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.

Does a brief surgeon training in negotiation theory principles decrease rates of contralateral prophylactic mastectomy?

PURPOSE: Despite the lack of any oncologic benefit, contralateral prophylactic mastectomy (CPM) use among women with unilateral breast cancer is increasing. This patient-driven trend is influenced by fear of recurrence and desire for peace of mind. Traditional educational strategies have been ineffective in reducing CPM rates. Here we employ training in negotiation theory strategies for counseling and determine the effect on CPM rates. METHODS: In consecutive patients with unilateral breast cancer treated with mastectomy from 05/2017 to 12/2019, we examined CPM rates before and after a brief surgeon training in negotiation skills. This comprised a systematic framework for patient counseling utilizing early setting of the default option, leveraging social proof, and framing. RESULTS: Among 2144 patients, 925 (43%) were treated pre-training and 744 (35%) post-training. Those treated in the 6-month transition period were excluded (n = 475, 22%). Median patient age was 50 years; most patients had T1-T2 (72%), N0 (73%), and estrogen receptor-positive (80%) tumors of ductal histology (72%). The CPM rate was 47% pre-training versus 48% post-training, with an adjusted difference of -3.7% (95% CI -9.4 to 2.1, p = 0.2). In a standardized self-assessment survey, all 15 surgeons reported a high baseline use of negotiation skills and no significant change in conversational difficulty with the structured approach. CONCLUSION: Brief surgeon training did not affect self-reported use of negotiation skills or reduce CPM rates. The choice of CPM is a highly individual decision influenced by patient values and decision styles. Further research to identify effective strategies to minimize surgical overtreatment with CPM is needed.

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.

Outcomes of Breast Cancer Patients with High Volume of Residual Disease Following Neoadjuvant Chemotherapy.

PURPOSE: The use of neoadjuvant chemotherapy (NAC) in patients with operable breast cancer allows for assessment of treatment response and subsequent tailoring of adjuvant therapy. Data are limited with respect to outcomes among patients with a heavy residual tumor burden after NAC. We report outcomes in patients who had exceptionally poor responses to NAC: those with >9 involved nodes after NAC or with 5 cm or more of residual disease in the breast. METHODS AND MATERIALS: Between June 2014 and April 2020, 1511 patients with breast cancer received NAC followed by surgery at our institution. Poor responders, defined as those with positive nodes or residual tumor in the breast, were identified for analysis. Patients were further classified into 3 groups for comparison purposes: (1) 1 to 3 positive nodes; (2) 4 to 9 positive nodes; or (3) >9 positive nodes and/or >5 cm of residual tumor, which was defined as high-volume residual (HVR). Recurrence and survival outcomes were compared based on residual disease burden after NAC. RESULTS: Among 934 poor responders, 539 patients had 1 to 3 positive nodes (ypN1), 215 had 4 to 9 positive nodes (ypN2), and 180 had HVR disease. Specifically, 118 had >9 positive nodes (HVR), and 62 patients had >5 cm of residual tumor in the breast. With a median follow-up of 31 months (interquartile range, 18-46), the 5-year overall survival rate was 88% among ypN1, 76% among ypN2, and 72% among patients with HVR disease (P < .001). The 5-year distant recurrence-free survival and locoregional recurrence incidences were 82% and 7.6% among ypN1 versus 67% and 8.4% among ypN2 versus 53% and 12% among HVR, respectively. CONCLUSIONS: Our work suggests that patients with HVR disease are at high risk for locoregional and distant recurrence as well as death, despite best available standard-of-care treatment. Intensification of locoregional therapies and/or alternative adjuvant systemic treatment may improve outcomes in these poor responders.

Omission of Intraoperative Frozen Section May Reduce Axillary Overtreatment Among Clinically Node-Negative Patients Having Upfront Mastectomy.

