BOSTONIn a prospective case-control study, individuals in the lowest quartile of circulating insulin-like growth factor binding protein -1 (IGFBP-1) had a twofold greater risk of developing pancreatic cancer than those in the three highest quartiles, lead author Brian Wolpin, MD, of Dana-Farber Cancer Institute, and his colleagues reported in Cancer Research (67:7923-7928, 2007).
"The levels of insulin and insulin-like growth factor (IGF) are modified by obesity and sedentary lifestyle, and there is evidence that these hormones may stimulate the growth of pancreatic cancer cells," Dr. Wolpin said. "When IGF binds to proteins like IGFBP-1, there may be less IGF available to bind to pancreatic cancer cells and promote their growth."
The investigators collected blood samples from 573 participants in four large ongoing health studies: the Health Professionals Follow-up Study, the Nurses' Health Study, the Physicians' Health Study, and the Women's Health Initiative. Four or more years later, they checked IGFBP-1 levels in the 144 people who developed pancreatic cancer and the 429 matched controls.
After adjusting for other risk factors, only participants in the lowest quartile of plasma IGFBP-1 had an elevated risk of pancreatic cancer (RR 2.07). The influence of low IGFBP-1 became progressively stronger with time, with an adjusted RR of 3.47 for those diagnosed 8 or more years after blood collection, and was most marked among the never-smokers.