Omission of Axillary Dissection Following Nodal Downstaging With Neoadjuvant Chemotherapy

Importance

Data on oncological outcomes after omission of axillary lymph node dissection (ALND) in patients with breast cancer that downstages from node positive to negative with neoadjuvant chemotherapy are sparse. Additionally, the best axillary surgical staging technique in this scenario is unknown.

Objective

To investigate oncological outcomes after sentinel lymph node biopsy (SLNB) with dual-tracer mapping or targeted axillary dissection (TAD), which combines SLNB with localization and retrieval of the clipped lymph node.

Design, Setting, and Participants

In this multicenter retrospective cohort study that was conducted at 25 centers in 11 countries, 1144 patients with consecutive stage II to III biopsy-proven node-positive breast cancer were included between April 2013 and December 2020. The cumulative incidence rates of axillary, locoregional, and any invasive (locoregional or distant) recurrence were determined by competing risk analysis.

Exposure

Omission of ALND after SLNB or TAD.

Main Outcomes and Measures

The primary end points were the 3-year and 5-year rates of any axillary recurrence. Secondary end points included locoregional recurrence, any invasive (locoregional and distant) recurrence, and the number of lymph nodes removed.

Results

A total of 1144 patients (median [IQR] age, 50 [41-59] years; 78 [6.8%] Asian, 105 [9.2%] Black, 102 [8.9%] Hispanic, and 816 [71.0%] White individuals; 666 SLNB [58.2%] and 478 TAD [41.8%]) were included. A total of 1060 patients (93%) had N1 disease, 619 (54%) had ERBB2 (formerly HER2)-positive illness, and 758 (66%) had a breast pathologic complete response. TAD patients were more likely to receive nodal radiation therapy (85% vs 78%; P = .01). The clipped node was successfully retrieved in 97% of TAD cases and 86% of SLNB cases (without localization). The mean (SD) number of sentinel lymph nodes retrieved was 3 (2) vs 4 (2) (P < .001), and the mean (SD) number of total lymph nodes removed was 3.95 (1.97) vs 4.44 (2.04) (P < .001) in the TAD and SLNB groups, respectively. The 5-year rates of any axillary, locoregional, and any invasive recurrence in the entire cohort were 1.0% (95% CI, 0.49%-2.0%), 2.7% (95% CI, 1.6%-4.1%), and 10% (95% CI, 8.3%-13%), respectively. The 3-year cumulative incidence of axillary recurrence did not differ between TAD and SLNB (0.5% vs 0.8%; P = .55).

Conclusions and Relevance

The results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after TAD vs SLNB. These results support omission of ALND in this population.

Contrast-Enhanced Mammography for Women with Palpable Breast Abnormalities

RATIONALE AND OBJECTIVES

To examine the role of contrast-enhanced mammography (CEM) in the work-up of palpable breast abnormalities.

MATERIALS AND METHODS

In this single-center combination prospective-retrospective study, women with palpable breast abnormalities underwent CEM evaluation prospectively, comprising the acquisition of low energy (LE) images and recombined images (RI) which depict enhancement, followed by targeted ultrasound (US). Two independent readers retrospectively reviewed the imaging and assigned BI-RADS assessment based on LE alone, LE plus US, RI with LE plus US (CEM plus US), and RI alone. Pathology results or 1-year follow-up imaging served as the reference standard.

RESULTS

237 women with 262 palpable abnormalities were included (mean age, 51 years). Of the 262 palpable abnormalities, 116/262 (44%) had no imaging correlate and 242/262 (92%) were benign. RI alone had better specificity compared to LE plus US (Reader 1, 94% versus 89% (p = 0.009); Reader 2, 93% versus 88% (p = 0.03)), better positive predictive value (Reader 1, 52% versus 42% (p = 0.04); Reader 2, 53% versus 42% (p = 0.04)), and better accuracy (Reader 1, 93% versus 89% (p = 0.05); Reader 2, 93% versus 90% (p = 0.06)). CEM plus US was not significantly different in performance metrics versus LE plus US.

CONCLUSION

RI had better specificity compared to LE in combination with US. There was no difference in performance between CEM plus US and LE plus US, likely reflecting the weight US carries in radiologist decision-making. However, the results indicate that the absence of enhancement on RI in the setting of palpable lesions may help avoid benign biopsies.

Do HER2-Low Tumors Have a Distinct Clinicopathologic Phenotype?

BACKGROUND

Breast cancer subtypes, distinguished by hormone receptor (HR) and HER2 status, have different clinicopathologic features. With recognition of the clinical relevance of HER2-low, there is debate as to whether this is a distinct subtype. Our study aimed to determine whether HER2-low breast cancers have specific clinicopathologic features that differ from those of HER2-negative and HER2-positive cancers.

PATIENTS AND METHODS

A total of 11,072 patients undergoing upfront surgery from 1998 to 2010 were identified from a single-institution prospectively maintained database. HER2 status was classified by immunohistochemistry (IHC)/fluorescence in situ hybridization (FISH) as HER2 negative (41.2%), HER2 low (45%; IHC 1+ or 2+ with negative FISH), and HER2 positive (13.7%), and stratified by HR status. Univariate (UVA) and multivariable multinomial logistic regression analysis (MVA) were performed to determine associations among variables and subtypes.

RESULTS

Compared with HER2-negative tumors, HER2 low was associated with lymphovascular invasion [odds ratio (OR) 1.2, 95% confidence interval (CI) 1.06-1.36; p = 0.003], multifocality (OR 1.26, 95% CI 1.12-1.42; p < 0.001), nodal micrometastasis (OR 1.15, 95% CI 1.02-1.31; p = 0.024), and lower rates of ≥ 3 positive nodes (OR 0.77, 95% CI 0.66-0.90, p = 0.001). When stratified by HR expression, in both HR-positive and HR-negative tumors, age and multifocality were associated with HER2 low on UVA. On MVA, no variables were independently associated with both HR-negative and HR-positive/HER2-low tumors compared with HER2-negative tumors. In contrast, HER2-positive tumors, regardless of HR status, were associated with multifocality and an extensive intraductal component.

CONCLUSION

Clinicopathologic features of HER2-low tumors appear to be primarily related to HR status. Our findings do not support the characterization of HER2 low as a separate subtype.

Comparison of Axillary Lymph Nodes on Breast MRI Before and After COVID-19 Booster Vaccination

RATIONALE AND OBJECTIVES

Vaccine-related lymphadenopathy is a frequent finding following initial coronavirus disease 2019 (COVID-19) vaccination, but the frequency after COVID-19 booster vaccination is still unknown. In this study we compare axillary lymph node morphology on breast MRI before and after COVID-19 booster vaccination.

MATERIALS AND METHODS

This retrospective, single-center, IRB-approved study included patients who underwent breast MRI between October 2021 and December 2021 after the COVID-19 booster vaccination. The axillary lymph node with the greatest cortical thickness ipsilateral to the side of vaccination was measured on MRI after booster vaccination and before initial COVID-19 vaccination. Comparisons were made between patients with and without increase in cortical thickness of ≥ 0.2 cm. Continuous covariates were compared using Wilcoxon rank-sum test and categorical covariates were compared using Fisher's exact test. Multiple comparison adjustment was made using the Benjamini-Hochberg procedure.

RESULTS

All 128 patients were included. Twenty-four of 128 (19%) displayed an increase in lymph node cortical thickness of ≥ 0.2 cm. Patients who received the booster more recently were more likely to present cortical thickening, with a median of 9 days (IQR 5, 20) vs. 36 days (IQR 18, 59) (p < 0.001). Age (p = 0.5) and type of vaccine (p = 0.7) were not associated with thickening. No ipsilateral breast cancer or malignant lymphadenopathy were diagnosed on follow-up.

CONCLUSION

Axillary lymphadenopathy on breast MRI following COVID-19 booster vaccination is a frequent finding, especially in the first 3 weeks after vaccination. Additional evaluation or follow-up may be omitted in patients with low concern for malignancy.

Patient-Reported Outcomes in Patients Undergoing Lumpectomy With and Without Defect Closure

BACKGROUND

The effect of lumpectomy defect repair (a level 1 oncoplastic technique) on patient-reported breast satisfaction among patients undergoing lumpectomy has not yet been investigated.

METHODS

Patients undergoing lumpectomy at our institution between 2018 and 2020 with or without repair of their lumpectomy defect during index operation, comprised our study population. The BREAST-Q quality-of-life questionnaire was administered preoperatively, and at 6 months, 1 year, and 2 years postoperatively. Satisfaction and quality-of-life domains were compared between those who did and did not have closure of their lumpectomy defect, and compared with surgeon-reported outcomes.

