Genomic landscape of malignant phyllodes tumors reveals multiple targetable opportunities.

BACKGROUND: Malignant phyllodes tumors (MPT) are rare fibroepithelial breast cancers with no known effective systemic therapy; metastatic progression portends a dismal prognosis. We sought to describe the genomic landscape of MPTs through genomic profiling and immunotherapeutic biomarker analysis. MATERIALS AND METHODS: Cases of sequenced MPT were identified from a Clinical Laboratory Improvement Amendments-certified, College of American Pathologists-accredited laboratory (Foundation Medicine). All cases underwent genomic profiling using adaptor ligation-based, next-generation sequencing assay of 324 genes. Tumor agnostic immunotherapy biomarkers, microsatellite instability, tumor mutational burden (TMB), and programmed death-ligand 1 (PD-L1) expression were evaluated. Fisher's Exact Tests and analysis of variance were used to test for differences between groups and for continuous variables as appropriate. RESULTS: Of 135 MPT cases identified; 94 (69.6%) were localized/locally recurrent and 41 (30.4%) were metastatic. Median age was 54 years (range 14-86). The median TMB was 2.5 mut/Mb and 3 were TMB-high (≥10 mut/Mb). 21.4% were PD-L1+ via Dako 22C3 assay (CPS ≥1). Most commonly altered genes included TERT-promoter (69.7%), CDKN2A (45.9%), TP53 (37.8%), NF1 (35.6%), CDKN2B (33.3%), MED12 (28.9%), MTAP (27.7%), KMT2D (22.2%), PIK3CA (20.0%), PTEN (18.5%), and RB1 (18.5%). Several tumors harboring genomic alterations with US Food and Drug Administration-approved indications in other tumor types were found including NF1, PIK3CA, EGFR Exon 19/20 insertions, and BRAF V600E mutations. CONCLUSIONS: In the largest genomic evaluation of MPT to date, multiple clinically actionable mutations were found. Routine sequencing of metastatic MPT may provide additional information to guide treatment decisions and clinical trial enrollment.

Effects of aerobic exercise on neurocognitive function in postmenopausal women receiving endocrine therapy for breast cancer: The Exercise Program in Cancer and Cognition randomized controlled trial.

Objective: The Exercise Program in Cancer and Cognition (EPICC) Study was a randomized controlled trial (RCT) designed to determine whether six months of moderate-intensity aerobic exercise improves neurocognitive function in women with breast cancer (BC) receiving endocrine therapy (ET). Methods: Postmenopausal women with hormone receptor+, early-stage BC, within two years post-primary therapy were randomized to the exercise intervention (six months, ≥150 minutes of moderate-intensity aerobic exercise/week) or usual care control condition. Outcomes were assessed at pre-randomization and after intervention completion. Groups were compared using linear mixed-effects modeling. Results: Participants (N=153) were X ¯ = 62.09 ± 8.27 years old, with stage I BC (64.1%) and a median of 4.7 months post-diagnosis. We found a group-by-time interaction (p=0.041) and a trend for the main effect of time (p=0.11) for processing speed with improved performance in the exercise group and no change in the controls. Similar main effects of time were observed for learning and memory (p=0.024) and working memory (p=0.01). Better intervention adherence was associated with improved processing speed (p=0.017). Conclusions: Six months of moderate-intensity aerobic exercise improves processing speed in postmenopausal women with BC receiving ET who initiate exercise within two years of completing primary therapy (surgery +/- chemotherapy). This is the first large-scale study to examine the effects of aerobic exercise on neurocognitive function in women with BC. Additional research is needed to address the long-term effects of aerobic exercise on cognitive function.

Lifetime Pain Management Experiences of Female Breast Cancer Survivors Aged 65+ Years.

