Alaska Natives are twice as likely to get colon cancer and die from the disease than the white population in the United States. When Mayo Clinic doctor took a trip to in the mid-1990’s that startling statistic caught his attention.
鈥淗ere they had one of the world’s highest rates of colon cancer and one of the world’s poorest outcomes in terms of survival from cancer – because of late diagnosis,” Ahlquist said.
The best way to prevent colon cancer is through screening, but Ahlquist realized that approach has flaws in rural Alaska. Colonoscopy equipment isn’t available in remote Native villages. A widely-used test that detects blood in stool isn’t effective because many Alaska Natives have a stomach bacteria called that also causes bleeding. 聽The colon cancer screening rate for Alaska Natives in some rural areas of the state is as low as 23 percent. In urban areas, it鈥檚 closer to 60 percent.
So Ahlquist began working on a test that can identify several altered genes that are present in colon cancer.
鈥淚t measures DNA changes that are shed from the surface of cancer or pre cancer into the stool and we can detect those changes that act as a signature as the presence of cancer or polyps,” he explains.
The test is expected to cost about $300, far less than the average colonoscopy in Alaska. Ahlquist compares his research to the advent of the pap smear.
鈥淭he pap smear took a target, cervical cancer, which at that time, in the ’50’s was the number one cancer killer in women in the United States. Now, it鈥檚 essentially been eradicated in women who are screened,” Ahlquist said.
According to published this year, the DNA colon cancer test finds 85 percent of colon cancers and . Ahlquist and the Mayo Clinic are working with a company called to commercially develop the test, and both will benefit financially if it comes on the market.
, at the Huntsman Cancer Institute in Utah, has high hopes, too.聽 鈥淚n the end, it could be a huge game changer.”
But Burt thinks it has to get better at detecting pre-cancerous polyps.
鈥淚s it enough to replace colonoscopies so we only do colonscopies on people with a positive stool test? Probably not yet. But it’s getting there,鈥 he says.
of the Fred Hutchinson Cancer Research Center in Seattle agrees that with more rigorous study, these tests could change cancer diagnosis and treatment.聽 He is working on another version of a DNA-based stool test for colon cancer detection. 聽聽DNA tests are also in the works for a long list of cancers including, lung, pancreatic and brain cancer.
鈥淚t鈥檚 very exciting, I think we’re going to really see a revolution in the way we take care of patients who have cancer.鈥
In Alaska, the Alaska Native Tribal Health Consortium began a three year trial of Ahlquist鈥檚 colon cancer DNA test. A hundred patients have enrolled.
If the FDA grants approval, the test could be available as soon as the middle of next year.
This story is part of a reporting partnership that includes , and Kaiser Health News.
