What We Don’t Know: The cause of new cancer cases.
The American Cancer Society found increases in the incidences of many cancers, including cancers of the breast, the prostate, the uterus, the oral cavity, the liver (in women but not men), the kidney, and the colon and rectum in middle-aged adults. Melanoma incidence also increased. The numbers were adjusted for changes in the size of the population.
Dr. William Dahut, chief scientific officer of the cancer society, said that while the overall rate of colorectal cancer had continued to decline, he was concerned about an increase in one group: people under age 55. In those younger people, the society reports, the incidence is now 18.5 per 100,000 and has been rising by 1 percent to 2 percent a year since the mid-1990s, with 30,500 people expected to be diagnosed this year.
In the late 1990s, colorectal cancer was the fourth leading cause of death for people younger than 50. Now it is the leading cause in men under 50 and the second leading cause in women. Doctors cannot say why.
“We don’t have a good explanation,” Dr. Dahut said. “We do a lot of hand waving. Is it diet? Is it obesity? Is it something in the environment? Is it in utero exposure?”
But colorectal cancer remains overwhelmingly a cancer of older people — among whom, in those over age 65, it has been declining by 3 percent a year, the cancer society says. Its incidence is now 155.4 per 100,000, with 87,500 people expected to be diagnosed this year.
Kaynak: briturkish.com
