Tumor microenvironment and immune system preservation in early-stage breast cancer: routes for early recurrence after mastectomy and treatment for lobular and ductal forms of disease.

BACKGROUND: Intra-ductal cancer (IDC) is the most common type of breast cancer, with intra-lobular cancer (ILC) coming in second. Surgery is the primary treatment for early stage breast cancer. There are now irrefutable data demonstrating that the immune context of breast tumors can influence growth and metastasis. Adjuvant chemotherapy may be administered in patients who are at a high risk of recurrence. Our goal was to identify the processes underlying both types of early local recurrences. METHODS: This was a case-control observational study. Within 2 years of receiving adjuvant taxan and anthracycline-based chemotherapy, as well as modified radical mastectomy (MRM), early stage IDC and ILC recurred. Vimentin, α-smooth muscle actin (SMA), platelet-derived growth factor (PDGF), matrix metalloproteinase (MMP1), and clustered differentiation (CD95) were investigated. RESULTS: Of the samples in the ductal type group, 25 showed local recurrence, and 25 did not. Six individuals in the lobular-type group did not experience recurrence, whereas seven did. Vimentin (p = 0.000 and 0.021), PDGF (p = 0.000 and 0.002), and CD95 (p = 0.000 and 0.045) expressions were significantly different in ductal and lobular carcinoma types, respectively. Measurement of ductal type was the sole significant difference found in MMP1 (p = 0.000) and α-SMA (p = 0.000). α-SMA and CD95 were two variables that helped the recurrence mechanism in the ductal type according to the pathway analysis. In contrast, the CD95 route is a recurrent mechanism for the lobular form. CONCLUSIONS: While the immune system plays a larger role in ILC, the tumor microenvironment and immune system both influence the recurrence of IDC. According to this study, improving the immune system may be a viable cancer treatment option.

The impact of histologic subtype on primary site surgery in the management of metastatic lobular versus ductal breast cancer: a population based study from the National Cancer Database (NCDB).

PURPOSE: Primary site surgery for metastatic breast cancer improves local control but does not impact overall survival. Whether histologic subtype influences patient selection for surgery is unknown. Given differences in surgical management between early-stage lobular versus ductal disease, we evaluated the impact of histology on primary site surgery in patients with metastatic breast cancer. METHODS: The National Cancer Database (NCDB, 2010-2016) was queried for patients with stage IV HR-positive, HER2-negative invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC). We compared clinicopathologic features, primary site surgery rates, and outcomes by histologic subtype. Multivariable Cox proportional hazard models with and without propensity score matching were used for overall survival (OS) analyses. RESULTS: In 25,294 patients, primary site surgery was slightly but significantly less common in the 6,123 patients with ILC compared to the 19,171 patients with IDC (26.9% versus 28.8%, p = 0.004). Those with ILC were less likely to receive chemotherapy (41.3% versus 47.4%, p < 0.0001) or radiotherapy (29.1% versus 37.9%, p < 0.0001), and had shorter OS. While mastectomy rates were similar, those with ILC who underwent lumpectomy had significantly higher positive margin rates (ILC 15.7% versus IDC 11.2%, p = 0.025). In both groups, the odds of undergoing surgery decreased over time, and were higher in younger patients with T2/T3 tumors and higher nodal burden. CONCLUSION: Lobular histology is associated with less primary site surgery, higher positive margin rates, less radiotherapy and chemotherapy, and shorter OS compared to those with HR-positive HER2-negative IDC. These findings support the need for ILC-specific data and treatment approaches in the setting of metastatic disease.

Pre-surgical cryoablation in ≤ 2 cm ER + /HER2-tumors. Prognostic factors for the presence of residual invasive carcinoma.

