Association of Residual Ductal Carcinoma In Situ With Breast Cancer Recurrence in the Neoadjuvant I-SPY2 Trial.

Importance: Pathologic 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).

Objective: To 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.

Standardizing Pathologic Evaluation of Breast Carcinoma After Neoadjuvant Chemotherapy.

Context.—: Neoadjuvant systemic therapy refers to the use of systemic agent(s) for malignancy prior to surgical treatment and has recently emerged as an option for most breast cancer patients eligible for adjuvant systemic therapy. Consequently, treated breast carcinomas have become routine specimens in pathology practices.

Randomized Phase II Study of Two Doses of Pixantrone in Patients with Metastatic Breast Cancer (NCCTG N1031, Alliance).

Background: Anthracycline use in metastatic breast cancer (MBC) is hindered by cumulative exposure limits and risk of cardiotoxicity. Pixantrone, a novel aza-anthracenedione with structural similarities to mitoxantrone and anthracyclines, is theorized to exhibit less cardiotoxicity, mainly due to lack of iron binding. We conducted a randomized phase II study to evaluate the efficacy and safety of 2 dosing schedules of pixantrone in patients with refractory HER2-negative MBC.

The breast tissue microbiome, stroma, immune cells and breast cancer.

Background: Stromal and immune cell composition alterations in benign breast tissue associate with future cancer risk. Pilot data suggest the innate microbiome of normal breast tissue differs between women with and without breast cancer. Microbiome alterations might explain tissue microenvironment variations associated with disease status.

Assessment of Residual Cancer Burden and Event-Free Survival in Neoadjuvant Treatment for High-risk Breast Cancer: An Analysis of Data From the I-SPY2 Randomized Clinical Trial.

Importance: Residual cancer burden (RCB) distributions may improve the interpretation of efficacy in neoadjuvant breast cancer trials.

Objective: To compare RCB distributions between randomized control and investigational treatments within subtypes of breast cancer and explore the relationship with survival.

Design, Setting, And Participants: The I-SPY2 is a multicenter, platform adaptive, randomized clinical trial in the US that compares, by subtype, investigational agents in combination with chemotherapy vs chemotherapy alone in adult women with stage 2/3 breast cancer at high risk of early recurrence.

Detailed Reanalysis of 500 Breast Cancers With Equivocal HER2 Immunohistochemistry and Borderline ERBB2 Fluorescence In Situ Hybridization Results.

Objectives: We investigated the impact of our laboratory's reflex testing process for resolving ERBB2 (HER2) status on breast cancer samples that require additional workup after fluorescence in situ hybridization (FISH), per guideline recommendations published in 2018 by the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP).

Methods: In total, 500 breast cancer specimens with ERBB2 FISH results in groups 2 through 4 (all reported as immunohistochemistry [IHC] equivocal [2+] at external laboratories) were resubmitted for IHC testing in our laboratory. Per the ASCO/CAP guideline, FISH was rescored when internal IHC was also equivocal (2+), targeted to tumor areas demonstrating more intense IHC staining, if observed.

Randomized Phase II Trial of Capecitabine and Lapatinib with or without IMC-A12 (Cituxumumab) in Patients with HER2-Positive Advanced Breast Cancer Previously Treated with Trastuzumab and Chemotherapy: NCCTG N0733 (Alliance).

Purpose: To compare efficacy and safety of capecitabine and lapatinib with or without IMC-A12 (cituxumumab) in patients with HER2-positive metastatic breast cancer (MBC) previously treated with trastuzumab.

Patients And Methods: Following an initial safety run-in cohort, patients were randomized 1:2 to Arm A (capecitabine and lapatinib) or to Arm B (capecitabine, lapatinib, and cituxumumab). Given the frequency of non-hematologic grade ≥ 3 adverse events in those receiving the three-drug combination in the safety cohort, lapatinib and capecitabine doses were reduced in Arm B only.

HER2 Testing for Breast Cancer in the Genomics Laboratory: A Sea Change for Fluorescence In Situ Hybridization.

Context.—: Guidelines for HER2 testing in breast cancer have changed over time, from the US Food and Drug Administration guideline to the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines published in 2007, 2013, and 2018.

Objective.

