Browsing by Subject "HER2-positive breast cancer"

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    A Multiparameter Molecular Classifier to Predict Response to Neoadjuvant Lapatinib plus Trastuzumab without Chemotherapy in HER2+ Breast Cancer
    (American Association for Cancer Research, 2023) Veeraraghavan, Jamunarani; Gutierrez, Carolina; De Angelis, Carmine; Davis, Robert; Wang, Tao; Pascual, Tomas; Selenica, Pier; Sanchez, Katherine; Nitta, Hiroaki; Kapadia, Monesh; Pavlick, Anne C.; Galvan, Patricia; Rexer, Brent; Forero-Torres, Andres; Nanda, Rita; Storniolo, Anna M.; Krop, Ian E.; Goetz, Matthew P.; Nangia, Julie R.; Wolff, Antonio C.; Weigelt, Britta; Reis-Filho, Jorge S.; Hilsenbeck, Susan G.; Prat, Aleix; Osborne, C. Kent; Schiff, Rachel; Rimawi, Mothaffar F.; Medicine, School of Medicine
    Purpose: Clinical trials reported 25% to 30% pathologic complete response (pCR) rates in HER2+ patients with breast cancer treated with anti-HER2 therapies without chemotherapy. We hypothesize that a multiparameter classifier can identify patients with HER2-"addicted" tumors who may benefit from a chemotherapy-sparing strategy. Experimental design: Baseline HER2+ breast cancer specimens from the TBCRC023 and PAMELA trials, which included neoadjuvant treatment with lapatinib and trastuzumab, were used. In the case of estrogen receptor-positive (ER+) tumors, endocrine therapy was also administered. HER2 protein and gene amplification (ratio), HER2-enriched (HER2-E), and PIK3CA mutation status were assessed by dual gene protein assay (GPA), research-based PAM50, and targeted DNA-sequencing. GPA cutoffs and classifier of response were constructed in TBCRC023 using a decision tree algorithm, then validated in PAMELA. Results: In TBCRC023, 72 breast cancer specimens had GPA, PAM50, and sequencing data, of which 15 had pCR. Recursive partitioning identified cutoffs of HER2 ratio ≥ 4.6 and %3+ IHC staining ≥ 97.5%. With PAM50 and sequencing data, the model added HER2-E and PIK3CA wild-type (WT). For clinical implementation, the classifier was locked as HER2 ratio ≥ 4.5, %3+ IHC staining ≥ 90%, and PIK3CA-WT and HER2-E, yielding 55% and 94% positive (PPV) and negative (NPV) predictive values, respectively. Independent validation using 44 PAMELA cases with all three biomarkers yielded 47% PPV and 82% NPV. Importantly, our classifier's high NPV signifies its strength in accurately identifying patients who may not be good candidates for treatment deescalation. Conclusions: Our multiparameter classifier differentially identifies patients who may benefit from HER2-targeted therapy alone from those who need chemotherapy and predicts pCR to anti-HER2 therapy alone comparable with chemotherapy plus dual anti-HER2 therapy in unselected patients.
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    TBCRC023: A Randomized Phase II Neoadjuvant Trial of Lapatinib Plus Trastuzumab Without Chemotherapy for 12 versus 24 Weeks in Patients with HER2-Positive Breast Cancer
    (AACR, 2020-02) Rimawi, Mothaffar F.; Niravath, Polly A.; Wang, Tao; Rexer, Brent; Forero, Andres; Wolff, Antonio C.; Nanda, Rita; Storniolo, Anna M.; Krop, Ian E.; Goetz, Matthew P.; Nangia, Julie R.; Jiralerspong, Sao; Pavlick, Anne C.; Veeraraghavan, Jamunarani; De Angelis, Carmine; Gutierrez, Carolina; Schiff, Rachel; Hilsenbeck, Susan G.; Osborne, C. Kent; Medicine, School of Medicine
    Purpose: Prior neoadjuvant trials with 12 weeks of dual anti-HER2 therapy without chemotherapy demonstrated a meaningful pathologic complete response (pCR) in patients with HER2-positive breast cancer. In this trial, we sought to determine whether longer treatment would increase the rate of pCR. Patients and Methods: TBCRC023 (NCT00999804) is a randomized phase II trial combining a Simon phase II design in the experimental arm with a pick-the-winner design, not powered for direct comparison. Women with HER2-positive breast tumors measuring ≥2 cm (median = 5 cm) were randomized in a 1:2 ratio to 12 versus 24 weeks of lapatinib and trastuzumab. Letrozole (along with ovarian suppression if premenopausal) was administered in patients whose tumors were also estrogen receptor (ER) positive. All evaluable patients were assessed for in-breast pCR. Results: Ninety-seven patients were enrolled (33 in 12-week arm and 64 in 24-week arm), of whom 94 were evaluable. Median age was 51 years, and 55% were postmenopausal. Median tumor size was 5 cm, and 65% were ER-positive. The rate of pCR in the 24-week arm was 28% and numerically superior to the 12-week arm (12%). This was driven by increased pCR in the ER-positive subgroup (33% vs. 9%). Study treatment was well tolerated, with grade 1–2 diarrhea and acneiform rash being the most common toxicities. Conclusions: Treatment with dual anti-HER2 therapy for 24 weeks led to a numeric increase in pCR rate in women with HER2-positive breast cancer, without using chemotherapy. If validated, this approach may help identify patients who may benefit from deescalation of therapy.