BACKGROUND: Breast cancer remains the most commonly diagnosed cancer in women. Breast-conserving surgery (BCS) is the standard approach for small low-risk tumors. If the efficacy of cryoablation is demonstrated, it could provide a minimally invasive alternative to surgery. PURPOSE: To determine the success of ultrasound-guided cryoablation in achieving the absence of Residual Invasive Cancer (RIC) for patients with ER + /HER2- tumors ≤ 2cm and sonographically negative axillary nodes. MATERIALS AND METHODS: This prospective study was carried out from April 2021 to June 2023, and involved 60 preoperative cryoablation procedures on ultrasound-visible, node-negative (cN0) infiltrating ductal carcinomas (IDC). Standard diagnostic imaging included mammography and tomosynthesis, supplemented by ultrasound-guided biopsy. MRI was performed in patients with associated intraductal carcinoma (DCIS) and an invasive component on core needle biopsy (18 out of 22 cases). All tumors were tagged with ferromagnetic seeds. A triple-phase protocol (freezing-thawing-freezing) with Argon was used, with an average procedure duration of 40 min. A logistic regression model was applied to determine significant correlation between RIC and the study variables. RESULTS: Fifty-nine women (mean age 63 ± 8 years) with sixty low-risk unifocal IDC underwent cryoablation prior to surgery. Pathological examination of lumpectomy specimens post-cryoablation revealed RIC in only one of 38 patients with pure IDC and in 4 of 22 mixed IDC/DCIS cases. All treated tumors had clear surgical margins, with no significant procedural complications. CONCLUSIONS: Cryoablation was effective in eradicating 97% of pure infiltrating ER + /HER2-tumors ≤ 2cm, demonstrating its potential as a surgical alternative in selected patients.

ASO Author Reflections: Toward Individualized Management of Heterogenous Mixed Invasive Ductolobular Breast Cancers.

Mixed invasive ductolobular breast cancer (MIDLC) is a rare breast cancer with varying lobular and ductal components. Characteristics, management, and outcomes of MIDLC are not well understood due to the rarity of the cancer and the lack of uniform diagnostic criteria and reporting. There is a need for better understanding and individualized management of this heterogeneous spectrum of breast cancers.

Nodal Surgery for Patients ≥ 70 Undergoing Mastectomy for DCIS? Choose Wisely.

BACKGROUND: Routine sentinel lymphadenectomy (SLNB) for early-stage HR+/HER2- breast cancer in women ≥70 is discouraged by Choosing Wisely, but whether SLNB can be routinely omitted in women ≥70 with DCIS undergoing mastectomy is unclear. This study aims to evaluate rates of axillary surgery and nodal positivity (pN+) in this population to determine the impact of axillary surgery on treatment decisions. METHODS: Females ≥70 with DCIS undergoing mastectomy were identified from the National Cancer Database (2012-2020). The rate of upstaging to invasive cancer (≥pT1) or pN+ was assessed. Subset analyses were conducted for ER+ patients. Adjuvant therapies were evaluated among ≥pT1 patients after stratifying by nodal status. RESULTS: Of 9,030 patients, 1,896 (21%) upstaged to ≥pT1. Axillary surgery was performed in 86% of patients, predominantly sentinel lymphadenectomy (SLNB, 65%). Post hoc application of Choosing Wisely criteria demonstrated that 93% of the entire cohort and 97% of ER+ DCIS patients could have avoided axillary surgery. Nodal positivity was 0.3% among those who didn't upstage, and 12% among those upstaging to ≥pT1, with <2% having pN2-3 disease, irrespective of receptor subtype. Node-positive patients had higher adjuvant therapy usage, but there was no recommendation for adjuvant chemotherapy or radiation for 71% and 66% of pN+ patients, respectively. CONCLUSIONS: Axillary surgery can be omitted for most patients ≥70 undergoing mastectomy for ER+ DCIS, aligning with recommendations for invasive cancer, and omission can be considered in those with ER- disease. Future guidelines incorporating preoperative imaging, as in the SOUND trial, may aid in identifying patients benefiting from axillary surgery.

Cryoablation Without Excision for Early-Stage Breast Cancer: ICE3 Trial 5-Year Follow-Up on Ipsilateral Breast Tumor Recurrence.

BACKGROUND: The ICE3 trial evaluated the safety and efficacy of cryoablation in women aged ≥60 years with low-risk, early-stage breast cancers, aiming to provide a non-operative treatment option and avoid potential surgical risks. This study presents 5-year follow-up trial results. METHODS: The ICE3 trial is an Institutional Review Board-approved, prospective, multicentered, non-randomized trial including women ≥ 60 years of age with unifocal, ultrasound visible, invasive ductal carcinoma ≤ 1.5 cm in size, histologic grade 1-2, hormone receptor (HR)-positive, and human epidermal growth factor receptor 2 (HER2)-negative. The primary study endpoint of 5-year ipsilateral breast tumor recurrence (IBTR) was evaluated based on Kaplan-Meier estimates. RESULTS: Overall, 194 patients meeting eligibility received successful cryoablation treatment per protocol and were included for analysis. The mean age was 74.9 years (55-94) with a mean tumor size of 7.4 mm transverse (2.8-14.0 mm) and 8.1 mm sagittal (2.5-14.9 mm). With a mean follow-up period of 54.16 months, the IBTR rate at 5 years was 4.3% and breast cancer survival was 96.7%. Of the 124 patients who received endocrine therapy only, the IBTR was 3.7%. No serious device-related adverse events were reported. Minor (88.2%) and moderate (9.6%) adverse events were mild in severity and resolved without residual effects. Quality-of-life score demonstrated statistically significant improvement (p < 0.001) in distress at 6 months as compared with baseline. CONCLUSIONS: Breast cryoablation presents a promising alternative to surgery in selected patients, offering the benefits of a minimally invasive procedure with minimal risks. Further studies are encouraged to confirm cryoablation as a viable alternative to surgical excision low-risk patients.

