Les antiangiogéniques en oncologie digestive

Anti-VEGF- and anti-VEGF receptor-induced vascular alteration in mouse healthy tissues

Systemic therapy with anti-VEGF drugs such as bevacizumab is widely used for treatment of human patients with various solid tumors. However, systemic impacts of such drugs in host healthy vasculatures remain poorly understood. Here, we show that, in mice, systemic delivery of an anti-VEGF or an anti-VEGF receptor (VEGFR)-2 neutralizing antibody caused global vascular regression. Among all examined tissues, vasculatures in endocrine glands, intestinal villi, and uterus are the most affected in response to VEGF or VEGFR-2 blockades. Thyroid vascular fenestrations were virtually completely blocked by VEGF blockade, leading to marked accumulation of intraendothelial caveolae vesicles. VEGF blockade markedly increased thyroid endothelial cell apoptosis, and withdrawal of anti-VEGF resulted in full recovery of vascular density and architecture after 14 d. Prolonged anti-VEGF treatment resulted in a significant decrease of the circulating level of the predominant thyroid hormone free thyroxine, but not the minimal isoform of triiodothyronine, suggesting that chronic anti-VEGF treatment impairs thyroid functions. Conversely, VEGFR-1-specific blockade produced virtually no obvious phenotypes. These findings provide structural and functional bases of anti-VEGF-specific drug-induced side effects in relation to vascular changes in healthy tissues. Understanding anti-VEGF drug-induced vascular alterations in healthy tissues is crucial to minimize and even to avoid adverse effects produced by currently used anti-VEGF-specific drugs.

[Toxicity of radiation therapy and antiangiogenics combination: a case report]

The combined administration of antiangiogenic agents (AA) and radiation is being evaluated. No AA has yet received Marketing Authorization in this indication. However, they are widely used in medical oncology and criteria for stopping their administration in case of irradiation have not been defined. We report the case of a 63-year-old man experiencing grade 2 skin toxicity while on radiation treatment and sorafenib (400mg twice daily) for a metastatic lesion developing between the vastus medialis muscle and the cortical of the mid-diaphysis of the right femur. Toxicity occurred at 21Gy, for a total dose of 36Gy (12 fractions of 3Gy). Cutaneous symptoms rapidly disappeared after treatment discontinuation. Radiotherapy alone was resumed after a few days and the total dose could be delivered, with good tolerance. At 2-month follow-up, the intramuscular lesion had regressed. Several other cases of patients with poor tolerance to the association of AA and radiotherapy have been reported. Further studies of the effectiveness and tolerance of the combination treatment are needed before indications for AA can be extended to other diseases.