Influence of paramagnetic melanin on the MRI contrast in melanoma: a combined high-field (11.7 T) MRI and EPR study.

Melanoma is the most dangerous form of skin cancer and its incidence is rising each year. Because the current methods of diagnosis based on the visual aspect of the tumor show limitations, several new techniques are emerging to help in this diagnosis, amongst which are magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR). The origin of the typical contrast pattern observable in melanoma in T1 - and T2 -weighted images remains to be elucidated and is a source of controversy. In addition, melanin could create sufficient magnetic inhomogeneities to allow its visualization on T2 *-weighted images using high-field MRI. In order to elucidate the possible role of melanin in the MRI contrast of melanoma, the present study was designed to correlate the paramagnetic content in melanin pigment to the contrast on T1 -, T2 - and T2 *-weighted images. MR images were obtained in vivo at 11.7 T using four types of experimental tumors with different pigmentations (B16, HBL, LND1 melanomas and KHT sarcomas). The paramagnetic content in melanin pigment was measured by EPR. No significant correlation was observed between the content in melanin and the relaxation times T1 , T2 and T2 *, emphasizing that the presence of pigment alone has negligible effect on the MRI contrast.

Phase II study of figitumumab in patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck: clinical activity and molecular response (GORTEC 2008-02).

BACKGROUND: Preclinical studies suggest that insulin-like growth factor-1 receptor (IGF-1R) blockage could be a promising therapeutic target in squamous cell carcinoma of the head and neck (SCCHN). Therefore, we investigated the efficacy and toxicity of figitumumab, an anti-IGF-1R monoclonal antibody, in palliative SCCHN. PATIENTS AND METHODS: Patients with palliative SCCHN progressing after platinum-based therapy were treated with figitumumab i.v. 20 mg/kg, every 3 weeks. The primary end point was the disease control rate at 6-8 weeks after treatment initiation. Tumor biopsies and plasma samples were collected before and after figitumumab administration to monitor the molecular response. RESULTS: Seventeen patients were included. Only two patients achieved stable disease at 6-8 weeks. Median overall survival and progression-free survival were 63 and 52 days, respectively. The main grade 3-4 adverse event was hyperglycemia (41%). Translational research showed that figitumumab downregulated IGF-1R at the surface of tumor cells with activation of the epidermal growth factor receptor (EGFR) pathway, as shown by the upregulation of p-EGFR in tumor cells (P=0.016), and an increase in the plasma level of tumor growth factor-alpha (P=0.006). CONCLUSION: Figitumumab monotherapy has no clinically significant activity in unselected palliative SCCHN.