Evaluating the Effect of MarginProbe® Use on Re-excisions After Partial Mastectomy: A Single-Institution Analysis.

BACKGROUND: Breast conservation therapy is a widely accepted approach in treating breast cancer, yet the average re-excision rates are approximately 25% despite surgical advancements. The Food and Drug Administration (FDA)-approved MarginProbe® device uses radiofrequency spectroscopy for intraoperative margin assessment, potentially reducing re-excision rates. This study evaluated the effectiveness of MarginProbe® in reducing re-excisions compared with standard of care (SOC). METHODS: A prospective cohort with MarginProbe® usage during partial mastectomies from June 2019 to July 2023 (153 patients) was compared with a retrospective control group without the device from January 2015 to May 2019 (300 patients). Both groups underwent partial mastectomies performed by two breast surgeons. Positive margins were defined as tumor on ink for invasive cancers and within 2 mm for ductal carcinoma in situ. RESULTS: When control was used for patient demographics and tumor characteristics, the findings showed that MarginProbe® significantly decreased the probability of re-excision by 58% (p < 0.001), although it led to a higher shave volume, with an average of 9.8 cc additional tissue removed compared with SOC (p < 0.001). Human epidermal growth factor 2 (HER2) positivity was significantly associated with increased odds of re-excision (p = 0.036). MarginProbe® demonstrated a sensitivity of 70.1% and a specificity of 47.5%. CONCLUSIONS: MarginProbe® is an effective adjunct for intraoperative margin assessment to decrease re-excision rates. However, patient selection is paramount. Given its significant increase in shave volume, women with small breasts may be at higher risk for poor cosmesis. Surgeons should exercise clinical judgement when determining the suitability of MarginProbe® use for patients undergoing breast conservation. Further research is necessary to refine MarginProbe®'s specificity and to optimize its clinical application.

Surgery Plays a Leading Role in Breast Cancer Treatment for Patients Aged ≥90 Years: A Large Retrospective Cohort Study.

BACKGROUND: The population aged ≥90 years is increasing worldwide, yet nearly 50% of elderly breast cancer (BC) patients receive suboptimal treatments, resulting in high rates of BC-related mortality. We analyzed clinical and survival outcomes of nonagenarian BC patients to identify effective treatment strategies. METHODS: This single-institution retrospective cohort study analyzed patients aged ≥90 years diagnosed with stage I-III BC between 2007 and 2018. Patients were categorized into three treatment groups: traditional surgery (TS), performed according to local guidelines; current-standard surgery (CS), defined as breast surgery without axillary surgery (in concordance with 2016 Choosing Wisely guidelines) and/or cavity shaving; and non-surgical treatment (NS). Clinicopathological features were recorded and recurrence rates and survival outcomes were analyzed. RESULTS: We collected data from 113 nonagenarians with a median age of 93 years (range 90-99). Among these patients, 43/113 (38.1%) underwent TS, 34/113 (30.1%) underwent CS, and 36/113 (31.9%) underwent NS. The overall recurrence rate among surgical patients was 10.4%, while the disease progression rate in the NS group was 22.2%. Overall survival was significantly longer in surgical patients compared with NS patients (p = 0.04). BC-related mortality was significantly higher in the NS group than in the TS and CS groups (25.0% vs. 0% vs. 7.1%, respectively; p = 0.01). There were no significant differences in overall survival and disease-free survival between the TS and CS groups (p = 0.6 and p = 0.8, respectively), although the TS group experienced a significantly higher overall postoperative complication rate (p < 0.001). CONCLUSIONS: Individualized treatment planning is essential for nonagenarian BC patients. Surgery, whenever feasible, remains the treatment of choice, with CS emerging as the best option for the majority of patients.

