Children's Environmental Health
The Minnesota Department of Health collects statewide data on childhood and adult cancer incidence and mortality. These data enable us to detect public health problems, to target goals for cancer control, and to inform citizens and health care providers about cancer risks, early detection, and treatment.
For a summary of information about childhood cancers, see the information below from the March 2003 report, Cancer in Minnesota.
Incidence and Mortality:
Each year, about 150 children under 15 years of age are diagnosed with cancer in Minnesota, and 25 children die of cancer each year. Of all cancers diagnosed in the state, 0.7 percent, or seven out of every 1,000, are in children. Based on current incidence and mortality rates in Minnesota, it is estimated that one of every 450 children will be diagnosed with cancer before age 15. Cancer is the leading cause of death from disease among children. Overall childhood incidence and mortality rates in Minnesota are very similar to what is reported nationally.
The cancers diagnosed among children are different than those diagnosed among adults. While breast, prostate, colorectal, and lung cancer are the most common among adults, children with cancer are more likely to be diagnosed with leukemia (28% of childhood cancers), brain cancer (19%), or lymphomas (12%). The rates and distribution of specific cancer types among children in Minnesota are similar to what is seen nationally.
The overall childhood cancer incidence rate in Minnesota has been fairly stable since cancer reporting was implemented in 1988. The incidence rate of leukemia, the most common childhood cancer, decreased significantly by about three percent per year. The overall mortality rate for childhood cancers has been decreasing by about two to three percent per year in Minnesota, and the decline is statistically significant when data for both sexes are combined. Nationally, the childhood cancer incidence rate has been stable since 1987, and the mortality rate has decreased significantly by 2.6 percent per year since 1987, almost identical to decreases observed in Minnesota.
Nonetheless, long-term trends from Surveillance, Epidemiology, and End Results (SEER) indicate that many types of childhood cancer became more common during the 1970s and 1980s. Incidence rates increased significantly from 1975-1986 for childhood cancers as a whole, bone and joint cancer, and leukemia. Despite these increases, the childhood cancer mortality rate in the U.S. has decreased by nearly 70 percent since 1950, reflecting major improvements in treatment and survival. The 5-year relative survival rate for childhood cancer increased from only 20 percent in 1950-1954 to nearly 80 percent in 1992-1998.
The overall cancer incidence rate is nearly twice as high among children under five years of age compared to those five to 14 years old. However, the age distribution varies by cancer type.
Boys are somewhat more likely to develop childhood cancer than girls.
There are too few cases of childhood cancer among children of color in Minnesota to meaningfully assess race differences in childhood cancer rates in the state. Based on cancers among children reported to the SEER program from 1995-1999, white children had the highest overall cancer rates (15.4 new cases per 100,000), followed by children of Asian/Pacific Islander origin (13.8), black children (11.6), and American Indian children (8.2). However, 5-year survival was poorer among black and American Indian children compared to white and Asian/Pacific Islander children for the most common cancers.
Despite active research, the causes of most childhood cancers remain unknown. Although genetics and ionizing radiation have been associated with increased risk for certain childhood cancers, it is likely that these factors only account for a small percentage of cases. Burkitt's lymphoma, a form of non-Hodgkin's lymphoma that is common among children in Africa, has been associated with Epstein-Barr virus. Because childhood leukemia has sometimes been reported to cluster geographically and temporally, it too, has been suspected of being associated directly or indirectly with exposure to a virus. However, a viral agent has yet to be identified, and the theory remains controversial. Recent research funded by the National Cancer Institute has not found an association between childhood cancer and radon, ultrasound during pregnancy, residential magnetic field exposure from power lines, or specific occupational exposures of parents.
There are no screening methods to detect cancer in asymptomatic children, and cancer is often difficult to diagnose in children until they are quite ill. Sudden, unexplained symptoms such as loss of energy, bruising, persistent localized pain or limping, rapid weight loss, or frequent headaches with vomiting should be brought to the attention of a physician.