Cancer by Inheritance The University of Chicago’s remarkable Professor Maud Slye last week did two remarkable things: 1) She autopsied her 119,185th mouse. 2) She published in the American Journal of Cancer strong evidence that susceptibility to cancer is inheritable. But the susceptibility can be bred out of a family by judicious marriage. Like light hair, it is a genetically recessive characteristic, whereas resistance to cancer is like dark hair, a dominant characteristic. Susceptibility alone probably is not enough to insure a person’s developing a cancer. There must also be an external factor (a bruise, for example) reacting with an internal factor (chronic irritation of the stomach, for example). Breeding mice, caring for them until they died of age or disease, and then cutting them open for microscopic study led Professor Slye to these conclusions. She started raising mice when she was a tiny child but her actual work began in 1908 when she was 29 and had six precious dollars to spend for six imported grey & white spotted Japanese mice. She intended to study their general genetic behavior. But when she crossed them with colored mice which she bought from the late Abby Lathrop, famed mouse fancier of Granby, Mass., and discovered cancer in a progeny. Professor Slye at once began to concentrate on the inheritance of cancer. Her laboratory now is a three-story, greystone house, at the west border of the University of Chicago campus, at No. 5825 Drexel Boulevard. Down at the corner is the new Lying-In Hospital. Across the street at No. 5822 is a smaller greystone house on the first floor of which she lives with her sister Katherine Alden and her jolly assistant, Edith Farrar, who speaks with a strong Southern accent and is very fond of The Nation. You can tell that there are mice inside when you stand on the front stoop of No. 5825 Drexel Boulevard. But you get used to the smell. Everything is very clean. In immaculate white linen dress Dr. Slye sits behind a rolltop steel desk littered with papers. Dolly, her fat bull terrier bitch (currently ill), wanders in & out. In the next room and upstairs and downstairs are rows and rows of small cages, piled one on top of the other, looking something like beehives. In them are 10,000 mice. Each mouse has a history. Cancerous mice, ranging anywhere from 50 to 100, are kept in separate cages. There are six dieners (helpers), Miss Farrar and Dr. Slye. Professor Slye has mice unto the 100th generation, which she says permits her to make observations that will let her make human comparisons over 3.000 years. She has all kinds of mice—albinos, red mice, Japanese dancing mice, etc., etc. And she can make any sort of mice to order—mice that will live three years (average age: six months), mice that will be obese and mice that will be lean, mice of any color.
Professor Slye’s pet idea for some time has been the organization of a central bureau where all human cancer cases would be registered so that studies could be made of the cases and histories be formed of all of them for better breeding of future generations. That is, do with humans what she has done with mice. She has tried to get the American College of Surgeons to keep the records in their plant, but so far she has not been successful. She calls genetics the “last outpost of science,” thinks some day people will pay the attention to their own breeding that they do now to their cows and horses and dogs.
After demonstrating that susceptibility to cancer can be inherited, Professor Slye turned her attention to the specific causes of the rise of cancer in susceptible people. She says cancer is not so much a disease as it is a growth-process. She points out that whereas the highest number of human cancers occur in the digestive tract below the esophagus, the same does not hold true for beasts. Of all the mouse autopsies she has performed, about 15,000 were cancerous mice, but only about 25 had intestinal tumors. The difference probably lies in the diet. For long years her mice received the same diet (mostly fresh bread, twice-pasteurized whole milk, timothy hay and bird seed). Thus most of their cancers came from irritations, cage-rubbing, fights, minor infections. This does not disprove her heredity theory, for the cancers occur only in the susceptible animals. Lately she has been working on mice fed diets comparable to the varied diets of human beings to see if she can increase the incidence of intestinal tumors. If so, she hopes to prove that some elements of human diet, such as heat, alcohol and condiments (never present in animal diets), are external hazards which cause cancer in susceptible humans. She says cancer can be bred out of humans in two generations. Two individuals, both of them entirely resistant to cancer, will breed children also free from cancer. An individual susceptible to the disease, when bred to a resistant, will have exempt children. But, because one parent was a potential cancer subject, the children although themselves exempt can transmit it to their offspring—if they mate with susceptible persons. On the other hand, should they marry cancer-resistant persons, results of such unions will also be exempt. But before you can do any of this with any degree of assurance you first must have histories of the families’ antecedents— what Professor Slye is fighting for—and you must make genetics romantic.
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