33 MammaPrint® and BluePrint® Predict Anthracycline Chemosensitivity in Patients With HR+HER2– Early-Stage Breast Cancer Enrolled in FLEX

Publication
Article
Miami Breast Cancer Conference® Abstracts Supplement41st Annual Miami Breast Cancer Conference® - Abstracts
Volume 38
Issue 4
Pages: 37

Background

Hormone receptor-positive (HR+), HER2-negative (HER2–) early- stage breast cancer (EBC) often yields low (< 10%) pathologic complete response (pCR) rates to neoadjuvant chemotherapy (NCT). The NBRST (NCT01479101) and the phase 2 I-SPY 2 (NCT01042379) neoadjuvant trials showed that the MammaPrint (MP) risk of distant recurrence and BluePrint (BP) molecular subtyping signatures identify cohorts of patients with HR+/ HER2– EBC with a high likelihood of achieving pCR from NCT. To identify potential patients likely to benefit from anthracycline- based NCT, we examined MP and BP utility to predict pCR rates for taxane and cyclophosphamide (TC) vs TC with anthracycline (AC-T) standard-of-care NCT regimens.

Methods

Patients with HR+/HER2–; MP high-risk tumors; treated with NCT; and enrolled in the ongoing prospective, observational FLEX trial (NCT03053193) were included (n=214). MP high-risk tumors were further classified as high 1 (H1; index 0.000 to –0.569) or high 2 (H2; index –0.570 to –1.000). BP subtypes were classified as either Luminal B-Type or Basal-Type. The associations between MP and BP, NCT regimen, and pCR outcomes were assessed.

Results

pCR Rates Among MP and BP Subtypes in HR+/HER2- FLEX Patients With NCT

pCR Rates Among MP and BP Subtypes in HR+/HER2- FLEX Patients With NCT

Of all HR+HER2– tumors, 66% were H1 and 34% were H2. Age, menopausal status, race, tumor stage, and lymph node status were comparable between both groups. Most H1 tumors were luminal B-type, while similar proportions of H2 tumors were basal-type (47%) and luminal B-type (53%). Among H1 tumors, pCR rates
to AC-T vs TC were comparable. In contrast, no H2 tumors achieved pCR to TC, whereas AC-T was significantly more effective for H2 compared with H1 (P <.001) tumors. Among H2 tumors, basal-type achieved the highest pCR rates with AC-T.

Conclusion

These data indicate that patients with MP H2 tumors, including luminal B and basal subtypes, are more likely to achieve a pCR in response to anthracycline-based NCT. In contrast, including anthracycline does not appear to improve pCR rates for patients with MP H1, luminal B-type tumors. These data are novel in demonstrating utility of MP and BP for optimizing specific NCT regimens for HR+/HER2– EBC.