PURPOSE: Explore factors influencing pain management among female breast cancer survivors aged 65+ years with moderate to severe pain based on a score of 4 or greater on the 0-10 numeric rating scale. DESIGN: Qualitative descriptive study. METHODS: We interviewed 21 purposefully sampled women aged 65+ years who experienced moderate to severe pain. Researchers coded interview transcripts for factors affecting study participants' pain management experiences. RESULTS: Pain management facilitators included patient-centered interactions with care teams and reliance on psychosocial assets. Challenges included ineffective care team interactions and participants' negative perceptions of opioid analgesia. Other factors included pain attributed to cancer treatment, pain management plan adherence, and psychosocial influencers. CONCLUSIONS: With regard to this sample, patient-centered communication and pain management education help female breast cancer survivors aged 65+ years manage their pain. Mitigation of opioid stigma and undermanaged painful comorbid conditions could further optimize pain management. Further research on the effects of breast cancer treatment, level of adherence to pain management recommendations, and psychosocial influences on pain management is needed. CLINICAL IMPLICATIONS: Providing contact information for care team members during and after clinic hours facilitates open communication, including timely reporting of new and undertreated pain. Collaborating with the patient and care team on a clear pain management plan and establishing parameters for when to notify the care team empower patients to optimize management of their pain. Verifying patients' understanding of prescribed analgesia and management of side effects and providing education as needed may reduce negative perceptions of opioid analgesia.

Single-institution outcomes after excision of benign phyllodes tumors: low recurrence risk even with positive margins.

PURPOSE: Benign phyllodes tumors (BPT) are rare breast neoplasms with clinical behavior that poses low recurrence risk. Guidelines regarding appropriate margins recommend surgical excision to negative margins, sometimes requiring re-excision surgery. Contemporary experience suggests that re-excision in the face of positive margins may not be needed. METHODS: This is a retrospective review of a single-institution experience with BPT from 2010 to 2019 with 102 patients. Demographics, outcomes and follow-up were analyzed. RESULTS: The median age was 37 years. 95% had a pre-operative biopsy and only 6% were confirmed BPT before surgery.56% had positive margins and were more likely to be younger and have a pre-operative diagnosis of fibroadenoma. The median follow-up was 33 months. Between the positive and negative margin groups, recurrence rates were not significantly different (p = 0.87). CONCLUSION: Positive margins on excision of BPT poses a low recurrence risk and re-excision surgery is not necessary.

Eliminating breast surgery for invasive breast cancer in exceptional responders to neoadjuvant systemic therapy: a multicentre, single-arm, phase 2 trial.

BACKGROUND: Neoadjuvant systemic therapy (NST) for triple-negative breast cancer and HER2-positive breast cancer yields a pathological complete response in approximately 60% of patients. A pathological complete response to NST predicts an excellent prognosis and can be accurately determined by percutaneous image-guided vacuum-assisted core biopsy (VACB). We evaluated radiotherapy alone, without breast surgery, in patients with early-stage triple-negative breast cancer or HER2-positive breast cancer treated with NST who had an image-guided VACB-determined pathological complete response. METHODS: This multicentre, single-arm, phase 2 trial was done in seven centres in the USA. Women aged 40 years or older who were not pregnant with unicentric cT1-2N0-1M0 triple-negative breast cancer or HER2-positive breast cancer and a residual breast lesion less than 2 cm on imaging after clinically standard NST were eligible for inclusion. Patients had one biopsy (minimum of 12 cores) obtained by 9G image-guided VACB of the tumour bed. If no invasive or in-situ disease was identified, breast surgery was omitted, and patients underwent standard whole-breast radiotherapy (40 Gy in 15 fractions or 50 Gy in 25 fractions) plus a boost (14 Gy in seven fractions). The primary outcome was the biopsy-confirmed ipsilateral breast tumour recurrence rate determined using the Kaplan-Meier method assessed in the per-protocol population. Safety was assessed in all patients who received VACB. This study has completed accrual and is registered with ClinicalTrials.gov, NCT02945579. FINDINGS: Between March 6, 2017, and Nov 9, 2021, 58 patients consented to participate; however, four (7%) did not meet final inclusion criteria and four (7%) withdrew consent. 50 patients were enrolled and underwent VACB following NST. The median age of the enrolled patients was 62 years (IQR 55-77); 21 (42%) patients had triple-negative breast cancer and 29 (58%) had HER2-positive breast cancer. VACB identified a pathological complete response in 31 patients (62% [95% CI 47·2-75·4). At a median follow-up of 26·4 months (IQR 15·2-39·6), no ipsilateral breast tumour recurrences occurred in these 31 patients. No serious biopsy-related adverse events or treatment-related deaths occurred. INTERPRETATION: Eliminating breast surgery in highly selected patients with an image-guided VACB-determined pathological complete response following NST is feasible with promising early results; however, additional prospective clinical trials evaluating this approach are needed. FUNDING: US National Cancer Institute (National Institutes of Health).

