ABSTRACT
Oral cancer accounts for about 3 to 5% of all cancers in most of the western countries, a sharp contrast with the 40% frequency rate of oral cancer in some parts of India. As J. J. Pindborg pointed out, comparisons between various population groups are difficult and frequently misleading. The 40% figure for the relative frequency of oral cancer in some areas of India was derived from data obtained in cancer hospitals and through cancer departments of teaching and research institutions. A special interest in the carcinogenic hydrocarbons was aroused when one of the most active polycyclic hydrocarbons, 20-methylcholanthrene, was synthesized from bile acids. Because the structural resemblance among the carcinogenic hydrocarbons to cholesterol, bile acids, and steroid hormones was so obvious, hopes were high that a common molecular structure, one that was elaborated by the body, would clarify the cancer problem.
