TY - JOUR
T1 - International harmonization of provisional diagnostic criteria for ErbB2-amplified metastatic colorectal cancer allowing for screening by next-generation sequencing panel
AU - Fujii, Satoshi
AU - Magliocco, Anthony M.
AU - Kim, Jihun
AU - Okamoto, Wataru
AU - Kim, Jeong Eun
AU - Sawada, Kentaro
AU - Nakamura, Yoshiaki
AU - Kopetz, Scott
AU - Park, Woong Yang
AU - Tsuchihara, Katsuya
AU - Kim, Tae Won
AU - Raghav, Kanwal
AU - Yoshino, Takayuki
N1 - Publisher Copyright:
© 2020 by American Society of Clinical Oncology
PY - 2020
Y1 - 2020
N2 - PURPOSE ERBB2 amplification (human epidermal growth factor receptor 2 positivity [HER2+]) in metastatic colorectal cancer (mCRC) has important therapeutic implications that necessitate the need for accurate diagnostics. The study purpose was to establish and validate harmonized diagnostic criteria for HER2+ mCRC among 3 groups (GI-SCREEN-Japan, NCTN-SWOG-USA, and Korea). PATIENTS AND METHODS We assessed HER2 status by immunohistochemistry (IHC), ERBB2/CEP17 ratio, gene copy number (GCN) by fluorescence in situ hybridization (FISH), and copy number variation (CNV) using two targeted next-generation sequencing (NGS) panels. Tumor samples from 475 and 16 patients with mCRC in exploratory and validation cohorts, respectively, were used for cross-validation of the NGS panels. RESULTS Consensus diagnostic criteria among the 3 groups for HER2+ mCRC were established as follows: IHC 3+ or IHC 2+ and ERBB2/CEP17 ratio by FISH ≥ 2.0, tumor content . 10% for surgically resected specimens, and necessary tumor content not defined for biopsy specimens. The median GCN and CNV for HER2+ patients were 10.9 and 27.7 compared with 2.5 (P, .0001) and 3.5 (P, .0001), respectively, in HER2-negative patients. These findings were validated in a validation cohort (GCN, 16.2 v 2.4 [P = .0002]; CNV, 42.5 v 2.0 [P = .0003]). GCN correlated with CNV in both cohorts (exploratory, r = 0.90; validation, r = 0.97; P, .0001). CNV in cross-validation of the 2 NGS panels also showed a strong correlation (r = 0.98; P, .0001). CNV in patients who fulfilled the consensus criteria was . 4.0 in all, which demonstrates the accuracy of the IHC/FISH criteria and cross-validation of NGS panels. CONCLUSION We have established and verified harmonized diagnostic criteria for HER2+ and demonstrated consistency between IHC/FISH and CNV determined by NGS in mCRC.
AB - PURPOSE ERBB2 amplification (human epidermal growth factor receptor 2 positivity [HER2+]) in metastatic colorectal cancer (mCRC) has important therapeutic implications that necessitate the need for accurate diagnostics. The study purpose was to establish and validate harmonized diagnostic criteria for HER2+ mCRC among 3 groups (GI-SCREEN-Japan, NCTN-SWOG-USA, and Korea). PATIENTS AND METHODS We assessed HER2 status by immunohistochemistry (IHC), ERBB2/CEP17 ratio, gene copy number (GCN) by fluorescence in situ hybridization (FISH), and copy number variation (CNV) using two targeted next-generation sequencing (NGS) panels. Tumor samples from 475 and 16 patients with mCRC in exploratory and validation cohorts, respectively, were used for cross-validation of the NGS panels. RESULTS Consensus diagnostic criteria among the 3 groups for HER2+ mCRC were established as follows: IHC 3+ or IHC 2+ and ERBB2/CEP17 ratio by FISH ≥ 2.0, tumor content . 10% for surgically resected specimens, and necessary tumor content not defined for biopsy specimens. The median GCN and CNV for HER2+ patients were 10.9 and 27.7 compared with 2.5 (P, .0001) and 3.5 (P, .0001), respectively, in HER2-negative patients. These findings were validated in a validation cohort (GCN, 16.2 v 2.4 [P = .0002]; CNV, 42.5 v 2.0 [P = .0003]). GCN correlated with CNV in both cohorts (exploratory, r = 0.90; validation, r = 0.97; P, .0001). CNV in cross-validation of the 2 NGS panels also showed a strong correlation (r = 0.98; P, .0001). CNV in patients who fulfilled the consensus criteria was . 4.0 in all, which demonstrates the accuracy of the IHC/FISH criteria and cross-validation of NGS panels. CONCLUSION We have established and verified harmonized diagnostic criteria for HER2+ and demonstrated consistency between IHC/FISH and CNV determined by NGS in mCRC.
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U2 - 10.1200/po.19.00154
DO - 10.1200/po.19.00154
M3 - Article
C2 - 35050726
AN - SCOPUS:85082510635
SN - 2473-4284
VL - 4
SP - 6
EP - 19
JO - JCO Precision Oncology
JF - JCO Precision Oncology
ER -