Aspects of infections in children with cancer.

There are some differences between pediatric and adult cancer patients in terms of the problem of infection but it is doubtful whether such discrepancies justify different therapeutic approaches. For example, according to the results of EORTC trial IV, children seem to show lower overall (3% vs 19%) and infectious (2% vs 8%) mortality than adults, probably due to differences in underlying diseases and to a basic better physical integrity. Central intravenous catheters appear to be indispensable in the modern management of neoplastic diseases, especially in pediatric oncology. A prospective study performed in our institution on 157 Broviac catheters, has shown: 1. Of all microbiologically documented infections, occurring in children undergoing cancer chemotherapy and radiotherapy, 27% are related to the catheter 2. Gram-positive cocci are the leading pathogens (78%) of such infections 3. Catheter-related infections often occur in non-neutropenic patients 4. Such infections can be successfully treated without removing the intravenous device. The experience of the EORTC Cooperative Group and of other centers throughout the world shows that gram-positive cocci are increasingly being isolated as the cause of infections in cancer patients. This phenomenon is probably multifactorial in origin and appears to be more evident in pediatrics. For example, in our institution, during the last 5 years gram-positive organisms have caused 69% of all bacteremias. Moreover, these organisms, while responding poorly to the presently used empirical antibiotic regimens, seem not to be as aggressive as gram-negative organisms and cause lower mortality. There is therefore controversy over whether or not to include anti-gram-positive coverage in early empirical regimens. In our institution, a pilot study comparing ceftazidime + amikacin (C + A) and ceftazidime + vancomycin (C + V) seems to show an overall advantage for C + V. This advantage, however, is not statistically significant. One finding to be pointed out is that five of ten staphylococcal infections failed to respond to C + V and that in these cases a third antibiotic had to be added. Therefore, it is likely that, at least in institutions in which methicillin-resistant staphylococci are prevalent, a triple antibiotic empirical regimen will provide the best coverage, but this can result in overtreatment. However, only prospective, randomized and multicenter trials will be able to answer such questions definitely.