Possible existence of predisposing factors in the etiology of selected cancers of nonsexual sites in females. A preliminary inquiry
✍ Scribed by Abraham M. Lilienfeld
- Publisher
- John Wiley and Sons
- Year
- 1956
- Tongue
- English
- Weight
- 892 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0008-543X
No coin nor oath required. For personal study only.
✦ Synopsis
UE of the well-substantiated epidemiologi-0 cal facts concerning cancer is the variation in the sex distribution of cancers of different sites. This is illustrated in Table in which there is presented the ratio of male to female age-adjusted-incidence rates of reported cancers of nonsexual sites for New York State (exclusive of New York City) for the period 1949 to 1951. From this we note that the incidence of cancers of the lip, larynx, lung and bronchus, tongue, and pharynx is higher in males than in iemales, whereas cancers of the gastrointestinal tract, although slightly more prevalent in males, are almost equally distributed between the two sexes. Cancers of two sites, the thyroid and the biliary passages, have an increased incidence in the female, as indicated by the low male: female ratio.
In attempting to interpret these differences in incidence between the two sexes, three hypotheses may be entertained. One hypothesis states that the difference is the result of increased exposure of the male to exogenous carcinogens; this may be called the environmental hypothesis. O n the other hand, the differences may be explained on the basis of increased predisposition of males, with exposure remaining the same for both sexes; this may be called the endogenous hypothesis. A third hypothesis is conceivable in that both factors-increased exposure and increased predisposition-may be involved, and the cancer is the result of the interaction of both sets of factors.
T h e prevailing opinion today favors the first hypothesis, because certain environmental agents, such as cigarette smoking and occupational factors, have been found to be associated with some of these cancers. Although