Colorectal cancer rates rising in younger adults
A new study of recent trends in colorectal cancer in the United States confirms that rates among those under the age of 50 years are rising. The findings also reveal that diagnoses of colorectal cancer in younger adults are more likely to be of advanced disease.
Previous investigations have shown that rates of colorectal cancer in the under 50s have risen since the 1970s.
For their study, Dr. Boone Goodgame, an assistant professor in the departments of internal medicine and oncology at the University of Texas at Austin, and his colleagues focused on more recent trends.
Using data from the National Cancer Database registry, they found that 12.2% of colorectal cancer diagnoses in the U.S. in 2015 were in people under the age of 50 years compared with 10% in 2004.
The team also found that the percentage of colorectal cancer diagnoses in younger individuals went up in urban but not rural regions.
In addition, doctors detected signs of advanced disease in more than half (51.6%) of colorectal cancer diagnoses in younger adults compared with 40% in the over 50s.
Colorectal cancer diagnoses in younger adults increased at the same rate across all income levels. However, the highest percentage of diagnoses was among the highest earners.
The team reports the study findings in a recent Cancer journal paper.
"Several studies have shown that the rates of colorectal cancer in younger adults have risen slowly in the U.S. since the 1970s," says Dr. Goodgame, who was senior author of the study.
"[B]ut, for practicing physicians, it feels like we are seeing more and more young people with colorectal cancer now than we were even 10 years ago," he adds.
Deaths to colorectal cancer have been falling
Colorectal cancer develops when cells in the colon or rectum grow out of control and form a mass, or tumor.
Often, the cancer starts as a polyp, or small growth, on the innermost layer of the wall of the colon or rectum.
Most polyps do not become cancerous, but those that do can take years to reach that stage.
If cancer does develop in a polyp, it can grow and invade other layers of the colon or rectum wall. From there, cancer cells can break away and travel through blood or lymph vessels to other parts of the body and set up secondary tumors.
The vast majority of colorectal cancers are of the adenocarcinoma type. These begin in the cells that make the lubricant, or mucus, that covers the lining of the colon and rectum.
Not counting cancers of the skin, of the cancers that doctors diagnose in both women and men in the U.S., colorectal cancer is the third most common, according to the American Cancer Society (ACS).
In 2019, the ACS estimate that 145,600 people in the U.S. will find out that they have colorectal cancer, and 51,020 will die of the disease.
Rates of death from colorectal cancer in the U.S. have been falling in both women and men for dozens of years. Today, there are more than 1 million people living in the U.S. who have survived colorectal cancer.
