 (96.7%) received chemo-HER2 therapy and 1013 (4.4%) received HER2 monotherapy. Propensity match identified 1995 patients who received chemo-HER2 therapy, and 666 who received HER2 monotherapy. After matching, adjuvant chemo-HER2 therapy was associated with a modest survival advantage over HER2 monotherapy (5-year OS 94.1% vs. 90.6%, P = 0.041).

CONCLUSIONS

Even though there is a modest OS advantage favoring adjuvant chemo-HER2 therapy in patients with pT1N0 HER2+ BC, HER2 monotherapy was associated with 5-year OS > 90%. Therefore, in select patients who have contraindications for cytotoxic chemotherapy, or decline adjuvant chemotherapy altogether, adjuvant trastuzumab monotherapy appears to be a reasonable alternative.

Neoadjuvant Endocrine Therapy as an Alternative to Neoadjuvant Chemotherapy Among Hormone Receptor-Positive Breast Cancer Patients: Pathologic and Surgical Outcomes

Background

Neoadjuvant chemotherapy (NCT) is considered more effective in downstaging hormone receptor-positive (HR+) breast cancer than neoadjuvant endocrine therapy (NET), particularly in node-positive disease. This study compared breast and axillary response and survival after NCT and NET in HR+ breast cancer.

Methods

Based on American College of Surgeons Oncology Group (ACOSOG) Z1031 criteria, women age 50 years or older with cT2-4 HR+ breast cancer who underwent NET or NCT and surgery were identified in the National Cancer Database 2010–2016. Chi-square and logistic regression analysis determined differences between the NCT and NET groups and therapy response, including downstaging and pathologic complete response (pCR, ypT0/is and ypN0).

Results

Of 19,829 patients, 14,025 (70.7%) received NCT and 5804 (29.3%) received NET. The NET patients were older (mean age, 68.9 vs. 60.3; P < 0.001) and had greater comorbidity (1+ Charlson–Deyo score, 21% vs. 16%; P < 0.001). Therapy achieved T downstaging (any) for 58% of the patients with NCT versus 40.5% of the patients with NET, and in-breast pCR was achieved for 9.3% of the NCT versus 1.3% of the NET patients (P < 0.001). Approximately half of the mastectomy procedures could have been potentially avoided for the patients with in-breast pCR (53.6% of the NCT and 43.8% of the NET patients). For the cN+ patients, N downstaging (any) was 29% for the NCT patients versus 18.3% for the NET patients (P < 0.001), and nodal pCR was achieved for 20.3% of the NCT versus 13.5% of the NET patients (P < 0.001). Among those with nodal pCR, axillary lymph node dissection (ALND) still was performed for 56% of the patients after NCT and 45% of the patients after NET.

Conclusions

Although the response rates after NCT were higher, NET achieved both T and N downstaging and pCR. Neoadjuvant endocrine therapy can be used to de-escalate surgery for patients who cannot tolerate NCT or when chemotherapy may not be effective based on genomic testing.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10459-3.

Surgery provides survival benefit over systemic therapy alone for stage IV triple negative breast cancer: A propensity matched analysis of the National Cancer Database

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Background: Conflicting data exist regarding benefit of surgery of the primary site for stage IV breast cancer, in which systemic therapy is standard of care and patient characteristics may bias treatment decisions. Metastatic triple negative breast cancer (TNBC) is an aggressive subtype with limited therapy options and poor prognosis. Our aim was to assess whether surgery for the primary tumor in stage IV TNBC provides a survival advantage over systemic therapy alone. Methods: The National Cancer Database was queried for patients with de-novo stage IV TNBC who received systemic therapy alone or systemic therapy and surgery of the primary breast site 2004-2016. Patients receiving surgery for metastatic tumor sites or with incomplete follow up data were excluded. 1:1 propensity matching was performed for demographics, comorbidities, clinical T and N stage, and metastatic sites to minimize confounding factors. Survival outcomes were analyzed using a stratified log-rank test and Cox proportional hazard regression analysis. Results: Of 2989 patients, 782 (26.21%) underwent surgery plus systemic therapy and 2207 (73.84%) were treated with systemic therapy alone. The majority of all patients were aged 51-70 with low co-morbidity, and treated in metropolitan areas. Patients treated at academic facilities (OR = 0.67, p = 0.025), with multiple metastatic sites (OR = 0.59, p < 0.001), or advanced clinical N stage (OR = 0.55, p < 0.001) were less likely to undergo surgery. Of those who completed surgery, 58% had unilateral mastectomy, and 63% had axillary lymph node dissection. Propensity matching identified 507 ‘paired’ patients with similar characteristics in the surgery and systemic therapy alone groups. After multivariable adjustment, surgery was associated with superior overall survival compared with systemic therapy alone (HR 0.73, P < 0.001). Older age (HR = 1.47, p < 0.001), greater comorbidity (HR = 1.28, p < 0.001) and multiple metastatic sites (HR = 1.53, p < 0.001) significantly decreased overall survival in the matched cohort. Median survival was shortest in the systemic therapy alone group (12.8 months, 95% CI 11.3-14.5) and longest in those undergoing systemic therapy plus simple mastectomy (18 months, 95% CI 14.3-21.2), though approximately 4 months of median survival was added for all patients undergoing any surgery vs. systemic therapy alone (p = 0.0001). Conclusions: In stage IV TNBC, surgical resection of the primary tumor site in addition to systemic therapy may provide a survival benefit in selected patients. Though in this retrospective study the sequence of treatment was unknown, surgery could be considered for low disease burden as in other malignancies with oligometastatic disease. Additional research is needed to determine if these findings persist in prospective studies and for other hormone-receptor subtypes.

