By Cole Petrochko, Staff Writer, MedPage Today
Israelis who were overweight as teenagers were more likely to have esophageal or gastroesophageal junction cancers later in life, researchers reported.
In a 1 million man cohort, teen overweight significantly increased the risk for esophageal or gastroesophageal junction adenocarcinoma (HR 2.1, 95% CI 1.1-4.3, P=0.032), according to Zohar Levi, MD, of Rabin Medical Center in Petach Tikva, Israel, and colleagues.
There were also significant associations between low socioeconomic status (HR 2.2, 95% CI 1.0-4.8, P=0.04) and low number of years of education (HR 1.9, 95% CI 1.1-3.19, P=0.02) with intestinal-type noncardia gastric cancer, they wrote online in Cancer.
Prior research from the authors found an association between adolescent overweight and colon, pancreatic, uroepithelial, and renal cancers.
In the new study, researchers analyzed associations between esophageal adenocarcinoma, gastroesophageal junction adenocarcinoma, and noncardia gastric cancer with body mass index, country of birth, years of education, and urban versus rural housing in a cohort of over 1 million Jewish Israeli males who were a mean 17.3 years-old at baseline.
All teens were screened at Israeli recruitment centers for assessment of suitability for military service and were followed for cancer incidence until 2006.
Body mass index at or greater than the 85th percentile was considered overweight and was based off of BMI at the time of physical assessment.
Socioeconomic status was determined by city, town, or village the teen's parents lived in. Authors also recorded years of education, country of birth, and whether the participant lived in a rural or urban environment.
Cancer incidence was matched to participants through the Israel National Cancer Registry. Data in the registry included the person's personal identification number, date of diagnosis, site affected, the International Classification of Diseases code for the tumor, and the histologic description of the tumor. Only gastroesophageal cancers with a histologic report of adenocarcinoma were included in the study.
At baseline, 12.2% of participants were overweight, roughly one-quarter were from a low socioeconomic background, and 11.4% had nine or fewer years of schooling -- the lowest education level.
They were followed for a mean 18.8 years, and 182 incident cases of gastroesophageal cancers were recorded, including 52 esophageal and gastroesophageal junction adenocarcinomas and 130 noncardia gastric cancers.
"We grouped esophageal and gastroesophageal junction adenocarcinoma cases together because these cancers are often misclassified," they wrote.
Among noncardia gastric cancers, 59.2% were intestinal type and 40.8% were mucinous type.
In addition to associations between overweight and cancer incidence, the authors measured the association with BMI in those with a BMI of 30 kg/m2 or greater, which was tied to a 7.6-fold hazard ratio (95% CI 2.68-21.5, P<0.001).
Associations between low socioeconomic status and noncardia gastric cancers were more common for intestinal-type tumors (HR 2.23, 95% CI 1.03-4.80, P=0.041). There were no associations between socioeconomic status with either of the other gastroesophageal cancers in the study.
Low education was also associated with noncardia gastric cancer (HR 1.53, 95% CI 1.01-2.13, P=0.043), as was birthplace in an Asian country (HR 3.0, 95% CI 1.64-5.48, P<0.001) or former Soviet country (HR 2.68, 95% CI 1.33-5.40, P=0.006).
There were no associations between cancer and urban versus rural residence.
They noted that the study was limited by lack of information about Helicobacter pylori status, dietary intake, alcohol consumption, and tobacco use. It was also limited by lack of abdominal obesity measurement, follow-up BMI measures, or follow-up socioeconomic status measures.
Professor Zvi Laron has been awarded The 2009 Israel Prize for Medical Research, the country's highest honor, for his groundbreaking research on growth hormone activity.