Cost-effectiveness of Choosing Wisely guidelines for axillary observation in women older than age 70 years with hormone receptor-positive, clinically node-negative, operable breast tumors.

BACKGROUND: The Society for Surgical Oncology's Choosing Wisely guidelines recommend against sentinel lymph node biopsy (SLNB) in favor of observation in this population. Recent analyses reveal that this has not been widely adopted. The purpose of this cost-effectiveness analysis is to compare the costs and benefits associated with observation or SLNB in women >70 years old with hormone receptor-positive, clinically node-negative, operable breast cancer. METHODS: A decision tree with Markov modeling was created to compare treatment strategies using long-term follow-up data from clinical trials in this population. Costs were estimated from published literature and publicly available databases. Breast cancer-specific health-state utilities were derived from the literature and expert opinion. One-way, 2-way, and probabilistic sensitivity analyses were conducted. A structural sensitivity analysis was performed to assess the effect of functional status and anxiety from nonevaluation of the axilla on cost-effectiveness. Costs and benefits, measured in life-years (LYs) and quality-adjusted life-years (QALYs), were tabulated across 10, 15, and 20 years and compared using incremental cost-effectiveness ratios (ICERs). RESULTS: SLNB is not cost-effective from the payer or societal perspectives with ICERs of $138,374/LY and $131,900/LY, respectively. When QALYs were considered, SLNB provided fewer QALYs (SLNB, 10.33 QALYs; observation, 10.53 QALYs) at a higher cost (SLNB, $15,845; observation, $4020). Structural sensitivity analysis revealed that SLNB was cost-effective in certain patients with significant anxiety related to axillary observation (ICER, $39,417/QALY). CONCLUSIONS: Routine SLNB in this population is not cost-effective. The cost-effectiveness of SLNB, however, is dependent on individual patient factors, including functional status as well as patient preference.

Timely cancer genetic counseling and testing for young women with breast cancer: impact on surgical decision-making for contralateral risk-reducing mastectomy.

PURPOSE: Genetic testing (GT) can identify individuals with pathogenic/likely pathogenic variants (PV/LPVs) in breast cancer (BC) predisposition genes, who may consider contralateral risk-reducing mastectomy (CRRM). We report on CRRM rates in young women newly diagnosed with BC who received GT through a multidisciplinary clinic. METHODS: Clinical data were reviewed for patients seen between November 2014 and June 2019. Patients with non-metastatic, unilateral BC diagnosed at age ≤ 45 and completed GT prior to surgery were included. Associations between surgical intervention and age, BC stage, family history, and GT results were evaluated. RESULTS: Of the 194 patients, 30 (15.5%) had a PV/LPV in a BC predisposition gene (ATM, BRCA1, BRCA2, CHEK2, NBN, NF1), with 66.7% in BRCA1 or BRCA2. Of 164 (84.5%) uninformative results, 132 (68%) were negative and 32 (16.5%) were variants of uncertain significance (VUS). Overall, 67 (34.5%) had CRRM, including 25/30 (83.3%) PV/LPV carriers and 42/164 (25.6%) non-carriers. A positive test result (p < 0.01) and significant family history were associated with CRRM (p = 0.02). For the 164 with uninformative results, multivariate analysis showed that CRRM was not associated with age (p = 0.23), a VUS, (p = 0.08), family history (p = 0.10), or BC stage (p = 0.11). CONCLUSION: In this cohort of young women with BC, the identification of a PV/LPV in a BC predisposition gene and a significant family history were associated with the decision to pursue CRRM. Thus, incorporation of genetic services in the initial evaluation of young patients with a new BC could contribute to the surgical decision-making process.