RESULTS

A total of 487 patients met eligibility criteria, 206 (42%) had their partial mastectomy defect repaired by glandular displacement. Median breast volume, as calculated from the mammogram, was smaller in patients undergoing defect closure (826 cm3 vs. 895 cm3, p = 0.006). There were no statistically significant differences in satisfaction with breasts (SABTR), physical well-being of the chest (PWB-CHEST), or psychosocial well-being (PsychWB) scores between the two cohorts at any time point. While patients undergoing defect closure had significantly higher sexual well-being (SexWB) scores compared with no closure (66 vs. 59, p = 0.021), there were no predictors of improvement in SexWB scores over time on multivariable analysis. Patients' self-reported scores positively correlated with physician-reported outcomes.

CONCLUSIONS

Despite a larger lumpectomy-to-breast volume ratio among patients undergoing defect repair, satisfaction was equivalent among those whose defects were or were not repaired at 2 years postsurgery. Defect repair was associated with clinically relevant improvement in patient-reported sexual well-being.

Examining Race and Patient-Reported Outcomes After Contralateral Prophylactic Mastectomy with Reconstruction

BACKGROUND

Little is known regarding racial differences in satisfaction and quality of life (QOL) after contralateral prophylactic mastectomy (CPM). In this study, we aim to characterize associations between race, and postoperative satisfaction and well-being, utilizing the validated BREAST-Q patient-reported outcome measure.

PATIENTS AND METHODS

Patients were eligible if they were diagnosed with stage 0-III unilateral breast cancer and underwent mastectomy with immediate reconstruction at our institution between 2016 and 2022. BREAST-Q surveys were administered in routine clinical care preoperatively and postoperatively to assess QOL. We assessed whether the relationship between race, and domains of satisfaction with breasts and psychosocial well-being differed by receipt of CPM compared with unilateral mastectomy at 6 months, 1 year, 2 years, and 3 years following reconstruction.

RESULTS

Of 3334 women, 2040 (61%) underwent unilateral mastectomy and 1294 (39%) underwent CPM. Compared with White and Asian women who received CPM, Black women who underwent CPM were more likely to have higher BMI (p < 0.001), undergo autologous reconstruction (p = 0.006), and receive postmastectomy radiation (PMRT) (p < 0.001). There was no association between race and domains of satisfaction of breasts or psychosocial well-being for women who underwent unilateral mastectomy (p = 0.6 and p > 0.9, respectively) or CPM (p = 0.8 and p = 0.9, respectively). PMRT was negatively associated with both satisfaction with breasts (p < 0.001) and psychosocial well-being (p = 0.007).

CONCLUSIONS

Differences in satisfaction with breasts and psychosocial well-being at 3-year follow-up were not associated with race but rather treatment variables, particularly the receipt of PMRT. Further investigations with a larger and more diverse population are needed to validate these findings.

Artificial Intelligence Decision Support for Triple-Negative Breast Cancers on Ultrasound

OBJECTIVE

To assess performance of an artificial intelligence (AI) decision support software in assessing and recommending biopsy of triple-negative breast cancers (TNBCs) on US.

METHODS

Retrospective institutional review board-approved review identified patients diagnosed with TNBC after US-guided biopsy between 2009 and 2019. Artificial intelligence output for TNBCs on diagnostic US included lesion features (shape, orientation) and likelihood of malignancy category (benign, probably benign, suspicious, and probably malignant). Artificial intelligence true positive was defined as suspicious or probably malignant and AI false negative (FN) as benign or probably benign. Artificial intelligence and radiologist lesion feature agreement, AI and radiologist sensitivity and FN rate (FNR), and features associated with AI FNs were determined using Wilcoxon rank-sum test, Fisher's exact test, chi-square test of independence, and kappa statistics.

RESULTS

The study included 332 patients with 345 TNBCs. Artificial intelligence and radiologists demonstrated moderate agreement for lesion shape and orientation (k = 0.48 and k = 0.47, each P <.001). On the set of examinations using 6 earlier diagnostic US, radiologists recommended biopsy of 339/345 lesions (sensitivity 98.3%, FNR 1.7%), and AI recommended biopsy of 333/345 lesions (sensitivity 96.5%, FNR 3.5%), including 6/6 radiologist FNs. On the set of examinations using immediate prebiopsy diagnostic US, AI recommended biopsy of 331/345 lesions (sensitivity 95.9%, FNR 4.1%). Artificial intelligence FNs were more frequently oval (q < 0.001), parallel (q < 0.001), circumscribed (q = 0.04), and complex cystic and solid (q = 0.006).

CONCLUSION

Artificial intelligence accurately recommended biopsies for 96% to 97% of TNBCs on US and may assist radiologists in classifying these lesions, which often demonstrate benign sonographic features.

Mutational Status is Associated with a Higher Rate of Pathologic Complete Response After Neoadjuvant Chemotherapy in Hormone Receptor-Positive Breast Cancer

BACKGROUND

Pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) occurs in up to 20% of hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancers. Whether this differs among BRCA mutation carriers is uncertain. This study compared pCR between BRCA1/2 mutation carriers and matched sporadic control subjects.

METHODS

From November 2013 to January 2022, this study identified 522 consecutive women with clinical stage I to III HR+/HER2- breast cancer treated with NAC and surgery. The study matched BRCA1/2 mutation carriers 1:2 to non-carriers in terms of age, clinical tumor (cT) and nodal (cN) stage, and differentiation. Two-sample non-parametric tests compared baseline characteristics. Multivariable logistic regression assessed pCR (i.e., ypT0/ispN0) by BRCA1/2 mutational status.

RESULTS

Of the 522 women (median age, 50 years), 59 had BRCA1/2 mutations, 78% of which were clinically node positive. Anthracycline-based NAC was administered to 97%. More BRCA1/2 mutation carriers were younger, had cT1 tumors, and had poorly differentiated disease. After matching, 58 BRCA1/2 mutation carriers were similar to 116 non-carriers in terms of age (p = 0.6), cT (p = 0.9), cN stage (p = 0.7), and tumor differentiation (p > 0.9). Among the mutation carriers, the pCR rate was 15.5% for BRCA1/2, 38% (8/21) for BRCA1, and 2.7% (1/37) for BRCA2 versus 7.8% (9/116) for the non-carriers (p < 0.001). After NAC, 5 (41.7%) of the 12 BRCA1 mutation carriers converted to pN0 versus 10 (37%) of the 27 BRCA2 mutation carriers and 19 (20.9%) of the 91 non-carriers (p = 0.3). In the multivariable analysis, BRCA1 mutation status was associated with higher odds of pCR than non-carrier status (odds ratio [OR] 6.31; 95% confidence interval [CI] 1.95-20.5; p = 0.002), whereas BRCA2 mutation status was not (OR 0.45; 95% CI 0.02-2.67; p = 0.5).

CONCLUSIONS

This study showed that BRCA1 mutation carriers with HR+/HER2- breast cancers have a higher rate of pCR than sporadic cancers and may derive greater benefit from chemotherapy. The use of NAC to downstage these patients should be considered.

Association of Moderate-Risk Breast Cancer Genes with Contralateral Prophylactic Mastectomy and Bilateral Disease

BACKGROUND

The impact of ATM, CHEK2, and PALB2, the three most prevalent moderate-risk breast cancer genes, on surgical decision making is not well known.

METHODS

Our retrospective study included patients with resectable non-metastatic breast cancer who underwent multigene panel testing between July 2014 and January 2020 with at least one genetic alteration (pathogenic or variant of uncertain significance [VUS] in ATM [n = 49], CHEK [n = 57], or PALB2 [n = 27]). Our objectives were to determine the rate of contralateral prophylactic mastectomy (CPM) and the rate of bilateral breast cancer. Univariable analyses (UVA) and multivariable analyses (MVA) were performed to identify factors associated with CPM and bilateral breast cancer.

RESULTS

The rate of CPM was 39% (n = 49/127), with 54% (n = 25/46) of patients with a pathogenic mutation and 30% (n = 24/81) of patients with a VUS choosing CPM. On MVA, premenopausal status (odds ratio [OR] 3.46) and a pathogenic alteration (OR 3.01) were associated with increased use of CPM. Bilateral disease was noted in 16% (n = 22/138). Patients with pathogenic mutations had a 22% (n = 11/51) incidence of bilateral breast cancer, while patients with VUS had a 13% (n = 11/87) incidence, although this was not statistically significant on UVA or MVA. On MVA, premenopausal status was associated with a decreased risk of bilateral disease (OR 0.33, p = 0.022). During follow-up, a breast cancer event occurred in 16% (n = 22/138).

CONCLUSIONS

Our study identified a high rate of CPM among those with ATM, CHEK2, and PALB2 alterations, including VUS. Further studies are needed to clarify reasons for CPM among patients with moderate-risk alterations.