Improved survival supports primary endocrine therapy in patients with hormone receptor positive/ HER-2 negative metastatic breast cancer

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Background: Current ASCO guidelines recommend endocrine therapy as preferred primary treatment for hormone receptor positive (HR+) metastatic breast cancer (MBC). We assessed survival outcomes of HR+/HER2- MBC patients undergoing endocrine therapy with and without chemotherapy. Methods: The National Cancer Database was queried 2004-2016 for patients with de novo HR+/HER2- MBC. Exclusion criteria were treatment with surgery or radiation at the primary site and missing oncologic and follow up data. Overall survival was compared between systemic treatment groups using multivariable cox proportional hazards regression modes. Results: 19,317 patients met inclusion criteria, among whom 2,360 (12%) received no systemic therapy, 2,617 (14%) received chemotherapy only, 10,078 (52%) received endocrine therapy only and 4,262 (22%) received both chemotherapy and endocrine therapy. Patients treated with chemotherapy only more frequently had lung (38%, p<0.001) or liver (36%, p<0.001) metastasis while those undergoing endocrine therapy only presented primarily with bone metastasis (82%, p<0.001). Patients with multiple metastatic sites more often received endocrine therapy alone than combined therapy (44 vs. 25%, p<0.001). Median overall survival was similar after combination therapy and endocrine therapy, and poorest after chemotherapy alone (33.1 vs 31.4 vs 19.8 months, p<0.001). After controlling for patient, facility, and tumor characteristics, endocrine therapy alone provided superior survival benefit to chemotherapy only, though combination systemic therapy resulted in the greatest overall survival (p<0.001). Conclusions: Primary endocrine therapy provided significant survival benefit over chemotherapy alone for HR+/HER2- MBC. Though combination systemic therapy may be warranted in progressive disease, our results align with recommendations for endocrine therapy as first line treatment for HR+/HER2- MBC. [Table: see text]

Metastatic site-specific utilization and outcome of immunotherapy in stage IV melanoma: A national perspective

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Background: Metastatic melanoma is an aggressive disease with a rapid systemic dissemination. We evaluated the effect of metastatic sites on the utilization immunotherapy and survival outcomes in stage IV melanoma. Methods: The National Cancer Database from 2010-2017 was queried for stage IV melanoma. Those with missing relevant data were excluded. Patients were grouped into five categories based on metastatic sites: lung metastasis only, brain metastasis only, liver metastasis only, bone metastasis only and multiple sites metastasis. Multivariable logistic regression was used to predict use of immunotherapy. Effects of immunotherapy on overall survival were assessed using Kaplan-Meier curves and Cox proportional hazards model. Results: A total 12, 315 were included in the study, among whom 2206 (17.9%) had lung metastasis only, 1,873 (15.2%) had brain metastasis only, 785 (6.4%) had liver metastasis only, 662 (5.4%) had bone metastasis only and 5,983 (48.6%) presented with multiple metastatic sites. Surgery at primary site was performed in 34.3% of patients with bone metastasis (p<0.001), and radiation therapy was delivered to 69.2% patients with brain metastasis (p<0.001). Site of metastatic disease was associated with immunotherapy utilization, with multiple sites (OR = 1.149, p=0.012), and distant lymph nodes (OR=2.867, p<0.001) demonstrating the strongest association, while patients with oligo brain metastasis were less likely to receive immunotherapy (OR = 0.486, p<0.001). Immunotherapy is associated with superior survival among metastatic melanoma patients (HR=0.433, P<0.001). The Kaplan-Meier curves showed the median overall survival among the immunotherapy group was 33.7 months for lung metastasis (vs. 13.4 months without immunotherapy, HR=0.633, p<0.001), 25 months for brain metastasis (vs. 6.7 months without immunotherapy, HR=0.447, P<0.001), 16.8 months for liver metastasis (vs. 4.2 months without immunotherapy, HR=0.449, P<0.001), 18.3 months in bone metastasis (vs. 7.6 months without immunotherapy, HR=0.615, p<0.001) and 12.1 months in multiple metastasis (vs. 3.8 months without immunotherapy, HR=0.338, p<0.001). Conclusions: Utilization of immunotherapy is influenced by location of metastatic disease in stage IV melanoma. Overall survival is improved for patients treated with immunotherapy.[Table: see text]

Limited Reporting of Histopathologic Details in a Multi-Institutional Academic Cohort of Phyllodes Tumors: Time for Standardization

BACKGROUND

Phyllodes tumors are rare fibroepithelial neoplasms that are classified by tiered histopathologic features. While there are protocols for the reporting of cancer specimens, no standardized reporting protocol exists for phyllodes.

METHODS

We performed an 11-institution contemporary review of phyllodes tumors. Granular histopathologic details were recorded, including the features specifically considered for phyllodes grade classification.

RESULTS

Of 550 patients, median tumor size was 3.0 cm, 68.9% (n = 379) of tumors were benign, 19.6% (n = 108) were borderline, and 10.5% (n = 58) were malignant. All cases reported the final tumor size and grade classification. Complete pathologic reporting of all histopathologic features was present in 15.3% (n = 84) of cases, while an additional 35.6% (n = 196) were missing only one or two features in the report. Individual details regarding the degree of stromal cellularity was not reported in 53.5% (n = 294) of cases, degree of stromal atypia in 58.0% (n = 319) of cases, presence of stromal overgrowth in 56.2% (n = 309) of cases, stromal cell mitoses in 37.5% (n = 206) of cases, and tumor border in 54.2% (n = 298) of cases. The final margin status (negative vs. positive) was omitted in only 0.9% of cases, and the final negative margin width was specifically reported in 73.8% of cases. Reporting of details was similar across all sites.