Margin Management and Adjuvant Therapy for Phyllodes Tumors: Practice Patterns of the American Society of Breast Surgeons Members.

BACKGROUND: Phyllodes tumors (PTs) are rare breast neoplasms with variable clinical behavior by histologic type: benign, borderline, or malignant. Until recently, management guidelines recommended one approach for all subtypes. METHODS: A 21-question survey was sent to American Society of Breast Surgeon members to evaluate management patterns by subtype. Surgeon demographics, decisions regarding management of margins, re-excision, surveillance, and synoptic reporting were collected. Chi-square or analysis of variance (ANOVA) were used as appropriate, with significance set at p < 0.05. RESULTS: A total of 493 of 2969 surveys were completed for a response rate of 18.3%. Among the survey takers, 55% were fellowship trained, 72% were in practice > 10 years, and 82% performed > 100 breast cases per year. Although 25% of respondents enucleate a mass with clinical suspicion of a PT alone, this decreased to 18% if a preoperative core biopsy performed was suggestive of PT. For margin management, 47% do not re-excise positive margins for benign PTs, but 96% would for a borderline or malignant PTs (p < 0.001). Only 2% perform axillary staging for malignant PTs, and 90% refer borderline or malignant PTs for radiation. Two-year surveillance was performed by about half of respondents for benign PT. However, two-thirds of respondents would increase surveillance to 5 years for borderline or malignant PTs. Only 38% report a templated synoptic pathology report at their institution. CONCLUSION: PT management patterns are evolving but still variable when looking at initial margin intent, decision for re-excision, radiation referral, pathologic reporting, and surveillance. This suggests the need for more specific management guidelines by subtype given differences in clinical behavior.

Disparities in Access to Postmastectomy Breast Reconstruction: Does Living in a Specific ZIP Code Determine the Patient's Reconstructive Journey?

BACKGROUND: Postmastectomy breast reconstruction (BR) has been shown to provide long-term quality of life and psychosocial benefits. Despite the policies initiated to improve access to BR, its delivery continues to be inequitable, suggesting that barriers to access have not been fully identified and/or addressed. The purpose of this study was to assess the influence of geographic location, socioeconomic status, and race in access to immediate BR (IBR). METHODS: An institutional review board-approved observational study was conducted. All patients who underwent breast cancer surgery from 2014 to 2019 were queried from our institutional Breast Cancer Registry. A geographical analysis was conducted using demographic characteristics and patient's ZIP codes. Euclidean distance from patient home ZIP code to UPMC Magee Women's Hospital was calculated, and χ2, Student t test, Mann-Whitney, and Kruskal-Wallis tests was used to evaluate differences between groups, as appropriate. Statistical significance was set at P < 0.05. RESULTS: Overall, 5835 patients underwent breast cancer surgery. A total of 56.7% underwent lumpectomy or segmental mastectomy, and 43.3% underwent modified, total, or radical mastectomy. From the latter group, 33.5% patients pursued BR at the time of mastectomy: 28.6% autologous, 48.1% implant-based, 19.4% a combination of autologous and implant-based, and 3.9% unspecified reconstruction. Rates of IBR varied among races: White or European (34.1%), Black or African American (27.7%), and other races (17.8%), P = 0.022. However, no difference was found between type of BR among races (P = 0.38). Moreover, patients who underwent IBR were significantly younger than those who did not pursue reconstruction (P < 0.0001). Patients who underwent reconstruction resided in ZIP codes that had approximately US $2000 more annual income, a higher percentage of White population (8% vs 11% non-White) and lower percentage of Black or African American population (1.8% vs 2.9%) than the patients who did not undergo reconstruction. CONCLUSIONS: While the use of postmastectomy BR has been steadily rising in the United States, racial and socioeconomic status disparities persist. Further efforts are needed to reduce this gap and expand the benefits of IBR to the entire population without distinction.

