ABSTRACT
Wounding can accelerate tumor development, and malignant tumors exhibit features which are characteristic of wounded and regenerating tissue. These features include cellular hyperproliferation and cell migration as well as invasive growth, suppression of tissue function, inflammatory processes, angiogenesis, apoptosis, necrosis, etc. It appears as if in a tumor physiological processes had become “locked-in”, which upon tissue damage are transiently activated under strictly controlled conditions. The acceleration of skin tumor development by irritation prompted Rous and co-workers7 to postulate two stages of carcinogenesis which they called “initiation” and “promotion”. Hyperplastic transformation, a critical condition of tumor promotion, is the general response of the skin to injury and irritation. It is characterized by a complex interaction between many different cell types, which finally generates the symptoms of hyperproliferation and inflammation.
