Improved outcome at end of treatment in the collaborative Wilms tumour Africa project

BACKGROUND

The Collaborative Wilms Tumour (WT) Africa Project has implemented an adapted WT treatment guideline in sub-Saharan Africa as a multi-centre prospective clinical trial. A retrospective, baseline evaluation of end-of-treatment outcome was performed for a 2-year period prior to the introduction of this guideline. The collaborative project aims to reduce both treatment abandonment and death during treatment to less than 10% for improving survival.

PROCEDURE

All participating centres obtained local Institutional Research Board (IRB) approval and implemented the adapted WT treatment guideline. End-of-treatment outcome was documented for 2 years. It was divided into alive without evidence of disease, treatment abandonment, death during treatment and persistent disease. The outcome of children enroled in the first 2 years of the prospective clinical trial has been compared to the outcome before the start of the project.

RESULTS

One hundred twenty-two patients were included in the baseline evaluation (2011-2012) and 133 in the first 2 years of the collaborative clinical trial (2014-2015). The percentage of patients alive without evidence of disease at the end of treatment increased from 52% (63/122) to 68% (90/133; P = 0.01). Treatment abandonment decreased from 23% (28/122) to 13% (17/133; P = 0.03). Death during treatment decreased from 21% (26/122) to 13% (17/133; P = 0.07).

CONCLUSION

This collaboration, using relatively simple and low-cost interventions, led to a significant decrease in treatment abandonment and increase in survival without evidence of disease at the end of treatment.

Survival of children with a Wilms tumor in Blantyre, Malawi

Wilms tumor (WT) has a survival rate above 90% in high income countries. Reported survival rates in sub-Saharan Africa are much lower and long-term outcome is not well known as follow-up is challenging. In Blantyre, Malawi, an adapted WT treatment guideline with preoperative chemotherapy, supportive care, and strategies to enable children and parents to complete treatment was introduced in 2006. Between 2006 and 2011, 73 children with a unilateral WT were treated. Follow-up, including home visits when needed, was done. Median follow-up time is 5 years (range 14-95 months). Two and five-year event free survivals are 46 and 42%. Causes of treatment failure are: 7% (5/73) abandonment of treatment, 15% (11/73) death during treatment and 30% (22/73) disease-related deaths (persistent disease and relapse). Long-term follow-up is challenging but necessary to be able to assess outcome and the true impact of interventions.

Characterization of enzymes involved in biotransformation of polycyclic aromatic hydrocarbons in terrestrial isopods

Little is known about the capacity of terrestrial invertebrates to transform organic soil pollutants such as polycyclic aromatic hydrocarbons (PAHs). Studies were designed to characterize microsomal mixed function oxygenase and accompanying conjugation enzymes from the hepatopancreas of the terrestrial isopods Porcellio scaber and Oniscus asellus using pyrene and 1-hydroxypyrene as model substrates. The hydroxylation of pyrene and the formation of pyreneglucoside and pyrenesulfate appeared to be sensitive measures for the activity of cytochrome P450 aryl hydrocarbon hydroxylase (AHH), uridinediphosphateglucosyltransferase (UDPGT), and aryl sulfotransferase (ST), respectively. Treatment with the antibiotic riphampicine demonstrated that the enzyme activities originate from the animals themselves and not from symbiotic microflora present in the hepatopancreas and the gut. In both species, ST has a very high affinity for 1-hydroxypyrene with Km values two orders of magnitude lower than that of UDPGT. The Vmax values of UDPGT, however, are 10- to 20-fold higher than that of ST. Taking the P450 activities into consideration, both species are expected to transform PAHs in an equally effective way. When the isopods were fed with food containing benz[a]pyrene and 3-methyl-cholanthrene, none of the enzyme activities appeared to be inducible except for a small enhancement of UDPGT in O. asellus. Our findings indicate that terrestrial isopods have a high, noninducible capacity for biotransformation of PAHs and that the sulfate conjugation pathway is as important as the carbohydrate conjugation pathway. This conclusion is consistent with the low body residues of parent PAHs found in the field.