Omission of Axillary Dissection Following Nodal Downstaging With Neoadjuvant Chemotherapy.

Importance: Data on oncological outcomes after omission of axillary lymph node dissection (ALND) in patients with breast cancer that downstages from node positive to negative with neoadjuvant chemotherapy are sparse. Additionally, the best axillary surgical staging technique in this scenario is unknown. Objective: To investigate oncological outcomes after sentinel lymph node biopsy (SLNB) with dual-tracer mapping or targeted axillary dissection (TAD), which combines SLNB with localization and retrieval of the clipped lymph node. Design, Setting, and Participants: In this multicenter retrospective cohort study that was conducted at 25 centers in 11 countries, 1144 patients with consecutive stage II to III biopsy-proven node-positive breast cancer were included between April 2013 and December 2020. The cumulative incidence rates of axillary, locoregional, and any invasive (locoregional or distant) recurrence were determined by competing risk analysis. Exposure: Omission of ALND after SLNB or TAD. Main Outcomes and Measures: The primary end points were the 3-year and 5-year rates of any axillary recurrence. Secondary end points included locoregional recurrence, any invasive (locoregional and distant) recurrence, and the number of lymph nodes removed. Results: A total of 1144 patients (median [IQR] age, 50 [41-59] years; 78 [6.8%] Asian, 105 [9.2%] Black, 102 [8.9%] Hispanic, and 816 [71.0%] White individuals; 666 SLNB [58.2%] and 478 TAD [41.8%]) were included. A total of 1060 patients (93%) had N1 disease, 619 (54%) had ERBB2 (formerly HER2)-positive illness, and 758 (66%) had a breast pathologic complete response. TAD patients were more likely to receive nodal radiation therapy (85% vs 78%; P = .01). The clipped node was successfully retrieved in 97% of TAD cases and 86% of SLNB cases (without localization). The mean (SD) number of sentinel lymph nodes retrieved was 3 (2) vs 4 (2) (P < .001), and the mean (SD) number of total lymph nodes removed was 3.95 (1.97) vs 4.44 (2.04) (P < .001) in the TAD and SLNB groups, respectively. The 5-year rates of any axillary, locoregional, and any invasive recurrence in the entire cohort were 1.0% (95% CI, 0.49%-2.0%), 2.7% (95% CI, 1.6%-4.1%), and 10% (95% CI, 8.3%-13%), respectively. The 3-year cumulative incidence of axillary recurrence did not differ between TAD and SLNB (0.5% vs 0.8%; P = .55). Conclusions and Relevance: The results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after TAD vs SLNB. These results support omission of ALND in this population.

Quality of Life After Axillary Lymph Node Dissection Among Racial and Ethnic Minority Women.

Importance: Higher lymphedema rates after axillary lymph node dissection (ALND) have been found in Black and Hispanic women; however, there is poor correlation between subjective symptoms, quality of life (QOL), and measured lymphedema. Additionally, racial and ethnic differences in QOL have been understudied. Objective: To evaluate the association of race and ethnicity with long-term QOL in patients with breast cancer treated with ALND. Design, Setting, and Participants: This cohort study enrolled women aged 18 years and older with breast cancer who underwent unilateral ALND at a tertiary cancer center between November 2016 and March 2020. Preoperatively and at 6-month intervals, arm volume was measured by perometer and QOL was assessed using the Upper Limb Lymphedema-27 (ULL-27) questionnaire, a validated tool for assessing lymphedema that evaluates how arm symptoms affect physical, psychological, and social functioning. Data were analyzed from November 2016 to October 2023. Exposures: Breast surgery and unilateral ALND in the primary setting or after sentinel lymph node biopsy. Main Outcomes and Measures: Scores in each domain of the ULL-27 were compared by race and ethnicity. Factors impacting QOL were identified using multivariable regression analyses. Results: The study included 281 women (median [IQR] age, 48 [41-58] years) with breast cancer who underwent unilateral ALND and had at least 6 months of follow-up. Of these, 30 patients (11%) self-identified as Asian individuals, 57 (20%) as Black individuals, 23 (8%) as Hispanic individuals, and 162 (58%) as White individuals; 9 individuals (3%) who did not identify as part of a particular group or who were missing race and ethnicity data were categorized as having unknown race and ethnicity. Median (IQR) follow-up was 2.97 (1.96-3.67) years. The overall 2-year lymphedema rate was 20% and was higher among Black (31%) and Hispanic (27%) women compared with Asian (15%) and White (17%) women (P = .04). Subjective arm swelling was more common among Asian (57%), Black (70%), and Hispanic (87%) women than White (44%) women (P < .001), and lower physical QOL scores were reported by racial and ethnic minority women at nearly every follow-up. For example, at 24 months, median QOL scores were 87, 79, and 80 for Asian, Black, and Hispanic women compared with 92 for White women (P = .003). On multivariable analysis, Asian race (ß = -5.7; 95% CI, -9.5 to -1.8), Hispanic ethnicity (ß = -10.0; 95% CI, -15.0 to -5.2), and having Medicaid (ß = -5.4; 95% CI, -9.2 to -1.7) or Medicare insurance (ß = -6.9; 95% CI, -10.0 to -3.4) were independently associated with worse physical QOL (all P < .001). Conclusions and Relevance: Findings of this cohort study suggest that Asian, Black, and Hispanic women experience more subjective arm swelling after unilateral ALND for breast cancer compared with White women. Black and Hispanic women had higher rates of objective lymphedema than their White counterparts. Both minority status and public medical insurance were associated with worse physical QOL. Understanding disparities in QOL after ALND is an unmet need and may enable targeted interventions to improve QOL for these patients.

