Ahrendt, Gretchen

Neoadjuvant chemotherapy (NAC) increases rates of successful breast-conserving surgery (BCS) in patients with breast cancer. However, some studies suggest that BCS after NAC may confer an increased risk of locoregional recurrence (LRR). We assessed LRR rates and locoregional recurrence-free survival (LRFS) in patients enrolled on I-SPY2 (NCT01042379), a prospective NAC trial for patients with clinical stage II to III, molecularly high-risk breast cancer. Cox proportional hazards models were used to evaluate associations between surgical procedure (BCS vs mastectomy) and LRFS adjusted for age, tumor receptor subtype, clinical T category, clinical nodal status, and residual cancer burden (RCB). In 1462 patients, surgical procedure was not associated with LRR or LRFS on either univariate or multivariate analysis. The unadjusted incidence of LRR was 5.4% after BCS and 7.0% after mastectomy, at a median follow-up time of 3.5 years. The strongest predictor of LRR was RCB class, with each increasing RCB class having a significantly higher hazard ratio for LRR compared with RCB 0 on multivariate analysis. Triple-negative receptor subtype was also associated with an increased risk of LRR (hazard ratio: 2.91, 95% CI: 1.8–4.6, P < 0.0001), regardless of the type of operation. In this large multi-institutional prospective trial of patients completing NAC, we found no increased risk of LRR or differences in LRFS after BCS compared with mastectomy. Tumor receptor subtype and extent of residual disease after NAC were significantly associated with recurrence. These data demonstrate that BCS can be an excellent surgical option after NAC for appropriately selected patients.

ImportancePathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in breast cancer strongly correlates with overall survival and has become the standard end point in neoadjuvant trials. However, there is controversy regarding whether the definition of pCR should exclude or permit the presence of residual ductal carcinoma in situ (DCIS).ObjectiveTo examine the association of residual DCIS in surgical specimens after neoadjuvant chemotherapy for breast cancer with survival end points to inform standards for the assessment of pathologic complete response.Design, Setting, and ParticipantsThe study team analyzed the association of residual DCIS after NAC with 3-year event-free survival (EFS), distant recurrence-free survival (DRFS), and local-regional recurrence (LRR) in the I-SPY2 trial, an adaptive neoadjuvant platform trial for patients with breast cancer at high risk of recurrence. This is a retrospective analysis of clinical specimens and data from the ongoing I-SPY2 adaptive platform trial of novel therapeutics on a background of standard of care for early breast cancer. I-SPY2 participants are adult women diagnosed with stage II/III breast cancer at high risk of recurrence.InterventionsParticipants were randomized to receive taxane and anthracycline-based neoadjuvant therapy with or without 1 of 10 investigational agents, followed by definitive surgery.Main Outcomes and MeasuresThe presence of DCIS and EFS, DRFS, and LRR.ResultsThe study team identified 933 I-SPY2 participants (aged 24 to 77 years) with complete pathology and follow-up data. Median follow-up time was 3.9 years; 337 participants (36%) had no residual invasive disease (residual cancer burden 0, or pCR). Of the 337 participants with pCR, 70 (21%) had residual DCIS, which varied significantly by tumor-receptor subtype; residual DCIS was present in 8.5% of triple negative tumors, 15.6% of hormone-receptor positive tumors, and 36.6% of ERBB2-positive tumors. Among those participants with pCR, there was no significant difference in EFS, DRFS, or LRR based on presence or absence of residual DCIS.Conclusions and RelevanceThe analysis supports the definition of pCR as the absence of invasive disease after NAC regardless of the presence or absence of DCIS.Trial RegistrationClinicalTrials.gov Identifier NCT01042379.

