Report: Deaths From Pancreatic Cancer Rise, Fall Along Racial Lines
Trends among whites and African-Americans go in opposite directions (November 12)
Pancreatic cancer death rates in whites and African-Americans have gone in opposite directions over the past several decades in the U.S., with the direction reversing in each ethnicity during those years. The finding comes from a new study by researchers at the American Cancer Society (ACS), who say the rising and falling rates are largely unexplainable by known risk factors.
The study was published online in the Journal of the National Cancer Institute.
To better understand the causes and risk factors for pancreatic cancer, the researchers examined long-term disease trends in pancreatic cancer death rates in the U.S. between 1970 and 2009. They found that, in white men, pancreatic cancer death rates decreased by 0.7% per year from 1970 to 1995, and then reversed, increasing by 0.4% per year through 2009 (the latest year for which data were available). Among white women, rates increased slightly from 1970 to 1984, stabilized until the late 1990s, and then increased by 0.5% per year through 2009.
In contrast, death rates among African-Americans increased between 1970 and the late 1980s (women) or early 1990s (men), after which they began to decrease. However, death rates continued to be substantially higher in African-Americans than in whites in both men and women.
The authors say the difference in mortality trends between African-Americans and whites is not fully explained by differences in patterns of smoking — widely recognized as the main contributor to decreases in pancreatic cancer death rates. The prevalence of smoking has decreased in both African-Americans and whites since 1965. The authors surmise that other factors may have modified the effects of smoking on pancreatic cancer, and say further studies on the mechanisms by which smoking causes pancreatic cancer are warranted.
While obesity has been linked with a 20% increased risk of death from pancreatic cancer, the lack of an increase in pancreatic cancer mortality rates in African-Americans, among whom obesity is more prevalent, would make obesity alone an unlikely culprit.
The authors say the decreasing mortality trend in African-Americans over the past 10 to 15 years is particularly interesting, as the factors that are likely contributing to recent increases in pancreatic cancer deaths in whites (e.g., obesity, diabetes, and improved diagnosis) have also increased in African-Americans.
Source: ACS; November 12, 2013.