Association of Tumor Molecular Subtype and Stage with Breast and Axillary Pathologic Complete Response After Neoadjuvant Chemotherapy for Breast Cancer.

BACKGROUND: Axillary pathologic complete response (pCR) confers higher overall and recurrence-free survival than residual axillary disease. Although breast pCR (ypT0) is associated with a pathologically negative axilla (ypN0) in human epidermal growth factor receptor 2-positive (HER2+) and triple-negative breast cancer (TNBC), how clinical T (cT) and N (cN) staging are associated with ypN0 in other tumor subtypes is incompletely understood. METHODS: A single-institution cancer registry was retrospectively reviewed for patients receiving neoadjuvant chemotherapy (NAC) followed by surgery from 2010 to 2018. Fisher's exact tests compared proportion of breast and axillary pCR by tumor subtype (hormone receptor [HR]-positive /HER2-,HR+/HER2+,HR-/HER2+,HR-/HER2-). Logistic regression determined factors associated with ypN0. Sensitivity analyses determined how cN status affected ypN status by tumor subtype. RESULTS: The study enrolled 1348 patients. The median age was 54 years (interquartile range [IQR], 44-63 years), and 55% of the patients (n = 736) were postmenopausal. The tumor subtypes were HR+/HER2- (12%, n = 155), HR+/HER2+ (48%, n = 653), HR-/HER2+ (25%, n = 343), and TNBC (15%, n = 197). In the study, cT included T0 (1%, n = 18), T1 (20%, n = 272), T2 (53%, n = 713), T3 (17%, n = 230), and T4 (9%, n = 111), and cN included cN0 (51%, n = 687), cN1 (41%, n = 549), cN2 (5%, n = 61), and cN3 (3%, n = 43). Breast pCR and ypN0 occurred most in the HER2+ and TNBC subtypes. A negative association was found between ypN0 and age at diagnosis (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97-0.99; p < 0.001), cT4 stage (OR, 0.29; 95% CI, 0.09-0.91; p = 0.034), and HR+ subtypes (HR+/HER2-: OR, 0.54; 95% CI, 0.31-0.94; p = 0.028; HR+/HER2+: OR, 0.60; 95% CI, 0.39-0.93; p = 0.024). The HR-/HER2+ subtype was associated with ypN0 (OR, 1.70; 95% CI, 1.05-2.73; p = 0.030), and cN2/cN3 was negatively associated with ypN0 in HR+/HER2+ disease (OR, 0.26; 95% CI, 0.11-0.61; p = 0.002), HR-/HER2+ disease (OR, 0.42; 95% CI, 0.22-0.77; p = 0.005), and TNBC (OR, 0.11; 95% CI, 0.03-0.40; p = 0.001). CONCLUSION: Tumor subtype, clinical stage, and age at diagnosis may be important in consideration of de-escalation of axillary staging.

Cutting Instruments to Cut Costs: A Simple Initiative with Breast Surgical Operating Room Trays that Resulted in Substantial Savings.

BACKGROUND: A substantial expense in surgical care is incurred in the operating room (OR). We evaluated the financial impact of a systematic reduction in instrument tray contents on charges for breast surgery procedures. METHODS: A catalog of OR trays historically used for breast procedures (excisional biopsy, segmental and total mastectomy with or without axillary staging) was reviewed by four dedicated breast surgeons and downsized to a single tray accommodating all surgeon preferences. A matched-case comparison was performed pre- and post-downsizing. Cost analysis for salary and benefits (S&B) and unit supply cost (USC) pre- and post-downsizing were carried out. Instrument number, OR tray weights, set-up, and breakdown times were also compared. RESULTS: Post-downsizing, OR tray counts were reduced from 132 to 67 instruments (49%) and tray weight decreased from 30 to 20 pounds (33%). Scrub technician set-up and breakdown times were shorter by 22% and 25%, respectively. Comparing 449 matched cases (239 pre- and 210 post-downsizing), S&B and USC post-downsizing were decreased collectively for all procedures (p < 0.0001). With an average variance of S&B and USC (pre- to post-intervention) of $354, and an annualized case load of 813 operations, this could translate into S&B and USC savings of $287,802 per year. CONCLUSION: Simply downsizing OR breast trays resulted in decreased combined S&B and USC per procedure, leading to a substantial cost savings for the healthcare system. This measure aligns with a value and quality-based approach to patient care and could be easily replicated across institutions and specialties.

