Using publicly available data from The Cancer Genome Atlas, an amplification and gain of copy number of IGF1R was observed in 38% of triple-negative breast tumors (n=82), 26% of estrogen receptor (ER)-negative tumors (n=174) and 10% of ER-positive tumors (n=594).
The aim of this study was to assess whether IGF-1R expression of breast tumors changes during neoadjuvant therapy and to study whether these changes were associated with survival.
To evaluate the impact of BRCA1 mutations on IGF-IR gene expression, we performed an immunohistochemical analysis of IGF-IR in primary breast tumors from BRCA1 mutation carriers and non-carriers.
Subgroup analysis revealed that, for early breast tumor relapses (within 4 years of initial breast tumor diagnosis), elevated levels of IGF-IR were strongly associated with IBTR (P = 0.004) but IGF-IR expression was not prognostic for IBTR from breast cancer patients with late relapses (P was not significant).
In 11 breast tumor samples with high (greater than or equal to 20 copies) IGF-1-R gene copy numbers, an additional amplification of either the c-myc gene (n = 3) or int-2/bcl-1 genes (n = 5) was observed, whereas no amplification of the HER2/neu gene was detected.