Biodynamic response prediction in breast cancer patients receiving neoadjuvant chemotherapy

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Background: Biodynamic signatures (temporal patterns of microscopic motion within a three-dimensional tumor explant) offer a phenomic biomarker that is highly predictive for therapeutic response. The purpose of this study is to evaluate predictive accuracy of a biodynamic drug response classifier in breast cancer patients receiving neoadjuvant chemotherapy (NAC). Methods: Consecutive breast cancer patients from 4 institutions were screened for enrollment in a prospective observational study (NCT03164863). Treatment-naïve needle biopsies were delivered to a central laboratory where biodynamic signatures were measured in living tumor fragments challenged by standard-of-care cytotoxins. Patients received NAC per institutional guidelines and were followed through surgical intervention. A four-point classifier was trained to predict pathologic complete response (CR) then prospectively validated. Results: Among patients completing neoadjuvant treatment and surgical intervention, 33% (24 of 72) achieved CR. The biodynamic classifier predicted CR with 96% sensitivity and 97% negative predictive value. Biodynamically “favored” (scoring ≥ 3) and “strongly favored” (scoring 4) regimens produced CR at rates of 56% (23 of 41) and 73% (19 of 26), respectively. Only 3% of patients (1 of 31) achieved CR from regimens scoring 1 or 2. Area under the receiver operating curve (AUC) was 87% (95% CI: 75% to 93%, p < .0001), with similar performance across all subtypes and therapy cohorts (range: 84% to 89%). Performance of the classifier on training and validation patients was statistically equivalent. Conclusions: Biodynamic scoring accurately predicts response in breast cancer patients receiving NAC and holds promise to substantially improve management of these patients. [Table: see text]

Abstract P3-11-17: A novel biodynamic imaging assay predicts success or failure of neoadjuvant chemotherapy in breast cancer patients

Background: Use of neoadjuvant chemotherapy (NAC) in breast cancer patients has increased significantly over the past decade. The clinical benefits of NAC, including potential to downstage disease, facilitation of breast conserving surgery and use of pathologic response as a prognostic marker, are well established. However, with multiple regimens approved and recommended for NAC, choosing the optimal therapy for individual patients remains a challenge. Biodynamic imaging (BI), a novel technology that captures cellular motility in living tissue via Doppler spectroscopy, could be used ex-vivo to prospectively evaluate the efficacy of systemic therapies in patient tumor samples prior to treatment. This study aimed to determine whether BI could accurately predict likelihood of response to NAC in breast cancer patients.

Methods: Fresh core biopsies were obtained from 84 patients prospectively enrolled in an IRB-approved clinical trial at 5 institutions between 1/5/17 and 8/3/2018. Patient tumor tissue was collected at time of routine diagnostic biopsy and sent to a central laboratory where it was divided into intact tumor fragments measuring approximately 1mm in diameter. Fragments were placed into 96 well plates and imaged using the BI assay (Onco4D™), while being challenged by various cytotoxic agents for up to 20 hours. Cellular characteristics and motility signatures were evaluated and compared to pathologic NAC response established upon surgical resection (mastectomy or lumpectomy).

Results: At the time of this analysis, centrally-confirmed pathologic response data were available for 17 patients treated with doxorubicin/cyclophosphamide + taxane (AC). Pathologic outcomes are pending for an additional 8 AC patients. The remainder of the 84 patients initially enrolled in the study either did not receive NAC (n=10), have not yet selected a course of therapy (n=12), or received NAC regimens other than AC (n=37). Of the 17 currently evaluable AC-treated patients, 4 had triple negative (TN) disease, 12 were hormone receptor positive, and 1 hormone receptor negative patient showed equivocal HER2 results. Two of the TN patients were known to harbor pathogenic BRCA1 mutations and received carboplatin in addition to AC. Seven of 17 patients (40%) displayed resistance to AC (2 with progressive and 5 with stable disease) while 10 experienced objective response (8 partial and 2 complete response). A multilinear regression model using 10 BI markers accurately classified 16 of 17 patients (94%) while producing 1 false prediction of partial response for a patient with stable disease clinically (R-squared=0.9994, p&lt;.0001). The positive predictive and negative predictive values of BI to AC response were 100% and 91%, respectively.