Abstract Background: Patients who achieve a pathological complete response (pCR- defined as no invasive cancer) after neoadjuvant chemotherapy (NAC) for breast cancer (BC) have improved outcomes, but there is still controversy about the significance of residual ductal carcinoma in situ (DCIS) on local recurrence rate (LRR). The I-SPY 2 TRIAL is an adaptive neoadjuvant platform trial evaluating novel experimental regimens in comparison to standard chemotherapy in women with high-risk breast cancer. The purpose of this study is to determine if residual DCIS after NAC in early BC affects LRR in patients with or without residual invasive disease in the I-SPY 2 TRIAL. Methods: 933 I-SPY 2 patients with residual cancer burden (RCB) and follow-up data were included in this analysis. Residual DCIS was defined as any carcinoma in situ &gt; 0% on RCB evaluation. Local recurrence was defined as recurrence in breast, chest wall or locoregional nodes and/or skin and subcutaneous tissue. We stratified our cohort into four groups: those without residual invasive disease (defined as RCB0) ± residual DCIS, and those with residual invasive disease (RCB&gt;0) ± residual DCIS. We estimated LRR within each group using the Kaplan Meier method; and used Cox proportional hazards models to assess LRR differences between groups, with: patients with no residual disease (invasive or in situ) as reference group. Results: Among 933 patients assessed, median follow up time was 3.9 years. RCB 0 status was achieved in 337 patients (36%). Of these, 267 (29%) had no residual DCIS, which represents our reference group, and 70 (7%) had residual DCIS. Among 596 (64%) patients who had RCB&gt;0, 296 (32%) had residual DCIS. For patients with RCB0 without DCIS and RCB0 with DCIS, the LRR at 3 years were similar: 2% vs 3% respectively (Hazard ratio: 1.29 [0.26-6.39]). Results were also similar in the RCB&gt;0 group, with a LRR of 10% at 3 years in those without residual DCIS, and 11% in those with residual DCIS. Both RCB&gt;0 groups had significantly higher LRR when compared to the patients with RCB0 without DCIS (Hazard ratio: 5.25 [2.20-12.5]) and HR 5.85 [2.47-13.9] respectively). Conclusion: There was no association between residual DCIS and LRR after neoadjuvant chemotherapy, regardless of resolution of invasive disease. Further work is needed to determine whether residual DCIS should drive locoregional therapy decisions after neoadjuvant chemotherapy for invasive breast cancer. Citation Format: Marie Osdoit, Christina Yau, W. Fraser Symmans, Judy C. Boughey, Smita M. Asare, Ron Balassanian, Jodi M. Carter, Yunn-Yi Chen, Kimberly Cole, Laila Khazai, Molly Klein, Dina Kokh, Gregor Krings, Sunati Sahoo, Gretchen Ahrendt, Akiko Chiba, Cheryl Ewing, Constantine Godellas, Nora Jaskowiak, Brigid Killelea, Helen Krontiras, Rachael Lancaster, Julie Lang, M. Catherine Lee, Arpana Naik, Roshni Rao, Julia Tchou, Shannon Tierney, Eleni Tousimis, Tod Tuttle, Anne Wallace, I-SPY 2 TRIAL Consortium, Bev Parker, Laura J. Esserman, Rita A. Mukhtar. The impact of residual ductal carcinoma in situ on breast cancer recurrence in the neoadjuvant I-SPY2 TRIAL [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-16.

1107 Background: The role of axillary ultrasound (AUS) after neoadjuvant chemotherapy (NAC) to assess for residual nodal disease in patients presenting with node positive breast cancer remains unclear. ACOSOG Z1071 is a prospective multi-institutional trial evaluating sentinel node biopsy in patients with biopsy proven node positive breast cancer (T0-4, N1-2, M0) receiving NAC. Herein we report on the secondary objective evaluating the correlation of lymph node (LN) features on AUS with residual nodal disease. Methods: AUS images from diagnosis and after NAC were centrally reviewed for cortex size, LN size and LN morphology. Morphologic features were defined as: type I, no visible cortex, type II, < 3 mm hypoechoic cortex, type III, > 3mm hypoechoic cortex, type IV, generalized lobulated hypoechoic cortex, type V, focal hypoechoic cortical lobulation, and type VI, totally hypoechoic node with no hilum. Type I and II are considered normal. Results: Surgical and imaging data are available on 294 patients. Median age was 50 years (range 23-93 years), mean initial tumor size 3cm (0 to 15cm) and clinical stage II in 64.5% and III in 35.5%. The maximum LN diameter decreased after NAC (mean 22mm pre-NAC to 14mm post-NAC)(p<0.0001); however, there was no significant difference after NAC between the pathologically N+ (13mm, range 5-46mm) and N0 cases (12mm, range 3-32mm)(p=0.13). LN cortical thickness correlated with residual nodal disease after NAC (p-value = 0.04). Using a cutoff point of cortical thickness of 3 mm, the sensitivity was 33% (48/145) and specificity 80% (66/82). AUS morphological features after NAC was associated with false negative rate 62%, false positive rate 28%, sensitivity 38%, and specificity 72%. Conclusions: AUS after NAC is useful to assess nodal response. Cortical thickness was the best predictor of residual nodal metastasis. LN size and morphological features do not reliably exclude residual nodal metastasis in patients after NAC. [Table: see text]