Articles in this issue

31 Adjuvant Abemaciclib Plus Endocrine Therapy for HR+, HER2–, High-Risk Early Breast Cancer: Results From a Preplanned MonarchE Overall Survival Interim Analysis, Including 5-Year Efficacy Outcomes
31 Adjuvant Abemaciclib Plus Endocrine Therapy for HR+, HER2–, High-Risk Early Breast Cancer: Results From a Preplanned MonarchE Overall Survival Interim Analysis, Including 5-Year Efficacy Outcomes
32 Neoadjuvant Pembrolizumab or Placebo Plus Chemotherapy Followed by Adjuvant Pembrolizumab or Placebo for Early-Stage Triple- Negative Breast Cancer: Updated Event-Free Survival Results From the Phase 3 KEYNOTE-522 Study
32 Neoadjuvant Pembrolizumab or Placebo Plus Chemotherapy Followed by Adjuvant Pembrolizumab or Placebo for Early-Stage Triple- Negative Breast Cancer: Updated Event-Free Survival Results From the Phase 3 KEYNOTE-522 Study
33 MammaPrint® and BluePrint® Predict Anthracycline Chemosensitivity in Patients With HR+HER2– Early-Stage Breast Cancer Enrolled in FLEX
33 MammaPrint® and BluePrint® Predict Anthracycline Chemosensitivity in Patients With HR+HER2– Early-Stage Breast Cancer Enrolled in FLEX
34 How Mobile Computing Devices Offer Support for Classic and Molecular Multidisciplinary and Tumor Boards
34 How Mobile Computing Devices Offer Support for Classic and Molecular Multidisciplinary and Tumor Boards
35 Impact of Comorbidities on Real-World (rw) Clinical Outcomes of Patients (pts) With Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2–Negative (HR+/HER2–) Advanced Breast Cancer (ABC) Treated With Palbociclib (PAL) and Enrolled in POLARIS
35 Impact of Comorbidities on Real-World (rw) Clinical Outcomes of Patients (pts) With Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2–Negative (HR+/HER2–) Advanced Breast Cancer (ABC) Treated With Palbociclib (PAL) and Enrolled in POLARIS
36 MONARCH 3: Final Overall Survival Results of Abemaciclib Plus a Nonsteroidal Aromatase Inhibitor as First-Line Therapy for HR+/HER2– Advanced Breast Cancer
36 MONARCH 3: Final Overall Survival Results of Abemaciclib Plus a Nonsteroidal Aromatase Inhibitor as First-Line Therapy for HR+/HER2– Advanced Breast Cancer
37 Estimating the Direct and Indirect Resource Burden of Treatment Management With Current Standard of Care or Elacestrant for ER+, HER2–, ESR1-Mutated Advanced or Metastatic Breast Cancer Patients: A Population- Level Provider Model
37 Estimating the Direct and Indirect Resource Burden of Treatment Management With Current Standard of Care or Elacestrant for ER+, HER2–, ESR1-Mutated Advanced or Metastatic Breast Cancer Patients: A Population- Level Provider Model
38 Influence of Race on Attainment of Textbook Oncologic Outcome Following Modified Radical Mastectomy for Breast Cancer
38 Influence of Race on Attainment of Textbook Oncologic Outcome Following Modified Radical Mastectomy for Breast Cancer
39 The Influence of Reconstruction Type on Outcomes in Women Undergoing Mastectomy With Immediate Reconstruction:  A Nationwide Study
39 The Influence of Reconstruction Type on Outcomes in Women Undergoing Mastectomy With Immediate Reconstruction: A Nationwide Study
40 Ethnic Disparities in Complication Rates and Outcomes  of Nipple-Sparing Mastectomy:  A Comprehensive Analysis
40 Ethnic Disparities in Complication Rates and Outcomes of Nipple-Sparing Mastectomy: A Comprehensive Analysis
41 A Case Series of Sarcomas
41 A Case Series of Sarcomas
42 Transitional Lymphedema: Understanding the Temporal Dynamics Post-Axillary Surgery
42 Transitional Lymphedema: Understanding the Temporal Dynamics Post-Axillary Surgery
43 Impact of Lymphatic Microsurgical Preventing Healing Approach (LYMPHA) on Postoperative Complication Rates in Mastectomy With Immediate Prosthetic-Based Breast Reconstruction
43 Impact of Lymphatic Microsurgical Preventing Healing Approach (LYMPHA) on Postoperative Complication Rates in Mastectomy With Immediate Prosthetic-Based Breast Reconstruction
44 Variant of Uncertain Significance (VUS) Genetic Testing Results and Mastectomy Choice in Lumpectomy-Eligible Patients
44 Variant of Uncertain Significance (VUS) Genetic Testing Results and Mastectomy Choice in Lumpectomy-Eligible Patients
45 Application of the 7-Gene Biosignature in Palpable Versus Nonpalpable Ductal Carcinoma In Situ in a Black Patient Population: Does Palpability Suggest a More Aggressive Genomic Risk?
45 Application of the 7-Gene Biosignature in Palpable Versus Nonpalpable Ductal Carcinoma In Situ in a Black Patient Population: Does Palpability Suggest a More Aggressive Genomic Risk?
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