NEW YORK (Reuters Health) - Individuals who are overweight in early adulthood have an increased risk of pancreatic cancer, while obesity in older age is associated with lower survival rates among patients with this difficult to treat malignancy, new research shows.
Being overweight or obese at younger age had a stronger association with pancreatic cancer risk than did subsequent weight gain at an older age, lead author Dr. Donghui Li, from M. D. Anderson Cancer Center, Houston, told Reuters Health.
“The second major finding,” Dr. Li added, “was that individuals who were overweight or obese from the ages of 20 to 49 years had an earlier onset of pancreatic cancer by 2 to 6 years.”
The findings, reported in the Journal of the American Medical Association for June 24, stem from a case-control study of 841 patients with pancreatic adenocarcinoma and a control group of 754 healthy subjects without cancer who were matched to the patients by age, race, and gender. Height and weight histories were obtained during personal interviews.
Subjects who were overweight from the ages of 14 to 39 years or obese from 20 to 49 years had a 1.67- and 2.58-fold higher risk of pancreatic cancer, respectively. The risk leveled off for those who were overweight or obese after age 40 and became statistically insignificant after age 50.
The link between elevated body mass index (BMI), a frequently used weight to height ratio, and pancreatic cancer was stronger in men than in women and in current or former smokers than in those who never smoked, the report indicates.
The researchers also found that obesity at an older age had its own disadvantages - it was tied to reduced survival of pancreatic cancer. The average length of survival in this population was 18 months for those with a normal body weight the year before pancreatic cancer diagnosis, while the average survival time declined to 13 months for overweight and obese patients, Li said.
In a related editorial, Dr. Robert R. McWilliams and Dr. Gloria M. Petersen, from the Mayo Clinic, Rochester, Minnesota, note that increased weight or obesity is associated with acceleration of the disease process — from the risk of developing cancer to its ultimate outcome - and “may provide biological insight into why pancreatic cancer portends such a poor prognosis.”
This study, they add, “represents an incremental advance in the understanding of clinical factors contributing to pancreatic cancer development and progression.”
SOURCE: Journal of the American Medical Association, June 24, 2009.