In a recent study titled “Correlation of Hypertension and Proteinuria with Outcome in Elderly Bevacizumab-Treated Patients with Metastatic Colorectal Cancer”, published in PlosOne, a team of Spanish researchers designed a retrospective analysis of two Phase II studies (BECA and BECOX) to evaluate if hypertension and proteinuria could predict disease outcome in older patients diagnosed with metastatic colorectal cancer (mCRC) and treated with bevacizumab.
Previous research had already noted a connection between hypertension, which is a common side effect of bevacizumab therapy, and disease outcome in patients with mCRC. Furthermore, proteinuria (excess of proteins in urine) is also known to occur in bevacizumab-treated patients.
In the BECA trial, patients older than 70 years of age were treated with capecitabine together with bevacizumab, while in the BECOX trial, patients received capecitabine with bevacizumab and oxaliplatin .
The primary goal of this retrospective analysis was to understand the relation between hypertension and proteinuria with overall response rate (ORR), time to progression (TTP) and overall survival (OS). In addition, the authors aimed to identify the risk factors linked to the development of hypertension and proteinuria, to understand if development of hypertension or proteinuria in the first 2 cycles of treatment was connected to ORR, disease-control rate (DCR), TTP or OS.
The results demonstrated that hypertension and DCR were correlated and that proteinuria was associated with both ORR and DCR. Importantly, the authors found that increased bevacizumab cycles were among risk factors for hypertension and proteinuria.
Unlike other targeted agents for which biomarkers indicating lack of response to treatment have been identified, it is not possible to predict which group of patients will respond to bevacizumab. As such, investigating alternative markers of response such as hypertension and proteinuria, both of which are common side effects of bevacizumab, is of great clinical relevance.
“This analysis of pooled data from the BECA and BECOX studies suggests that hypertension is significantly correlated with OS but not with ORR and TTP, whereas proteinuria is correlated with ORR but not with OS and TTP. The presence of hypertension or proteinuria in elderly bevacizumab-treated patients with mCRC are related with the duration of bevacizumab treatment and do not represent an independent prognostic factor”, the authors conclude in their study.