CONCLUSION

In this academic cohort of phyllodes tumors, one or more histopathologic features were frequently omitted from the pathology report. While all features were considered by the pathologist for grading, this limited reporting reflects a lack of reporting consensus. We recommend that standardized reporting in the form of a synoptic-style cancer protocol be implemented for phyllodes tumors, similar to other rare tumors.

Behavioral Implications of the Complete Absence of Guests on a Zoo-Housed Gorilla Troop

Research conducted on the effects that zoo visitors have on primate behavior has yielded inconsistent patterns. This study aims to contribute to the growing body of literature regarding visitor effects on zoo-housed primate's activity budgets, with the purpose of quantifying the behavioral variability under two conditions: guest presence and guest absence. Due to the COVID-19 pandemic, many zoos were closed to the public for varying lengths of time. The Buffalo Zoo was closed to guests for an 18-week period including the summer of 2020, which allowed us to effectively control for zoo guest presence. This case report compares data on the zoo's gorilla troop from the same time period in 2019. We found inconsistent results, similar to prior studies conducted with zoo-housed gorilla troops. Most gorillas were observed foraging less and exhibiting more inactivity in 2020, whereas the adult male silverback showed the opposite pattern. Abnormal or undesirable behaviors were performed less frequently when guests were absent however, these differences were not significant. We encourage others to compare behavior patterns during the pandemic shutdown to add to our knowledge base of visitor effects. We suggest that researchers do not try and generalize their individual and troop results to the entire population of gorillas in managed care, as both intrinsic and extrinsic factors contribute to individual differences in behavioral response.

Minimally Invasive Mastectomy Could Achieve Non-inferior Oncological Outcome in Appropriately Selected Patients: Propensity Matched Analysis of the National Cancer Database

BACKGROUND

Minimally invasive mastectomy (MIM) was emerged as an approach to decrease morbidity and increase patient satisfaction through improved cosmetic results; however, there is a paucity of data regarding the long-term oncologic outcomes of these minimally invasive approaches.

METHODS

Patients who underwent mastectomy procedures were identified in the National Cancer Database (2010-2016). Patients were categorized as MIM or open mastectomy. A 1:1 propensity match was performed to balance the bias on reconstruction, nipple sparing, lymph node procedures, and other confounding factors between the cohorts. Short- and long-term outcomes were compared.

RESULTS

A total of 328 811 patients met the criteria: 327 643 (99.6%) received open mastectomy and 1168 (.4%) received MIM. Propensity match identified 384 "pairs" of MIM and open mastectomy patients. Among them, MIM was associated with shorter length of stay (LOS) (mean 1.3 vs. 1.06 days, P = .003). No differences were observed in the rates of positive margins, unplanned readmissions, or 90-day mortality between the 2 operative approaches. Overall survival (OS) was equivalent between MIM and open mastectomy patients. Cox proportional hazard regression showed no effect of the procedure performed on OS.

DISCUSSION

MIM is associated with shorter LOS, and it is non-inferior to open mastectomy in terms of other short-term outcomes and long-term oncologic survival outcomes. These data suggest that MIM may be considered in appropriately selected breast cancer patients as an additional approach to the community.

Despite Equivalent Outcomes, Men Receive Neoadjuvant Chemotherapy Less Often Than Women for Lymph Node-Positive Breast Cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) downstages breast cancer and provides prognostic information. Males with breast cancer are known to receive less treatment overall and have poorer outcomes relative to females. We hypothesized that males would be less likely to receive NAC.

PATIENTS AND METHODS

Patients with a primary diagnosis of cN1-3 breast cancer were identified in the National Cancer Database (2004-2016). Multivariable logistic regression determined the association between NAC utilization and sex, and the relationship between sex and NAC response, controlling for demographic and tumor factors. Overall survival was analyzed using a multivariable Cox model.

RESULTS

In total, 196,027 patients (194,010 females, 2017 males) met inclusion criteria. A significantly greater proportion of males underwent mastectomy (80% vs. 60%, P < 0.001), and axillary lymph node dissection (76% vs. 74%, P = 0.022). Overall fewer men received chemotherapy than women (73% vs. 84%, P < 0.001); men also received NAC at a significantly lower rate (26% men vs. 45% women, P < 0.001). After accounting for demographic and oncologic factors including hormone receptor (HR) subtype, females remained more likely to undergo NAC (OR 1.84, P < 0.001). On multivariable analysis, sex was not associated with pathologic response or overall survival after NAC.

CONCLUSIONS

Although oncologic outcomes after NAC were similar, males with node-positive breast cancer received less NAC and more aggressive surgery than females. These data suggest men achieve outcomes comparable to women with cN1-3 disease, and NAC should be used in appropriate male patients to downstage the breast and axilla.

