RESUMO
Total duration of breastfeeding and of exclusive breastfeeding was studied and compared in 99 childhood cancer cases and 90 controls. The difference between the average duration of breastfeeding in cases and controls was significant (p < 0.05), but when average duration of exclusive breastfeeding was compared in cases and controls the difference was highly significant (p < 0.001). In lymphoma cases and controls the difference between the average duration of breastfeeding was moderately significant (p < 0.01). However, when average duration of exclusive breastfeeding was compared in lymphoma cases and controls the difference was highly significant (p < 0.001). When other cancer groups and controls were compared with respect to their total duration of breastfeeding and duration of exclusive breastfeeding the differences when insignificant (p > 0.05). Cases and controls were not different with respect to their age, sex, birth year, birth order, age and educational status of mothers, smoking of fathers and socioeconomic status. However, a positive family history of cancer was obtained in 4 (4%) of cases whereas in controls it was obtained in only 1 (1.1%).
PIP: Between April 1991 and June 1992 in India, physicians compared data on 99 childhood cancer cases with data on 90 sex, age, and hospital matched controls to examine the relationship between duration of total breast feeding and exclusive breast feeding and childhood cancer. Most of the children were patients at G.S.V.M. Medical College in Kanpur or at K.G. Medical College in Lucknow. Cases and controls were essentially the same in respect to birth order, age and educational status of mothers, smoking of fathers, and socioeconomic status. 65.7% of cases had leukemia. The duration of total breast feeding was significantly longer for controls than cases (10 months vs. 8 months; p .05). The difference between mean duration of exclusive breast feeding between mean duration of exclusive breast feeding between cases and controls was significant (4.6 months vs. 3.2 months; p .001). Controls were more likely to have undergone a longer duration of total breast feeding and exclusive breast feeding than were lymphoma cases (10 months vs. 6.15 months; p .01 and 4.6 months vs. 3 months; p .001, respectively). 58% of lymphoma cases had non-Hodgkins lymphoma. When the researchers compared other cancer groups and controls, no significant difference between the 2 groups existed in respect to total breast feeding and exclusive breast feeding. These results suggest that breast feeding has a protective effect against childhood cancer. Further, they indicate that exclusive breast feeding provides more beneficial immunological effects than breast feeding supplemented by artificial feeding. The high rate of breast feeding in India may explain the low incidence of childhood cancer in India (e.g., around 6/100,000 vs. 18/100,000 in Israel).