Society of Surgical Oncology Breast Disease Site Working Group Statement on Contralateral Mastectomy: Indications, Outcomes, and Risks.

Rates of contralateral mastectomy (CM) among patients with unilateral breast cancer have been increasing in the United States. In this Society of Surgical Oncology position statement, we review the literature addressing the indications, risks, and benefits of CM since the society's 2017 statement. We held a virtual meeting to outline key topics and then conducted a literature search using PubMed to identify relevant articles. We reviewed the articles and made recommendations based on group consensus. Patients consider CM for many reasons, including concerns regarding the risk of contralateral breast cancer (CBC), desire for improved cosmesis and symmetry, and preferences to avoid ongoing screening, whereas surgeons primarily consider CBC risk when making a recommendation for CM. For patients with a high risk of CBC, CM reduces the risk of new breast cancer, however it is not known to convey an overall survival benefit. Studies evaluating patient satisfaction with CM and reconstruction have yielded mixed results. Imaging with mammography within 12 months before CM is recommended, but routine preoperative breast magnetic resonance imaging is not; there is also no evidence to support routine postmastectomy imaging surveillance. Because the likelihood of identifying an occult malignancy during CM is low, routine sentinel lymph node surgery is not recommended. Data on the rates of postoperative complications are conflicting, and such complications may not be directly related to CM. Adjuvant therapy delays due to complications have not been reported. Surgeons can reduce CM rates by encouraging shared decision making and informed discussions incorporating patient preferences.

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.

Managing the Morbidity: Individualizing Risk Assessment, Diagnosis, and Treatment Options for Upper Extremity Lymphedema.

In the setting where breast cancer-related lymphedema (BCRL) remains a feared and common complication of breast cancer, here we review important factors for the development, diagnosis, prevention, and treatment of BCRL. We find that race/ethnicity affect BCRL development risk, that future studies should focus on understanding the biological reasons behind the increased susceptibility of certain racial minorities to BCRL, that surveillance, early detection, exercise programs, and arm compression can reduce the risk of BCRL, and that surgical techniques to preserve and restore lymphatic drainage being evaluated in randomized trials may become transformative in reducing BCRL risk for high-risk patients.

Feasibility and Clinical Utility of Prediction Models for Breast Cancer-Related Lymphedema Incorporating Racial Differences in Disease Incidence.