Abstract PS14-12: Trends in breast and axillary surgery for T1-T2 male breast cancer: A study from the national cancer database

Introduction: Due to the low incidence of male breast cancer, large scale prospective trials to guide therapy are lacking. Historically males with breast cancer present at more advanced stages than females and have been surgically treated with modified radical mastectomy. Recent studies suggest that breast-conserving therapy for early-stage male breast cancer yields similar outcomes as for female patients, and that sentinel lymph node biopsy (SLNB) can be used in place of axillary lymph node dissection (ALND) for appropriate clinically node-negative patients. Our study investigates trends in breast and axillary surgery for male breast cancer patients, focusing specifically on the treatment of early-stage disease. Methods: The National Cancer Database (NCDB) was utilized to identify male and female patients diagnosed with clinical T1-2 breast cancer from 2004-2016. Patient, tumor, facility, and surgical treatment factors were examined. Patients were stratified by surgery type: partial, unilateral, and bilateral mastectomy; simple versus modified radical mastectomy; SLNB (removal of ≤ 5 lymph nodes) and ALND (&gt;5 lymph nodes). Trends in surgery type were compared between male and female patients and over the study period for each gender. Results: 9,782 males and 1,078,105 females with T1-2 breast cancer were identified. Men were significantly older at diagnosis than women (31.4% vs. 23.6% age &gt;70, p&lt;0.0001), were more often insured by Medicare (44.5% vs. 35.3%, p&lt;0.0001), and had greater co-morbidity (21.9% vs. 15.6% Charlson Deyo Score &gt;0). ER/PR+ disease (94.2% vs. 84.1%, p&lt;.0001), moderate/high grade histology (85.4% vs. 77.8%, p&lt;.0001) and lymphovascular invasion (24% vs. 15.3%, p&lt;.0001) were also more common in males vs. females. The majority of all patients were clinically node negative (80.4% of males, 85% of females) and had AJCC clinical stage I or II disease (92.3% men, 95.2% women). Unilateral mastectomy was performed most commonly for men (67.1% men vs. 24.1% women, p&lt;0.001), while women more frequently underwent partial mastectomy (64.7% women vs. 26.4% men, p&lt;0.001). The rates of each surgery type remained disparate by gender and stable over the study period: male unilateral mastectomy rate 59.8% in 2004 and 66.1% in 2016; female partial mastectomy rate 65.9% in 2004, 68.4% in 2016. Modified radical mastectomy rates decreased in favor of simple mastectomy for both genders, 61.8% to 24.1% in males and 58.7% to 20.2% in females, 2004 to 2016. There was a similar overall increase in SLNB vs. ALND for all patients, though SLNB was not adopted as the more common procedure in male patients until 2009. In 2016, 78.2% of females and 65.3% of males underwent SLNB vs. 51.1% and 39.8% in 2004, respectively. Conclusions: Although breast-conserving therapy is the treatment of choice for female patients with early-stage breast cancer and could be similarly used to treat men with T1-T2 disease, the majority of male breast cancer patients continue to undergo unilateral mastectomy for early-stage disease. In more recent years, SLNB has surpassed ALND for men, mirroring the trend for women, though in a more delayed and gradual fashion. Partial mastectomy and SLNB warrant consideration for men with T1 and T2 breast cancer, in particular since male breast cancer patients present at older ages and with more co-morbidity than their female counterparts, and may benefit from de-escalation of surgical treatment.

Citation Format: Rashi Singh, Lifen Cao, Anuja L Sarode, Michael Kharouta, Robert Shenk, Megan E Miller. Trends in breast and axillary surgery for T1-T2 male breast cancer: A study from the national cancer database [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-12.

Abstract PS14-10: Trends in incidence and stage of male breast cancer, 2004-2016: An analysis from the national cancer database

Background: Male breast cancer has been less well studied due to the rarity of this condition compared with female breast cancer. Men have traditionally presented at later stages than women, leading to disparities in outcomes. Our aim was to identify the incidence of male breast cancer in recent years and determine trends in clinical and pathologic stage that could be utilized to improve breast cancer care. Methods: Patients diagnosed with primary breast cancer between 2004 and 2016 were identified using the National Cancer Database (NCDB), which collects hospital registry data from over 1,500 Commission on Cancer (CoC)-accredited facilities and represents more than 70% of newly diagnosed cancer cases in the United States. Patient, tumor, treatment, and facility data was compared between male and female patients. Incidence of male and female breast cancer was stratified by both AJCC clinical stage and pathologic stage (I-IV) and evaluated over the study period. Results: 17,814 male breast cancer patients and 2,001,551 female patients with breast cancer were identified. The incidence of male breast cancer increased by 1.5-fold from 1044 cases per year in 2004 to 1565 cases per year in 2016. The number of female breast cancer cases was 123,799 in 2004 and reached the highest annual volume of 184,718 in 2015. In 2010 incident male breast cancer cases rose by nearly 100% compared with the prior year, the majority of which represented early stage disease. In that year alone, for males there was a 99.6% increase (276 vs. 556 cases) in pathologic stage I disease, 89% increase (200 vs. 378 cases) in pathologic stage II disease and 94.7% increase (68 vs. 132 cases) in patients diagnosed with in situ disease. After 2010, incidence patterns for male breast cancer stabilized with ratio changes for Stage I or II at the level of only 1% to 7.3% per year. Interestingly, the proportion of male to female breast cancer incident cases remained constant over the study period, with males representing 0.8-0.9% of the total cases. Overall, a minority of patients presented with Stage III (6.6%) and Stage IV (4.6%) disease, though a greater proportion of males than females had advanced stage disease at diagnosis (16.88% of males vs. 11.14% females, p&lt; 0.001). The incidence of clinical Stage I and II disease increased over time for both genders, though a greater proportion of female breast cancer was Stage I (43.2% female vs. 35.93% male, p&lt;0.001), and Stage II disease was more common in men (33.83% male vs 24.22% female, p&lt;0.001). When pathologic stage was considered, Stage I and II represented the majority of male breast cancer cases, 74.7% to 80% per year, and was slightly higher than the combination of Stage I and II at clinical diagnosis, 65.7% to 78.7% per year. Conclusions: Over past 15 years, the incidence of male breast cancer has increased substantially, yet remains a stable proportion of total breast cancer cases. The greater frequency of Stage II, III and IV disease in men likely reflects the difference in diagnosis by clinical exam or symptoms in men vs. screening programs in women. Education to increase awareness of male breast cancer, promote symptom recognition, and encourage appropriate use of genetic testing should be emphasized to improve early diagnosis of breast cancer in men.

