BMC Cancer 2008, 8:355 http://www.biomedcentral.com/1471-2407/8/355 Our study ranks amongst the largest investigations of migrant-specific cancer survival probability. It is based on the highly comprehensive nationwide German Child- hood Cancer Registry. The mortality follow-up followed routinely established procedures and showed very similar results for both groups, with a surprisingly low loss to fol- low-up due to out-migration. Our approach to identify cases with Turkish ethnicity relies on the assumption that children with Turkish names indeed have a Turkish descent, and that there is no differential uptake of German names with regard to cancer prognosis. We cannot exclude a small bias through this mechanism. However, the number of mixed German-Turkish marriages has only increased in more recent years. A major proportion of these marriages occurs between partners of whom one has taken up German nationality, but is of Turkish descent. Thus, Turkish first or family names are likely to be retained in many mixed marriages. Children from mixed marriages with neither a Turkish first or last name are likely to be rare. In our study we could not differentiate between different migrant generations. Potentially, such information could further elucidate the differences in survival probability seen in early phases of the GCCR, but such data are not likely to become available in registry – based studies. This latter comment is also true for information on the socioe- conomic status of cases or their families, which is not rou- tinely recorded in the registry. While the overall number of deaths allows for relatively precise estimates, the stratifications by diagnosis and period we performed led to rather small numbers of cases in some strata. In addition, multiple comparisons should be noted, but since our study had an explorative character, no adjustment for multiple testing seemed warranted. Thus, some of the differences noted as statistically signifi- cant are possibly due to chance. Due to the absence of routine data to assess cancer inci- dence and survival probability according to ethnic back- ground, this is the first study in Germany on this topic, and one of the few investigations published in Europe so far. McKinney [8] assessed the cancer survival probability in a cohort of 1979 children with cancer in Yorkshire, using a name-based approach to identify children of South Asian origin. No survival probability differences were found between South Asian and other children, and indications that higher levels of deprivation were linked with lower survival probability were not statistically sig- nificant. In a large study of all childhood cancer cases between 1981 and 1996 in the UK, Stiller [9] found little evidence of ethnic differences in survival probabilities. The UK Children's Cancer Study Group register contains primary information on the ethnic group of patients, which allows comparisons across different ethnic groups. For acute lymphoid leukaemia, the authors reported slightly lower long-term survival probabilities for children of South Asian origin. Our own finding of survival proba- bility differences in lymphoid leukaemia mirrors this observation in one of the largest migrant groups in Ger- many. Several studies from the US report ethnic differences in cancer survival probability, most of them with a focus on leukaemia. In a series of cases from the St. Jude Children's Research Hospital spanning 30 years of incident diag- noses, Pui [10] found large survival disadvantages for black children in the early periods which disappeared in the 1980s and 1990s. A single centre study of 412 children with acute lymphoid leukaemia treated in Memphis also showed no differences in survival probability [11]. Con- versely, Bhatia concluded from a review of available sin- gle-and multi centre studies that black children with acute lymphoid leukaemia continue to have lower survival probabilities than white children in the US [12]. For acute myeloid leukaemias a survival disadvantage of black chil- dren has recently been described based on experiences from two US Children's Oncology Group trials [13]. Inter- estingly, there was only a low proportion of black children with appropriate matched family donors for transplants. Overall, the small body of studies available is relatively consistent with regard to cancer survival probability, showing generally few differences between cases with and without migrant background or by ethnic origin. Haema- tological cancers could be an exception, as, amongst oth- ers, the recent results from the US indicate. In our own study, differences in survival probabilities from lymphoid leukaemia were limited to children diagnosed between 1980 and 1987. Nevertheless, as leukaemias are the larg- est group of childhood cancers, continued surveillance of survival using updated markers of ethnic or geographical origin may be warranted. Conclusion In summary, our study demonstrates increasing and very similar 5-year cancer survival probabilities among chil- dren with and without Turkish descent living in Germany. This finding is consistent with the small body of available information on overall cancer survival of ethnic minority children from other countries. We interpret this as show- ing the non-discriminative nature of current childhood cancer care in Germany and the provision of equitable access to modern therapeutic and follow-up regimes, irre- spective of migrant status. Competing interests The authors declare that they have no competing interests. Page 6 of 7 (page number not for citation purposes)