Importance: Breast cancer-related lymphedema (BCRL) is a common complication of axillary lymph node dissection (ALND) but can also develop after sentinel lymph node biopsy (SLNB). Several models have been developed to predict the risk of disease development before and after surgery; however, these models have shortcomings that include the omission of race, inclusion of variables that are not readily available to patients, low sensitivity or specificity, and lack of risk assessment for patients treated with SLNB. Objective: To create simple and accurate prediction models for BCRL that can be used to estimate preoperative or postoperative risk. Design, Setting, and Participants: In this prognostic study, women with breast cancer who underwent ALND or SLNB from 1999 to 2020 at Memorial Sloan Kettering Cancer Center and the Mayo Clinic were included. Data were analyzed from September to December 2022. Main Outcomes and Measures: Diagnosis of lymphedema based on measurements. Two predictive models were formulated via logistic regression: a preoperative model (model 1) and a postoperative model (model 2). Model 1 was externally validated using a cohort of 34 438 patients with an International Classification of Diseases diagnosis of breast cancer. Results: Of 1882 included patients, all were female, and the mean (SD) age was 55.6 (12.2) years; 80 patients (4.3%) were Asian, 190 (10.1%) were Black, 1558 (82.8%) were White, and 54 (2.9%) were another race (including American Indian and Alaska Native, other race, patient refused to disclose, or unknown). A total of 218 patients (11.6%) were diagnosed with BCRL at a mean (SD) follow-up of 3.9 (1.8) years. The BCRL rate was significantly higher among Black women (42 of 190 [22.1%]) compared with all other races (Asian, 10 of 80 [12.5%]; White, 158 of 1558 [10.1%]; other race, 8 of 54 [14.8%]; P < .001). Model 1 included age, weight, height, race, ALND/SLNB status, any radiation therapy, and any chemotherapy. Model 2 included age, weight, race, ALND/SLNB status, any chemotherapy, and patient-reported arm swelling. Accuracy was 73.0% for model 1 (sensitivity, 76.6%; specificity, 72.5%; area under the receiver operating characteristic curve [AUC], 0.78; 95% CI, 0.75-0.81) at a cutoff of 0.18, and accuracy was 81.1% for model 2 (sensitivity, 78.0%; specificity, 81.5%; AUC, 0.86; 95% CI, 0.83-0.88) at a cutoff of 0.10. Both models demonstrated high AUCs on external (model 1: 0.75; 95% CI, 0.74-0.76) or internal (model 2: 0.82; 95% CI, 0.79-0.85) validation. Conclusions and Relevance: In this study, preoperative and postoperative prediction models for BCRL were highly accurate and clinically relevant tools comprised of accessible inputs and underscored the effects of racial differences on BCRL risk. The preoperative model identified high-risk patients who require close monitoring or preventative measures. The postoperative model can be used for screening of high-risk patients, thus decreasing the need for frequent clinic visits and arm volume measurements.

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

BACKGROUND: Nipple-sparing mastectomy is associated with a higher risk of mastectomy skin-flap necrosis than conventional skin-sparing mastectomy. There are limited prospective data examining modifiable intraoperative factors that contribute to skin-flap necrosis after nipple-sparing mastectomy. METHODS: Data on consecutive patients undergoing nipple-sparing mastectomy between April 2018 and December 2020 were recorded prospectively. Relevant intraoperative variables were documented by both breast and plastic surgeons at the time of surgery. The presence and extent of nipple and/or skin-flap necrosis was documented at the first postoperative visit. Necrosis treatment and outcome was documented at 8-10 weeks after surgery. The association of clinical and intraoperative variables with nipple and skin-flap necrosis was analysed, and significant variables were included in a multivariable logistic regression analysis with backward selection. RESULTS: Some 299 patients underwent 515 nipple-sparing mastectomies (54.8 per cent (282 of 515) prophylactic, 45.2 per cent therapeutic). Overall, 23.3 per cent of breasts (120 of 515) developed nipple or skin-flap necrosis; 45.8 per cent of these (55 of 120) had nipple necrosis only. Among 120 breasts with necrosis, 22.5 per cent had superficial, 60.8 per cent had partial, and 16.7 per cent had full-thickness necrosis. On multivariable logistic regression analysis, significant modifiable intraoperative predictors of necrosis included sacrificing the second intercostal perforator (P = 0.006), greater tissue expander fill volume (P < 0.001), and non-lateral inframammary fold incision placement (P = 0.003). CONCLUSION: Modifiable intraoperative factors that may decrease the likelihood of necrosis after nipple-sparing mastectomy include incision placement in the lateral inframammary fold, preserving the second intercostal perforating vessel, and minimizing tissue expander fill volume.

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.

Is Nodal Clipping Beneficial for Node-Positive Breast Cancer Patients Receiving Neoadjuvant Chemotherapy?