Citation Format: Lifen Cao, Rashi Singh, Anuja L Sarode, Michael Kharouta, Robert Shenk, Megan E Miller. Trends in incidence and stage of male breast cancer, 2004-2016: An analysis from the national cancer database [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-10.

Contemporary Multi-Institutional Cohort of 550 Cases of Phyllodes Tumors (2007-2017) Demonstrates a Need for More Individualized Margin Guidelines

PURPOSE

Phyllodes tumors (PTs) are rare breast neoplasms, which have little granular data on margins. Current guidelines recommend ≥ 1 cm margins; however, recent data suggest narrower margins are sufficient, and for benign PT, a negative margin may not be necessary.

METHODS

We performed an 11-institution contemporary (2007-2017) review of PT practices. Demographics, surgical, and histopathologic data were captured. Logistic regression was used to estimate the association of select covariates with local recurrence (LR).

RESULTS

Of 550 PT patients, the majority underwent excisional biopsy (55.3%, n = 302/546) or lumpectomy (wide excision) (38.5%, n = 210/546). Median tumor size was 30 mm, 68.9% (n = 379) were benign, 19.6% (n = 108) borderline, and 10.5% (n = 58) malignant. Surgical margins were positive in 42% (n = 231) and negative in 57.3% (n = 311). A second operation was performed in 38.0% (n = 209) of the total cohort, including 51 patients with an initial negative margin (82.4% with < 2 mm), and 157 with an initial positive margin, with residual disease only found in six (2.9%). Notably, 32.0% (n = 74) of those with an initial positive margin did not undergo a second operation, among whom only 2.7% (n = 2) recurred. Recurrence occurred in 3.3% (n = 18) of the total cohort (n = 15 LR, n = 3 distant), at median follow-up of 36.7 months. LR (all PT grades) was not reduced with wider negative margin width (≥ 2 mm v < 2 mm: odds ratio [OR] = 0.39; 95% CI, 0.07 to 2.10; P = .27) or final margin status (positive v negative: OR = 0.96; 95% CI, 0.26 to 3.52; P = .96).

CONCLUSION

In current practice, many patients are managed outside of current guidelines. For the entire cohort, a wider margin width was not associated with a reduced risk of LR. We do not recommend re-excision of a negative margin for benign PT, regardless of margin width, as a progressively wider surgical margin is unlikely to reduce LR.

Hospital System Adoption of Magnetic Seeds for Wireless Breast and Lymph Node Localization

BACKGROUND

As an alternative to traditional wire localization, an inducible magnetic seed system can be used to identify and remove nonpalpable breast lesions and axillary lymph nodes intraoperatively. We report the largest single-institution experience of magnetic seed placement for operative localization to date, including feasibility and short-term outcomes.

METHODS

Patients who underwent placement of a magnetic seed in the breast or lymph node were identified from July 2017 to March 2019. Imaging findings, core needle biopsy, surgical pathology results, and type of surgery were collected. Outcomes included procedural complications, magnetic seed and biopsy clip retrieval rates, and need for additional surgery.

RESULTS

A total of 842 magnetic seeds were placed by nine radiologists in 673 patients and retrieved by six surgeons at six operative locations. The majority of breast lesions were malignant (395/659, 59.9%); 136 seeds were placed for lymph node localization. The overall magnetic seed retrieval rate was 98.6%, whereas the biopsy clip retrieval rate was 90.9%. Only six patients (0.7%) experienced a complication from magnetic seed placement. Reexcision was performed in 15.2% of patients with breast cancer; 9.6% of benign/high risk lesions were upgraded to malignancy at surgical excision.

CONCLUSIONS

The magnetic seed technique is safe, effective, and accurate for localization of breast lesions and lymph nodes, and importantly uncouples surgery from the localization procedure. The high magnetic seed retrieval rate and low reexcision rate may reflect the accuracy of magnetic marker placement as a "second chance" localization procedure, especially in cases with biopsy clip migration.

Germline Genetic Mutations in a Multi-center Contemporary Cohort of 550 Phyllodes Tumors: An Opportunity for Expanded Multi-gene Panel Testing

BACKGROUND

A paucity of data exists regarding inherited mutations associated with phyllodes tumors (PT); however, some are reported (TP53, BRCA1, and RB1). A PT diagnosis does not meet NCCN criteria for testing, including within Li-Fraumeni Syndrome (TP53). We sought to determine the prevalence of mutations associated with PT.

METHODS

We performed an 11-institution review of contemporary (2007-2017) PT practice. We recorded multigenerational family history and personal history of genetic testing. We identified patients meeting NCCN criteria for genetic evaluation. Logistic regression estimated the association of select covariates with likelihood of undergoing genetic testing.

RESULTS

Of 550 PT patients, 59.8% (n = 329) had a close family history of cancer, and 34.0% (n = 112) had ≥ 3 family members affected. Only 6.2% (n = 34) underwent genetic testing, 38.2% (n = 13) of whom had only BRCA1/BRCA2 tested. Of 34 patients tested, 8.8% had a deleterious mutation (1 BRCA1, 2 TP53), and 5.9% had a BRCA2 VUS. Of women who had TP53 testing (N = 21), 9.5% had a mutation. Selection for testing was not associated with age (odds ratio [OR] 1.01, p = 0.55) or PT size (p = 0.12) but was associated with grade (malignant vs. benign: OR 9.17, 95% CI 3.97-21.18) and meeting NCCN criteria (OR 3.43, 95% confidence interval 1.70-6.94). Notably, an additional 86 (15.6%) patients met NCCN criteria but had no genetic testing.

