Abstract
The authors attempted to show that certain families in the general population show a profound paucity of cancer. Furthermore they demonstrated that a sizeable proportion of the normal population (approximately 46%) show an absence of cancer amongst first degree relatives, while a minority of the population (approximately 7%) are cancer prone, as evidenced by 3 or more occurrences of cancer in first degree relatives. These findings have implications for research in carcinogenesis, in that it may be as important to know why certain members of the population are at reduced risk for cancer as it is to know why those in the population are remarkably cancer prone. Cancer control implications also exist in that an important risk factor to be considered in any cancer control program is family history. This even applies to other obvious risk factors such as cigarette smoking, wherein it is well known that family history of lung cancer significantly increases the likelihood of the cigarette smoker developing lung cancer. Finally, these studies indicate a wide range of cancer susceptibility in humans, a phenomenon that is a function of both genetic and non genetic factors, and which is very similar to findings observed at the infrahuman level.