Risk Factors for Developing Cancer Traced Back to Adolescence in New Study

Weight, immigration and socioeconomic factors during adolescence may influence a person's cancer risk later on in life, according to a study by researchers from the Rabin Medical Center.

Led by Dr. Zohar Levi, the researchers measured the body mass index of one million Israeli adolescent males who underwent a general health examination at an average age of 17 years from 1967 and 2005. Using the nation's cancer registry, they were then able to identify those who went on to develop cancer. In all, participants were followed from 2.5 to nearly 40 years, with an average follow-up of just under 19 years.

According to the results published in the journal CANCER, adolescents who were overweight more than doubled their risk of developing esophageal cancer, while those of a low socioeconomic status saw a 2.2-fold increase in their risk of developing intestinal type gastric cancer. Individuals with nine or less years of education exhibited a 1.9-fold increased risk of developing the same disease. Finally, immigrants born in Asian and former USSR countries saw a three-fold and 2.28-fold increase in gastric cancer, respectively.

The results, Levi argues, suggest that risk factors for cancer begin earlier in life than is often discussed.

"Adolescents who are overweight and obese are prone to esophageal 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," Levi said. "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."

The researcher noted that whether losing weight or increasing one's socioeconomic status later in life reduced the risks observed in the study is unclear.