CONCLUSIONS

Very few women with PT undergo germline testing; however, in those selected for testing, a deleterious mutation was identified in ~ 10%. Multigene testing of a PT cohort would present an opportunity to discover the true incidence of germline mutations in PT patients.

Thyroid cytology smear slides: An untapped resource for ThyroSeq testing

BACKGROUND

Molecular testing of thyroid nodules with indeterminate fine-needle aspiration (FNA) cytology is commonly used to guide patient management and is typically performed on freshly collected FNA samples. In this study, the authors evaluated the performance of the ThyroSeq test in cytology smear slides.

METHODS

Air-dried Diff-Quik (DQ)-stained and alcohol-fixed Papanicolaou (Pap)-stained smears were used to determine required cellularity and sensitivity of mutation detection and to compare ThyroSeq v3 Genomic Classifier (GC) results obtained in cytology smears and fresh FNA samples from the same nodules.

RESULTS

ThyroSeq testing of 31 cytology smears revealed that 25 smears (81%) were adequate for ThyroSeq analysis, including 14 Pap-stained smears (100%) and 11 DQ-stained smears (65%), whereas 6 DQ-stained smears (35%) failed RNA sequencing. The overall accuracy for detecting molecular alterations was 98%, with 100% concordance for mutations and gene expression alterations, 96% concordance for fusions, and 94% concordance for copy number alterations. Cytology smears were adequate for ThyroSeq analysis when at least 200 to 300 cells were present in 1 to 3 slides. ThyroSeq detected all studied mutations down to 5% allele frequency and BRAF mutations down to 1% allele frequency. Testing of smears yielded a positive ThyroSeq GC result in all nodules originally classified as positive.

CONCLUSIONS

Thyroid FNA cytology smear slides with adequate cellularity can be successfully used for ThyroSeq GC testing in approximately 80% of cases, with an even higher success rate in Pap-stained smears. Compared with FNA samples collected into preservative solution, 94% to 100% of different genetic alterations could be accurately detected in smears, validating cytology smears as an alternative for ThyroSeq testing in patients with indeterminate thyroid cytology.

Risk of Contralateral Breast Cancer in Women with Ductal Carcinoma In Situ Associated with Synchronous Ipsilateral Lobular Carcinoma In Situ

BACKGROUND

Lobular carcinoma in situ (LCIS) is a risk factor for breast cancer, but the effect of LCIS found in association with ductal carcinoma in situ (DCIS) is unknown. In this study, we compared contralateral breast cancer (CBC) and ipsilateral breast tumor recurrence (IBTR) rates among women with DCIS with or without synchronous ipsilateral LCIS treated with breast-conserving surgery (BCS).

METHODS

DCIS patients undergoing BCS from 2000 to 2011 with a contralateral breast at risk were stratified by the presence or absence of synchronous ipsilateral LCIS with the index DCIS (DCIS + LCIS vs. DCIS). Those with contralateral, bilateral, or prior ipsilateral LCIS were excluded. Associations of patient, tumor, and treatment factors with CBC and IBTR were evaluated.

RESULTS

Of 1888 patients identified, 1475 (78%) had DCIS and 413 (22%) had DCIS + LCIS. At median follow-up of 7.2 (range 0-17) years, 307 patients had a subsequent first breast event; 207 IBTR and 100 CBC. The 10-year cumulative incidence of IBTR was similar in both groups: 15.0% vs. 14.2% (log-rank, p = 0.8) for DCIS + LCIS vs. DCIS, respectively. The 10-year cumulative incidence of CBC was greater in the DCIS + LCIS group: 10.9% vs. 6.1% for DCIS (log-rank, p < 0.001). After adjustment for other factors, CBC risk remained higher in DCIS + LCIS compared with DCIS (hazard ratio 2.06, 95% confidence interval 1.36-3.11, p = 0.001); there was no significant difference in IBTR risk.

CONCLUSIONS

Compared with DCIS alone, DCIS + LCIS is associated with similar IBTR risk but double the risk of CBC. This finding should inform treatment decisions, in particular regarding endocrine therapy for risk reduction.

Abstract P5-18-01: Risk of contralateral breast cancer (CBC) in women with ductal carcinoma in situ (DCIS) with and without and synchronous lobular carcinoma in situ (LCIS)

Background: LCIS is considered a risk factor for bilateral breast cancer, but the effect of LCIS diagnosed concurrently with DCIS is not known. We sought to compare CBC and ipsilateral breast tumor recurrence (IBTR) rates in women with DCIS with and without synchronous LCIS treated with breast conserving surgery (BCS).

Methods: A prospectively maintained database of DCIS patients undergoing BCS from 2000-2011 was used to identify women with a contralateral breast at risk. Patients with synchronous ipsilateral LCIS found at core needle biopsy or surgical excision were included in the “DCIS + LCIS” group; those with contralateral or bilateral LCIS were excluded. Associations of patient, tumor, and treatment factors with CBC and IBTR were evaluated using logistic regression.

Results: Of the 1888 patients identified, 1475 (78%) had DCIS only and 413 (22%) had DCIS with synchronous LCIS. Median follow-up was 7.5 years (range 0-17 years). 305 patients had a subsequent breast event; 216 IBTR and 89 CBC.

The 5 and 10-year cumulative incidence of IBTR was similar in both groups: 6.3% and 14.4% for DCIS only, compared with 5.9% and 14.0% for DCIS + LCIS (p = 0.94), respectively. The 5 and 10-year cumulative incidence of CBC was significantly greater in the DCIS + LCIS group: 5.7% and 10.0%, compared with 2.4% and 5.0% for DCIS only (p &lt; 0.001).

