Fibroblast growth factor family aberrations in cancers: clinical and molecular characteristics

Fibroblast growth factor ligands and receptors (FGF and FGFR) play critical roles in tumorigenesis, and several drugs have been developed to target them. We report the biologic correlates of FGF/FGFR abnormalities in diverse malignancies. The medical records of patients with cancers that underwent targeted next generation sequencing (182 or 236 cancer-related genes) were reviewed. The following FGF/FGFR genes were tested: FGF3, 4, 6, 7, 10, 12, 14, 19, 23 and FGFR1, 2, 3, and 4. Of 391 patients, 56 (14.3%) had aberrant FGF (N = 38, all amplifications) and/or FGFR (N = 22 including 5 mutations and one FGFR3-TACC3 fusion). FGF/FGFR aberrations were most frequent in breast cancers (26/81, 32.1%, p = 0.0003). In multivariate analysis, FGF/FGFR abnormalities were independently associated with CCND1/2, RICTOR, ZNF703, RPTOR, AKT2, and CDK8 alterations (all P < 0.02), as well as with an increased median number of alterations (P < 0.0001). FGF3, FGF4, FGF19 and CCND1 were co-amplified in 22 of 391 patients (5.6%, P < 0.0001), most likely because they co-localize on the same chromosomal region (11q13). There was no significant difference in time to metastasis or overall survival when comparing patients harboring FGF/FGFR alterations versus those not. Overall, FGF/FGFR was one of the most frequently aberrant pathways in our population comprising patients with diverse malignancies. These aberrations frequently co-exist with anomalies in a variety of other genes, suggesting that tailored combination therapy may be necessary in these patients.

Abstract P4-04-15: UC San Diego molecular tumor board: Experience in breast cancer

Background: To realize the promise of personalized medicine, it is important to build the infrastructure to match patients to the most promising therapies using evolving genomic information to inform clinical trial and treatment recommendations.

Methods: A molecular tumor board was established in December 2012 consisting of representatives of medical oncology, surgery, radiation, pathology, radiology, clinical genetics, molecular genetics and diagnostics, basic and translational science, and bioinformatics and pathway analysis. Patients with metastatic breast cancer signed consent for collection of data in a registry format related to clinical history, genomic analysis, treatment recommendations, and response. Tumor specimens from patients with metastatic breast cancer were subjected to a next generation sequencing diagnostic test (Foundation One™) in a CLIA-certified lab (Foundation Medicine) and analyzed for genomic alterations in a 182 gene panel or a 236 gene panel. Clinical cases and genomic alterations were discussed at Molecular Tumor Board where clinical trials and treatment recommendations were considered, with the final decision made by the treating oncologist.

Results: Genomic analyses of metastatic breast cancer specimens from 17 consented patients had at least one genomic alteration and no tumors had the same genomic alterations. 12/17 had ≥ 2 and 4/17 had 6 or 7 genomic alterations. The most common genomic alterations were in PIK3CA observed in tumors from 6/17 patients. 1/17 tumor specimens had only a single genomic alteration for which there are no current targeted drugs in clinical studies or available commercially (GATA3). Radiographic and/or tumor marker response have been observed to date in 3/4 heavily pretreated patients following treatment with a targeted therapy or a targeted therapy informed by the genomic data in combination with other drugs.

Conclusions: The strategy of matching targeted clinical trial and commercially available therapies to genomic alterations of tumor specimens from individual patients with metastatic breast cancer may offer promise to patients with advanced refractory disease. Biopsies of metastatic disease, genomic analysis in CLIA labs, establishment of molecular tumor boards, definition of “matched” versus “non-matched” therapies, capturing data in a registry to create a learning environment, and most importantly, availability of targeted therapies in clinical trials or commercially, are required for this individual patient strategy to inform current and future treatment options for much larger patient populations.

Funding from UC San Diego Moores Cancer Center MyAnswerToCancer philanthropic fund.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-04-15.