Short-term follow-up of contrast-enhanced mammography lesions after negative breast MRI in women with elevated breast cancer risk

PURPOSE

To determine the outcome of enhancing lesions detected on contrast-enhanced mammography (CEM) that had no correlate on magnetic resonance imaging (MRI) and underwent short-term follow-up CEM.

METHODS

In this retrospective single-center study, we identified patients with elevated breast cancer risk who had a CEM between 2014 and 2021 showing indeterminate enhancement on recombined images (BI-RADS 0, 3, 4) that had no correlate on subsequent MRI (performed within one month), and therefore underwent short-term follow-up CEM (performed within eight months). Medical records and imaging studies were reviewed to collect data on patient and lesion characteristics, and outcomes. Cancer incidence with 95% confidence interval (CI) was calculated.

RESULTS

This study included 71 women (median age 49 years) with 81 enhancing CEM lesions who underwent short-term follow-up CEM (median 6.2 months) after MRI reported no correlate. Of 81 lesions (median size = 0.7 cm), 73 (90%) were non-mass enhancement and 8 (10%) were enhancing masses. No sonographic correlate was identified for 75 lesions that had a same-day targeted ultrasound. Two cancers (2.5%, 95% CI 0.3-8.6) were diagnosed during the short-term follow-up period, one at 6-months (invasive ductal carcinoma) and one at 12-months (ductal carcinoma in situ). The remaining 79 lesions were benign at 6-month follow-up CEM and at one-year mammographic follow-up.

CONCLUSIONS

Follow-up CEM of MRI-occult lesions is prudent and may be reasonable to perform at one-year given the low incidence of cancer detected at six-months (one of 81) in our small study sample.

Satisfaction and Well-Being After Contralateral Prophylactic Mastectomy Among BRCA Mutation Carriers and Noncarriers: A Longitudinal Analysis of BREAST-Q Domains

INTRODUCTION

Contralateral prophylactic mastectomy (CPM) is recommended for BRCA mutation carriers; its use in noncarriers relies on patient choice. We characterized differences in satisfaction and well-being after CPM between BRCA carriers and noncarriers.

METHODS

BREAST-Q data were obtained before and after CPM with immediate reconstruction performed at a single institution from 2016 to 2022. Associations between BRCA status and satisfaction with breasts, psychosocial well-being, and sexual well-being were assessed, with adjustment for preoperative scores and relevant confounders.

RESULTS

In total, 149 BRCA carriers and 842 noncarriers were included. Response rates varied over time (preoperative, 56%; 6 months, 78%; 1 year, 51%; 2 years, 52%; 3 years, 59%). BRCA carriers were younger (p < 0.001), with a higher rate of neoadjuvant chemotherapy (p < 0.001). More noncarriers had HR+/HER2- tumors (p < 0.001) and underwent endocrine therapy (p < 0.001). Baseline satisfaction with breasts was higher among BRCA carriers (median [interquartile range] score, 70 [53-82] vs. 58 [48-70]; p = 0.006); psychosocial (p = 0.20) and sexual (p = 0.14) well-being were not significantly different between groups. BRCA carriers had a greater decrease in satisfaction with breasts (p = 0.04) and psychological well-being (p = 0.05) from baseline to 6 months; decrease in sexual well-being (p = 0.38) was not significantly different between groups. On univariate and multivariable analyses, BRCA status was not associated with satisfaction with breasts, sexual well-being, or psychosocial well-being.

CONCLUSIONS

Satisfaction and well-being were similar between BRCA carriers and noncarriers treated with CPM. Relative to noncarriers, BRCA carriers experienced a greater decline in satisfaction with breasts and psychological well-being at 6 months after CPM.

Long-Term Patient-Reported Outcomes Comparing Oncoplastic Breast Surgery and Conventional Breast-Conserving Surgery: A Propensity Score-Matched Analysis

INTRODUCTION

Oncoplastic breast surgery (OBS) combines plastic surgery techniques with conventional breast-conserving surgery (BCS) and expands BCS eligibility. Limited data are available on patient-reported outcomes (PROs) after OBS. Here we compare long-term PROs after OBS and BCS utilizing the BREAST-Q.

PATIENTS AND METHODS

Women undergoing OBS or BCS between 2006 and 2019 who completed ≥ 1 long-term BREAST-Q survey 3-5 years postoperatively were identified. Baseline characteristics were compared between women who underwent OBS/BCS. Women who underwent OBS were paired with those who underwent BCS using 1:2 propensity matching [by age, body mass index (BMI), race, T stage, and multifocality]. BREAST-Q scores were compared preoperatively and 3-5 years postoperatively.

RESULTS

A total of 297 patients were included for analysis (99 OBS/198 BCS). Women who underwent OBS were younger (p < 0.001) and had higher BMI (p = 0.005) and multifocal disease incidence (p = 0.004). There was no difference between groups in nodal stage, re-excision rates, axillary surgery, chemotherapy, endocrine therapy, or radiotherapy. After propensity matching preoperatively, women who underwent OBS reported lower psychosocial well-being (63 versus 100, p = 0.039) but similar breast satisfaction and sexual well-being compared with women who underwent BCS; however, only three patients who underwent BCS had preoperative BREAST-Q scores available for review. In long-term follow-up, women who underwent OBS reported lower psychosocial scores (74 versus 93, p = 0.011) 4 years postoperatively, but not at 5 years (76 versus 77, p = 0.83). There was no difference in long-term breast satisfaction or sexual well-being.

CONCLUSIONS

Women who undergo OBS present with a larger disease burden and may represent a group of non-traditional BCS candidates; they reported similar long-term breast satisfaction and sexual well-being compared with women who undergo BCS. While women who underwent OBS reported lower psychosocial well-being scores preoperatively and during a portion of the follow-up period, this difference was no longer seen at 5 years postoperatively.

High-Temporal/High-Spatial Resolution Breast Magnetic Resonance Imaging Improves Diagnostic Accuracy Compared With Standard Breast Magnetic Resonance Imaging in Patients With High Background Parenchymal Enhancement

PURPOSE

To compare breast magnetic resonance imaging (MRI) diagnostic performance using a standard high-spatial resolution protocol versus a simultaneous high-temporal/high-spatial resolution (HTHS) protocol in women with high levels of background parenchymal enhancement (BPE).

MATERIALS AND METHODS

We conducted a retrospective study of contrast-enhanced breast MRIs performed at our institution before and after the introduction of the HTHS protocol. We compared diagnostic performance of the HTHS and standard protocol by comparing cancer detection rate (CDR) and positive predictive value of biopsy (PPV3) among women with high BPE (ie, marked or moderate).

RESULTS

Among women with high BPE, the HTHS protocol demonstrated increased CDR (23.6 per 1,000 patients v 7.9 per 1,000 patients; P = 0. 013) and increased PPV3 (16.0% v 6.3%; P = .021) compared with the standard protocol. This corresponded to a 9.8% (95% CI, 1.29 to 18.3) decrease in the proportion of unnecessary biopsies among high-BPE patients and an additional cancer yield of 15.7 per 1,000 patients (95% CI, 1.3 to 18.3).

CONCLUSION

Among women with high BPE, HTHS MRI improved diagnostic performance, leading to an additional cancer yield of 15.7 cancers per 1,000 women and concomitantly decreasing unnecessary biopsies by 9.8%. A multisite prospective trial is warranted to confirm these findings and to pave the way for more widespread clinical implementation.

A Review of the Estimation of Sensitivity and Specificity in the Context of Time-Dependent Outcomes

Time is an essential element in the field of survival analysis. Time to an event is essential in adjudicating diagnostic utility and determining the effectiveness of treatment. However, time-to-event outcomes-in a sense-are complicated to deal with, since they involve both a binary component, which is the outcome itself (death or recurrence) and a continuous component, which is the time for the occurrence of the outcome. In such scenarios, simpler metrics such as sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve are insufficient to establish the utility of a diagnostic marker. Given the above constraint, this review discusses established ways in which sensitivity and specificity can be determined and are therefore sufficient in establishing utility in the context of time-dependent outcomes. This review also discusses how studies investigating the sensitivity and specificity of a diagnostic marker in the context of time-dependent outcomes can be improved through the use of existing user-friendly statistical software. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 3.

Does Non-Classic Lobular Carcinoma In Situ at the Lumpectomy Margin Increase Local Recurrence?

BACKGROUND

The clinical significance of nonclassic, lobular carcinoma in situ (NC-LCIS) at the surgical margin of excisions for invasive cancer is unknown. We sought to determine whether NC-LCIS at or near the margin in the setting of a concurrent invasive carcinoma is associated with risk of ipsilateral breast tumor recurrence (IBTR) and locoregional recurrence (LRR).

METHODS

Patients with stage 0-III breast cancer and NC-LCIS who underwent lumpectomy between January 2010 and January 2022 at a single institution were retrospectively identified. NC-LCIS margins were stratified as <2 mm, ≥2 mm, or within shave margin. Rates of IBTR and LRR were examined.

