New Treatments for Pancreatic Cancer
Pancreatic cancer accounts for approximately 27,000 deaths per year in the United States and 50,000 deaths per year in Europe (excluding the former USSR). Only 1% to 4% of patients with adenocarcinoma of the pancreas will be alive 5 years after diagnosis. Thus, incidence rates are virtually identical to mortality rates. In the United States in 1995, pancreatic cancer was be the fifth leading cause of adult deaths from cancer (after lung, colorectal, breast, and prostate cancers) and was responsible for close to 5% of all cancer-related deaths.
The incidence of pancreatic cancer declined slightly from 1973 to 1991, with 26,300 new cases (2% of all cancer diagnoses) estimated in 2006. Studies evaluating this trend suggest that the decreased incidence is due to a steady decline in the rate for white men, which peaked during the period 1970 to 1974. By contrast, rates for white women, black men, and black women have not fallen. In Japan, the incidence of cancer of the pancreas has increased sharply from 1.8/100,000 in 1960 to 5.3 in 100,000 in 1985. Overall, incidence in mortality statistics are very similar for the United States and Western Europe. Between 1989 and 1991, mortality rates for pancreatic cancer in the United States were 10 in 100,000 for men, and 7.2 in 100,000 for women. Although overall mortality rates in industrialized societies appear similar, geographically and ethnically dissimilar populations show considerable differences in mortality rates from pancreatic cancer.
The risk of developing pancreatic cancer is low in the first three to four decades of life but increases sharply after age 50, with most patients between ages 65 and 80 at diagnosis. The male to female ratio has ranged from 1.7:1.0 in older series to 1.3:1.0 in a more contemporary series. Historically, the male to female ratio was reported to decrease with age; however, this trend was not observed in a recent series from Memorial Sloan-Kettering Cancer Center. Interestingly, in several animal models of pancreatic cancer, tumors are more reproducibly induced in male animals.
Racial differences in mortality rates for pancreatic cancer have also been observed. Pancreatic cancer mortality rates for American blacks are higher than for any other ethnic group in the United States and are considerably higher than the rates observed for African blacks, suggesting an environmental contribution to this increased risk.
These broad epidemiologic categories do little to identify persons at high risk for pancreatic cancer. To define high-risk groups, we must consider the contribution of specific etiologic factors.