Trends in cancer incidence among adults under age 50 in the United States from 1975-2003. Free

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Background Although the overall death rates from cancer (CA) are on the decline, CA remains to be the second leading cause of death among both men and women in the U.S. Based on the American Cancer Society (ACS) 2006 estimates, the leading sites of CA deaths among men are lung, colo-rectal, prostate, and pancreatic CA. Among women, lung CA also is estimated to be the leading cause of death, followed by breast, colo-rectal, and pancreatic CA. Moreover, prostate, lung, and colorectal CAs are estimated to account for the largest number of new CA cases in men; while breast, lung and colorectal CA are the highest incident CAs in women. While pancreatic CA accounts for only 2% of new cases among both men and women, it remains to be one of the four leading causes of CA deaths in the US. Overall, CA incidence rates appear to be steady or declining in both sexes and for all ages combined. Very few studies have examined trends of the leading and most lethal CAs among younger age categories. Trends analyses (TAs) are a useful indicator for monitoring changes in CA incidence over time. Aims The purpose of this abstract is to examine age and gender trends among these leading lethal CAs from 1975-2003 in order to identify potential trend changes, variations, or disparities over time in younger age categories and possible reasons for these changes. Methods The Epidemiology and Genetics Research Program (EGRP) of the National Cancer Institute (NCI) in collaboration with the Surveillance and Epidemiology End Results (SEER) Program have performed preliminary TAs for incidence rates of malignant cases of breast, colorectal, lung, pancreas and prostate CA in individuals less than 50 years of age. Annual percent changes (APCs) were calculated for incidence rates in 5 year age group from 1975-2003 (www.seer.cancer.gov; SEER*Stat database). Further TAs by CA type, age group, and gender will be performed to identify possible variations in trends among these lethal CAs. Results Preliminary TAs of the SEER data shows an overall increase in incidence in men under age 50 for colorectal and prostate CA from1975-2003. Women under age 50 show increased incidence of pancreatic CA in recent years (1999-2003). This age group of women also exhibits an overall increased incidence of breast CA (1975-2003); however, rates show a significant decline from 1994-2003. The overall lung CA incidence for both men and women under 50 is on the decline; yet incidence rates appear to be rising for younger women from 1999-2003. More specific results of the TAs by age categories will be reported. Conclusions TAs are a useful indicator for monitoring cancer direction and changes. Many factors can be assessed in association with such trends that may be useful for monitoring rise of some CAs among certain age or gender groups and hence necessitate future research to identify such issues. These may include advances in screening, major prevention efforts, and observations of perceived birth cohort risk.