Overweight teens are at increased risk for developing oesophageal cancer later in life, new research says.
Oesophageal cancer occurs when a tumour develops in the tube that connects the throat with the stomach.
In addition, social and economic status, and education levels appear to be factors in the development of stomach (or "gastric") cancer, the study indicated.
The study included 1 million male teens in Israel who underwent general health checkups at an average age of 17 between 1967 and 2005. The participants were followed for between 30 months and nearly 40 years, with an average follow-up of nearly 19 years.
Overweight teens had a more than two-fold increased risk of developing oesophageal cancer later in life, while poor teens had more than twice the risk of developing intestinal-type stomach cancer, the study authors found. Teens with nine years or less of education had a nearly doubled increased risk of developing this type of cancer.
Due to reflux
The risk of stomach cancer was three times higher in teens born in Asia and more than two times higher in those born in former Soviet Union countries, according to the study published in the online edition of the journal Cancer.
"Adolescents who are overweight and obese are prone to oesophageal cancer, probably due to reflux that they have throughout their life. Also, a lower socioeconomic position as a child has a lot of impact upon incidence of gastric cancer as an adult," study author Dr Zohar Levi, of the Rabin Medical Centre in Israel, said in a journal news release.
"We look at obesity as dangerous from cardiovascular aspects at ages 40 and over, but here we can see that it has effects much earlier," he added.
While the study found links between child obesity, socioeconomic status and education levels in male teens with later cancer diagnosis, it did not prove cause and effect.
It is unclear whether losing weight later in life or achieving a higher social or economic status might reduce the increased risk of developing these types of cancer, Levi said.
The American Academy of Family Physicians has more about stomach cancer.