Breast Conservation Project: Clinical Outcomes of Extreme Oncoplastic Breast-Conserving Therapy Versus Mastectomy for Large and Multiple Lesions.

INTRODUCTION: Patients with multiple or large malignant breast lesions are classically considered mastectomy candidates, but extreme oncoplastic breast-conservation surgery (eOBCS) has become an alternative approach. There is a paucity of outcomes data comparing eOBCS with mastectomy. METHODS: We reviewed our prospectively maintained, single-institution database. We included patients with non-metastatic breast cancer with multiple ipsilateral or single large (≥ 5 cm) malignant breast lesions identified preoperatively who underwent either eOBCS or mastectomy. Patient demographics, clinicopathologic features, and surgical, oncologic, and cosmetic outcomes were evaluated. RESULTS: Seventy-six (88%) patients underwent eOBCS and 10 (12%) underwent mastectomy. Median follow-up was 24.8 months. Mastectomy patients had larger lesions than eOBCS patients (median 70 mm vs. 32.5 mm; p = 0.06). Six (60%) index mastectomy patients underwent at least one additional surgery. For eOBCS patients, 34 (44%) required re-excision, 7 of whom underwent more than one subsequent surgery to obtain negative margins, and 6 (7.9%) ultimately underwent mastectomy. For patients undergoing additional surgery (n = 40), median time between index and final operation was 315 days for mastectomy versus 21 days for eOBCS patients (p < 0.001). Mastectomy patients more frequently experienced complications (p = 0.001) and underwent cosmetic revision (p < 0.001). There was no difference in cosmetic scores, and eOBCS patients reported less pain (p = 0.009). There were two local and three distant recurrences in the eOBCS cohort and one distant recurrence in the mastectomy group. CONCLUSION: Breast conservation was attainable in over 90% of eOBCS patients. Increased postoperative complications and discomfort and longer duration of surgical treatment in mastectomy patients without oncologic superiority should drive informed patient discussions.

Is the Number or Proximity of Margins Less than 2 mm Associated with an Increased Mastectomy Rate in Patients Attempting Breast Conservation Therapy for Ductal Carcinoma In Situ?

BACKGROUND: Consensus guidelines recommend ≥ 2 mm margins in patients undergoing partial mastectomy (PM) for ductal carcinoma in situ (DCIS). It is unknown whether the number or proximity of margins less than 2 mm is associated with an increased mastectomy rate in patients attempting breast conservation therapy (BCT) for DCIS. The aim of this study is to examine this relationship. PATIENTS AND METHODS: An institutional database review identified 208 patients with DCIS who underwent PM at a tertiary referral center and community hospitals from July 2020 to June 2023. Patients with a history of breast cancer, previous surgery for breast cancer, ipsilateral invasive carcinoma, papillary carcinoma, Paget's disease, more lobular carcinoma in situ (LCIS) than DCIS present, initial mastectomy, no DCIS present, routine shave margins (of all vectors), and ≥ 2 mm margins of all six vectors were excluded. Selective intraoperative margin re-excisions were included. RESULTS: A total of 208 patients who met inclusion criteria were retrospectively reviewed. 122 (25%) had one close/positive (< 2 mm) margin and 86 (18%) had two or more close/positive margins. Of the patients with one close/positive margin, 7% (9/122) eventually underwent mastectomy. Of the patients with two or more close/positive margins, 20% (17/86) eventually underwent mastectomy. Overall, no patients with opposing margins underwent mastectomy. CONCLUSIONS: Patients undergoing PM for DCIS have a mastectomy rate that is increased threefold, with two or more close/positive margins at initial PM, when compared with those with only one close/positive margin. The presence of opposing close/positive margins at initial PM did not increase the mastectomy rate and most were cleared with re-excision.

Guideline-Concordant Surgical Care for Lobular Versus Ductal Inflammatory Breast Cancer.