BACKGROUND: The growing use of postmastectomy radiation/regional nodal irradiation (PMRT) has resulted in many women receiving both axillary dissection (ALND) and PMRT, increasing lymphedema rates. After developing standardized PMRT criteria, we adopted a policy of ALND omission among cN0 patients with 1-2 positive sentinel nodes (+SLNs) requiring PMRT. We evaluated how often overtreatment with ALND+PMRT was avoided with this approach. METHODS: A retrospective review of a prospectively maintained database was performed beginning 1 year before policy adoption. Intraoperative SLN evaluation was routine pre- and post-policy. ALND was performed for SLN macrometastasis pre-policy, and selectively performed post-policy for 1-2 +SLNs based on PMRT criteria. ALND+PMRT was required for ≥ 3 +SLNs. RESULTS: From March 1, 2018 to November 30, 2020, a total of 2207 cT1-3N0 patients had mastectomy and 231 had +SLNs; 109 (47%) were treated pre-policy and 122 (53%) post-policy. Most (81%) had 1-2 +SLNs. There was no change in rates of ALND+PMRT (64% pre-policy vs. 58% post-policy, p = 0.09), including in patients with 1-2 +SLNs (61% vs. 51%, p = 0.20). Post-policy, ALND was omitted in 9 (7%) patients recognized intraoperatively as PMRT candidates; avoidable ALND was performed in 40 (33%) patients not identified as PMRT candidates until receipt of final pathology. Overall, had intraoperative SLN evaluation been deferred, only 5.7% of patients would have required completion ALND: 2.2% (n = 49/2207) for ≥ 3 +SLNs and 3.5% (n = 77/2207) for 1-2 +SLNs without PMRT indication. CONCLUSIONS: Most patients could have avoided ALND+PMRT if decision making was deferred until final pathology was available. Selective intraoperative SLN evaluation in cN0 patients having upfront mastectomy may reduce avoidable overtreatment.

The Effect of Age on Outcomes After Neoadjuvant Chemotherapy for Breast Cancer.

BACKGROUND: Younger women (age ≤ 40 years) with breast cancer undergoing neoadjuvant chemotherapy (NAC) have higher rates of pathologic complete response (pCR); however, it is unknown whether axillary or breast downstaging rates differ by age. In this study, we compared pCR incidence and surgical downstaging rates of the breast and axilla post NAC, between patients aged ≤ 40, 41-60, and ≥ 61 years. METHODS: We identified 1383 women with stage I-III breast cancer treated with NAC and subsequent surgery from November 2013 to December 2018. pCR and breast/axillary downstaging rates were assessed and compared across age groups. RESULTS: Younger women were significantly more likely to have ductal histology, poorly differentiated tumors, and BRCA mutations; 35% of tumors were hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-), 36% were HER2-positive (HER2+), and 29% were triple negative (TN), with similar subtype distribution across age groups (p = 0.6). Overall, pCR rates did not differ by age, however among patients with TN tumors (n = 394), younger women had higher pCR rates (52% vs. 35% among those aged 41-60 years and 29% among those aged ≥61 years; p = 0.007) and were more likely to have tumors with high tumor-infiltrating lymphocyte (TIL) concentrations (p < 0.001). Downstaging to breast-conserving surgery (BCS) eligibility post NAC among initially BCS-ineligible patients was similar across age groups; younger women chose BCS less often (p < 0.001). Among cN1 patients (n = 813), 52% of women ≤40 years of age avoided axillary lymph node dissection (ALND) with NAC, versus 39% and 37% in the older groups (p < 0.001). CONCLUSIONS: Younger women undergoing NAC for axillary downstaging were more likely to avoid ALND across all subtypes; however, overall pCR rates did not differ by age. Despite equivalent breast downstaging and BCS eligibility rates across age groups, younger women were less likely to undergo BCS.

Margin Width and Local Recurrence in Patients Undergoing Breast Conservation After Neoadjuvant Chemotherapy.

