Word: colon
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Dates: during 1990-1999
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...medical genetics at the University of Helsinki. "It doesn't work at all like we and others had thought." As reported in Science, the researchers estimate that 1 in 200 people carries the defective gene. Of the 95% of them who will eventually develop cancer, 60% will get colon cancer and the rest will develop a variety of other malignancies, including tumors of the uterus, stomach, pancreas or urinary tract...
Even though the researchers have not yet isolated the gene, they suspect that it represents an entirely new pathway to peril. In the past, most genes linked to cancer, including a few linked to colon cancer, have been genes that play a role in regulating cell division, in some cases stopping cell growth when DNA is damaged. When such genes are themselves deranged, genetic errors can rapidly accumulate. But the newly discovered defect is not in a damage- control gene. Instead, it seems to be a direct agent of damage that somehow unleashes wave upon wave of DNA mutations over...
This fundamental instability may help explain why patients suffering from hereditary colon cancer seem to respond better to treatment than those whose disease arises in other ways. Apparently their tumor cells are already so heavily damaged that the malignant tissue is actually more susceptible to chemotherapy and radiation than other types of cancer cells...
Just as important, the marker may lead to better screening tests. Early detection makes all the difference to colon-cancer patients. About 90% of people whose tumors are found early are still alive five years after their diagnosis. That figure plummets to less than 10% once the cancer has spread beyond the intestines. However, according to a recent study, the most widely used screening test, which detects blood in stool samples, misses more than 70% of all tumors...
Vogelstein expects that within three years there will be a better diagnostic test based on the newly discovered genetic defect. The first to benefit from such a blood test will be the 5 million to 10 million Americans who are now considered to be at an increased risk of colon cancer because of a strong family history (usually defined as having three or more relatives with the disease, one of them stricken before age 50). The test could cost $300 a family, according to Vogelstein. About three-fourths of family members will learn that they do not carry the gene...