INTRODUCTION: Quality of surgical care is understudied for lobular inflammatory breast cancer (IBC), which is less common, more chemotherapy-resistant, and more mammographically occult than ductal IBC. We compared guideline-concordant surgery (modified radical mastectomy [MRM] without immediate reconstruction following chemotherapy) for lobular versus ductal IBC. METHODS:  Female individuals with cT4dM0 lobular and ductal IBC were identified in the National Cancer Database (NCDB) from 2010-2019. Modified radical mastectomy receipt was identified via codes for "modified radical mastectomy" or "mastectomy" and "≥10 lymph nodes removed" (proxy for axillary lymph node dissection). Descriptive statistics, chi-square tests, and t-tests were used. RESULTS: A total of 1456 lobular and 10,445 ductal IBC patients were identified; 599 (41.1%) with lobular and 4859 (46.5%) with ductal IBC underwent MRMs (p = 0.001). Patients with lobular IBC included a higher proportion of individuals with cN0 disease (20.5% lobular vs. 13.7% ductal) and no lymph nodes examined at surgery (31.2% vs. 24.5%) but were less likely to be node-negative at surgery (12.7% vs. 17.1%, all p < 0.001). Among those who had lymph nodes removed at surgery, patients with lobular IBC also had fewer lymph nodes excised versus patients with ductal IBC (median [interquartile range], 7 (0-15) vs. 9 (0-17), p = 0.001). CONCLUSIONS: Lobular IBC patients were more likely to present with node-negative disease and less likely to be node-negative at surgery, despite having fewer, and more frequently no, lymph nodes examined versus ductal IBC patients. Future studies should investigate whether these treatment disparities are because of surgical approach, pathologic assessment, and/or data quality as captured in the NCDB.

Clinicopathological Predictors of Positive Resection Margins in Breast-Conserving Surgery.

BACKGROUND: Ductal carcinoma in situ (DCIS) is associated with risk of positive resection margins following breast-conserving surgery (BCS) and subsequent reoperation. Prior reports grossly underestimate the risk of margin positivity with IBC containing a DCIS component (IBC + DCIS) due to patient-level rather than margin-level analysis. OBJECTIVE: The aim of this study was to delineate the relative risk of IBC + DCIS compared with pure IBC (without a DCIS component) on margin positivity through detailed margin-level interrogation. METHODS: A single institution, retrospective, observational cohort study was conducted in which pathology databases were evaluated to identify patients who underwent BCS over 5 years (2014-2019). Margin-level interrogation included granular detail into the extent, pathological subtype and grade of disease at each resection margin. Predictors of a positive margin were computed using multivariate regression analysis. RESULTS: Clinicopathological details were examined from 5454 margins from 909 women. The relative risk of a positive margin with IBC + DCIS versus pure IBC was 8.76 (95% confidence interval [CI] 6.64-11.56) applying UK Association of Breast Surgery guidelines, and 8.44 (95% CI 6.57-10.84) applying the Society of Surgical Oncology/American Society for Radiation Oncology guidelines. Independent predictors of margin positivity included younger patient age (0.033, 95% CI 0.006-0.060), lower specimen weight (0.045, 95% CI 0.020-0.069), multifocality (0.256, 95% CI 0.137-0.376), lymphovascular invasion (0.138, 95% CI 0.068-0.208) and comedonecrosis (0.113, 95% CI 0.040-0.185). CONCLUSIONS: Compared with pure IBC, the relative risk of a positive margin with IBC + DCIS is approximately ninefold, significantly higher than prior estimates. This margin-level methodology is believed to represent the impact of DCIS more accurately on margin positivity in IBC.

Implementation of the Targeted Axillary Dissection Procedure in Clinically Node-Positive Breast Cancer: A Retrospective Analysis.

BACKGROUND: The targeted axillary dissection (TAD) procedure is used in clinically positive lymph node (cN+) breast cancer to assess whether pathological complete response (pCR) is achieved after neoadjuvant systemic therapy (NST) to decide on de-escalation of axillary lymph node dissection (ALND). In this study, we review the implementation of the TAD procedure in a large regional breast cancer center. METHODS: All TAD procedures between 2016 and 2022 were reviewed. The TAD procedure consists of marking pre-NST the largest suspected metastatic lymph node(s) using a radioactive I-125 seed. During surgery, the marked node was excised together with a sentinel node procedure. Axillary therapy (ALND, axillary radiotherapy, or nothing) recommendations were based on the amount of suspected positive axillary lymph nodes (ALNs < 4 or ≥ 4) pre-NST and if pCR was achieved after NST. RESULTS: A total of 312 TAD procedures were successfully performed in 309 patients. In 134 (43%) cases, pCR of the TAD lymph nodes were achieved. Per treatment protocol, 43 cases (14%) did not receive any axillary treatment, 218 cases (70%) received adjuvant axillary radiotherapy, and 51 cases (16%) underwent an ALND. During a median follow-up of 2.8 years, 46 patients (14%) developed recurrence, of which 11 patients (3.5%) had axillary recurrence. CONCLUSIONS: Introduction of the TAD procedure has resulted in a reduction of 84% of previously indicated ALNDs. Moreover, 18% of cases did not receive adjuvant axillary radiotherapy. These data show that implementation of de-escalation axillary treatment with the TAD procedure appeared to be successful.