RESULTS

A total of 511 female patients (median age 60 years [interquartile range (IQR) 52-69]) with NC-LCIS and an associated ipsilateral breast cancer with a median follow-up of 3.4 years (IQR 2.0-5.9) were identified. Final margins for NC-LCIS were ≥2 mm in 348 patients (68%), <2 mm in 37 (7.2%), and within shave margin in 126 (24.6%). Crude incidence of IBTR was 3.3% (n = 17) and that of LRR was 4.9% (n = 25). There was no difference in the crude rate of IBTR by NC-LCIS margin status (IBTR rate: 3.7% ≥2 mm, 0% <2 mm, 3.2% within shave margin, p = 0.8) nor in LRR (LRR rate: 4.9% ≥2 mm, 2.7% <2 mm, 5.6% within shave margin, p = 0.9).

CONCLUSIONS

For completely excised invasive breast cancers associated with NC-LCIS, extent of margin width for NC-LCIS was not associated with a difference in IBTR or LRR. These data suggest that the decision to perform reexcision of margin after lumpectomy should be driven by the invasive cancer, rather than the NC-LCIS margin.

Automated Triage of Screening Breast MRI Examinations in High-Risk Women Using an Ensemble Deep Learning Model

OBJECTIVES

The aim of the study is to develop and evaluate the performance of a deep learning (DL) model to triage breast magnetic resonance imaging (MRI) findings in high-risk patients without missing any cancers.

MATERIALS AND METHODS

In this retrospective study, 16,535 consecutive contrast-enhanced MRIs performed in 8354 women from January 2013 to January 2019 were collected. From 3 New York imaging sites, 14,768 MRIs were used for the training and validation data set, and 80 randomly selected MRIs were used for a reader study test data set. From 3 New Jersey imaging sites, 1687 MRIs (1441 screening MRIs and 246 MRIs performed in recently diagnosed breast cancer patients) were used for an external validation data set. The DL model was trained to classify maximum intensity projection images as "extremely low suspicion" or "possibly suspicious." Deep learning model evaluation (workload reduction, sensitivity, specificity) was performed on the external validation data set, using a histopathology reference standard. A reader study was performed to compare DL model performance to fellowship-trained breast imaging radiologists.

RESULTS

In the external validation data set, the DL model triaged 159/1441 of screening MRIs as "extremely low suspicion" without missing a single cancer, yielding a workload reduction of 11%, a specificity of 11.5%, and a sensitivity of 100%. The model correctly triaged 246/246 (100% sensitivity) of MRIs in recently diagnosed patients as "possibly suspicious." In the reader study, 2 readers classified MRIs with a specificity of 93.62% and 91.49%, respectively, and missed 0 and 1 cancer, respectively. On the other hand, the DL model classified MRIs with a specificity of 19.15% and missed 0 cancers, highlighting its potential use not as an independent reader but as a triage tool.

CONCLUSIONS

Our automated DL model triages a subset of screening breast MRIs as "extremely low suspicion" without misclassifying any cancer cases. This tool may be used to reduce workload in standalone mode, to shunt low suspicion cases to designated radiologists or to the end of the workday, or to serve as base model for other downstream AI tools.

Multisite MRI Intravoxel Incoherent Motion Repeatability and Reproducibility across 3 T Scanners in a Breast Diffusion Phantom: A BReast Intravoxel Incoherent Motion Multisite (BRIMM) Study

BACKGROUND

Monoexponential apparent diffusion coefficient (ADC) and biexponential intravoxel incoherent motion (IVIM) analysis of diffusion-weighted imaging is helpful in the characterization of breast tumors. However, repeatability/reproducibility studies across scanners and across sites are scarce.

PURPOSE

To evaluate the repeatability and reproducibility of ADC and IVIM parameters (tissue diffusivity (Dt ), perfusion fraction (Fp ) and pseudo-diffusion (Dp )) within and across sites employing MRI scanners from different vendors utilizing 16-channel breast array coils in a breast diffusion phantom.

STUDY TYPE

Phantom repeatability.

PHANTOM

A breast phantom containing tubes of different polyvinylpyrrolidone (PVP) concentrations, water, fat, and sponge flow chambers, together with an MR-compatible liquid crystal (LC) thermometer.

FIELD STRENGTH/SEQUENCE

Bipolar gradient twice-refocused spin echo sequence and monopolar gradient single spin echo sequence at 3 T.

ASSESSMENT

Studies were performed twice in each of two scanners, located at different sites, on each of 2 days, resulting in four studies per scanner. ADCs of the PVP and water were normalized to the vendor-provided calibrated values at the temperature indicated by the LC thermometer for repeatability/reproducibility comparisons.

STATISTICAL TESTS

ADC and IVIM repeatability and reproducibility within and across sites were estimated via the within-system coefficient of variation (wCV). Pearson correlation coefficient (r) was also computed between IVIM metrics and flow speed. A P value <0.05 was considered statistically significant.

RESULTS

ADC and Dt demonstrated excellent repeatability (<2%; <3%, respectively) and reproducibility (both <5%) at the two sites. Fp and Dp exhibited good repeatability (mean of two sites 3.67% and 5.59%, respectively) and moderate reproducibility (mean of two sites 15.96% and 13.3%, respectively). The mean intersite reproducibility (%) of Fp /Dp /Dt was 50.96/13.68/5.59, respectively. Fp and Dt demonstrated high correlations with flow speed while Dp showed lower correlations. Fp correlations with flow speed were significant at both sites.

DATA CONCLUSION

IVIM reproducibility results were promising and similar to ADC, particularly for Dt . The results were reproducible within both sites, and a progressive trend toward reproducibility across sites except for Fp .

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 1.

The Impact of Breast-Conserving Surgery Re-excision on Patient-Reported Outcomes Using the BREAST-Q

BACKGROUND

Approximately 14% of women undergoing breast-conserving surgery (BCS) require re-excision to achieve negative margins following the Society of Surgical Oncology (SSO) and American Society for Radiation Oncology (ASTRO) margin guidelines, which may influence patient-reported outcomes (PROs). Few studies have assessed the impact of re-excision on PROs following BCS.

PATIENTS AND METHODS

Women with stage 0-III breast cancer undergoing BCS who completed a BREAST-Q PRO measure from 2010 to 2016 were identified from a prospective database. Baseline characteristics were compared between women who underwent one BCS and those who underwent ≥ 1 re-excision surgery for positive margins (R-BCS). Linear mixed models were used to analyze associations between number of excisions and BREAST-Q scores over time.

RESULTS

Of 2543 eligible women, 1979 (78%) had one BCS and 564 (22%) had R-BCS. Younger age, lower BMI, surgery pre-SSO Invasive Guidelines issuance, ductal carcinoma in situ (DCIS), multifocal disease, radiation therapy receipt, and endocrine therapy omission were more common in the R-BCS group. Breast satisfaction and sexual well-being were lower in the R-BCS group 2 years postoperatively. There were no differences in psychosocial well-being between groups over 5 years. On multivariable analysis, re-excision was associated with lower breast satisfaction and sexual well-being (p= 0.007 and p= 0.049, respectively), but there was no difference in psychosocial well-being (p= 0.250).

CONCLUSIONS

Women with R-BCS had lower breast satisfaction and sexual well-being 2 years postoperatively, but this difference did not remain long term. Psychosocial well-being in women who underwent one BCS were largely comparable over time to the R-BCS group. These findings may help in counseling women who are concerned about satisfaction and quality-of-life outcomes with BCS if re-excision is necessary.

Misclassification simulation extrapolation method for a Weibull accelerated failure time model

The problem of misclassification in covariates is ubiquitous in survival data and often leads to biased estimates. The misclassification simulation extrapolation method is a popular method to correct this bias. However, its impact on Weibull accelerated failure time models has not been studied. In this paper, we study the bias caused by misclassification in one or more binary covariates in Weibull accelerated failure time models and explore the use of the misclassification simulation extrapolation in correcting for this bias, along with its asymptotic properties. Simulation studies are carried out to investigate the numerical properties of the resulting estimator for finite samples. The proposed method is then applied to colon cancer data obtained from the cancer registry at Memorial Sloan Kettering Cancer Center.

A Diagnostic Dilemma: New Enhancing Suspicious Findings on Breast MRI Following Neoadjuvant Chemotherapy

OBJECTIVE

Evaluate the incidence and outcome of new enhancing findings on breast MRI after neoadjuvant chemotherapy (NAC).

METHODS

This IRB-approved retrospective review included women with breast cancer undergoing MRI to evaluate NAC response at our institution from January 1, 1998 to March 3, 2021. Post-NAC MRIs given BI-RADS 4 or 5 with new enhancing findings were identified. Patients were excluded if they lacked pretreatment MRI or insufficient follow-up, or if the finding was a satellite of the primary tumor. Medical records and imaging studies were reviewed to identify patients and to find characteristics and outcomes.