Table 1.Performance Characteristics  Clinical   OutcomeResponseNon-ResponseTotalClassifierResponse10111 Non-Response066 Total10717

Conclusion: BI was able to accurately predict patient response to neoadjuvant AC, demonstrating the potential for the platform to support personalized patient therapy. This clinical trial is ongoing and will report out results for TC (docetaxel/cyclophosphamide), TCHP (docetaxel/carboplatin/trastuzumab + pertuzumab), and additional AC patients as outcome data are accrued.

Citation Format: Whitacre E, Manahan E, Burak W, Morgan T, An R, Loesch D. A novel biodynamic imaging assay predicts success or failure of neoadjuvant chemotherapy in breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-11-17.

Correction to: Phase 2 Open-Label Trial Investigating Percutaneous Laser Ablation for Treatment of Early-Stage Breast Cancer: MRI, Pathology, and Outcome Correlations

The article "Phase 2 Open-Label Trial Investigating Percutaneous Laser Ablation for Treatment of Early-Stage Breast Cancer: MRI, Pathology, and Outcome Correlations", written by Barbara Schwartzberg et al., was originally published electronically on the publisher's internet portal (currently SpringerLink) on July 9, 2018, without open access.

Phase 2 Open-Label Trial Investigating Percutaneous Laser Ablation for Treatment of Early-Stage Breast Cancer: MRI, Pathology, and Outcome Correlations

Background

An institutional review board-approved, multicenter clinical trial was designed to determine the efficacy and outcome of percutaneous laser ablation (PLA) in the treatment of invasive ductal breast carcinoma (IDC). Post-ablation magnetic resonance imaging (MRI) was compared with surgical pathology in evaluation of residual post-ablation IDC and ductal carcinoma in situ.

Methods

Patients with a single focus of IDC 20 mm or smaller by pre-ablation MRI were treated with PLA. The patients underwent a 28-day post-ablation MRI, followed by surgical resection. Cell viability criteria were applied to pre- and post-ablation pathology specimens, which evaluated hematoxylin–eosin (H&E), cytokeratin (CK) 8/18, estrogen receptor, and Ki67 staining patterns.

Results

In this study, 61 patients were reported as the intention-to-treat cohort for determination of PLA efficacy. Of these 61 patients, 51 (84%) had complete tumor ablation confirmed by pathology analysis. One subject’s MRI imaging was not performed per protocol, which left 60 subjects evaluable for MRI pathology correlation. Five patients (8.3%) had residual IDC shown by both MRI and pathology. Post-ablation discordance was noted between MRI and pathology, with four patients (6.7%) false-positive and four patients (6.7%) false-negative. The negative predictive value (NPV) of MRI for all the patients was 92.2% (95% confidence interval [CI], 71.9–91.9%). Of the 47 patients (97.9%) with tumors 15 mm or smaller, 46 were completely ablated, with an MRI NPV of 97.7% (95% CI, 86.2–99.9%).

Conclusions

Percutaneous laser ablation is a potential alternative to surgery for treatment of early-stage IDC. Strong correlations exist between post-ablation MRI and pathologic alterations in CK8/18, ER, and Ki67 staining.

Reasons for re-excision after lumpectomy for breast cancer: insight from the American Society of Breast Surgeons Mastery(SM) database

BACKGROUND

There is marked variability of re-excision rates after initial lumpectomy for breast cancer. Reasons for re-excision and variability across surgeons have not been well documented. We hypothesized the American Society of Breast Surgeons (ASBrS) Mastery(SM) Program can identify reasons for re-excision.

METHODS

Data from January 1 to 7 November 2013 were evaluated in the ASBrS Mastery(SM) Program to determine re-excision lumpectomy rate (RELR). On 1 June 2013, a tool to track reasons for re-excision was developed. Variation in re-excision rate by surgeon and patient characteristics was performed by Chi square test and Fisher's test for univariate analysis, then logistic regression with backwards elimination method for multivariate analysis.