Determination of Factors Associated with Upstage in Atypical Ductal Hyperplasia to Identify Low-Risk Patients Where Active Surveillance May be an Alternative.

BACKGROUND: Excision is routinely recommended for atypical ductal hyperplasia (ADH) found on core biopsy given cancer upstage rates of near 20%. Identifying a cohort at low-risk for upstage may avoid low-value surgery. Objectives were to elucidate factors predictive of upstage in ADH, specifically near-complete core sampling, to potentially define a group at low upstage risk. PATIENTS AND METHODS: This retrospective, cross-sectional, multi-institutional study from 2015 to 2019 of 221 ADH lesions in 216 patients who underwent excision or active observation (≥ 12 months imaging surveillance, mean follow-up 32.6 months) evaluated clinical, radiologic, pathologic, and procedural factors for association with upstage. Radiologists prospectively examined imaging for lesional size and sampling proportion. RESULTS: Upstage occurred in 37 (16.7%) lesions, 25 (67.6%) to ductal carcinoma in situ (DCIS) and 12 (32.4%) to invasive cancer. Factors independently predictive of upstage were lesion size ≥ 10 mm (OR 5.47, 95% CI 2.03-14.77, p < 0.001), pathologic suspicion for DCIS (OR 12.29, 95% CI 3.24-46.56, p < 0.001), and calcification distribution pattern (OR 8.08, 95% CI 2.04-32.00, p = 0.003, "regional"; OR 19.28, 95% CI 3.47-106.97, p < 0.001, "linear"). Near-complete sampling was not correlated with upstage (p = 0.64). All three significant predictors were absent in 65 (29.4%) cases, with a 1.5% upstage rate. CONCLUSIONS: The upstage rate among 221 ADH lesions was 16.7%, highest in lesions ≥ 10 mm, with pathologic suspicion of DCIS, and linear/regional calcifications on mammography. Conversely, 30% of the cohort exhibited all low-risk factors, with an upstage rate < 2%, suggesting that active surveillance may be permissible in lieu of surgery.

Clipped Axillary Node as a Potential Surrogate for Overall Axillary Nodal Status in Inflammatory Breast Cancer Patients after Neoadjuvant Chemotherapy.

BACKGROUND: Axillary lymph node dissection is the current standard for management of the axilla in inflammatory breast cancer (IBC). The present study aims to determine whether the initially positive node identified by clip placement accurately represents the overall nodal status of axilla after neoadjuvant chemotherapy (NAC) in IBC. PATIENTS AND METHODS: A retrospective study was conducted on patients with IBC who underwent operation (2014-2023). For patients with IBC who had clip placement in a positive axillary node at diagnosis, operative notes, specimen radiographs, and pathology reports were reviewed to confirm final pathologic status of clipped nodes. RESULTS: In total, 92 patients with IBC (90 cN+) were identified (median age 54 years, 78% invasive ductal, 10% invasive lobular, and 12% mixed); 81 (90%) were biopsy-proven cN+, with a clip placed in the positive node for 62/81 (77%). All patients were treated with NAC and axillary surgery with median 19 (range 4-49) nodes removed. Among 28 (out of 56) patients with retrieved clipped nodes that were pathologically negative (ypN0), only 1 had an additional positive node with micrometastasis for a false negative rate of 4% (95% CI 1-19%). Conversely, 3/3 patients with isolated tumor cells (ITCs) only in the clipped node had additional axillary disease (ITCs in 1, macrometastasis in 2), and 20/23 (87%) of patients with pathologically positive clipped node (micrometastasis or greater) had additional positive nodes [19/20 (95%) with macrometastasis]. CONCLUSIONS: The clipped biopsy-positive axillary node in IBC accurately represented the post-NAC overall axillary nodal status. ITCs post-NAC should be considered positive as an indicator of additional nodes with metastasis.

Impact of Margin Status on Local Recurrence in Patients with Breast Cancer Undergoing Breast-Conserving Surgery After Neoadjuvant Chemotherapy: A Retrospective Multi-Institutional Cohort Study.

