The risk profile of childhood leukaemia in Greece: a nationwide case-control study

Abstract

Summary The risk profile of childhood leukaemia in Greece was studied through a case-control investigation that included all 153 incident cases of the disease, ascertained throughout the country during 1993 and 1994, and two hospital controls for every case matched for gender, age and place of residence. The data were analysed using conditional logistic regression and the associations are expressed in terms of adjusted odds ratios (OR) and their 95% confidence intervals. Cases were born to mothers of a higher standard education, the OR for an increment of four schooling years being 1.48 (1.17-1.87) and had higher birth weight, the OR for an increment of 500 g being 1.36 (1.04-1.77). Pet ownership and birth after a pregnancy with anaemia were associated with increased risk, the ORs being 2.18 (1.14-4.16) and 2.60 (1.39-4.86) respectively. From the frequency analyses, indicative inverse associations were found with birth order, household crowding and previous hospitalization with allergic diseases, whereas indicative positive associations were found with diabetes mellitus during pregnancy and with neonatal jaundice. Substantial or significant elevations were not found with respect to maternal smoking and coffee drinking during pregnancy, diagnostic radiography and ultrasonographic examinations or blood transfusions. A significant inverse association with maternal consumption of alcohol could be due to multiple comparisons, but a detrimental effect can probably be excluded. A non-significant positive association with total shots of viral vaccinations and a weak non-significant inverse association with breast feeding were also found. We interpret the findings of this study as being compatible with acute childhood leukaemia being linked with delayed development of herd immunity to fairly common infectious agents, in conjunction with accelerated perinatal and early post-natal growth.

Childhood malignancy and maternal diabetes or other auto-immune disease during pregnancy

“…This was apparently not an effect of macrosomia at birth. An increased risk of childhood cancer with high birth weight has been reported (Daling et al, 1984;Greenberg et al, 1985;Kaye et al, 1991;Petridou et al, 1997) and was also present in our material, though stratification for birth weight did not remove the statistically significant increase in OR. The observed increased risk at low birth weight was also found by Forsberg and Källén (1990).…”

“…A Danish study (Mellemkjaer et al, 2000) revealed a moderately increased risk for childhood lymphomas and leukaemia of borderline statistical significance, while a positive association between childhood leukaemia and maternal diabetes was reported from Greece (Petridou et al, 1997).…”

Breastfeeding patterns and risk of childhood acute lymphoblastic leukaemia

“…To date, 13 case -control studies (Davis et al, 1988;Magnani et al, 1988;van Duijn et al, 1988;Shu et al, 1995;Petridou et al, 1997;Dockerty et al, 1999;McKinney et al, 1999;Schüz et al, 1999;Rosenbaum et al, 2000;Hardell and Dreifaldt, 2001; UK Childhood Cancer Study Investigators, 2001;Lancashire and Sorahan, 2003;Jourdan-Da Silva et al, 2004) have reported no association between breastfeeding and overall childhood leukaemia or ALL risk. Two of these previous studies restricted their analysis to children diagnosed between age 2 and 5 years and found no significant effect of breastfeeding on risk of leukaemia (Shu et al, 1995;UK Childhood Cancer Study Investigators, 2001).…”

Breastfeeding and childhood cancer

“…The results from the UKCCS study with respect to breastfeeding were compared with relevant results from other epidemiological studies of childhood cancer (van Steensel-Moll et al, 1986;McKinney et al, 1987;Davis et al, 1988;Hartley et al, 1988;Magnani et al, 1988;Golding et al, 1990;Shu et al, 1995;Petridou et al, 1997;Grufferman et al, 1998;Dockerty et al, 1999;Schüz et al, 1999;Shu et al, 1999;Smulevich et al, 1999;Infante-Rivard et al, 2000;Rosenbaum et al, 2000;Bener et al, 2001;Hardell and Dreifaldt, 2001). The UKCCS results did not differ significantly from those of previous studies, they have been combined with these and the overall results are shown for leukaemia (Figure 1), Hodgkin's disease (Figure 2), non-Hodgkin's lymphoma (Figure 3), other childhood cancers (Figure 4) and all childhood cancers combined ( Figure 5).…”

“…Several case-control studies of children with leukaemia have reported a significantly reduced risk associated with having been breastfed as infants (Shu et al, 1999;Smulevich et al, 1999;Infante-Rivard et al, 2000;Bener et al, 2001), although not all studies have noted such a relationship (van Steensel-Moll et al, 1986;McKinney et al, 1987;Davis et al, 1988;Magnani et al, 1988;Shu et al, 1995;Petridou et al, 1997;Dockerty et al, 1999;Schüz et al, 1999;Rosenbaum et al, 2000;Hardell and Dreifaldt, 2001). Others have reported a significantly reduced risk of Hodgkin's disease (Grufferman et al, 1998) and non-Hodgkin's lymphoma (Bener et al, 2001) in breastfed children.…”