A report published by the American Cancer Society in January suggests that rates of colorectal cancer are rising rapidly among people in their 20s, 30s and 40s — even as incidence is declining in people over the age of 65.
“It’s unfortunately becoming a bigger problem every year,” said Dr. Michael Cecchini, a co-director of the colorectal program in the Center for Gastrointestinal Cancers and a medical oncologist at Yale Cancer Center.He added that early-onset colorectal cancers have been increasing by about 2% per year since the mid-1990s. This increase has moved colorectal cancer up to being the top cause of cancer deaths in men under the age of 50 and the second-leading cause of cancer deaths in women under 50 in the United States.
Colon and rectal cancers share many similarities and are typically lumped into one category, called colorectal cancer. Studies, however, show that the increase in diagnoses is mainly driven by a rise in rectal cancers and cancers found in the left, or distal, side of the colon, near the rectum. “That maybe provides an important clue for understanding what might be going on,” said Caitlin Murphy, an associate professor and cancer researcher at UTHealth Houston.
When cancer is found at a younger-than-usual age, doctors usually suspect that genetic mutations may be to blame. And some molecular studies suggest that tumors in early-onset colorectal cancers do have different mutations driving the cancer compared with tumors in older adults. Another piece of evidence that there is a genetic component: It is clear that having a first-degree relative who had colorectal cancer — or even a precancerous polyp — can increase your risk, Cecchini said. But genetic changes do not explain the full picture, he said.
Some research has linked lifestyle and dietary changes to increased rates of colorectal cancer in both young people and older adults.
Experts are beginning to investigate if there are other environmental drivers of early-onset cancer. For instance, some small studies have hinted at the idea that people who develop colorectal cancer at an early age have an imbalance of “good” and “bad” bacteria in their gut.
Some experts believe exposure to toxic chemicals in the environment may also be to blame.
“It’s unfortunately becoming a bigger problem every year,” said Dr. Michael Cecchini, a co-director of the colorectal program in the Center for Gastrointestinal Cancers and a medical oncologist at Yale Cancer Center.He added that early-onset colorectal cancers have been increasing by about 2% per year since the mid-1990s. This increase has moved colorectal cancer up to being the top cause of cancer deaths in men under the age of 50 and the second-leading cause of cancer deaths in women under 50 in the United States.
Colon and rectal cancers share many similarities and are typically lumped into one category, called colorectal cancer. Studies, however, show that the increase in diagnoses is mainly driven by a rise in rectal cancers and cancers found in the left, or distal, side of the colon, near the rectum. “That maybe provides an important clue for understanding what might be going on,” said Caitlin Murphy, an associate professor and cancer researcher at UTHealth Houston.
When cancer is found at a younger-than-usual age, doctors usually suspect that genetic mutations may be to blame. And some molecular studies suggest that tumors in early-onset colorectal cancers do have different mutations driving the cancer compared with tumors in older adults. Another piece of evidence that there is a genetic component: It is clear that having a first-degree relative who had colorectal cancer — or even a precancerous polyp — can increase your risk, Cecchini said. But genetic changes do not explain the full picture, he said.
Some research has linked lifestyle and dietary changes to increased rates of colorectal cancer in both young people and older adults.
Experts are beginning to investigate if there are other environmental drivers of early-onset cancer. For instance, some small studies have hinted at the idea that people who develop colorectal cancer at an early age have an imbalance of “good” and “bad” bacteria in their gut.
Some experts believe exposure to toxic chemicals in the environment may also be to blame.