Squamous cell cancer spreads via the lymph system and can involve bone, liver and brain. Metastases increase to a rate of 11 percent when SCC involves the oral and genital membranes and to 10 to 30 percent when the lesions are on areas of the skin previously injured from burns.
What Causes It Most skin cancers are caused by excessive exposure to sunlight. Genetic background is also a factor, since light-skinned people suffer a more adverse reaction to the sun's ultraviolet radiation.
