PURPOSE: Biomarkers from two randomized phase III trials were analyzed to optimize selection of patients for lapatinib therapy. EXPERIMENTAL DESIGN: In available breast cancer tissue from EGF30001 (paclitaxel +/- lapatinib in HER-2-negative/unknown metastatic breast cancer, n = 579) and EGF100151 (capecitabine +/- lapatinib in HER-2-positive metastatic breast cancer, n = 399), HER-2 gene amplification by fluorescence in situ hybridization (FISH), HER-2 mRNA by reverse transcription-PCR (RT-PCR), HER-2 protein expression by HercepTest immunohistochemistry (IHC), epidermal growth factor receptor (EGFR) mRNA level by RT-PCR, and EGFR protein by IHC were analyzed and compared with clinical outcome. HER-2 was determined by FISH in an academic reference/research laboratory and in a large, high-volume commercial reference laboratory. RESULTS: The HER-2 gene was amplified in 47% (344 of 733) and IHC was 3+ in 35% (279 of 798), with significant correlation (P < 0.01) between FISH and IHC. Positive EGFR immunostaining (IHC 1+, 2+, or 3+) in 28% (213 of 761) correlated with EGFR mRNA levels by RT-PCR (r = 0.59; P < 0.01). HER-2 gene amplification/overexpression was associated with improved clinical outcomes (progression-free survival; P < 0.001) in both trials. A significant improvement in outcome was seen in FISH-positive and IHC 0, 1+, or 2+ patients. HER-2 mRNA expression correlated with HER-2 FISH (r = 0.83) and IHC status (r = 0.72; n = 138). No correlation was found between EGFR expression (IHC or mRNA) and responsiveness to lapatinib regardless of HER-2 status. Although a significant correlation with lapatinib responsiveness was observed among "HER-2-negative" breast cancer patients in the large, high-volume commercial reference laboratory, this was not confirmed in the academic reference/research laboratory. CONCLUSIONS: Women with HER-2-positive metastatic breast cancer benefit from lapatinib, whereas women with HER-2-negative metastatic breast cancer derive no incremental benefit from lapatinib.
PURPOSE: Biomarkers from two randomized phase III trials were analyzed to optimize selection of patients for lapatinib therapy. EXPERIMENTAL DESIGN: In available breast cancer tissue from EGF30001 (paclitaxel +/- lapatinib in HER-2-negative/unknown metastatic breast cancer, n = 579) and EGF100151 (capecitabine +/- lapatinib in HER-2-positive metastatic breast cancer, n = 399), HER-2 gene amplification by fluorescence in situ hybridization (FISH), HER-2 mRNA by reverse transcription-PCR (RT-PCR), HER-2 protein expression by HercepTest immunohistochemistry (IHC), epidermal growth factor receptor (EGFR) mRNA level by RT-PCR, and EGFR protein by IHC were analyzed and compared with clinical outcome. HER-2 was determined by FISH in an academic reference/research laboratory and in a large, high-volume commercial reference laboratory. RESULTS: The HER-2 gene was amplified in 47% (344 of 733) and IHC was 3+ in 35% (279 of 798), with significant correlation (P < 0.01) between FISH and IHC. Positive EGFR immunostaining (IHC 1+, 2+, or 3+) in 28% (213 of 761) correlated with EGFR mRNA levels by RT-PCR (r = 0.59; P < 0.01). HER-2 gene amplification/overexpression was associated with improved clinical outcomes (progression-free survival; P < 0.001) in both trials. A significant improvement in outcome was seen in FISH-positive and IHC 0, 1+, or 2+ patients. HER-2 mRNA expression correlated with HER-2 FISH (r = 0.83) and IHC status (r = 0.72; n = 138). No correlation was found between EGFR expression (IHC or mRNA) and responsiveness to lapatinib regardless of HER-2 status. Although a significant correlation with lapatinib responsiveness was observed among "HER-2-negative" breast cancerpatients in the large, high-volume commercial reference laboratory, this was not confirmed in the academic reference/research laboratory. CONCLUSIONS:Women with HER-2-positive metastatic breast cancer benefit from lapatinib, whereas women with HER-2-negative metastatic breast cancer derive no incremental benefit from lapatinib.
Authors: Brian D Lehmann; Joshua A Bauer; Xi Chen; Melinda E Sanders; A Bapsi Chakravarthy; Yu Shyr; Jennifer A Pietenpol Journal: J Clin Invest Date: 2011-07 Impact factor: 14.808
Authors: Thomas Worzfeld; Jakub M Swiercz; Mario Looso; Beate K Straub; Kishor K Sivaraj; Stefan Offermanns Journal: J Clin Invest Date: 2012-03-01 Impact factor: 14.808
Authors: M J Labonte; P M Wilson; D Yang; W Zhang; R D Ladner; Y Ning; A Gerger; P O Bohanes; L Benhaim; R El-Khoueiry; A El-Khoueiry; H-J Lenz Journal: Ann Oncol Date: 2011-10-11 Impact factor: 32.976
Authors: M A Gordon; H M Gundacker; J Benedetti; J S Macdonald; J C Baranda; W J Levin; C D Blanke; W Elatre; P Weng; J Y Zhou; H J Lenz; M F Press Journal: Ann Oncol Date: 2013-03-22 Impact factor: 32.976