RESEARCH Open Access FGFR-1 amplification in metastatic lymph-nodal and haematogenous lobular breast carcinoma

Background: Lobular breast carcinoma usually shows poor responsiveness to chemotherapies and often lacks targeted therapies. Since FGFR1 expression has been shown to play pivotal roles in primary breast cancer tumorigenesis, we sought to analyze the status of FGFR1 gene in a metastatic setting of lobular breast carcinoma, since promising FGFR1 inhibitors has been recently developed. Methods: Fifteen tissue metastases from lobular breast carcinomas with matched primary infiltrative lobular breast carcinoma were recruited. Eleven cases showed loco-regional lymph-nodal and four haematogenous metastases. FGFR-1 gene (8p12) amplification was evaluated by chromogenic in situ hybridization (CISH) analysis. Her-2/neu and topoisomerase-IIα gene status was assessed. E-cadherin and Hercept Test were also performed. We distinguished amplification (>6 or cluster of signals) versus gains (3–6 signals) of the locus specific FGFR-1 gene. Results: Three (20%) primary lobular breast carcinomas showed>6 or cluster of FGFR1 signals (amplification), six cases (40%) had a mean of three (range 3–6) chromogenic signals (gains) whereas in 6 (40%) was not observed any abnormality. Three of 15 metastasis (20%) were amplified, 2/15 (13,4%) did not. The ten remaining cases (66,6%) showed three chromogenic signals. The three cases with FGFR-1 amplification matched with those primary breast carcinomas showing FGFR-