RESULTS

For 6,725 patients undergoing initial lumpectomy for cancer, 328 surgeons reported 1,451 (21.6 %) patients had one or more re-excisions. The most common reasons for re-excision were ink positive margins in 783 (49.7 %), margin <1 mm (34.3 %), and margin 1-2 mm (7.2 %). By multivariate analysis, re-excision rates were lower in patients aged less than 35 years, with White (non-) Hispanic ethnicity, and, among surgeons in solo practice, more years in practice and higher-volume practice.

CONCLUSION

Half of re-excisions after initial lumpectomy were performed for margins that are positive. Most of the remainder were for negative close (<1-2 mm) margins. This information corroborates surgeon survey data regarding reasons for re-excision and provides proof of concept the Mastery(SM) Program can capture surgical outcome data in real time, providing opportunity and a method for future performance improvement.

Two year analysis of treatment efficacy and cosmesis by the American Society of Breast Surgeons (ASBS) MammoSite Breast Brachytherapy Registry Trial in patients treated with accelerated partial breast irradiation (APBI)

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Background: This report presents 2-year data on treatment efficacy and cosmesis for patients enrolled on the ASBS sponsored MammoSite Registry trial. Methods: 1449 patients were treated with the MammoSite device to deliver APBI. 924 patients have been followed ≥ 12 months, 586 ≥ 18 months, 316 ≥ 24 months and 52 ≥ 36 months. Median follow-up for surviving patients was 14 months. Results: Eleven patients (0.8%) developed an ipsilateral breast tumor recurrence (IBTR) as some component of their initial failure (prior to distant metastases [DM]) for a 2-yr actuarial rate of 1.2%. The 2-yr actuarial rate of isolated IBTR was 0.8% (n=8). Six patients (0.4%) developed an axillary failure (AF) as some component of their initial failure (prior to DM) for a 2-yr actuarial rate of 1.0%. The 2-yr actuarial rate of isolated AF was 0.6% (n=3). The only variable associated with the development of an isolated IBTR (n=8) included an extensive intraductal component (p=0.073) (patient age, margin status, grade, histology, tumor size, nodal status, use of systemic therapy and method of device placement were not associated with IBTR). The only variable associated with the development of all IBTRs (n=11) was tumor location (inner quadrant, p=0.079). The percentage of patients with good/excellent cosmetic results at 6, 12, 18, 24 and 36 months were as follows: 95.1% (n=769 patients), 93.7% (n=621 patients), 91.3% (n=344 patients), 93.5% (n=248 patients), and 90.4% (n=52 patients) (p=NS). For the 174 patients with both a 12-month and 24 month cosmetic assessment, the rate of good/excellent cosmetic results was 94% at 12 and 24 months. At 24 months (n=248 patients), factors associated with good/excellent cosmetic results included increased skin spacing as a categorical variable (94.8% versus 86.1%, p=0.064), no infection (94.8% versus 85.7%, p=0.057), and no systemic chemotherapy treatment (95.3% versus 82.4%, p=0.012). Conclusions: Treatment efficacy and cosmesis 2 years after treatment with APBI using the MammoSite device are excellent and appear similar to those reported with standard whole breast RT.

No significant financial relationships to disclose.

Initial Outcomes for Patients Treated on the American Society of Breast Surgeons MammoSite Clinical Trial for Ductal Carcinoma-In-Situ of the Breast

BACKGROUND

The MammoSite device was designed as a breast brachytherapy applicator and is currently used to deliver accelerated partial breast irradiation (APBI). We hypothesized that APBI delivered with the MammoSite device would be well tolerated and be associated with a good cosmetic outcome in patients with ductal carcinoma-in-situ (DCIS).

METHODS

From 2002 to 2004, 191 patients with DCIS were enrolled in a registry trial to assess the MammoSite applicator. Fifteen patients were excluded from analysis because of device- or patient-related factors; 7 patients were excluded after receiving a radiotherapy boost, thus leaving 169 patients available for study. Follow-up information was available for 158 patients. The average length of follow-up was 7.35 months. Forty-three patients had at least 1 year of follow-up.