RESULTS

Over the study period, 2880 post-NAC breast MRIs were performed. Of 128 post-NAC MRIs given BI-RADS 4 or 5 (4.4%), 35 new suspicious findings were found on 32 MRIs, incidence rate 1.1% (32/2880). Most were characterized as nonmass enhancement (17/35, 49%), followed by mass (11/35, 31%), and then focus (7/35, 20%), with an average maximum dimension of 1.3 cm (range 0.3-7.1 cm). New findings were ipsilateral to the index cancer in 20/35 (57%) of cases. Of the 35 suspicious findings, 22 underwent image-guided biopsy (62%), 1 was surgically excised (3%), 7 underwent mastectomy (20%), 5 were stable or resolved on follow-up (8%), and none were malignant. Thirty-three were benign (94%), and two were benign high-risk lesions (atypical ductal hyperplasia, radial scar) (6%).

CONCLUSION

New suspicious breast MRI findings after NAC are uncommon with a low likelihood of malignancy. Further study is warranted using multi-institutional data for this low incidence finding.

Factors Affecting Antidepressant Response Trajectories: A Veterans Affairs Augmentation and Switching Treatments for Improving Depression Outcomes Trial Report

Background

In this secondary analysis of the VA Augmentation and Switching Treatments for Improving Depression Outcomes (VAST-D) study we used antidepressant response trajectories to assess the association of treatment and multiple clinical/demographic factors with the probability of response.

Methods

Using data from VAST-D, a multi-site, randomized, single-blind trial with parallel-assignment to one of three treatment interventions in 1522 Veterans whose major depressive disorder was unresponsive to at least one antidepressant trial, we evaluated response patterns using group-based trajectory modeling (GBTM). A weighted multinomial logistic regression analysis with backward elimination and additional exploratory analyses were performed to evaluate the association of multiple clinical/demographic factors with the probability of inclusion into specific trajectories. Additional exploratory analyses were used to identify factors associated with trajectory group membership that could have been missed in the primary analysis.

Results

GBTM showed the best fit for depression symptom change was comprised of six trajectories, with some trajectories demonstrating minimal improvement and others showing a high probability of remission. High baseline depression and anxiety severity scores decreased, and early improvement increased, the likelihood of inclusion into the most responsive trajectory in both the GBTM and exploratory analyses.

Conclusion

While multiple factors influence responsiveness, the probability of inclusion into a specific depression symptom trajectory is most strongly influenced by three factors: baseline depression, baseline anxiety, and the presence of early improvement.

Is Surgical Excision of Focal Atypical Ductal Hyperplasia Warranted? Experience at a Tertiary Care Center

BACKGROUND

The core-needle biopsy (CNB) diagnosis of atypical ductal hyperplasia (ADH) generally mandates follow-up excision, but controversy exists on whether small foci of ADH require surgical management. This study evaluated the upgrade rate at excision of focal ADH (fADH), defined as 1 focus spanning ≤ 2 mm.

METHODS

We retrospectively identified in-house CNBs with ADH as the highest-risk lesion obtained between January 2013 and December 2017. A radiologist assessed radiologic-pathologic concordance. All CNB slides were reviewed by two breast pathologists, and ADH was classified as fADH and nonfocal ADH based on extent. Only cases with follow-up excision were included. The slides of excision specimens with upgrade were reviewed.

RESULTS

The final study cohort consisted of 208 radiologic-pathologic concordant CNBs, including 98 fADH and 110 nonfocal ADH. The imaging targets were calcifications (n = 157), a mass (n = 15), nonmass enhancement (n = 27), and mass enhancement (n = 9). Excision of fADH yielded seven (7%) upgrades (5 ductal carcinoma in situ (DCIS), 2 invasive carcinoma) versus 24 (22%) upgrades (16 DCIS, 8 invasive carcinoma) at excision of nonfocal ADH (p = 0.01). Both invasive carcinomas found at excision of fADH were subcentimeter tubular carcinomas away from the biopsy site and deemed incidental.

CONCLUSIONS

Our data show a significantly lower upgrade rate at excision of focal ADH than nonfocal ADH. This information can be valuable if nonsurgical management of patients with radiologic-pathologic concordant CNB diagnosis of focal ADH is being considered.

Improving access to breast cancer screening and treatment in Nigeria: The triple mobile assessment and patient navigation model (NCT05321823): A study protocol

BACKGROUND

In Nigeria, breast cancer incidence is rising, late presentation is common, and outcomes are poor. Patient-related factors such as lack of awareness and misperceptions in addition to health system deficiencies such as lack of a clearly defined framework for breast cancer screening and referral are some of the major drivers of this poor outlook. Guidelines for breast cancer screening in high-income countries have limited applicability in low-middle-income countries, hence the need for innovative, resource-compatible strategies to combat the negative trend. This manuscript presents our study protocol which aims to evaluate the impact of a novel breast cancer early detection program developed to address delayed presentation and lack of access to diagnostic and treatment facilities in South-West Nigeria. This entails the use of mobile technology (innovative handheld iBreast Exam [iBE] device, mobile breast ultrasound, and mobile mammography) and patient navigation as interventions at the community level.

METHODS

The study (ClinicalTrials.gov identifier: NCT05321823) will adopt a randomized two group clinical trial design with one local government area (LGA) serving as an intervention arm and another serving as the control. Both LGAs will receive breast cancer awareness education but only one will receive the interventions. In the intervention arm, asymptomatic (40-70 years) and symptomatic (30-70 years) women will be invited for breast evaluation which will be performed by trained Community Health Nurses using Clinical Breast Exam (CBE), and iBE. Those with positive findings will proceed to imaging using mobile mammography and ultrasound brought to the LGA every month. Symptomatic women with negative findings on CBE and iBE will be scheduled for repeat clinical evaluation on a short-term basis (one month). The Radiologist will obtain core needle biopsies as indicated and transfer them for prompt pathological assessment. Women presenting to the Primary Healthcare Centers in the control LGA will be referred directly to Obafemi Awolowo University Teaching Hospitals Complex as per the current standard of care. Records of all breast cancer cases seen in the two LGAs during the study period will be obtained. The program metrics will include screening participation rate, cancer detection rate, stage at diagnosis, and timeline from detection to initiation of treatment. The stage at diagnosis and timeline from detection to treatment compared between the two LGAs will be used to assess the impact of the intervention. The study is proposed for 2 years; however, a descriptive analysis will be carried out at 1.5 years to evaluate the retention of the study participants.

STUDY SIGNIFICANCE

It is anticipated that this study will provide vital data to support wider breast cancer screening efforts in Nigeria.

Strategies to avoid mastectomy skin-flap necrosis during nipple-sparing mastectomy

BACKGROUND

Nipple-sparing mastectomy is associated with a higher risk of mastectomy skin-flap necrosis than conventional skin-sparing mastectomy. There are limited prospective data examining modifiable intraoperative factors that contribute to skin-flap necrosis after nipple-sparing mastectomy.

METHODS

Data on consecutive patients undergoing nipple-sparing mastectomy between April 2018 and December 2020 were recorded prospectively. Relevant intraoperative variables were documented by both breast and plastic surgeons at the time of surgery. The presence and extent of nipple and/or skin-flap necrosis was documented at the first postoperative visit. Necrosis treatment and outcome was documented at 8-10 weeks after surgery. The association of clinical and intraoperative variables with nipple and skin-flap necrosis was analysed, and significant variables were included in a multivariable logistic regression analysis with backward selection.

RESULTS

Some 299 patients underwent 515 nipple-sparing mastectomies (54.8 per cent (282 of 515) prophylactic, 45.2 per cent therapeutic). Overall, 23.3 per cent of breasts (120 of 515) developed nipple or skin-flap necrosis; 45.8 per cent of these (55 of 120) had nipple necrosis only. Among 120 breasts with necrosis, 22.5 per cent had superficial, 60.8 per cent had partial, and 16.7 per cent had full-thickness necrosis. On multivariable logistic regression analysis, significant modifiable intraoperative predictors of necrosis included sacrificing the second intercostal perforator (P = 0.006), greater tissue expander fill volume (P < 0.001), and non-lateral inframammary fold incision placement (P = 0.003).

CONCLUSION

Modifiable intraoperative factors that may decrease the likelihood of necrosis after nipple-sparing mastectomy include incision placement in the lateral inframammary fold, preserving the second intercostal perforating vessel, and minimizing tissue expander fill volume.

A role for breast ultrasound Artificial Intelligence decision support in the evaluation of small invasive lobular carcinomas

OBJECTIVE

To evaluate the diagnostic performance of an Artificial Intelligence (AI) decision support (DS) system in the ultrasound (US) assessment of invasive lobular carcinoma (ILC) of the breast, a cancer that can demonstrate variable appearance and present insidiously.

