[Role of the vascular component in growth of solid tumors: a historical review].

Angiogenesis is a fundamental biological process by which new capillary blood vessels are formed. It is essential in many physiological conditions, such as embryonic development, ovulation and wound repair, and pathological ones, such as arthritis, diabetic retinopathy, and tumours. Solid tumours have angiogenesis capacity, and tumour growth and metastasis are angiogenesis-dependent. Neoplastic cell populations can grow to form a clinically evident tumour only if the host produces a vascular network sufficient to sustain tumour growth. Furthermore, the new blood vessels provide a gateway for tumour cells to enter the circulation and metastasize to distant sites. Tumour angiogenesis is essentially mediated by angiogenic molecules elaborated by tumour cells. We review here the most important literature on this topic and emphasize the crucial and paradigmatic role of this biological process and its relevance in a possible anti-angiogenic therapeutic approach to the treatment of solid tumours.