Early onset cancers defined as cancers discovered in adults younger than 50 years old, have "dramatically increased" around the world over the last few decades, according to a new report by researchers at Boston's Brigham and Women's Hospital.
Researchers said breast, colon, esophagus, kidney, liver, and pancreas cancers among others have shown a drastic rise beginning in the 1990s.
"From our data, we observed something called the birth cohort effect. This effect shows that each successive group of people born at a later time (e.g., decade-later) have a higher risk of developing cancer later in life, likely due to risk factors they were exposed to at a young age," Shuji Ogino, MD, Ph.D., professor and physician-scientist, said in the report, suggesting increasing risk with each generation.
According to Brigham and Women's Hospital's report, exposures from conception to when someone's 19 years old play a role in cancer diagnoses before a person turns 50.
The study found that rising incidence is partially attributable to early screenings for some of these cancers, however, early life exposures such as people's diet, weight, lifestyle, environmental exposure, and microbiome may factor into what's contributing to early-onset cancer, but more information on individual exposures is needed, according to the report.
"Even in-utero exposures can lead to cellular reprogramming, including epigenetic alterations, that might have long-lasting effects on susceptibility to chronic diseases," researchers wrote.
Factors such as alcohol consumption increases the risk of cancers, the report found. Between the 1960s to early 2010s, alcohol consumption increased in many countries.
Another study from April found that moderate alcohol consumption has increased the risk of cancer in women.
"We're finding that probably anywhere between 5% to 10% of all cancers worldwide are due to alcohol use," Dr. Suneel Kamath, a GI clinical oncologist at Cleveland Clinic Cancer Center, told "Good Morning America" in April.
An American Cancer Society report from January found that almost 2 million new cancer cases are expected to be diagnosed in the U.S. this year, with over 600,000 Americans dying from cancer in 2022.
ABC News' Mary Kekatos contributed to this report.