RESULTS

Skin spacing for the MammoSite applicator was as follows: < 5 mm, 3 patients (1.78%); 5 to 7 mm, 18 patients (10.65%); and > or = 7 mm, 148 patients (87.57%). Patients with a device-to-skin distance of > or = 7 mm had the best cosmetic result. Patients with a device-to-skin distance of > or = 7 mm also had a lower incidence of radiation dermatitis. Data on 43 patients who were followed up for at least 1 year confirmed these findings. Additional adverse events were primarily related to skin changes, with breast infections occurring in five patients (3.16%). No patient in the study has experienced a recurrence.

CONCLUSIONS

APBI delivered via MammoSite is well tolerated in patients with DCIS, and the lowest toxicity was obtained in patients with the greatest device-to-skin distance. Long-term follow-up data regarding patient satisfaction, cosmesis, and efficacy are needed and will be determined from a recently opened large randomized study.

Descriptions and outcomes of insertion techniques of a breast brachytherapy balloon catheter in 1403 patients enrolled in the American Society of Breast Surgeons MammoSite breast brachytherapy registry trial

BACKGROUND

The use of the MammoSite brachytherapy balloon catheter is 1 option for the delivery of accelerated partial breast irradiation during breast cancer therapy. The device can be inserted into the breast using 3 different techniques. This report describes these methods of insertion and correlates the technique with outcome data collected in a multi-institutional registry trial.

METHODS

In the registry trial, MammoSite catheters were inserted either (1) at the time of lumpectomy into an open cavity, (2) after surgery with ultrasound guidance through a separate small lateral incision into a closed cavity, or (3) after surgery by entering directly through the lumpectomy wound (the scar entry technique). Device placement techniques in 1403 patients with early stage breast cancer treated at 87 institutions by 223 different investigators were documented in the registry. Data collected included number of cases of each technique, age of patient, tumor size, skin spacing, catheter pull rates and reasons, infection, radiation recall, cosmesis, and recurrence.

RESULTS

Catheter placement at the time of lumpectomy was performed in 619 patients (44%), after surgery with ultrasound guidance in 576 patients (41%), and the scar entry technique technique in 197 patients (14%). The type of technique was not associated with age of patient, tumor size, bra size, catheter size, skin spacing, infection, radiation recall, cosmesis, or recurrence. There was a statistically significant increased incidence of premature catheter removals for pathologically related reasons with the open-cavity technique compared with the 2 postoperative methods secondary to final histology reports disqualifying the patient after MammoSite placement.

CONCLUSIONS

These registry data show that the MammoSite catheter can be inserted with any 1 of 3 different techniques. A postoperative placement, after the final pathology report is issued, decreases the incidence of premature removal of the catheter because of disqualifying pathology.

Surgical benefits conveyed by biopsy site marking system using ultrasound localization

BACKGROUND

With vacuum-assisted biopsy technology all, or most, of a breast lesion may be removed during the initial biopsy; in such cases a metallic marker is often inserted at the site of the biopsy for future localization. The aim of this study was to evaluate the efficacy and impact of the Gel Mark Ultra biopsy site marking system (SenoRx, Aliso Viejo, CA) on the practice of needle localization breast biopsy.

METHODS

We retrospectively analyzed the experience of 45 general surgeons across the United States in a variety of practice settings using the Gel Mark Ultra clip. Imaging-guided biopsy technique, localization quality, surgeon confidence, and margin status were assessed and compared against the broad data reported in the literature.

RESULTS

A total of 432 records of patients who underwent imaging-guided breast biopsy with placement of Gel Mark Ultra clip were reviewed. Of these, 63 (15%) patients required definitive surgical intervention, for which 41 cases were localized with ultrasound and assessed for margin clearance. Clear margins were achieved in 37 (90%) of the 41 cases. These results are statistically superior (P < .01) to positive margins rates reported in the literature.

CONCLUSIONS

The Gel Mark Ultra biopsy site marking system is a new localization device that provides a safe and effective alternative to traditional localization methods with a significant reduction in the percentage of positive margins, as well as advantages in terms of surgical approach, time, and patient comfort.