BACKGROUND: A margin of "no ink on tumor" has been established for primary breast conservation therapy (BCT), but the appropriate margin following neoadjuvant chemotherapy (NAC) remains controversial. We examined the impact of margin width on ipsilateral breast tumor recurrence (IBTR) in the NAC-BCT population. METHODS: Consecutive patients receiving NAC-BCT were identified from a prospective database. The associations between clinicopathologic characteristics, margin width, and isolated IBTR were evaluated. RESULTS: From 2013 to 2019 we identified 582 patients with 586 tumors who received NAC-BCT. The median age of the cohort was 54 years (IQR 45, 62); 84% of patients had cT1/T2 tumors and 61% were clinically node positive. The majority of tumors were HER2+ (38%) or triple negative (TN) (31%). Pathologic complete response was observed in 29%. Margin width was > 2 mm in 517 tumors (88%) and ≤ 2 mm in 69 (12%). At a median follow-up of 39 months, 14 patients had IBTR as a first event, with 64% occurring within 24 months of surgery. The 4-year IBTR rate was 2% (95% CI 1-4%), and there was no difference based on margin width (3% ≤ 2 mm vs 2% > 2 mm; p = not significant). On univariate analysis, clinical and pathologic T stage and receptor subtype, but not margin width, were associated with IBTR (p < 0.05). On multivariable analysis, TN subtype and higher pathologic T stage were associated with isolated IBTR (both p < 0.05). CONCLUSION: Pathologic features and tumor biology, not margin width, were associated with IBTR in NAC-BCT patients.

Is local recurrence higher among patients who downstage to breast conservation after neoadjuvant chemotherapy?

BACKGROUND: In early studies, local recurrence (LR) rates were higher after neoadjuvant chemotherapy (NAC) in comparison with upfront surgery. Modern outcomes are uncertain, particularly among those who are initially breast-conserving surgery-ineligible (BCSi) and downstage to being breast-conserving surgery-eligible (BCSe). METHODS: Among patients with cT1-3 breast cancer treated from 2014 to 2018 who were BCSe after NAC, clinicopathologic characteristics and LR were compared between initially BCSe patients and BCSi patients who downstaged. Breast-conserving surgery (BCS) eligibility was determined prospectively. RESULTS: Among 685 patients, 243 (35%) were BCSe before and after NAC and had BCS; 282 (41%) were BCSi before NAC, downstaged to BCSe, and had BCS; and 160 (23%) were BCSi before NAC, downstaged to BCSe, and chose mastectomy. The median age was 52 years, and most cancers were cT1-2 (84%), cN+ (61%), and human epidermal growth factor receptor 2-positive (HER2+; 38%) or triple-negative (34%). Those who were BCSe before NAC had a lower cT stage, whereas those who chose mastectomy were younger (P < .05). NAC was usually ACT (doxorubicin, cyclophosphamide, and a taxane)-based (92%), 99% of HER2+ patients received dual blockade, and 99% of BCS patients received adjuvant radiation. At a median follow-up of 35 months, 22 patients (3.2%) had developed LR. The Kaplan-Meier 4-year LR rates were not different among the groups (1.9% for those who were BCSe before and after NAC, 6.3% for those who downstaged to being BCSe and underwent BCS, and 2.7% for those who downstaged and underwent mastectomy; P = .17). CONCLUSIONS: LR rates are low after NAC and BCS, even among BCSi patients who downstage, and they are not improved in patients who downstage and choose mastectomy. Mastectomy can be safely avoided in BCSi patients who downstage with NAC.

Local Recurrence is Frequent After Heroic Mastectomy for Classically Inoperable Breast Cancers.