Table 1 summarizes uni-and multi-variable analyses of risk factors associated with CBC and IBTR among women with DCIS treated with BCS. After adjustment for other factors, CBC risk was more than 2-fold higher in the DCIS + LCIS group compared with the DCIS only group (HR 2.37, 95% CI 1.54-3.65, p &lt; 0.001). There was no difference in IBTR risk based on presence of synchronous LCIS. Younger age and receipt of endocrine therapy were significantly associated with decreased risk of CBC.

Table 1:Risk factors associated with CBC and IBTR in patients with DCIS treated with BCS  Univariate Analysis Multivariate Analysis  Hazard Ratio (95% CI) Hazard Ratio (95% CI)  CBC IBTR CBC IBTRAge (continuous)1.02 (1.01-1.04) *0.99 (0.98-1.0)1.02 (1.0-1.04) *0.99 (0.97-1.0) *Presentation    Radiologic1111Clinical0.36 (0.11-1.14)1.56 (1.05-2.3) *0.41 (0.13-1.31)1.67 (1.12-2.47) *Family history    Yes1.32 (0.87-2.01)1.0 (0.76-1.32)1.33 (0.87-2.03)1.03 (0.78-1.35)Grade    Low1111Intermediate/high1.83 (1.0-3.37)1.32 (0.93-1.88)1.74 (0.92-3.29)1.62 (1.11-2.35) *Radiation    Yes1.16 (0.75-1.8)0.7 (0.54-0.92) *1.14 (0.71-1.82)0.64 (0.48-0.86) *Endocrine Therapy    Yes0.43 (0.23-0.81) *0.51 (0.35-0.74) *0.42 (0.22-0.8) *0.53 (0.36-0.77) *DCIS group    DCIS only1111DCIS + LCIS2.28 (1.49-3.5) *0.99 (0.71-1.36)2.37 (1.54-3.65) *0.99 (0.71-1.37)* p &lt; 0.05

Conclusions: LCIS diagnosed concurrently with DCIS is not associated with IBTR, but increases the risk of CBC two-fold. Endocrine therapy should be considered both for the index DCIS and for prevention of subsequent CBC.

Citation Format: Miller ME, Muhsen S, Zabor EC, Flynn J, Olcese C, Giri D, Van Zee KJ, Pilewskie M. Risk of contralateral breast cancer (CBC) in women with ductal carcinoma in situ (DCIS) with and without and synchronous lobular carcinoma in situ (LCIS) [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 P5-18-01.

Bridging the Gap: Interdepartmental Quality Improvement and Patient Safety Curriculum Created by Hospital Leaders, Faculty, and Trainees

BACKGROUND

The Accreditation Council for Graduate Medical Education Clinical Learning Environment Review recommends that quality improvement/patient safety (QI/PS) experts, program faculty, and trainees collectively develop QI/PS education.

OBJECTIVE

Faculty, hospital leaders, and resident and fellow champions at the University of Chicago designed an interdepartmental curriculum to train postgraduate year 1 (PGY-1) residents on core QI/PS principles, measuring outcomes of knowledge, attitudes, and event reporting.

METHODS

The curriculum consisted of 3 sessions: PS, quality assessment, and QI. Faculty and resident and fellow leaders taught foundational knowledge, and hospital leaders discussed institutional priorities. PGY-1 residents attended during protected conference times, and they completed in-class activities. Knowledge and attitudes were assessed using pretests and posttests; graduating residents (PGY-3-PGY-8) were controls. Event reporting was compared to a concurrent control group of nonparticipating PGY-1 residents.

RESULTS

From 2015 to 2017, 140 interns in internal medicine (49%), pediatrics (33%), and surgery (13%) enrolled, with 112 (80%) participating and completing pretests and posttests. Overall, knowledge scores improved (44% versus 57%, P < .001), and 72% of residents demonstrated increased knowledge. Confidence comprehending quality dashboards increased (13% versus 49%, P < .001). PGY-1 posttest responses were similar to those of 252 graduate controls for accessibility of hospital leaders, filing event reports, and quality dashboards. PGY-1 residents in the QI/PS curriculum reported more patient safety events than PGY-1 residents not exposed to the curriculum (0.39 events per trainee versus 0.10, P < .001).

CONCLUSIONS

An interdepartmental curriculum was acceptable to residents and feasible across 3 specialties, and it was associated with increased event reporting by participating PGY-1 residents.

Thermal sensitivity of Calonectria henricotiae and Calonectria pseudonaviculata conidia and microsclerotia

Knowledge of the thermal sensitivity of conidia and microsclerotia is useful for developing plant disease management approaches that deploy heat to inactivate infectious vegetative propagules of fungal pathogens. For boxwood blight disease, heat treatment of cuttings that harbor conidia and microsclerotia would provide a useful management tool for suppressing the pathogenic activity of Calonectria pseudonaviculata (present in the United States) and C. henricotiae (a quarantine pathogen not present in the United States). In this study, we investigated the thermal sensitivity of conidia and microsclerotia of the boxwood blight pathogens C. henricotiae and C. pseudonaviculata treated in water at 45, 47.5, 50, 52.5, and 55 C. For conidia, as time of exposure increased at each temperature, the proportion of germinated conidia decreased. The predicted time required to inactivate 90% of C. pseudonaviculata conidia (LD₉₀) decreased as water temperature increased from 45 to 55 C and ranged from 35.4 to 5.6 min, respectively. Inactivation of conidia was dependent on isolate, species of Calonectria, and length of exposure at each temperature tested. Microsclerotia of C. henricotiae and C. pseudonaviculata displayed reduced germination with increasing exposure and higher temperatures of hot water. Microsclerotia of C. henricotiae were significantly more resistant to heat treatment than C. pseudonaviculata at 47.5 and 50 C, whereas microsclerotia of both species were rapidly killed at 55 C.