Abstract Background: The American College of Surgeons Oncology Group (ACOSOG) Z1071 trial (Alliance) reported a false negative rate (FNR) of 12.6% with sentinel lymph node (SLN) surgery after neoadjuvant chemotherapy in women presenting with node-positive breast cancer. Proposed methods to decrease the FNR include clip placement in the positive node at initial diagnosis with confirmation of resection of the clipped node at surgery and inclusion of residual metastatic cells identified by immunohistochemistry (IHC) for cytokeratins and disease measuring &lt;0.2mm on H&E in the definition of node positivity after chemotherapy. Herein we evaluate the impact of these methods on FNR. Methods: Z1071 was a prospective multi-institutional trial in which women with clinical T0-4,N1-2,M0 breast cancer underwent both SLN surgery and axillary dissection (ALND) after neoadjuvant chemotherapy. The primary endpoint defined nodal metastasis as disease &gt;0.2mm on H&E. Slides were submitted for central IHC staining when H&E-negative, unless performed locally. For this analysis, we expanded the definition of node positivity to include metastases less than 0.2mm on H&E and metastatic deposits identified by IHC. In 171 cases, a clip was placed in the node at initial biopsy and in these cases the SLNs and ALND were evaluated by x-ray or pathology to document clip location. FNR in the clip cohort is reported using the primary endpoint definition of node positive disease (&gt;0.2mm on H&E). Results: In the 113 cases where the clip was found in the SLN the FNR was 6.4% (1.8-15.5%). In the 29 cases where the clip was found in the ALND specimen, the FNR was 22.2% (6.4-47.6%). IHC was available on 470 of 525 patients with cN1 disease and 2 SLNs resected. Using the definition of H&E metastasis &gt;0.2mm, the FNR in these patients was 11.3% (34/301, 8.0-15.4%) which decreased to 8.7% (27/311, 5.6-11.8%) when including any disease &lt;0.2mm. SLNs from 16 patients had disease &lt;0.2mm in size. Seven patients previously classified as false negative SLN changed to true positive with identification of disease in the SLN. Nine patients changed from node-negative to node-positive with the only disease being &lt;0.2mm disease found in the SLN. Nodal pathologic complete response rate changed from 36.0% to 33.8% with the inclusion of metastases &lt;0.2mm. NResidual disease identified in SLNs or ALNDFNR (%)95% CINode positive definitionSLN metastases &gt;0.2mm by H&E470301 (64.0%)11.38.0-15.4SLN metastasis any size on IHC or H&E470311 (66.2%)8.75.6-11.8Clip locationClip in SLN11462 (54.4%)6.41.8-15.5Clip in ALND2918 (62.1%)22.26.4-47.6Clip location unknown2920 (69.0%)14.33.0-36.3Clip not placed354207 (58.5%)13.59.1-18.9 Conclusion: Placement of a clip at initial diagnosis of node positive disease with identification of the clip during the SLN surgery reduces the FNR. Use of IHC with inclusion of metastases &lt;0.2mm in the definition of residual nodal disease in women with node positive breast cancer after chemotherapy also improves the accuracy of SLN surgery. Use of one or both of these methods should be considered when performing SLN in this setting. Citation Format: Judy C Boughey, Karla V Ballman, William F Symmans, Linda M McCall, Elizabeth A Mittendorf, Gretchen M Ahrendt, Lee G Wilke, Bret Taback, Kelly K Hunt. Methods impacting the false negative rate of sentinel lymph node surgery in patients presenting with node positive breast cancer (T0-T4,N1-2) who receive neoadjuvant chemotherapy – Results from a prospective trial – ACOSOG Z1071 (Alliance) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-02.

Purpose The American College of Surgeons Oncology Group Z1071 trial reported a 12.6% false-negative rate (FNR) for sentinel lymph node (SLN) surgery after neoadjuvant chemotherapy (NAC) in cN1 disease. Patients were not selected for surgery based on response, but a secondary end point was to determine whether axillary ultrasound (AUS) after NAC after fine-needle aspiration cytology can identify abnormal nodes and guide patient selection for SLN surgery. Patients and Methods Patients with T0-4, N1-2, M0 breast cancer underwent AUS after neoadjuvant chemotherapy. AUS images were centrally reviewed and classified as normal or suspicious lymph nodes. AUS findings were tested for association with pathologic nodal status and SLN FNR. The impact of AUS results to select patients for SLN surgery to reduce the FNR was assessed. Results Postchemotherapy AUS images were reviewed for 611 patients. One hundred thirty (71.8%) of 181 AUS-suspicious patients were node positive at surgery compared with 243 (56.5%) of 430 AUS-normal patients (P < .001). Patients with AUS-suspicious nodes had a greater number of positive nodes and greater metastasis size (P < .001). The SLN FNR was not different based on AUS results; however, using a strategy where only patients with normal AUS undergo SLN surgery would potentially reduce the FNR in Z1071 patients with ≥ two SLNs removed from 12.6% to 9.8% when preoperative AUS results are considered as part of SLN surgery. Conclusion AUS is recommended after chemotherapy to guide axillary surgery. An FNR of 9.8% with the combination of AUS and SLN surgery would be acceptable for the adoption of SLN surgery for women with node-positive breast cancer treated with neoadjuvant chemotherapy.