BACKGROUND: In cN1 patients rendered cN0 with neoadjuvant chemotherapy, the false-negative rate of sentinel lymph node biopsy (SLNB) is < 10% when ≥ 3 sentinel lymph nodes (SLNs) are removed. The added value of nodal clipping in this scenario is unknown. Here we determine how often the clipped node is a sentinel node when ≥ 3 SLNs are retrieved. METHODS: We identified cT1-3N1 patients treated between 02/2018 and 10/2021 with a clipped lymph node at presentation. SLNB was performed with a standardized approach of dual-tracer mapping and retrieval of ≥ 3 SLNs. Clipped nodes were not localized; SLNs were X-rayed intraoperatively to determine clip location. Axillary lymph node dissection (ALND) was performed for any residual disease or retrieval of < 3 SLNs. RESULTS: Of 269 patients, 251 (93%) had ≥ 3 SLNs. Median age was 51 years; the majority (92%) had ductal histology; 46% were HR+/HER2-. The median number of SLNs removed was 4 (IQR 3,5). The clipped node was an SLN in 88% (220/251) of cases. Of the 31 where the clipped node was not, 13 had a positive SLN mandating ALND, and the clip was identified in the ALND specimen. In the remaining 18, where ≥ 3 negative SLNs were retrieved and an ALND was not performed, the clip was not retrieved, with no axillary failures in this group (median follow-up: 55 months). CONCLUSION: When the SLNB procedure is optimized with dual tracer and retrieval of ≥ 3 SLNs, the clipped node is an SLN in the majority of cases, suggesting that failure to retrieve the clipped node should not be an indication for ALND.

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

INTRODUCTION: Rates of downstaging and tolerability to NAC in women age ≥ 70 years with operable breast cancer have not been well studied. We sought to compare downstaging rates and NAC completion between women age 50-69 years and age ≥ 70 years. METHODS: Consecutively treated women age ≥ 50 years with cT1-3N0-1 breast cancer receiving NAC followed by surgery from November 2013 to April 2020 were studied. Rates of downstaging from breast-conserving surgery (BCS)-ineligible to BCS-eligible and avoidance of axillary dissection (ALND) in cN1 patients were compared between patients age 50-69 and ≥ 70 years. NAC regimens and rates of completion also were assessed. RESULTS: Overall, 651 women, age ≥ 50 years, with 668 cT1-3N0-1 breast cancers that were treated with NAC, were identified; 75 (11.1%) were age ≥ 70 years. Patients age ≥ 70 years were less likely to have lobular cancers (5% vs. 10%, p = 0.03), receive an anthracycline-based regimen (69% vs. 93%, p < 0.001), and complete their entire prescribed regimen (57% vs. 78%, p < 0.001). Of 312 BCS-ineligible patients eligible for downstaging, conversion rates to BCS-eligibility were similar between age groups (72% [≥ 70] vs. 74% [50-69], p > 0.9). Women age ≥ 70 years who converted to BCS-eligible post-NAC were more likely to undergo BCS than younger patients (93% vs. 74%, p = 0.04). Of 390 cN1 patients, 162 (42%) achieved a nodal pCR; ALND avoidance was similar between age groups (43% [≥ 70] vs. 42% [50-69], p > 0.9). CONCLUSIONS: While patients age ≥ 70 years received less anthracycline-based NAC and were less likely to complete their prescribed regimen, they experienced high rates of breast and axillary downstaging, similar to younger patients, suggesting that well-selected elderly patients can safely receive NAC with substantial clinical benefit.

Risk Factors and Racial and Ethnic Disparities in Patients With Breast Cancer-Related Lymphedema.

Importance: Risk factors for breast cancer-related lymphedema (BCRL) after axillary lymph node dissection (ALND) are poorly understood. Objective: To evaluate rates of and risk factors associated with BCRL in a prospective cohort of women treated with ALND. Design, Setting, and Participants: This prospective BCRL screening study performed at a tertiary cancer center enrolled women with breast cancer 18 years and older undergoing breast surgery and unilateral ALND in the primary setting or after sentinel lymph node biopsy. Exposures: Risk of BCRL during the first 2 years after ALND and radiotherapy. Main Outcomes and Measures: Patients were prospectively evaluated with arm volume (perometer) measurements, and BCRL was defined as a relative volume change of 10% or greater from baseline. Cumulative incidence of BCRL was assessed using competing risk analysis. Risk factors for BCRL were assessed on univariate and multivariable analyses. Results: From November 2016 to March 2020, 304 patients were enrolled; 276 had at least 1 longitudinal measurement. Median (IQR) age was 48 (40-57) years; median (IQR) body mass index, calculated as weight in kilograms divided by height in meters squared, was 26.4 (22.5-31.2). Of the 276 patients included in the analysis, 29 (11%) self-identified as Asian, 55 (20%) as Black, 16 (6%) as Hispanic, 166 (60%) as White, and 10 (3%) as unknown race and ethnicity; 70% received neoadjuvant chemotherapy (NAC); 93% received nodal irradiation. The 24-month BCRL rate was 23.8% (95% CI, 17.9%-29.8%), with significant variation by race and ethnicity (24-month rate: 37.2% [Black], 27.7% [Hispanic], 22.5% [Asian], and 19.8% [White]; P = .004). The BCRL rates were also higher among patients receiving NAC vs up-front surgery (24-month rate: 29.3% vs 11.1%; P = .01). On multivariable analysis, Black race and Hispanic ethnicity (compared with White race) (odds ratio [OR], 3.88; 95% CI, 2.14-7.08 and OR, 3.01; 95% CI, 1.10-7.62, respectively; P < .001 for each), receipt of NAC (compared with up-front surgery) (OR, 2.10; 95% CI, 1.16-3.95; P = .01), older age (OR, 1.04; 95% CI, 1.02-1.07 per 1-year increase; P = .001), and a longer follow-up interval (OR, 1.57; 95% CI, 1.30-1.90 per 6-month increase; P < .001) were independently associated with an increased risk of BCRL, while ERBB2-positive subtype was associated with a decreased risk of BCRL (compared with hormone receptor positive/ERBB2 negative): OR, 0.50; 95% CI, 0.23-0.99; P = .04). Conclusion and Relevance: In this cohort study, Black race, Hispanic ethnicity, NAC receipt, older age, and longer follow-up were independently associated with risk of BCRL. Studies are warranted to evaluate the biologic mechanisms behind racial and ethnic disparities in BCRL development and alternatives to NAC to avoid ALND in tumor subtypes unlikely to achieve nodal pathologic complete response.

