Studies Address Issues of Risk and Survival in Rapidly Increasing Gastrointestingal Cancers
Studies published today by the American Gastroenterological Association shed new light on risk factors and predictors of survival associated with two types of cancer that are among the most rapidly increasing in the Western world - esophageal and stomach cancer.
Women, Overweight Survive Longer with Esophageal and Stomach Cancer, Researchers Say (Demographic and Lifestyle Predictors of Survival in Patients with Esophageal or Gastric Cancers, Trivers et al.)
In the journal Clinical Gastroenterology and Hepatology, researchers from the University of North Carolina at Chapel Hill publish findings of a population-based, case-control study of 1,142 patients diagnosed with esophageal or gastric cancer. After seven years of follow up, survival rates for both cancers were low - between 12 and 20 percent. However, three factors increased the likelihood of survival:
· Those who were overweight before diagnosis (BMI 25-30 kg/m2) had an approximately 30 percent lower risk of death compared to normal and underweight patients.
· Patients with moderate to high incomes (= $15,000 per year) had an up to 38 percent lower risk of death compared to low-income patients (< $15,000 per year).
· Women survived longer than men.
“Unfortunately, some of the characteristics associated with survival in this study are not easily modifiable, but we hope the findings will give patients more information about the possible course of their cancer,” said lead study author Katrina F. Trivers, MSPH. “A better understanding of what can increase survival could help uncover preventive strategies.”
While researchers are not currently able to pinpoint the underlying reasons for the study’s results, they are certain the results are not attributed to traditional prognostic factors such as tumor stage or grade. In addition, age, education, cigarette smoking, alcohol intake, gastroesophageal reflux disease (GERD) and non-steroidal anti-inflammatory drug use were not predictors of survival.
Researchers: Premature Birth Significantly Increases Risk of Esophageal Cancer
(Preterm Birth, Low Birth Weight and Risk for Esophageal Adenocarcinoma, Kaijser et al.)
In the journal Gastroenterology, researchers from the Karolinska Institutet in Stockholm, Sweden publish findings illustrating that premature birth is associated with an up to 11-fold increase in the relative risk of esophageal adenocarcinoma. This is the first study linking prenatal factors to the risk of developing esophageal cancer decades later.
“Gastroesophageal reflux disease is potentially the connection between premature birth and esophageal adenocarcinoma. GERD is one of the few established risk factors for esophageal cancer, and is quite common among infants born prematurely or with low birth weight,” noted lead study author Magnus Kaijser, MD.
After following more than 3,000 individuals for more than 40 years, researchers found that low birth weight (less than 4.4 lbs.) significantly increases the risk for esophageal adenocarcinoma. The study also found birth before 35 weeks of gestation was associated with a more than six-fold increase in risk.
Researchers emphasize that the study findings are based on small numbers and not cause for alarm, but illustrate the need for further research to confirm or refute the link between prenatal exposures and esophageal cancer. The time window of interest for research on esophageal cancer must be broadened, since this study suggests that the disease may be initiated far earlier than previously known.
Esophageal cancer is three to four times more common among men than women and about 50 percent more common among African Americans than among whites. Because esophageal cancer is usually diagnosed at a late stage, most people with the disease eventually die. According to the American Cancer Society, 14,520 people will be diagnosed with esophageal cancer in the United States in 2005 and 13,570 will die from the disease.
At one time, stomach cancer was the leading cause of cancer deaths in the United States. Over the last few decades, the incidence has declined, partially due to increased use of refrigeration and antibiotics to treat childhood infections. Only 22 percent of patients with stomach cancer are diagnosed at an early enough stage to bring about significant survival benefit. In 2005, approximately 21,860 people will be diagnosed with stomach cancer and 11,550 are expected to die from the disease.
SOURCE: American Gastroenterological Association
Revision date: July 4, 2011
Last revised: by Andrew G. Epstein, M.D.