BACKGROUND: Despite advances in neoadjuvant systemic therapy (NST), some patients with aggressive T4 breast cancers do not respond. The efficacy of 'heroic' mastectomy in maintaining local control is unclear. METHODS: In consecutive patients with primary or recurrent T4 cancers with < 50% shrinkage on NST who underwent mastectomy from 2007 to 2017, clinicopathologic characteristics and locoregional recurrence (LRR) were examined. RESULTS: Among 104 patients, 59 (57%) had primary T4M0, 12 (12%) had locally recurrent T4M0, and 33 (32%) had T4M1 disease. Median age was 58.5 years and the majority had high-grade (74%) ductal cancers (85%); 45 (44%) were estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-), 26 (25%) were HER2 positive (HER2+), and 31 (30%) were triple negative (TN). Postoperative complications developed in 41 (39%) patients. At a median follow-up of 37 months, 42 (40%) patients developed LRR. TN (hazard ratio [HR] 7.5) and HER2+ (HR 2.67) subtypes, lymphovascular invasion (LVI; HR 3.80), and positive margins (HR 4.09) were predictive of LRR. The 3-year LRR rate was highest and overall survival (OS) was lowest among patients with TN cancers, at 66% (95% confidence interval [CI] 48-83%) and 30% (95% CI 14-47%), respectively. CONCLUSIONS: After heroic mastectomy, postoperative complications were frequent and LRR occurred in 40% of patients despite a median OS of 3.8 years. Among TN patients, the 3-year LRR rate of 66% and 3-year OS of 30% suggest limited surgery benefit. Careful patient selection is prudent when considering heroic mastectomy.

Nodal Recurrence in Patients With Node-Positive Breast Cancer Treated With Sentinel Node Biopsy Alone After Neoadjuvant Chemotherapy-A Rare Event.

IMPORTANCE: Prospective trials have demonstrated sentinel lymph node (SLN) false-negative rates of less than 10% when 3 or more SLNs are retrieved in patients with clinically node-positive breast cancer rendered clinically node-negative with neoadjuvant chemotherapy (NAC). However, rates of nodal recurrence in such patients treated with SLN biopsy (SLNB) alone are unknown because axillary lymph node dissection (ALND) was performed in all patients, limiting adoption of this approach. OBJECTIVE: To evaluate nodal recurrence rates in a consecutive cohort of patients with clinically node-positive (cN1) breast cancer receiving NAC, followed by a negative SLNB using a standardized technique, and no further axillary surgery. DESIGN, SETTING, AND PARTICIPANTS: From November 2013 to February 2019, a cohort of consecutively identified patients with cT1 to cT3 biopsy-proven N1 breast cancer rendered cN0 by NAC underwent SLNB with dual tracer mapping and omission of ALND if 3 or more SLNs were identified and all were pathologically negative. Metastatic nodes were not routinely clipped, and localization of clipped nodes was not performed. The study was performed in a single tertiary cancer center. INTERVENTION: Omission of ALND in patients with cN1 breast cancer after NAC if 3 or more SLNs were pathologically negative. MAIN OUTCOME AND MEASURES: The primary outcome was the rate of nodal recurrence among patients with cN1 breast cancer treated with SLNB alone after NAC. RESULTS: Of 610 patients with cN1 breast cancer treated with NAC, 555 (91%) converted to cN0 and underwent SLNB; 234 (42%) had 3 or more negative SLNs and had SLNB alone. The median (IQR) age of these 234 patients was 49 (40-58) years; median tumor size was 3 cm; 144 (62%) were ERBB2 (formerly HER2)-positive, and 43 (18%) were triple negative. Most (212 [91%]) received doxorubicin-based NAC; 205 (88%) received adjuvant radiotherapy (RT), and 164 (70%) also received nodal RT. At a median follow-up of 40 months, there was 1 axillary nodal recurrence synchronous with local recurrence in a patient who refused RT. Among patients who received RT (n = 205), there were no nodal recurrences. CONCLUSIONS AND RELEVANCE: This cohort study found that in patients with cN1 disease rendered cN0 with NAC, with 3 or more negative SLNs with SLNB alone, nodal recurrence rates were low, without routine nodal clipping. These findings potentially support omitting ALND in such patients.