BACKGROUND: Questions have been raised as to an increased risk of local recurrence with breast-conserving surgery (BCS) post NAC highlighting the uncertainty around optimal margin width in this patient population. We examined the association between margin status and local recurrence-free survival (LRFS) in patients who underwent BCS following NAC. METHODS: We performed a retrospective cohort study of adult female patients with stage I-III breast cancer who underwent NAC followed by BCS between 2012 and 2021 at two cancer centers. Margins were categorized as "close" if they were < 1 mm. RESULTS: The full cohort included 544 patients with a median age of 53 years (interquartile range [IQR] 44-64). Pathologic complete response (pCR) was achieved in 41.2% of the overall cohort (n = 224). Of the 320 with residual disease, 29.4% (n = 94) had at least one close margin, and 10.9% (n = 35) had ≥2 close margins. Median follow-up was 55 months (IQR 32-83); 4.8% had an ipsilateral breast recurrence (n = 26). Patients with pCR had a higher 5-year LRFS than those with residual disease (98.0% vs. 91.6%, p = 0.02). There was no difference in 5-year LRFS between the margin categories (clear vs. 1 close margin vs. ≥2 close margins) in those with residual disease (92.2% vs. 88.9% vs. 92.9%) (p = 0.78). CONCLUSIONS: In patients undergoing BCS post-NAC, those who achieved pCR had a significantly higher LRFS compared with those with residual disease at the time of surgery, but LRFS was not associated with margin width nor the number of close margins.

Contrast-Enhanced Mammography in Local Staging of Screen-Detected Breast Cancer.

BACKGROUND: BreastScreen Australia, the population mammographic screening program for breast cancer, uses two-view digital screening mammography ± ultrasound followed by percutaneous biopsy to detect breast cancer. Secondary breast imaging for further local staging, not performed at BreastScreen, may identify additional clinically significant breast lesions. Staging options include further mammography, bilateral ultrasound, and/or contrast-based imaging (CBI) [magnetic resonance imaging (MRI) or contrast-enhanced mammography (CEM)]. CBI for local staging of screen-detected cancer was introduced at an academic hospital breast service in Melbourne, VIC, Australia. We report findings for otherwise occult disease and resulting treatment changes. MATERIAL AND METHODS: Patients staged using CEM between November 2018 and April 2022 were identified from hospital records. Data were extracted from radiology, pathology, and breast unit databases. CEM-detected abnormalities were documented as true positive (TP) for invasive cancer or ductal carcinoma in situ (DCIS), or otherwise false positive (FP). The impact on surgical decisions was assessed. RESULTS: Of 202 patients aged 44-84 years, 60 (30%) had 74 additional findings [34 (46%) TP, 40 (54%) FP]. These were malignant in 29/202 (14%) patients (79% invasive cancers, 21% DCIS). CEM resulted in surgical changes in 43/202 (21%) patients: wider resection (24/43), conversion to mastectomy (6/43), contralateral breast surgery (6/43), additional ipsilateral excision (5/43), and bracketing (2/43). Additional findings were more common for patients with larger index lesions and for invasive cancer, but there was no significant variation by age, breast density, or index lesion grade. CONCLUSIONS: CEM for local staging of screen-detected breast cancers identified occult malignancy in 14% of patients. CEM improves local staging and may facilitate appropriate management of screen-detected breast cancers.

Positive Nipple Margins in Nipple-Sparing Mastectomy: Management of Nipples Containing Cancer or Atypia.

BACKGROUND: Nipple-sparing mastectomy (NSM) is an oncologically safe approach for breast cancer treatment and prevention; however, there are little long-term data to guide management for patients whose nipple margins contain tumor or atypia. METHODS: NSM patients with tumor or atypia in their nipple margin were identified from a prospectively maintained, single-institution database of consecutive NSMs. Patient and tumor characteristics, treatment, recurrence, and survival data were assessed. RESULTS: A total of 3158 NSMs were performed from June 2007 to August 2019. Nipple margins contained tumor in 117 (3.7%) NSMs and atypia only in 164 (5.2%) NSMs. Among 117 nipple margins that contained tumor, 34 (29%) margins contained invasive cancer, 80 (68%) contained ductal carcinoma in situ only, and 3 (3%) contained lymphatic vessel invasion only. Management included nipple-only excision in 67 (57%) breasts, nipple-areola complex excision in 35 (30%) breasts, and no excision in 15 (13%) breasts. Only 23 (24%) excised nipples contained residual tumor. At 67 months median follow-up, there were 2 (1.8%) recurrences in areolar or peri-areolar skin, both in patients with nipple-only excision. Among 164 nipple margins containing only atypia, 154 (94%) nipples were retained. At 60 months median follow-up, no patient with atypia alone had a nipple or areola recurrence. CONCLUSIONS: Nipple excision is effective management for nipple margins containing tumor. No intervention is required for nipple margins containing only atypia. Our results support broad eligibility for NSM with careful nipple margin assessment.

