TY - JOUR
T1 - Genetic profiling of advanced radioactive iodine-resistant differentiated thyroid cancer and correlation with axitinib efficacy
AU - Schechter, Rebecca B.
AU - Nagilla, Madhavi
AU - Joseph, Loren
AU - Reddy, Poluru
AU - Khattri, Arun
AU - Watson, Sydeaka
AU - Locati, Laura D.
AU - Licitra, Lisa
AU - Greco, Angela
AU - Pelosi, Giuseppe
AU - Carcangiu, Maria Luisa
AU - Lingen, Mark W.
AU - Seiwert, Tanguy Y.
AU - Cohen, Ezra E.W.
N1 - Funding Information:
This study was supported by Pfizer , Inc.
Publisher Copyright:
© 2015 Elsevier Ireland Ltd.
PY - 2015/4/10
Y1 - 2015/4/10
N2 - Biomarkers predicting which patients with advanced radioiodine-resistant differentiated thyroid cancer (DTC) may benefit from multi-kinase inhibitors are unavailable. We aimed to describe molecular markers in DTC that correlate with clinical outcome to axitinib. Pretreatment thyroid cancer blocks from 18 patients treated with axitinib were collected and genomic DNA was isolated. The OncoCarta™ Mutation Panel was used to test for 238 oncogenic mutations. Copy number of VEGFR1-3 and PIK3CA was determined using qPCR on enriched tumor samples. Genomic DNA was analyzed for all coding regions of VEGFR1-3 with custom primers. Protein expressions of VEGFR1-3, c-Met, and PIK3CA were evaluated with immunohistochemistry. Clinical response to axitinib, including best response (BR) and progression free survival (PFS), was ascertained from corresponding patients. Fisher's exact test and logistic regression models were used to correlate BR with molecular findings. Cox proportional hazards regression was used to correlate PFS with molecular defects. A total of 22 pathology samples (10 primary, 12 metastatic) were identified. In patients with 2 samples (n = 4), genetic results were concordant and only included once for analysis. Tumors from 4 patients (22%) harbored BRAF V600E mutations, 2 (11%) had KRAS mutations (G12A, G13D) and 2 (11%) had HRAS mutations (Q61R, Q61K). One metastatic sample with mutated KRAS also harbored a PIK3CA (H1047R) mutation. qPCR showed increased copy numbers of PIK3CA in 6 (33%) tumors, VEGFR1 in 0 (0%) tumors, VEGFR2 in 4 (22%) tumors, and VEGFR3 in 6 (33%) tumors. VEGFR sequencing was significant for a possibly damaging non-synonymous SNP in VEGFR2 (G539R) in 2 samples (11%), a possibly damaging SNP in VEGFR3 (E350V) in 1 sample (6%), and a potentially novel mutation in VEGFR2 (T439I) in 2 samples (11%). Immunohistochemistry (VEGFR1, -2, -3; c-MET; PIK3CA) revealed positive staining in the majority of samples. No significant relationship was seen between BR or PFS and the presence of molecular alterations. Molecular evaluation of DTC specimens did not predict clinical response to axitinib but our data were limited by sample size. We did identify molecular changes in VEGFR that should be further explored. While DTC is genetically heterogeneous, primary and metastatic lesions showed identical oncogenic alterations in four cases.
AB - Biomarkers predicting which patients with advanced radioiodine-resistant differentiated thyroid cancer (DTC) may benefit from multi-kinase inhibitors are unavailable. We aimed to describe molecular markers in DTC that correlate with clinical outcome to axitinib. Pretreatment thyroid cancer blocks from 18 patients treated with axitinib were collected and genomic DNA was isolated. The OncoCarta™ Mutation Panel was used to test for 238 oncogenic mutations. Copy number of VEGFR1-3 and PIK3CA was determined using qPCR on enriched tumor samples. Genomic DNA was analyzed for all coding regions of VEGFR1-3 with custom primers. Protein expressions of VEGFR1-3, c-Met, and PIK3CA were evaluated with immunohistochemistry. Clinical response to axitinib, including best response (BR) and progression free survival (PFS), was ascertained from corresponding patients. Fisher's exact test and logistic regression models were used to correlate BR with molecular findings. Cox proportional hazards regression was used to correlate PFS with molecular defects. A total of 22 pathology samples (10 primary, 12 metastatic) were identified. In patients with 2 samples (n = 4), genetic results were concordant and only included once for analysis. Tumors from 4 patients (22%) harbored BRAF V600E mutations, 2 (11%) had KRAS mutations (G12A, G13D) and 2 (11%) had HRAS mutations (Q61R, Q61K). One metastatic sample with mutated KRAS also harbored a PIK3CA (H1047R) mutation. qPCR showed increased copy numbers of PIK3CA in 6 (33%) tumors, VEGFR1 in 0 (0%) tumors, VEGFR2 in 4 (22%) tumors, and VEGFR3 in 6 (33%) tumors. VEGFR sequencing was significant for a possibly damaging non-synonymous SNP in VEGFR2 (G539R) in 2 samples (11%), a possibly damaging SNP in VEGFR3 (E350V) in 1 sample (6%), and a potentially novel mutation in VEGFR2 (T439I) in 2 samples (11%). Immunohistochemistry (VEGFR1, -2, -3; c-MET; PIK3CA) revealed positive staining in the majority of samples. No significant relationship was seen between BR or PFS and the presence of molecular alterations. Molecular evaluation of DTC specimens did not predict clinical response to axitinib but our data were limited by sample size. We did identify molecular changes in VEGFR that should be further explored. While DTC is genetically heterogeneous, primary and metastatic lesions showed identical oncogenic alterations in four cases.
KW - Advanced differentiated thyroid cancer
KW - Axitinib
KW - BRAF
KW - PIK3CA
KW - RAS
KW - VEGFR
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U2 - 10.1016/j.canlet.2015.01.024
DO - 10.1016/j.canlet.2015.01.024
M3 - Article
C2 - 25641339
AN - SCOPUS:84923116474
SN - 0304-3835
VL - 359
SP - 269
EP - 274
JO - Cancer Letters
JF - Cancer Letters
IS - 2
ER -