1. Percentage Distribution of Leading Cancer Types Among Children in Texas, 1990-1993
2. Childhood Cancer Incidence in Texas, 1990
3. Childhood Cancer Mortality in Texas, 1990-1993

Childhood Cancer Incidence and Mortality

Until recently, only information on childhood cancer deaths in Texas was available and the incidence of cancer in children was unknown. The Texas Cancer Registry (TCR) of the Texas Department of Health (TDH), in collaboration with the Childhood Cancer Subcommittee of the American Cancer Society, Texas Division, Inc., conducted a special study of childhood cancer incidence to fill this data need.

METHODS

Data on newly diagnosed cases of cancer in 1990 among Texas children under 15 years of age were collected from hospitals and other institutions across the state and were edited, consolidated, and analyzed by the staff of the TCR. Childhood cancer site codes were assigned according to a classification scheme based primarily on cancer cell type.2 This differs from the coding scheme for adult cancers, which is based primarily on cancer site.

In addition to incidence data, information on deaths from childhood cancers for the years 1990-1993 was examined. Data for all cancer deaths reported among Texas children under 15 years of age were derived from computerized data files provided by the TDH Bureau of Vital Statistics. The TCR staff reviewed the death certificates of these children to confirm the cause of death and assigned a cause-of-death code based on the same coding scheme used for the incidence data.

All rates presented are per million children (under age 15) and are unadjusted. Data for the major childhood cancer types are presented. The small numbers of cases preclude detailed breakdown of some broad cancer groupings.

RESULTS

In 1990, a total of 590 cases of cancer were newly diagnosed among Texas children less than 15 years of age. An average of 143 childhood cancer deaths occurred annually during the years 1990-1993. Acute lymphocytic leukemia is the leading cancer diagnosed in children (representing almost one-fourth of the total cancer incidence) and the second leading cause of cancer mortality (accounting for 18 percent of total cancer deaths). Malignant tumors of the brain and central nervous system (CNS) are the primary cause of childhood cancer mortality in Texas (26 percent of all cancer deaths) and the second leading cause of childhood cancer (22 percent of all cases). Although acute non-lymphocytic leukemia (ANL) represents only five percent of all incident cases, it is responsible for 14 percent of all childhood cancer deaths.

The annual total cancer incidence rate is 150 per million among Texas males under 15 years of age and 139 per million for Texas females. In contrast, total childhood cancer mortality rates are four to five times lower, an indication that survival from childhood cancers is good.

Male incidence rates exceed those of females for most childhood cancer types except ANL, neuroblastoma, and malignant bone tumors. This pattern also is seen in childhood cancer mortality, excluding soft-tissue sarcomas.

CONCLUSIONS

Despite the optimistic picture of survival presented by the ratio of incidence to mortality, childhood cancer remains a major cause of illness and death in Texas. Much work remains to identify risk factors for childhood cancers and to design intervention strategies. The continued collection of incidence data and mortality data is critical to gaining a better understanding of the causes of childhood cancers and meeting the ultimate goal of preventing cancer in children.

Literature Cited:

1. Bleyer WA. What can be learned about childhood cancer from "Cancer Statistics Review 1973-1988". Cancer 1993; 71:3229-3236.
2. Birch JM, Marsden HB. A classification scheme for childhood cancer. International Journal of Cancer 1987; 40:620-624.