METHODS

Retrospective review was performed of 75 patients with 83 ILC diagnosed by core biopsy or surgery between November 2017 and November 2019. ILC characteristics (size, shape, echogenicity) were recorded. AI DS output (lesion characteristics, likelihood of malignancy) was compared to radiologist assessment.

RESULTS

The AI DS system interpreted 100% of ILCs as suspicious or probably malignant (100% sensitivity, and 0% false negative rate). 99% (82/83) of detected ILCs were initially recommended for biopsy by the interpreting breast radiologist, and 100% (83/83) were recommended for biopsy after one additional ILC was identified on same-day repeat diagnostic ultrasound. For lesions in which the AI DS output was probably malignant, but assigned a BI-RADS 4 assessment by the radiologist, the median lesion size was 1 cm, compared with a median lesion size of 1.4 cm for those given a BI-RADS 5 assessment (p = 0.006). These results suggest that AI may offer more useful DS in smaller sub-centimeter lesions in which shape, margin status, or vascularity is more difficult to discern. Only 20% of patients with ILC were assigned a BI-RADS 5 assessment by the radiologist.

CONCLUSION

The AI DS accurately characterized 100% of detected ILC lesions as suspicious or probably malignant. AI DS may be helpful in increasing radiologist confidence when assessing ILC on ultrasound.

Preoperative localization of breast lesions: Comparing digital breast tomosynthesis-guided radioactive seed localization versus standard 2D stereotactic radioactive seed localization

PURPOSE

To compare single seed digital breast tomosynthesis-guided radioseed localization (DBT-L) to standard 2D stereotactic-guided radioseed localization (SGL) of the breast.

METHODS

A retrospective review of a large tertiary cancer center's database yielded 68 women who underwent preoperative DBT-L from March 2019-December 2019 and a matched cohort of 65 women who underwent SGL during the same period. The electronic medical record and radiology were reviewed for patient characteristics including breast density, exam technique, pre- and post-operative pathology, exam duration, and radiation dose to the patient. To compare margin outcomes between the groups, the chi-square test of independence was used; to compare continuous outcomes such as exam duration and total dose, the Wilcoxon rank sum test was used.

RESULTS

DBT-L and SGL localization targets included biopsy marker (62/68, 91% vs 55/65, 85%), distortion (4/68, 6% vs 2/65, <3%), focal asymmetry (1/68 and 1/65, < 2% for both), calcifications (1/68, <2% vs 4/65, 6%), and anatomic landmarks (0% vs 3/65, 5%). 72% and 71% of localizations were performed for malignant pathology in the DBT-L and SGL groups, respectively. The median duration of DBT-L was 8.3 min vs 10.3 min for SGL, representing statistically significant time savings (p = 0.003). The median total organ dose of DBT-L was 8.6 mGy vs 10.4 mGy for SGL, representing statistically significant dose savings (p = 0.018). The incidence of positive margins at surgery was not statistically different between the groups (p = 0.26).

CONCLUSION

DBT-L demonstrates both time and dose savings for the patient compared to SGL without compromising surgical outcome.

Contrast-enhanced mammography in the assessment of residual disease after neoadjuvant treatment

PURPOSE

To investigate the utility of contrast-enhanced mammography (CEM) as an alternative to breast MRI for the evaluation of residual disease after neoadjuvant treatment (NAT).

METHODS

This prospective study enrolled consecutive women undergoing NAT for breast cancer from July 2017-July 2019. Breast MRI and CEM exams performed after completion of NAT were read independently by two breast radiologists. Residual disease and lesion size on MRI and CEM recombined (RI) and low-energy images (LEI) were compared. Histopathology was considered the reference standard. Statistical analysis was performed using McNemar's and Leisenring's tests. Multiple comparison adjustment was made using Bonferroni procedure. Lesion sizes were correlated using Kendall's tau coefficient.

RESULTS

There were 110 participants with 115 breast cancers. Residual disease (invasive cancer or ductal carcinoma in situ) was detected in 83/115 (72%) lesions on pathology, 71/115 (62%) on MRI, 55/115 (48%) on CEM RI, and 75/115 (65%) on CEM LEI. When using multiple comparison adjustment, no significant differences were detected between MRI combined with CEM LEI and CEM RI combined with CEM LEI, in terms of accuracy (MRI: 77%, CEM: 72%; p ≥ 0.99), sensitivity (MRI: 88%, CEM: 81%; p ≥ 0.99), specificity (MRI: 47%, CEM: 50%; p ≥ 0.99), PPV (MRI: 81%, CEM: 81%; p ≥ 0.99), or NPV (MRI: 60%, CEM: 50%; p ≥ 0.99). Size correlation between pathology and both MRI combined with CEM LEI and CEM RI combined with CEM LEI was moderate: τ = 0. 36 vs 0.33 (p ≥ 0.99).

CONCLUSION

Contrast-enhanced mammography is an acceptable alternative to breast MRI for the detection of residual disease after neoadjuvant treatment.

Abstract P5-08-09: Does Breast Inflammation Contribute to Lymphedema Risk in Patients Treated with Axillary Lymph Node Dissection?

Background Chronic inflammatory responses initiated by lymphatic injury play a key role in the pathophysiology of secondary lymphedema. However, it is unclear if baseline inflammation or ethnic/racial variability in inflammatory responses increase lymphedema risk. Crown-like structures of the breast (CLS-B), consisting of macrophages engulfing necrotic adipocytes, are a marker of systemic inflammation and have been implicated in the pathogenesis of breast cancer, but their role in lymphedema development is unknown. Here we determine whether baseline differences in inflammation, characterized by the presence of CLS-B, contributed to lymphedema risk in a diverse cohort of patients treated with ALND.

Methods Patients ≥ 18 years undergoing ALND were enrolled in a prospective lymphedema screening study. Body mass index (BMI) and volumetric arm measurements (perometer) were performed at baseline, postoperatively, and every 6 months. Breast tissue obtained at definitive surgery was assessed for CLS-B with CD-68 IHC stain in non-tumor breast tissue. Inflammation severity was determined by number of CLS-B/cm2, with the median used to differentiate between mild and severe inflammation. Lymphedema was defined as a relative arm volume change of ≥10%. Lymphedema incidence was assessed using competing risk analysis and compared between patients with and without CLS-B. Uni- and multivariable analysis was performed to identify factors associated with lymphedema development.

Results Between 11/2016-03/2020, 304 ALND patients were enrolled; 281 had at least 6 months of follow-up and were included in the study. Eleven percent self-identified as Asian, 20% Black, 6% Hispanic, and 60% White. Median age was 48 years; median BMI was 26.3 kg/m2, with higher BMI observed in Black and Hispanic women compared to Asian and White women (p &lt; 0.001). Overall, 54% had CLS-B, with severe inflammation (&gt; 0.4 CLS-B/cm2) identified in 71 (25%) patients. CLS-B presence correlated with BMI (36% [BMI &lt; 25], 63% [BMI 25-30], 70% [BMI &gt; 30], p &lt; 0.001) and varied across racial/ethnic groups, with a higher prevalence in Black and Hispanic women (68% [Black], 69% [Hispanic] vs 59% [Asian], 46% [White], p = 0.03) (Table). Inflammation severity did not differ by race/ethnicity (p = 0.11). At 2.1 years median follow-up (IQR 1.6-3.1), 66 women developed lymphedema, with a 2-year lymphedema rate of 21.3% (95% CI 16.4-26.8). Lymphedema incidence was higher among Black and Hispanic women, compared to Asian and White women (2-year rate: 33.8% [Black], 31% [Hispanic], 17.4% [Asian], 18.2% [White], p = 0.002), and was higher among women with CLS-B (2-year rate: 28.2% [CLS-B] vs 12.9% [no CLS-B], p = 0.02). On multivariable analysis, Black race (White [referent]: HR 2.85, 95% CI 1.4-5.8; p = 0.03), receipt of NAC (upfront surgery [referent]: HR 2.46, 95% CI 1.04-5.8, p = 0.04) and older age (HR 1.03, 95% CI 1.01-1.06 per 1-year increase; p = 0.009) were independently associated with lymphedema development, while CLS-B was not (HR 1.37, 95% CI 0.81-2.34, p = 0.2).

Conclusions In a prospective cohort of patients treated with ALND, Black race, receipt of NAC, and increasing age, but not CLS-B, were independently associated with lymphedema risk. However, the higher CLS-B prevalence in Black women suggests that they may have a propensity for increased inflammation, which may in part be contributing to the higher lymphedema risk observed, but is likely not the only inflammatory mechanism that modulates risk.