Micropapillary breast carcinoma in comparison with invasive duct carcinoma. Does it have an aggressive clinical presentation and an unfavorable prognosis?

BACKGROUND: Invasive micropapillary carcinoma (IMPC) was first proposed as an entity by Fisher et al. In the 2003 World Health Organization (WHO) guidelines for histologic classification of the breast tumors. IMPC was recognized as a distinct, rare histological subtype of breast cancer. IMPC is emerging as a surgical and oncological challenge due to its tendency to manifest as a palpable mass, larger in size and higher in grade than IDC with more rate of lymphovascular invasion (LVI) and lymph node (LN) involvement, which changes the surgical and adjuvant management plans to more aggressive, with comparative prognosis still being a point of ongoing debate. AIM OF THE STUDY: In this study, we compared the clinicopathological characteristics, survival and surgical management of breast cancer patients having invasive micropapillary carcinoma pathological subtype in comparison to those having invasive duct carcinoma. METHOD: This is a comparative study on female patients presented to Baheya center for early detection and treatment of breast cancer, in the period from 2015 to 2022 diagnosed with breast cancer of IMPC subtype in one group compared with another group of invasive duct carcinoma. we analyzed 138 cases of IMPC and 500 cases of IDC. RESULTS: The incidence of LVI in the IMPC group was 88.3% in comparison to 47.0% in the IDC group (p < 0.001). IMPC had a higher incidence of lymph node involvement than the IDC group (68.8% and 56% respectively). IMPC had a lower rate of breast conserving surgery (26% vs.37.8%) compared with IDC. The survival analysis indicated that IMPC patients had no significant difference in overall survival compared with IDC patients and no differences were noted in locoregional recurrence rate and distant metastasis rate comparing IMPCs with IDCs. CONCLUSION: The results from our PSM analysis suggested that there was no statistically significant difference in prognosis between IMPC and IDC patients after matching them with similar clinical characteristics. However, IMPC was found to be more aggressive, had larger tumor size, greater lymph node metastasis rate and an advanced tumor stage.

Can we skip invasive biopsy of sentinel lymph nodes? A preliminary investigation to predict sentinel lymph node status using PET/CT-based radiomics.

BACKGROUND: Sentinel lymph node (SLN) biopsy (SLNB) is considered the gold standard for detecting SLN metastases in patients with invasive ductal breast cancer (IDC). However, SLNB is invasive and associated with several complications. Thus, this study aimed to evaluate the diagnostic performance of a non-invasive radiomics analysis utilizing 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) for assessing SLN metastasis in IDC patients. METHODS: This retrospective study included 132 patients with biopsy-confirmed IDC, who underwent 18F-FDG PET/CT scans prior to mastectomy or breast-conserving surgery with SLNB. Tumor resection or SLNB was conducted within one-week post-scan. Clinical data and metabolic parameters were analyzed to identify independent SLN metastasis predictors. Radiomic features were extracted from each PET volume of interest (VOI) and CT-VOI. Feature selection involved univariate and multivariate logistic regression analysis, and the least absolute shrinkage and selection operator (LASSO) method. Three models were developed to predict SLN status using the random forest (RF), decision tree (DT), and k-Nearest Neighbors (KNN) classifiers. Model performance was assessed using the area under the receiver operating characteristic curve (AUC). RESULTS: The study included 91 cases (32 SLN-positive and 59 SLN-negative patients) in the training cohort and 41 cases (29 SLN-positive and 12 SLN-negative patients) in the validation cohort. Multivariate logistic regression analysis identified Ki 67 and TLG as independent predictors of SLN status. Five PET-derived features, three CT-derived features, and two clinical variables were selected for model development. The AUC values of the RF, KNN, and DT models for the training cohort were 0.887, 0.849, and 0.824, respectively, and for the validation cohort were 0.856, 0.830, and 0.819, respectively. The RF model demonstrated the highest accuracy for the preoperative prediction of SLN metastasis in IDC patients. CONCLUSION: The PET-CT radiomics approach may offer robust and non-invasive predictors for SLN status in IDC patients, potentially aiding in the planning of personalized treatment strategies for IDC patients.