De novo metastasis in breast cancer: occurrence and overall survival stratified by molecular subtype

Breast cancer molecular subtypes, categorized jointly by hormone receptors (HR) and human epidermal growth factor-2 (HER2), are utilized to guide systemic therapy. We hypothesized distinct patterns of de novo metastasis and overall survival by molecular subtype using a retrospective cohort of 399,772 women in the National Cancer Database diagnosed with first primary invasive breast cancer between 2010 and 2014, of whom 13,924 were diagnosed with de novo metastasis from 2010 to 2013 and had follow up data. The relationship of molecular subtype with patient and tumor characteristics, including site of de novo metastasis, were examined using Chi-squared tests. Kaplan-Meier and Cox proportional hazards analyses were used to examine overall survival by molecular subtype. Bone was the most frequent de novo metastatic site for all molecular subtypes. Compared to HR+/HER2-, patients with HR-/HER2+ experienced 4.5, 3.0, and 6.0 times the de novo brain, lung, and liver metastasis respectively. In survival analyses of women diagnosed with de novo metastasis, the mortality risk relative to HR+/HER2- was twice as high for triple-negative (hazard ratio = 2.02, 95% CI 1.89-2.16) and modestly lower for HR+/HER2+ (hazard ratio = 0.83, 95% CI 0.78-0.88). The median survival difference between metastatic patients with and without chemotherapy was 28.6 months in HR+/HER2+ and 28.2 months in HR-/HER2+, but only 10.9 months in triple-negative and 5.2 months in HR+/HER2-. In conclusion, despite unfavorable patterns of de novo metastasis, HER2+ breast cancers had relatively better survival in recent years, probably due to treatment differences. Utilizing molecular subtype and site of de novo metastasis may predict prognosis and guide treatment.

Cognitive Performance Does not Limit Physical Activity Participation in the Lifestyle Interventions and Independence for Elders Pilot Study (LIFE-P)

OBJECTIVES

We examined whether multiple domains of baseline cognitive performance were associated with prospective physical activity (PA) adherence in the Lifestyle Interventions and Independence for Elders Pilot study (LIFE-P).

DESIGN, SETTING, PARTICIPANTS

The LIFE-P study was a single-blind, multicenter, randomized controlled trial of a PA intervention compared to a successful aging educational intervention in sedentary, mobility-limited older adults.

INTERVENTION

A 12-month structured, moderate-intensity, multi-modal PA program that included walking, resistance training, and flexibility exercises. For the first 2 months (adoption), 3 center-based exercise sessions (40-60 min) / week were conducted. During the next 4 months (transition), center-based sessions were conducted 2 times / week. The subsequent maintenance phase consisted of optional once-to-twice-per-week center-based sessions and home-based PA.

MEASUREMENTS

Tests of executive and global cognitive functioning, working memory and psychomotor speed were administered at baseline. Median test scores were used to dichotomize participants into low or high cognitive performance groups.

RESULTS

52 mobility-limited older adults (age: 76.9 ±5 yrs) were randomized to the PA arm of LIFE-P. Compared to participants with high cognitive performance, participants with low performance had similar PA adherence rates (all P ≥ 0.34). Furthermore, weak and non-significant univariate relationships were elicited between all measures of cognition and overall PA adherence levels (r values ranged: -0.20 to 0.12, P ≥ 0.12).

CONCLUSION

These data suggest that cognitive performance does not limit long-term PA adherence in mobility-limited older adults. Additional studies in larger cohorts are warranted to verify these findings.

Contralateral Breast Cancer Risk in Women with Ductal Carcinoma In Situ: Is it High Enough to Justify Bilateral Mastectomy?

BACKGROUND

Women with ductal carcinoma in situ (DCIS) are increasingly choosing bilateral mastectomy. We sought to quantify rates of contralateral breast cancer (CBC) and ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery (BCS) for DCIS, and to compare risk factors for CBC and IBTR.

METHODS

From 1978 to 2011, DCIS patients undergoing BCS with a contralateral breast at risk were identified from a prospectively maintained database. The association of clinicopathologic and treatment factors with CBC and IBTR were evaluated using Kaplan-Meier analysis, multivariable Cox regression, and competing risk regression (CRR).

RESULTS

Of 2759 patients identified, 151 developed CBC and 344 developed IBTR. Five- and 10-year Kaplan-Meier CBC rates were 3.2 and 6.4%. Overall, 10-year IBTR rates were 2.5-fold higher than CBC rates, and, without radiation, 4-fold higher. On CRR, 5- and 10-year rates were 2.9 and 5.8% for CBC, and 7.8 and 14.5% for IBTR. CBC risk and invasive CBC risk were not significantly associated with age, family history, presentation, nuclear grade, year of surgery, or radiation. By multivariable Cox regression, endocrine therapy was associated with lower CBC risk (hazard ratio 0.57, p = 0.03). Ten-year risk of subsequent CBC in the subset of patients who developed IBTR was similar to the cohort as a whole (8.1 vs. 6.4%).

CONCLUSIONS

CBC rates were low across all groups, including those who experienced IBTR. CBC was not associated with factors that increase IBTR risk. While factors associated with IBTR risk are important in decision making regarding management of the index DCIS, they are not an indication for contralateral prophylactic mastectomy.