Table. Clinical characteristics of study cohort stratified by the presence of CLS-B

Citation Format: Andrea V. Barrio, Giacomo Montagna, Varadan Sevilimedu, Ethan Gomez, Dilip Giri, Babak Mehrara, Monica Morrow. Does Breast Inflammation Contribute to Lymphedema Risk in Patients Treated with Axillary Lymph Node Dissection? [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 P5-08-09.

Abstract GS4-02: Oncological Outcomes Following Omission of Axillary Lymph Node Dissection in Node Positive Patients Downstaging To Node Negative with Neoadjuvant Chemotherapy: the OPBC-04/EUBREAST-06/OMA study

Background: Data on the oncologic safety of omission of axillary lymph node dissection (ALND) in node positive (N+) patients who downstage to ypN0 with neoadjuvant chemotherapy (NAC) is sparse. Additionally, there is no consensus on which axillary staging procedure should be used in this setting, sentinel lymph node biopsy (SLNB) alone or in combination with localization and retrieval of the clipped positive node, also known as targeted axillary dissection (TAD). Whether the reduction in the false negative rate observed with TAD translates into a significant reduction in the rate of axillary recurrence is unknown. We sought to evaluate oncologic outcomes after omission of ALND in a large, real-world cohort of breast cancer (BC) patients and to compare rates of axillary recurrence after SLNB with dual tracer mapping vs. TAD.

Methods: Data were collected from 19 centers in the Oncoplastic Breast Consortium (OPBC) and EUBREAST networks. Patients with T1-4 biopsy-proven N1-3 BC who underwent NAC followed by axillary staging with either SLNB with dual tracer mapping or TAD and who were pathologically node negative (ypN0) were included. ypN0 was defined as the absence of any tumor or isolated tumor cells. Competing risk analysis was performed to assess the cumulative incidence rates of axillary recurrence, locoregional recurrence, and any invasive (locoregional or distant) recurrence. Two-year cumulative incidence rates were compared between TAD and SLNB using the Gray’s test. Type I error rate was set to 0.05 (α).

Results: We included 785 patients (565 treated with SLNB and 220 with TAD) treated with NAC followed by surgery from 01/2014-12/2020. Median patient age was 50 years. The majority (57%) of patients had clinical T2 tumors, and 95% had N1 disease. Most (55%) were HER2+, and 21% were triple negative. Most patients (81%) received anthracycline and taxane-based chemotherapy regimens, but NAC regimens differed between patients treated with TAD and those treated with SLNB (Table 1). All patients with HER2+ tumors received anti HER2 therapy. Nodal radiotherapy was administered to 76% of patients, and was more common in patients who underwent TAD (82% TAD vs 74% SLNB, p=0.017). Breast pathologic complete response (ypT0/is) was more frequent among those patients that had TAD (80% TAD vs. 66% SLNB, p&lt; 0.001). TAD localization was with wire in 46%, radioactive seed in 40%, ultrasound in 5%, tattoo in 2%, and with a combination of these techniques in 7%. The clipped node was successfully retrieved in 94% of TAD cases. The median number of lymph nodes removed was lower in the TAD group compared to the SLNB group [3 (IQR 3-5) vs 4 IQR 3-5), p&lt; 0.001], as was the median number of sentinel lymph nodes [3 (IQR 2-4) vs 4 IQR 3-5), p&lt; 0.001] (Table 1). The 5-year rates of any axillary recurrence, locoregional recurrence, and any invasive recurrence in the entire cohort were 1.1% (95%CI 0.39-2.4%), 3.1% (95%CI 1.6-5.3%) and 10% (95%CI 7.6-13%), respectively. The two-year cumulative incidence of axillary recurrence did not differ between patients treated with TAD compared to SLNB (0% vs 0.9%, p=0.19).

Conclusion: Early axillary recurrence after omission of ALND in patients who successfully downstage from N+ to ypN0 with NAC is a rare event following both SLNB or TAD, and was not significantly lower in TAD than SLNB. Although longer follow-up is needed to confirm these findings, the main advantage of TAD seems to be a reduction in the number of lymph nodes removed. Overall, these results support omission of ALND in patients who successfully downstage to node negative disease after NAC.

Table 1: Clinicopathological Features of the Study Cohort, Stratified by Axillary Staging Technique

Citation Format: Giacomo Montagna, Mary Mrdutt, Astrid Botty, Andrea V. Barrio, Varadan Sevilimedu, Judy C. Boughey, Tanya L. Hoskin, Laura H. Rosenberger, E Shelley Hwang, Abigail Ingham, Bärbel Papassotiropoulos, Bich Doan Nguyen-Sträuli, Christian Kurzeder, Danilo Diaz Aybar, Denise Vorburger, Dieter Michael Matlac, Edvin Ostapenko, Fabian Riedel, Florian Fitzal, Francesco Meani, Franziska Fick, Jacqueline Sagasser, Jörg Heil, Konstantin J. Dedes, Laszlo Romics, Maggie Banys-Paluchowski, Maria Del Rosario Cueva Perez, Marcelo Chavez Diaz, Martin Heidinger, Mathias K. Fehr, Mattea Reinisch, Nadia Maggi, Nicola Rocco, Nina Ditsch, Oreste Davide Gentilini, Regis Resende Paulinelli, Sebastian Sole Zarhi, Sherko Küemmel, Simona Bruzas, Simona Di Lascio, Tamara Parissenti, Uwe Güth, Valentina Ovalle, Christoph Tausch, Monica Morrow, Thorsten Kühn, Walter P. Weber. Oncological Outcomes Following Omission of Axillary Lymph Node Dissection in Node Positive Patients Downstaging To Node Negative with Neoadjuvant Chemotherapy: the OPBC-04/EUBREAST-06/OMA study [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 GS4-02.

Timing of Chemotherapy and Patient-Reported Outcomes After Breast-Conserving Surgery and Mastectomy with Immediate Reconstruction

INTRODUCTION

Receipt of chemotherapy is associated with decreased satisfaction after breast surgery, but whether timing as adjuvant versus neoadjuvant (NAC) affects patient-reported outcomes (PROs) is unclear. We examined associations between chemotherapy timing and PROs after breast-conserving surgery (BCS) and mastectomy with immediate reconstruction (M-IR).

METHODS

In this retrospective cohort study of patients with stage I-III breast cancer undergoing chemotherapy between January 2017 and December 2019, we compared satisfaction with breasts (SABTR) and chest physical well-being (PWB-CHEST) between chemotherapy groups in BCS and M-IR cohorts. Median SABTR and PWB-CHEST scores (scale 0-100) were compared between chemotherapy groups at baseline and for 3 years postoperatively. Factors associated with SABTR and PWB-CHEST at 1 and 2 years were assessed with multivariable linear regression.

RESULTS

Overall, 640 patients had BCS and 602 had M-IR; 210 (33%) BCS patients and 294 (49%) M-IR patients had NAC. Following BCS, SABTR was higher than baseline at all postoperative timepoints, whereas 3-year SABTR remained similar to baseline following M-IR, independent of chemotherapy timing. In both surgical cohorts, PWB-CHEST was lowest after NAC at 6 months compared with baseline but was similar to adjuvant counterparts by 3 years. NAC was not a statistically significant predictor of SABTR or PWB-CHEST in either surgical cohort on multivariable analysis.

CONCLUSIONS

For patients with breast cancer who require chemotherapy, neoadjuvant versus adjuvant timing does not impact long-term PROs in this study. These findings may inform shared decision making regarding the sequence of treatment in patients with operable disease.

Do non-classic invasive lobular carcinomas derive a benefit from neoadjuvant chemotherapy?

PURPOSE

Invasive lobular breast cancers (ILCs) respond poorly to neoadjuvant chemotherapy (NAC). The degree of benefit of NAC among non-classic ILC (NC-ILC) variants compared with classic ILCs (C-ILCs) is unknown.

METHODS

Consecutive patients with Stage I-III ILC treated from 2003 to 2019 with NAC and surgery were identified, and grouped as C-ILC or NC-ILC as per the original surgical pathology report, with pathologist (A.G.) review performed if original categorization was unclear. A subset of similarly treated invasive ductal cancers (IDCs) was identified for comparison. Clinicopathologic characteristics and pathologic complete response (pCR) rates were evaluated.

RESULTS

Of 145 patients with ILC, 101 (70%) were C-ILC and 44 (30%) were NC-ILC (IDC cohort: 1157 patients). ILC patients were older, more often cT3/T4 and cN2/N3, and less often high-grade compared to IDC patients. Those with NC-ILC were less often ER+/HER2- (55% versus 93%), and more often HER2 + (25% versus 7%) and TN (21% versus 0%, all p < 0.001). Breast pCR was more common among NC-ILC, but most frequent in IDC. Nodal pCR rates were also lowest among C-ILC patients, but similar among NC-ILC and IDC patients. On multivariable analysis, C-ILC (OR 0.09) and LVI (OR 0.51) were predictive of lack of breast pCR; non-ER+/HER2- subtypes and breast pCR were predictive of nodal pCR. When our analysis was repeated with patients stratified by receptor subtype, histology was not independently predictive of either breast or nodal pCR.