Adoption of SSO-ASTRO Margin Guidelines for Ductal Carcinoma in Situ: What Is the Impact on Use of Additional Surgery?

BACKGROUND: Historically, more than one-third of patients with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery (BCS) underwent additional surgery. The SSO-ASTRO guidelines advise 2 mm margins for patients with DCIS having BCS and whole-breast radiation (WBRT). Here we examine guideline impact on additional surgery and factors associated with re-excision. PATIENTS AND METHODS: Patients treated with BCS for pure DCIS from August 2015 to January 2018 were identified. Guidelines were adopted on September 1, 2016, and all patients had separately submitted cavity-shave margins. Clinicopathologic characteristics, margin status, and rates of additional surgery were examined. RESULTS: Among 650 patients with DCIS who attempted BCS, 50 (8%) converted to mastectomy. Of 600 who had BCS as final surgery, 336 (56%) received WBRT and comprised our study group. One hundred twenty-eight (38%) were treated pre-guideline and 208 (62%) were treated post-guideline. Characteristics and margin status were similar between groups. The re-excision rate was 38% pre-guideline adoption and 29% post-guideline adoption (p = 0.09), with 91% having only one re-excision. Re-excision for ≥ 2 mm margins was uncommon (6% pre-guideline vs. 5% post-guideline). On multivariate analysis, younger age (OR 0.97, 95% CI 0.94-0.99, p = 0.02) and larger DCIS size (OR 1.43, 95% CI 1.2-1.8, p < 0.001) were predictive of re-excision; guideline era was not. Younger age (OR 0.93, 95% CI 0.9-0.97, p < 0.001) and larger size (OR 1.64, 95% CI 1.3-2.1, p < 0.001) were predictive of conversion to mastectomy, but residual tumor burden was low. CONCLUSIONS: The SSO-ASTRO guidelines did not significantly change re-excision rates for DCIS in our practice, likely since re-excision for margins ≥ 2 mm was uncommon even prior to guideline adoption, dissimilar to historically observed variations in surgeon practices. Younger age and larger DCIS size were associated with additional surgery.

Extranodal Tumor Deposits in the Axillary Fat Indicate the Need for Axillary Dissection Among T1-T2cN0 Patients with Positive Sentinel Nodes.

BACKGROUND: The American College of Surgeons Oncology Group (ACOSOG) Z0011 trial demonstrated the safety of omitting axillary lymph node dissection (ALND) in T1-T2cN0 patients with fewer than three positive sentinel nodes (SLNs) undergoing breast-conservation therapy. While microscopic extracapsular extension (mECE) > 2 mm is associated with increased nodal burden, the significance of extranodal tumor deposits (ETDs) in the axillary fat is uncertain. METHODS: Consecutive patients with T1-T2cN0 breast cancer undergoing sentinel node biopsy and ALND for SLN metastases from January 2010 to December 2018 were identified. ETDs were defined as intravascular tumor emboli or metastatic deposits in the axillary fat. Clinicopathologic characteristics and nodal burden were compared by ETD status. RESULTS: Among 1114 patients, 113 (10%) had ETDs: 81 (72%) were intravascular tumor emboli and 32 (28%) were soft tissue deposits. Patients with ETDs had larger tumors (median 2.2 vs. 2.1 cm; p = 0.033) and more often had mECE (83% vs. 44%; p < 0.001). On univariable analysis, presence of ETDs (odds ratio [OR] 9.66, 95% confidence interval [CI] 6.36-14.68), larger tumors (OR 1.47, 95% CI 1.25-1.72), and mECE (OR 10.73, 95% CI 6.86-16.78) were associated with four or more additional positive non-SLNs (NSLNs; all p < 0.001). On multivariable analysis, ETDs remained associated with four or more positive NSLNs (OR 5.67, 95% CI 3.53-9.08; p < 0.001). ETDs were strongly associated with four or more positive NSLNs (OR 7.15, 95% CI 4.04-12.67) among patients with one to two positive SLNs (n = 925). CONCLUSIONS: Among T1-T2cN0 patients with SLN metastases, ETDs are strongly associated with four or more positive NSLNs at ALND. Even among those who may otherwise meet the criteria for omission of ALND, the presence of ETDs in axillary fat warrants consideration of ALND.

