Cancer Incidence Rates in Eddy and Lea Counties

New Mexico, 1970-1994

Childhood Cancer-All Sites

Cancers in children 14 years old and under are comparatively rare (ACS 1995). Relatively common childhood cancers include leukemia, Hodgkin's disease, non-Hodgkin's lymphomas, and cancers of the bone and joints, brain and other nervous system, kidney and renal pelvis, and soft tissues. Leukemia and brain and other nervous system cancers account for about 50% of all childhood cancers (NCI 1993; Cotran 1994).

Risk factors for childhood cancers include exposure to ionizing radiation; exposure to certain chemicals, such as benzene (although no cases have been reported) and diethylstilbestrol (given to pregnant women in the 1950s to prevent miscarriage); a family history of cancers; and congenital defects (NCI 1993).

Nationally, incidence rates for childhood cancers of all sites increased slightly over the last two decades from 12.6 in 1973 to 13.7 in 1990 (NCI 1993). In New Mexico, incidence rates of childhood cancers of all sites were comparable to, or slightly lower than, US rates during the period studied (Figure 52). Rates did not display a increasing or decreasing trend from 1970 to 1992, although they varied widely for intervening years, ranging from a low of approximately 95 per 1,000,000 (9.5 per 100,000) in 1979 to a high of 150 per 1,000,000 (15.0 per 100,000) in 1990.

Spatial Variation

Spatial variation of incidence rates for childhood cancer, for the period between 1970 and 1992, among residents under 15 years old of New Mexico, Eddy County, and Lea County, is presented in Tables 45, 46 and 47. Incidence rates for childhood cancer are expressed in rate per 1,000,000 people per year.

Non-Hispanic Whites: During the period studied, the incidence rate for childhood cancer of all sites among non-Hispanic white males and females combined was 130 per 1,000,000 statewide, and ranged from a low of no cases in De Baca, Harding, and Mora counties to a high of 274 in Guadalupe County. The incidence rate for all non-Hispanic whites (combined) residing in Lea County was below the corresponding statewide rate. The incidence rate for childhood cancer of all sites among non-Hispanic white males in Eddy County was also lower than the corresponding statewide rate.

Hispanic Whites: During the period studied, the incidence rate for childhood cancer of all sites among Hispanic white males and females combined was 109 per 1,000,000 statewide, and ranged from a low of no cases in Catron County to a high of 374 in De Baca County. The incidence rate of childhood cancer among Hispanic white males in Lea County was 180 per 1,000,000 (the seventh highest county rate among Hispanic white males in New Mexico). The childhood cancer incidence rate among Hispanic white males in Eddy County was lower than the statewide rate.

Temporal Variation

Temporal variation of incidence rates for childhood cancers, for the period between 1970 and 1994, among residents under 15 years old in Eddy County and Lea County, is presented in Figures 53 and 54. Incidence rates for childhood cancer are expressed in rate per 1,000,000 people per year.

By Sex: Statewide, incidence rates for childhood cancer of all sites combined were generally higher for males than for females during the period studied. In Eddy County, incidence rates showed no large increase overall during the study period, but varied for intervening years, from a low of approximately 25 per 1,000,000 from 1972 to 1976 and 1988 to 1989, to a high of 220 in 1983. Childhood cancer incidence rates during the study period were higher among females than males in Eddy County, but were higher among males than females in Lea County. Incidence rates for cancer of all sites appear to have remained steady overall for males, but increased overall for females, from approximately 45 per 1,000,000 in 1973 to 95 in 1993. However, rates varied widely, and no cancers were reported among children during many of the years studied.

By Ethnicity: Statewide, incidence rates for childhood cancer of all sites combined increased for Hispanic whites from approximately 85 per 1,000,000 in 1971 to 120 in 1993, and decreased overall for non-Hispanic whites, from 145 in 1971 to 100 in 1993. In Eddy County, incidence rates for childhood cancer of all sites varied widely for both ethnicities, with no cases reported for many of the years studied, and a large peak in incidence rates among both ethnicities between 1978 and 1985. In Lea County, incidence rates for cancer of all sites among both ethnicities were variable during the period studied, with no clear increasing or decreasing trends. Peaks occurred for incidence rates of cancer of all sites for Hispanic whites around 1976 and 1988.