Influence Of The Number Of Platelets And Hemoglobin Concentrations In Predicting The Development Of Proteinuria Induced By The Administration Of Bevacizumab

Bevacizumab neutralizes a key stimulation factor in tumour angiogenesis - vascular endothelial growth factor (VEGF). The origin of VEGF is related to platelets, and the basic stimulus for its production is hypoxia. By neutralizing VEGF, changes occur in the blood that are manifested at the platelet and haemoglobin levels. Study results indicate that proteinuria is a side effect of bevacizumab treatment. The aim of the present study was to examine the percentages of proteinuria in patients with metastatic colorectal cancer after the administration of bevacizumab. The correlation between the degree of proteinuria and changes in the number of platelets and concentration of haemoglobin in patients, as well as in relation to the age (< 60 i ≥ 60) and gender of the patients, was examined.

The study group of respondents included 20 patients with metastatic colorectal cancer (9 men and 11 women) ranging in age from 43 to 73 years. Proteinuria was tested using “Laboquick” test strips. The levels of platelets and haemoglobin were measured using an autoanalyser, the type Cell Dyn 3700 – Abbott, according to the protocol prescribed by The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC).

Statistically significant differences were recorded for the platelet measurements before and after therapy in the overall group of respondents (p= 0.025). Statistically significant decreases in platelet counts and increases in haemoglobin concentrations were also noted in women (Plt: p=0.0036; Hb: p=0.0286) and in patients < 60 years old (Plt: p=0.0270; Hb: p=0.0553). No significant differences were identified in men or in patients ≥ 60 years of age. Proteinuria was detected in one case in which demonstrating an increase in only the recorded number of platelets and a decrease in the level of haemoglobin.

Platelets and haemoglobin may serve as prognostic biomarkers of the risk of proteinuria. Based on the initial values of these parameters, we can predict the target group, in terms of gender and age, that may obtain the most benefit from bevacizumab therapy.