RESULTS
This study, involved an evaluation of 104 cases and 99 controls with a median age of 6.05 years for the case group and 6.06 years for the control group. Out of the case group, 45.2% (n=47) were female, and 54.8% (n=57) were male; while the control group comprised 51.5% (n=51) female and 48.5% (n=48) male. Details of socio-demographic features and cancer-related risk factors are presented in Table 1 and Table 2, respectively. Cancer patients are classified according to ICCC-3 classification system and their distribution is shown in Table 3.
According to the Table 4, the smoking status of parents was assessed, revealing no significant difference between the case and control groups in terms of pre-conceptional, during pregnancy and current smoking behaviors of the mothers based on questionnaire responses. However, it was observed that in the case group 68.1% (n=64) of the fathers had a history of regular smoking, while in the control group, 81.8% (n=81) of the fathers stated the same (p<0.05). Furthermore, smoking rates of fathers during the pre-conceptional period and throughout the mother’s pregnancy with the case (61.7%) were found significantly lower compared to the control group (75.8%) (p<0.05).
In the event of the mother, father, another household member (such as a brother, grandparent, etc.) or any another individual (such as a teacher, bus driver, friend, etc.) being a regular smoker, exposure to ETS was considered to be present. According to the questionnaire, the ETS exposure rate of the case group (n=66, 68.8%) was found to be significantly lower than the ETS exposure rate of the control group (n=83, 83.8%) (p<0.05), as presented in Table 5.
The mean hair cotinine levels for children in the case group were 0.224±0.088 ng/mg, while the mean hair cotinine levels of the control group were 0.136±0.048 ng/mg. The hair cotinine levels in the case group were significantly higher than the control group. The cut-off value for cotinine for ETS exposure were accepted as 0.2 ng/mg5. According to the results of cotinine analysis, the ETS exposure rate in children with cancer was 59.4% (n=60) while it was only 14.1% (n=14) in the control group. The analysis showed that ETS exposure was found to be significantly higher in children with cancer according to cotinine levels (p<0.001) (Table 6)