139th National Cancer Advisory Board
Colorectal cancer trends may be temporally affected by an increase in colorectal screening, as seen, for instance, when President Reagan had his colon cancer diagnosed. National figures appear to be influenced by the number of organizations that encourage and promote utilization of screening for colorectal cancer. Both the incidence and mortality rates in colorectal cancer have been dropping for men and women.
Regarding thyroid cancer, there has been a long-term increase in incidence since 1980 for most groups. Some researchers suggest that this possibly is a diagnostic artifact of small papillary tumors based on the use of ultrasound and fine needle aspirates. Moreover, diagnostic scrutiny is associated with more prevalent thyroid disease in women. Finally, environmental factors, such as radiation exposures from nuclear weapons testing and accidents, radiotherapy, and diagnostic exposures, may be additional causes.
For Latinos, cancer incidence trends (1999-2003) are lower than non-Hispanic whites for most cancers; reveal that Latinos are less likely to be diagnosed with localized stage for cancers of the lung, colon and rectum, prostate, female breast, and cervix; and have higher incidence rates for myeloma (female) and cancers of the stomach, liver, and cervix than non-Latino white populations. Among minority populations, Asian Pacific Islanders show the highest incidence and mortality for liver cancer, whereas the black population has the highest mortality for stomach cancer. In addition, the incidence and mortality trends for kidney and renal cancers are on the rise for most populations. The black population has the highest incidence and mortality rate for pancreatic cancer.
Dr. Edwards next explained the rank ordering of cancer sites among the Latino population, compared with the non-Latino white population. Many of the top 10 cancer sites for Latino men, for instance, are the same as non-Latino white men, except that stomach and liver are included in Latino men, and melanoma of skin is included in the top cancers for non-Latino white men (and women). Additionally, although the cancer sites for both populations may be similar, the overall age-adjusted incidence rates are typically lower in the Latino population. Similar patterns are seen in women. Cervical cancer, which also is high among black women, is in the top 10 list of cancers for Latinas. Mortality for cervical cancer is highest, however, among the African American women.
The report also describes incidence rate by county-level poverty measurement for Latino and non-Latino white men and women. Dr. Edwards showed charts reflecting the attempt to evaluate social and economic factors that might be associated with differences in cancer rates. Groups were created based on the general poverty or affluence levels of resident counties, such as less than 10 percent or more than 20 percent of that population is in poverty; the most affluent would be less than 10 percent, and the least affluent would be more than 20 percent. For men, there is a small relationship for prostate cancer, with higher rates among men who may live in more affluent populations, whereas for lung and bronchus the non-Latino white population living in the more affluent populations have the lowest lung cancer rates and the least affluent having higher rates. There is not much gradient seen among the Latino male population. Latina women who reside in more affluent areas have a greater gradient for lung cancer. For breast cancer, both Latina and non-Latina white women from more affluent areas have higher breast cancer rates. Cervical cancer, however, is more prevalent among women from less affluent areas for Latina and non-Latina white women.
In conclusion, research findings regarding the Latino population, in which more than 90 percent of that population in the United States are covered, point to lower cancer rates, including lung, colorectal, breast, and prostate. A number of sites, however, such as myeloma in women, are higher. Dr. Edwards explained that efforts will continue to be focused on interpreting health disparities; the NCI currently is