The study released by the American Cancer Society found that the risk for colorectal, endometrial, pancreatic, kidney, bone marrow and gallbladder cancer showed startling increases among younger adults age 24-49.
"The risk of cancer is increasing in young adults for half of the obesity-related cancers with the increase steeper in progressively younger ages," said co-author Ahmedin Jemal, who is the Vice President of the Surveillance and Health Services Research Program for the American Cancer Society.
The study found that the most significant increases in the millennial age bracket are coming at a time when overall cancer is decreasing in men and stabilizing in women in the U.S., according to Jemal.
For example, the average annual increase for pancreatic cancer was more than four percent for patients ranging in age from 25-29, but less than one percent for those age 40-44. The study found that overall the risk of colorectal, endometrial, pancreatic and gallbladder cancers in millennials was about double the rate that baby boomers had at the same age.
Most of these cancers have traditionally shown up in patients later in life- usually in their 60s and 70s.
MD Anderson Cancer Center's Dr. George Chang, who was not associated with the analysis, warns against overgeneralizing on the basis of an epidemiological study. "The study was not set up to establish causation," Chang said. "We know there are many factors that are associated with both obesity and cancer, such as lack of exercise and poor diet. How much each of those factors contributes to cancer is less clear."