[Tumors in children with birth defects. Current data from the Czech Republic]

An analysis of birth defects incidences in a co-incidence with children age tumors in the Czech Republic in 1994 - 2005. Some bio-social factors (maternal age, birth weight, gestational week at birth) and their roles were studied as well.

Retrospective demografic-epidemiological analysis of birth defects and children age tumors incidences in children born in the Czech Republic during 1994 - 2005.

Data from the National Birth Defects Register and National Oncological Register (both run in the Institute for Health Information and Statistics) in the Czech Republic were used along with some additional data from the Register of newborns and Register of mothers at childbirth. Out of these data, a group of children with both birth defect and tumor was analyzed according to particular diagnoses and to some selected bio-social factors. Out of the total number 1707 children with tumor (934 (54.7%) boys and 773 (45.3%) girls) were 1572 children without birth defect and 135 with both tumor and birth defect. Total number of children with birth defect were 39 197 (39 059 live births and 138 stillbirths), 22 741 (58.1%) boys and 16 435 (41.9%) girls (in 21 cases the sex was not specified). In these children totally 53 539 birth defect diagnoses were registered (30 739 in boys, 22 781 in girls and 19 in children with unspecified sex).

In 1572 children without birth defect and with tumor, a mean age at time of tumor diagnosis was 3.6 years, in 135 children with both tumor and birth defect was 2.2 years, which is significantly lower (p < 0.001, Mann-Whitney U test). No statistically significant difference was found in birthweight and birthlenght and gestational week and maternal age at time of delivery. An increased frequency of tumors in the group of children with birth defect was found in groups mesothelial tumors (C45 - C49), tumors of urinary tract (C64 - C68) and tumors of head and neck (C00 - C14, C30 - C31). On the other hand, a decreased tumor frequency in the group of children with birth defect was found in groups of lymfoid and haematopoietic tumors ((C81 - C96) and tumors of eye and brain (C69 - C72). As a risk factor of tumorigenesis in in children with birth defect was a birth defect from groups of defects of cardiovascular system, uropoietic system, chromosal aberrations and other unspecified defects. In children with both birth defect and tumor a decreased survival rate (p = 0.0437, Log-rank test) was found. A decreased survival rate was also confirmed after tumor diagnosis, although this decrease was not statistically significant (p = 0.2021, Log-rank test). There is also a highly statistically significant difference (p < 0.001, Log-rank test) in survival between groups with and without a birth defect prior to tumor diagnosis.

A higher risk of tumorigenesis in children with birth defect (compared to children without birth defect) was confirmed. There was also a lower survival in a group of children with tumor and birth defect compared to those with tumor and without birth defects. A higher risk of tumorigenesis in some types of birt defects was also found.