CONCLUSION

NC-ILC patients were significantly more likely to achieve breast and nodal pCR compared with C-ILC patients, but when stratified by subtype, histology was not independently predictive of breast or nodal pCR.

Axillary Staging Is Not Justified in Postmenopausal Clinically Node-Negative Women Based on Nodal Disease Burden

BACKGROUND

RxPONDER showed no benefit of adjuvant chemotherapy in postmenopausal women with estrogen receptor (ER) positive/human epidermal growth factor receptor 2 (HER2) negative breast cancer and limited nodal burden (pN1) with a recurrence score ≤ 25, suggesting that axillary staging could be omitted in cN0 patients if significant numbers of such women do not have pN2-3 disease. Here we evaluate the pN2-3 disease rate in a large cohort of postmenopausal women presenting with cN0 breast cancer.

PATIENTS AND METHODS

Consecutive postmenopausal patients presenting with T1-2N0 breast cancer who underwent axillary surgery from February 2006 to December 2011 were identified. Clinicopathologic characteristics associated with pN2-3 disease were examined using chi-square or Fisher's exact tests.

RESULTS

Of 3363 postmenopausal women with cT1-2N0 breast cancer (median age 58 years, IQR 48-67 years), median tumor size was 1.3 cm (IQR 0.90-1.90cm). Post-axillary staging, 2600 (77.3%) were pN0, 643 (19.1%) were pN1, and 120 (3.6%) were pN2-3. The pN2-3 disease rate did not differ across subtypes (4.4% HER2+, 3.5% HR-/HER2-, 3.5% HR+/HER2-, p = 0.70). In the subset with HR+/HER2- tumors, on multivariable analysis, age < 65 years (odds ratio [OR] 2.38, 95% confidence interval [CI] 1.32-4.49), lymphovascular invasion (OR 5.29, 95% CI 2.72-11.2), multifocal/centric tumors (OR 3.08, 95% CI 1.79-5.32), and tumor size > 2 cm (OR 5.51, 95% CI 3.05-10.4) were significantly associated with pN2-3 nodal burden. Of 506 patients with tumors > 2 cm, 49 (9.7%) had pN2-3 disease; in the subset of 90 patients age < 65 years who had multifocal/centric tumors > 2 cm, 23 (25.6%) had pN2-3 disease.

CONCLUSIONS

In postmenopausal women with cN0 disease, pN2-3 nodal burden is uncommon; omitting axillary staging would not miss a significant number of patients who might benefit from adjuvant chemotherapy. Information available preoperatively indicating a higher risk of nodal disease such as younger age and large, multifocal tumors should be considered in the multidisciplinary management of the axilla.

Patient-Reported Outcome Measures for Patients Who Have Clinical T4 Breast Cancer Treated via Mastectomy with and Without Reconstruction

BACKGROUND

Patients with clinical T4M0 breast cancer are recommended to undergo neoadjuvant chemotherapy, modified radical mastectomy, and postmastectomy radiotherapy. This study determined whether BREAST-Q scores differ by decision to pursue reconstruction or timing of reconstruction.

METHODS

This retrospective, single-institutional study analyzed cT4 breast cancer patients from 2014 to 2021 without evidence of distant metastatic disease undergoing mastectomy with or without reconstruction. As routine care, BREAST-Q was administered preoperatively, then 6 months, 1 year, and 2 years postoperatively. Satisfaction and quality-of-life domains were compared between mastectomy with no reconstruction (NR), immediate reconstruction (IR), and delayed reconstruction (DR) groups.

RESULTS

Of the 144 patients eligible for this study, 71 (49%) had NR, 36 (25%) had DR, and 37 (26%) had IR. The patients undergoing reconstruction were younger and more likely to elect contralateral prophylactic mastectomy. Timing of reconstruction was not associated with significant differences in satisfaction with breasts (SATBR) at any time point. For the patients who had DR, breast satisfaction increased over time after reconstructive surgery. Physical well-being of the chest (PWB-CHEST) did not significantly differ among IR, DR, and NR at any time point. The patients who underwent DR experienced improvement in PWB-CHEST scores from preoperative scores. The patients with IR and NR experienced PWB-CHEST decline over time. Psychosocial well-being (PSWB) did not differ significantly across time or by subgroup.

CONCLUSIONS

The patients with T4 breast cancer who elected reconstruction did not differ in patient-reported outcomes based on timing of reconstruction. In the DR cohort, SATBR significantly improved after reconstructive surgery. These data can help inform breast reconstructive decision-making for patients facing the choice among DR, IR, and NR.

ASO Visual Abstract: Patient-Reported Outcome Measures in Patients with Clinical T4 Breast Cancer Treated with Mastectomy With and Without Reconstruction

AIM

Do patient-reported outcome measures differ among clinical T4 patients undergoing mastectomy with and without reconstruction?

FINDINGS

Neither reconstruction nor timing of reconstruction were associated with superior outcomes for breast satisfaction, physical well-being of the chest, or psychosocial well-being at any timepoint.

Neoadjuvant Chemotherapy for Breast Cancer In the Elderly: Are We Accomplishing Our Treatment Goals?

INTRODUCTION

Rates of downstaging and tolerability to NAC in women age ≥ 70 years with operable breast cancer have not been well studied. We sought to compare downstaging rates and NAC completion between women age 50-69 years and age ≥ 70 years.

METHODS

Consecutively treated women age ≥ 50 years with cT1-3N0-1 breast cancer receiving NAC followed by surgery from November 2013 to April 2020 were studied. Rates of downstaging from breast-conserving surgery (BCS)-ineligible to BCS-eligible and avoidance of axillary dissection (ALND) in cN1 patients were compared between patients age 50-69 and ≥ 70 years. NAC regimens and rates of completion also were assessed.

RESULTS

Overall, 651 women, age ≥ 50 years, with 668 cT1-3N0-1 breast cancers that were treated with NAC, were identified; 75 (11.1%) were age ≥ 70 years. Patients age ≥ 70 years were less likely to have lobular cancers (5% vs. 10%, p = 0.03), receive an anthracycline-based regimen (69% vs. 93%, p < 0.001), and complete their entire prescribed regimen (57% vs. 78%, p < 0.001). Of 312 BCS-ineligible patients eligible for downstaging, conversion rates to BCS-eligibility were similar between age groups (72% [≥ 70] vs. 74% [50-69], p > 0.9). Women age ≥ 70 years who converted to BCS-eligible post-NAC were more likely to undergo BCS than younger patients (93% vs. 74%, p = 0.04). Of 390 cN1 patients, 162 (42%) achieved a nodal pCR; ALND avoidance was similar between age groups (43% [≥ 70] vs. 42% [50-69], p > 0.9).

CONCLUSIONS

While patients age ≥ 70 years received less anthracycline-based NAC and were less likely to complete their prescribed regimen, they experienced high rates of breast and axillary downstaging, similar to younger patients, suggesting that well-selected elderly patients can safely receive NAC with substantial clinical benefit.

Use of a supervised machine learning model to predict Oncotype DX risk category in node-positive patients older than 50 years of age

PURPOSE

The use of the Oncotype DX recurrence score (RS) to predict chemotherapy benefit in patients with hormone receptor-positive/HER2 negative (HR+/HER2-) breast cancer has recently expanded to include postmenopausal patients with N1 disease. RS availability is limited in resource-poor settings, however, prompting the development of statistical models that predict RS using clinicopathologic features. We sought to assess the performance of our supervised machine learning model in a cohort of patients > 50 years of age with N1 disease.

METHODS

We identified patients > 50 years of age with pT1-2N1 HR+/HER2- breast cancer and applied the statistical model previously developed in a node-negative cohort, which uses age, pathologic tumor size, histology, progesterone receptor expression, lymphovascular invasion, and tumor grade to predict RS. We measured the model's ability to predict RS risk category (low: RS ≤ 25; high: RS > 25).

RESULTS

Our cohort included 401 patients, 60.6% of whom had macrometastases, with a median of 1 positive node. The majority of patients had a low-risk observed RS (85.8%). For predicting RS category, the model had specificity of 97.3%, sensitivity of 31.8%, a negative predictive value of 87.9%, and a positive predictive value of 70.0%.

CONCLUSION

Our model, developed in a cohort of node-negative patients, was highly specific for identifying cN1 patients > 50 years of age with a low RS who could safely avoid chemotherapy. The use of this model for identifying patients in whom genomic testing is unnecessary would help decrease the cost burden in resource-poor settings as reliance on RS for adjuvant treatment recommendations increases.