Cancer Incidence Rates in Eddy and Lea Counties

New Mexico, 1970-1994

Stomach Cancer

Stomach cancer is the second most frequently diagnosed cancer worldwide, and in many countries is the most frequently diagnosed cancer (NCI 1993). In the US, incidence of stomach cancer is less than it used to be in the early 1900s. In 1994 in New Mexico, 112 new cases of in situ and invasive stomach cancer were diagnosed, accounting for 1.7% of all cancers (NMTR 1996).

Men are diagnosed with this cancer twice as often as women (NCI 1993). Risk factors for stomach cancer include a family history of stomach cancer; having blood type A; diets high in preserved foods, such as foods preserved with salt; cigarette smoking; exposure to ionizing radiation; exposure to certain industrial chemicals; and infection with the bacteria Helicobacter pylori.

Nationally, invasive stomach cancer incidence rates have decreased over the last two decades from 10.3 per 100,000 in 1973 to 7.3 in 1990 (NCI 1993). In New Mexico, incidence rates of invasive stomach cancer also decreased over the period of study, from approximately 11 per 100,000 in 1971 to 7 in 1993 (Figure 43), and were comparable to US rates.

Spatial Variation

Spatial variation of incidence rates for stomach cancer, for the period between 1970 and 1992, among residents of New Mexico, Eddy County, and Lea County, is presented in and Tables 38, 39 and 40.

Non-Hispanic Whites: During the period studied, the incidence rate for stomach cancer among non-Hispanic white males and females combined was 5.6 per 100,000 statewide, and ranged from a low of 0.9 in De Baca County to a high of 14.7 in Socorro County. The stomach cancer incidence rate among non-Hispanic white males in Eddy County was 9.3 per 100,000 (the seventh highest county rate among non-Hispanic white males in New Mexico), and was higher than for non-Hispanic white females (3.6).

Hispanic Whites: During the period studied, the incidence rate for stomach cancer among Hispanic white males and females combined was 14.5 per 100,000 statewide, and ranged from a low of no cases in Harding County to a high of 25.2 in Roosevelt County. The stomach cancer incidence rate among Hispanic white males in Lea County was 23.7 per 100,000 (the sixth highest county rate among Hispanic white males in New Mexico). The stomach cancer incidence rate among Hispanic white females in Eddy County was 11.0 per 100,000 (the tenth highest county rate among Hispanic white females in New Mexico).

Temporal Variation

Temporal variation of incidence rates for stomach cancer, for the period between 1970 and 1994, among residents of Eddy County and Lea County is presented in Figures 44 and 45.

By Sex: Statewide, stomach cancer incidence rates decreased over the period studied for males, from approximately 14 per 100,000 in 1971 to 9 in 1993, and for females, from approximately 8 per 100,000 in 1971 to less than 5 in 1993. In Eddy County, stomach cancer incidence rates were less at the end than at the beginning of the study period, decreasing from approximately 9 per 100,000 in 1971 to 7.5 in 1993; however, rates varied widely with no obvious trend. In general, rates for males in Eddy County were higher than for females, but the rates for females were equal to or higher than rates for males in 1972, 1984, and 1992. In Lea County, stomach cancer incidence rates for both sexes began and ended the study period at approximately 7 or 8 per 100,000, but varied asymmetrically during intervening years. Rates for females peaked in 1992, at approximately 10 per 100,0000, and rates for males peaked in 1974, at approximately 18 per 100,000.

By Ethnicity: Statewide, stomach cancer incidence rates decreased among non-Hispanic whites during the study period from approximately 7 per 100,000 in 1971 to under 5 in 1993, and among Hispanic whites from approximately 20 per 100,000 in 1971 to 11 in 1993. In general, incidence rates of stomach cancer among Hispanic whites were higher than among non-Hispanic whites. In Eddy and Lea counties, the pattern of stomach cancer incidence rates among non-Hispanic whites were similar to the pattern for Hispanic whites, and did not change substantially during the period studied. Among Hispanic whites residing in Eddy and Lea counties, stomach cancer incidence rates varied widely, peaking several times in both counties (in Eddy County in 1971, 1976, 1982, and 1988, and in Lea County in 1971, 1973, and 1975).