Selecting Node-Positive Patients for Axillary Downstaging with Neoadjuvant Chemotherapy.

BACKGROUND: Axillary lymph node dissection (ALND) can be avoided in node-positive patients who receive neoadjuvant chemotherapy (NAC) if three or more negative sentinel lymph nodes (SLNs) are retrieved. We evaluate how often node-positive patients avoid ALND with NAC, and identify predictors of identification of three or more SLNs and of nodal pathological complete response (pCR). METHODS: From November 2013 to July 2019, all patients with cT1-3, biopsy-proven N1 tumors who converted to cN0 after NAC received SLN biopsy (SLNB) with dual mapping and were identified from a prospectively maintained database. RESULTS: 630 consecutive N1 patients were eligible for axillary downstaging with NAC; 573 (91%) converted to cN0 and had SLNB, and 531 patients (93%) had three or more SLNs identified. Lymphovascular invasion (LVI; odds ratio [OR] 0.46, 95% confidence interval [CI] 0.24-0.87; p = 0.02) and increasing body mass index (BMI; OR 0.77, 95% CI 0.62-0.96 per 5-unit increase; p = 0.02) were significantly associated with failure to identify three or more SLNs. 255/573 (46%) patients achieved nodal pCR; 237 (41%) had adequate mapping. Factors associated with ALND avoidance included high grade (OR 2.51, 95% CI 1.6-3.94, p = 0.001) and receptor status (HR+/HER2- [referent]: OR 1.99, 95% CI 1.15-3.46 [p = 0.01] for HR-/HER2-, OR 3.93, 95% CI 2.40-6.44 [p < 0.001] for HR+/HER2+, and OR 8.24, 95% CI 4.16-16.3 [p < 0.001] for HR-/HER2+). LVI was associated with a lower likelihood of avoiding ALND (OR 0.28, 95% CI 0.18-0.43; p < 0.001). CONCLUSIONS: ALND was avoided in 41% of cN1 patients after NAC. Increased BMI and LVI were associated with lower retrieval rates of three or more SLNs. ALND avoidance rates varied with receptor status, grade, and LVI. These factors help select patients most likely to avoid ALND.

Treatment of Ductal Carcinoma in Situ: Considerations for Tailoring Therapy in the Contemporary Era.

PURPOSE OF REVIEW: Standard options for the treatment of ductal carcinoma in situ (DCIS) include breast-conserving surgery (BCS) alone; BCS with radiotherapy or endocrine therapy, or both; and mastectomy. Survival is excellent with all options, but rates of local recurrence (LR) vary, as do quality-of-life measures. Here we discuss treatment outcomes, risk factors for LR, and tools for risk estimation. RECENT FINDINGS: After BCS, radiotherapy reduces the risk of LR by half, and endocrine therapy reduces the risk by a third. Young age, inadequate margins, and greater volume of disease are associated with higher risk of LR after BCS, while young age, high grade, and microinvasion are associated with higher risk of locoregional recurrence after mastectomy. Clinical tools, including the Memorial Sloan Kettering Cancer Center (MSKCC) DCIS nomogram, provide LR risk estimates after BCS that appear more accurate than current genomic assays. The safety of active surveillance for seemingly low-risk patients remains uncertain. SUMMARY: Estimation of LR risk, utilizing a multitude of clinicopathologic and treatment factors, can help a woman balance that risk with her values and priorities, and allow her to choose the optimal treatment option for her.