Post-operative Nausea and Analgesia Following Total Mastectomy is Improved After Implementation of an Enhanced Recovery Protocol.

BACKGROUND: Enhanced Recovery Protocols (ERPs) provide a multimodal approach to perioperative care, with the aims of improving patient outcomes while decreasing perioperative antiemetic and narcotic requirements. With high rates of post-operative nausea or vomiting (PONV) following total mastectomy (TM), we hypothesized that our institutional designed ERP would reduce PONV while improving pain control and decrease opioid use. METHODS: An ERP was implemented at a single institution for patients undergoing TM with or without implant-based reconstruction. Patients from the first two months of implementation (ERP group, N = 72) were compared with a retrospective usual-care cohort from a three-month period before implementation (UC group, N = 83). Outcomes included PONV incidence, measured with antiemetic use; patient-reported pain scores; perioperative opioid consumption, measured by oral morphine equivalents (OME); and length of stay (LOS). RESULTS: The characteristics of the two groups were similar. PONV incidence and perioperative opioid consumption were lower in the ERP than the UC group (21% vs. 40%, p 0.011 and mean 44.1 OME vs. 104.3 OME, p < 0.001), respectively. These differences in opioid consumption were observed in the operating room and post-anesthesia care unit (PACU); opioid consumption on the floor was similar between the two groups. Patient-reported pain scores were lower in the ERP than the UC group (mean highest pain score 6.4 vs. 7.4, p 0.003). PACU and hospital LOS were similar between the two groups. CONCLUSION: ERP implementation was successful in decreasing PONV following TM with and without reconstruction, while simultaneously decreasing overall opioid consumption without compromising patient comfort.

Metaplastic breast carcinoma: a clinical-pathologic study of 97 cases with subset analysis of response to neoadjuvant chemotherapy.

Metaplastic breast carcinoma is a rare heterogeneous category of breast cancer, often associated with a poor prognosis. Clinical-pathologic studies with respect to varied morphologic subtypes are lacking. There is also a dearth of studies assessing the response of metaplastic breast carcinoma to neoadjuvant chemotherapy. Cases of metaplastic breast carcinoma diagnosed between 2007 and 2017 were identified. Various clinical-pathologic variables were tested for association with survival. Patients who underwent neoadjuvant chemotherapy were assessed for pathologic response. Median age at diagnosis with metaplastic breast carcinoma was 64 years. With a median follow-up of 39 months, 26 patients (27%) recurred (24 distant and 2 loco-regional). The overall survival rate of the cohort was 66% (64/97). A number of variables were associated with survival in univariable analysis; however, in multivariable analysis, only lymph node status and tumor size (pT3 vs. pT1/2) were significantly associated with all survival endpoints: recurrence-free survival, distant recurrence-free survival, overall survival and breast cancer-specific survival. Twenty-nine of 97 (30%) patients with metaplastic breast carcinoma received neoadjuvant chemotherapy. Five (17%) patients achieved pathologic complete response. Matrix-producing morphology was associated with higher probability of achieving pathologic complete response (p = 0.027). Similar to other breast cancer subtypes, tumor size and lymph node status are prognostic in metaplastic carcinomas. The pathologic complete response rate of metaplastic breast carcinoma in our cohort was 17%, higher than previously reported. Although the matrix-producing subtype was associated with pathologic complete response, there was no survival difference with respect to tumor subtypes.

Magee Equation 3 predicts pathologic response to neoadjuvant systemic chemotherapy in estrogen receptor positive, HER2 negative/equivocal breast tumors.