Longitudinal Prospective Evaluation of Quality of Life After Axillary Lymph Node Dissection.

BACKGROUND: Patients often fear axillary lymph node dissection (ALND) because of its associated complications; however, its effect on quality of life (QOL) is not well described. We aimed to evaluate the effect of ALND on QOL over time and to identify predictors of worse QOL. PATIENTS AND METHODS: Breast cancer patients undergoing ALND were enrolled in a prospective lymphedema screening study. Arm volumes were measured and QOL questionnaires completed at baseline, postoperatively, and at 6-month intervals. The upper limb lymphedema-27 questionnaire was used to assess the effect of upper extremity symptoms on QOL in three domains (physical, psychological, and social). Predictors of QOL were identified by univariate and multivariable regression analyses. RESULTS: From November 2016 through March 2020, 304 ALND patients were enrolled; 242 patients with at least two measurements and 6 months of follow-up were included. Median age was 48 years, and median follow-up was 1.2 years. The 18-month lymphedema rate was 18%. Overall, QOL scores in all three domains decreased postoperatively and improved over time. On multivariable analysis, after adjusting for baseline scores, symptoms necessitating lymphedema therapy referral (p = 0.006) were associated with worse physical QOL. Younger age (p = 0.005) and lymphedema therapy referral (p = 0.006) were associated with worse psychological QOL. Arm volume was not correlated with QOL. CONCLUSIONS: QOL scores initially decreased after ALND but improved by 6 months post-surgery. Decreases in QOL were independent of arm volume. Patients with worse QOL more often sought lymphedema therapy, although the effect of therapy on QOL remains unknown.

Incidence of brain metastases in patients with early HER2-positive breast cancer receiving neoadjuvant chemotherapy with trastuzumab and pertuzumab.

The addition of pertuzumab (P) to trastuzumab (H) and neoadjuvant chemotherapy (NAC) has decreased the risk of distant recurrence in early stage HER2-positive breast cancer. The incidence of brain metastases (BM) in patients who achieved pathological complete response (pCR) versus those who do not is unknown. In this study, we sought the incidence of BM in patients receiving HP-containing NAC as well as survival outcome. We reviewed the medical records of 526 early stage HER2-positive patients treated with an HP-based regimen at Memorial Sloan Kettering Cancer Center (MSKCC), between September 1, 2013 to November 1, 2019. The primary endpoint was to estimate the cumulative incidence of BM in pCR versus non-pCR patients; secondary endpoints included disease free-survival (DFS) and overall survival (OS). After a median follow-up of 3.2 years, 7 out of 286 patients with pCR had a BM while 5 out of 240 non-pCR patients had a BM. The 3-year DFS was significantly higher in the pCR group compared to non-pCR group (95% vs 91 %, p = 0.03) and the same trend was observed for overall survival. In our cohort, despite the better survival outcomes of patients who achieved pCR, we did not observe appreciable differences in the incidence of BM by pCR/non-pCR status. This finding suggests that the BM incidence could not be associated with pCR. Future trials with new small molecules able to cross the blood brain barrier should use more specific biomarkers rather than pCR for patients' selection.