Cancer Incidence Rates in Eddy and Lea Counties

New Mexico, 1970-1994

Laryngeal Cancer

In 1994 in New Mexico, 47 new cases of in situ and invasive cancer of the larynx were reported, accounting for 0.7% of total cancers (NMTR 1996).

Males develop laryngeal cancer more often than women (NCI 1993). Risk factors for cancer of the larynx include use of tobacco (both smoking and chewing) (ACS 1995); heavy alcohol consumption; and exposure to certain substances including asbestos, mustard gas, and nickel or nickel compounds (NCI 1993). The use of tobacco increases the risk of developing laryngeal cancer approximately ten times. The risk associated with tobacco is directly related to the amount of tobacco used, and is compounded by alcohol consumption.

Nationally, incidence rates of cancer of the larynx have not changed overall during the last two decades (NCI 1993). However, rates for men decreased slightly from 8.4 per 100,000 in 1973 to 8.0 in 1990, while rates for women have increased from 1.3 per 100,000 in 1973 to 1.7 in 1990. In New Mexico, incidence rates of laryngeal cancer were lower than US rates, and were fairly stable over the period of study, with rates for men decreasing slightly from approximately 5.7 per 100,000 in 1971 to 5.0 in 1993, and rates for women remaining steady overall (Figure 22).

Spatial Variation

Spatial variation of incidence rates for laryngeal cancer, for the period between 1970 and 1992, among residents of New Mexico, Eddy County, and Lea County, is presented in Tables 21, 22 and 23.

Non-Hispanic Whites: During the period studied, the incidence rate of cancer of the larynx among non-Hispanic white males and females combined was 3.7 per 100,000 statewide, and ranged from a low of no cases in De Baca and Guadalupe counties to a high of 6.9 in Torrance County. The incidence rate of laryngeal cancer among non-Hispanic white males was 8.5 per 100,000 (the sixth highest county rate among non-Hispanic white males in New Mexico). The incidence rate of laryngeal cancer among non-Hispanic white females residing in Lea County was 1.7 per 100,000 (the eighth highest county rate among non-Hispanic white females in New Mexico). Laryngeal cancer incidence rates in Eddy and Lea counties were higher for non-Hispanic white males than non-Hispanic white females: 8.5 vs. 1.5 in Eddy County and 5.6 vs. 1.7 in Lea County.

Hispanic Whites: During the period studied, the incidence rate for cancer of the larynx among Hispanic white males and females combined was 2.6 per 100,000 statewide, and ranged from a low of no cases in Catron, De Baca, Harding, and Union counties to a high of 7.7 in Lea County. Among Hispanic white males residing in Lea County, the incidence rate of laryngeal cancer was 13.9 per 100,000 (the highest county rate among Hispanic white males in New Mexico), and among Hispanic white females residing in Lea County, the incidence rate of laryngeal cancer was 2.3 (the second highest county rate among Hispanic white females in New Mexico). Laryngeal cancer incidence rates for Hispanic white males residing in Eddy and Lea counties were higher than for Hispanic white females: 3.7 vs. 0.00 in Eddy County and 13.9 vs. 2.3 in Lea County.

Temporal Variation

Temporal variation of incidence rates for laryngeal cancer, for the period between 1970 and 1994, among residents of Eddy County and Lea County is presented in Figures 23 and 24.

By Sex: Statewide, incidence rates for cancer of the larynx remained stable during the period studied for both sexes. Laryngeal cancer incidence rates among males were higher than among females during the study period. In Eddy and Lea counties, laryngeal cancer incidence rates were higher among males than among females, and no cases of laryngeal cancer were reported among females for many of the years studied. In Eddy County, the incidence rates for both sexes combined decreased, from approximately 5 per 100,000 in 1971 to 3 in 1993. However, among males, the incidence rates of laryngeal cancer in Eddy County began and ended the period of study at approximately 5.5 or 6.0 per 100,000. In Lea County, laryngeal cancer incidence rates for both sexes combined appeared to increase slightly during the period studied, from approximately 2 per 100,000 in 1971 to 4 in 1993, and rates for males also increased, from approximately 4 per 100,000 in 1971 to 7 in 1993.

By Ethnicity: Statewide, laryngeal cancer incidence rates among both ethnicities did not change substantially during the period studied, and in general, statewide rates were higher among non-Hispanic whites than among Hispanic whites. In Eddy and Lea counties, no cases of laryngeal cancer were reported for Hispanic whites for many of the years studied. In Eddy County, laryngeal cancer incidence rates for non-Hispanic whites decreased during the period studied, from approximately 6 per 100,000 in 1971 to 4 in 1993. In Lea County, laryngeal cancer incidence rates for non-Hispanic whites increased during the period studied, from approximately 1 per 100,000 in 1971 to 4 in 1993.