Magee Equations were derived as an inexpensive, rapid alternative to Oncotype DX. The Magee Equation 3 utilizes immunohistochemical and FISH data for estrogen receptor (ER), progesterone receptor (PR), HER2 and Ki-67 for its calculation (24.30812+ERIHC × (-0.02177)+PRIHC × (-0.02884)+(0 for HER2 negative, 1.46495 for equivocal, 12.75525 for HER2 positive)+Ki-67 × 0.18649). We hypothesize that Magee Equation 3 scores from pre-therapy core biopsy can predict response to neoadjuvant systemic chemotherapy. A prospectively-maintained database of patients who received neoadjuvant systemic therapy from 2010 to 2014 at a single institution was retrospectively reviewed. Pathologic complete response was defined as absence of invasive tumor in the breast and regional lymph nodes. Of the 614 cases, tumors with missing immunohistochemical results and those that were ER negative or HER2 positive were excluded. This resulted in 237 ER positive, HER2 negative/equivocal tumors that formed the basis of this study. Magee Equation 3 scores were divided into 3 categories similar to Oncotype DX, ie, 0 to <18 (low), 18 to <31 (intermediate), and 31 or higher (high) scores. The pathologic complete response rate for low, intermediate and high Magee Equation 3 scores was 0%, 4%, and 36%, respectively. Patients with high Magee Equation 3 scores were 13 times more likely to achieve pathologic complete response compared to those with Magee Equation 3 scores less than 31 (95% CI 5.09-32.87, P<0.0001). For patients that did not achieve pathologic complete response, high Magee Equation 3 correlated with higher recurrence rate, with the majority occurring in patients with positive lymph nodes in the resection specimen. Magee Equation 3 score ≥31 predicts pathologic complete response in the neoadjuvant setting and for tumor recurrence, when pathologic complete response is not achieved. These results show the utility of Magee Equation 3 in predicting patients who will benefit from chemotherapy but warrant prospective multi-institutional validation.

Axillary Staging After Neoadjuvant Chemotherapy for Breast Cancer: A Pilot Study Combining Sentinel Lymph Node Biopsy with Radioactive Seed Localization of Pre-treatment Positive Axillary Lymph Nodes.

BACKGROUND: Neoadjuvant chemotherapy (NAC) downstages axillary disease in 55 % of node-positive (N1) breast cancer. The feasibility and accuracy of sentinel lymph node biopsy (SLNB) after NAC for percutaneous biopsy-proven N1 patients who are clinically node negative (cN0) by physical examination after NAC is under investigation. ACOSOG Z1071 reported a false-negative rate of <10 % if ≥3 nodes are removed with dual tracer, including excision of the biopsy-proven positive lymph node (BxLN). We report our experience using radioactive seed localization (RSL) to retrieve the BxLN with SLNB (RSL/SLNB) for cN0 patients after NAC. METHODS: We performed a retrospective review of a single-institution, prospectively maintained registry for the years 2013 to 2014. Patients with BxLN who received NAC and had RSL/SLNB were identified. All BxLNs were marked with a radiopaque clip before NAC to facilitate RSL. RESULTS: Thirty patients with BxLN before NAC were cN0 after NAC and underwent RSL/SLNB. Median age was 55 years. Disease stage was IIA-IIIB. Twenty-nine of 30 had ductal cancer (12 triple negative and 16 HER-2 positive). One to 11 nodes were retrieved. Twenty-nine of 30 BxLN were successfully localized with RSL. Note was made of the BxLN-containing isotope and/or dye in 22 of 30. Nineteen patients had no residual axillary disease; 11 had persistent disease. All who remained node positive had disease in the BxLN. CONCLUSIONS: RSL/SLNB is a promising approach for axillary staging after NAC in patients whose disease becomes cN0. The status of the BxLN after NAC predicted nodal status, suggesting that localization of the BxLN may be more accurate than SLNB alone for staging the axilla in the cN0 patient after NAC.