History of cancer investigation.

A revision was made of the most important biological hypothesis that try to explain the carcinogenesis mechanism. Most of them postulate that malignization is the result of cell genetic material alterations. On the other hand information obtained from cell exposure to chemical, physical and viral carcinogens was analyzed. Resulting data support the idea that carcinogenesis is carried out by means of somatic mutations. We conclude that internal and external factors are involved in the malignization process and that the approach to the cancer problem might depend upon future advances in molecular genetics and biology.