Association of Event-Free and Distant Recurrence-Free Survival With Individual-Level Pathologic Complete Response in Neoadjuvant Treatment of Stages 2 and 3 Breast Cancer: Three-Year Follow-up Analysis for the I-SPY2 Adaptively Randomized Clinical Trial.

Importance: Pathologic complete response (pCR) is a known prognostic biomarker for long-term outcomes. The I-SPY2 trial evaluated if the strength of this clinical association persists in the context of a phase 2 neoadjuvant platform trial.

Objective: To evaluate the association of pCR with event-free survival (EFS) and pCR with distant recurrence-free survival (DRFS) in subpopulations of women with high-risk operable breast cancer treated with standard therapy or one of several novel agents.

N083E (Alliance): long-term outcomes of patients treated in a pilot phase II study of docetaxel, carboplatin, trastuzumab, and lapatinib as adjuvant therapy for early-stage HER2-positive breast cancer.

Background: The addition of lapatinib (L) to trastuzumab (T) was previously found to be synergistic in preclinical models and in the neoadjuvant setting. Prior to the results of the ALTTO trial, this study assessed the safety and feasibility of adding L to the standard adjuvant docetaxel, carboplatin, and trastuzumab (TCH) regimen in early-stage HER2-positive breast cancer (HER2+ BC).

Methods: In this single-arm, 2-stage, phase II study, patients with stages I-III HER2+ BC received TCH plus L at 1000 mg daily for a total of 12 months.

Pan-TRK Immunohistochemistry: A Useful Diagnostic Adjunct For Secretory Carcinoma of the Breast.

Secretory carcinoma is a special-type breast carcinoma underpinned by a recurrent t(12;15)(p13;q25) translocation resulting in ETV6-NTRK3 gene fusion. Immunohistochemistry (IHC) using a pan-TRK antibody has been recently shown to help identify NTRK rearrangements in other tumor types. The purpose of this study was to assess the diagnostic utility of pan-TRK IHC in secretory carcinoma of the breast.

Ability of Intraoperative Pathologic Analysis of Ductal Carcinoma to Guide Selective Use of Sentinel Lymph Node Surgery.

For patients with ductal carcinoma In Situ (DCIS), sentinel lymph node (SLN) surgery is generally reserved for patients at high risk of being upstaged to invasive disease. The use of frozen section (FS) pathologic analysis of the primary tumor may allow for selective surgical nodal staging within one procedure. We sought to define the reliability of FS for detection of upstaging.

Integrated Analysis of HER2 Copy Number by Cytogenomic Microarray in Breast Cancers With Nonclassical In Situ Hybridization Results.

Objectives: To develop and test an integrated approach to human epidermal growth factor receptor 2 (HER2) copy number analysis in breast cancer using in situ hybridization (ISH) and cytogenomic microarray (CMA).

Methods: CMA was performed on four clinical breast cancer samples with nonclassical patterns of HER2 ISH results. Integrated analysis was performed by correlating the data from pathology review, ISH, and CMA.

A Validated Nomogram to Predict Upstaging of Ductal Carcinoma in Situ to Invasive Disease.

Background: Approximately 8-56% of patients with a core needle biopsy (CNB) diagnosis of ductal carcinoma in situ (DCIS) will be upstaged to invasive disease at the time of excision. Patients with invasive disease are recommended to undergo axillary nodal staging, most often requiring a second operation. We developed and validated a nomogram to preoperatively predict percentage of risk for upstaging to invasive cancer.

Breast implant capsule-associated squamous cell carcinoma: a report of 2 cases.

The use of prosthetic implants for breast augmentation has become commonplace. Although implants do not increase the risk of conventional mammary carcinoma, they are rarely associated with anaplastic large cell lymphoma. We report 2 cases of breast implant capsule-associated squamous cell carcinoma with poor clinical outcomes.

Update on Immunohistochemical Analysis in Breast Lesions.

Context: - The utility of immunohistochemistry (IHC) in breast lesions needs to be updated with exceptions among these lesions. Biomarker studies with IHC in triple-negative breast carcinoma may help develop targeted therapies for this aggressive breast cancer. The distinction of metastatic lung adenocarcinoma to the breast and invasive breast carcinoma has significant prognostic and therapeutic implications.