Hypertension as predictive factor for bevacizumab-containing first-line therapy in metastatic breast and colorectal cancer in BRECOL (GEICAM/2011-04) study.

Background: Retrospective data suggest an association between bevacizumab efficacy and the incidence of arterial hypertension (AHT). Additionally, epigenetic mechanisms have been related to AHT.

Methods: This prospective observational study conducted by GEICAM Spanish Breast Cancer Research Group included metastatic breast (MBC) or colorectal (mCRC) cancer patients treated with bevacizumab-containing chemotherapy as first-line treatment. Blood pressure (BP) levels were measured (conventional and 24-h Holter monitoring) at baseline and up to cycle 3. Primary endpoint assessed BP levels increase as predictive factor for progression-free survival (PFS). Germline DNA methylation profile was explored in pre-treatment blood samples; principal component analysis was used to define an epigenetic predictive score for increased BP levels.

Results: From Oct-2012 to Jul-2016, 143 (78 MBC and 65 mCRC) patients were included. The incidence of AHT according to guidelines was neither predictive of PFS nor of best overall tumor response (BOR). No statistically significant association was observed with systolic BP nor diastolic BP increment for PFS or BOR. Grade 3 and 4 adverse events were observed in 37 and 5% of patients, respectively. We identified 27 sites which baseline methylation status was significantly associated to BP levels increase secondary to bevacizumab-containing chemotherapy.

Conclusions: Neither the frequency of AHT nor the increase of BP levels were predictive of efficacy in MBC and mCRC patients treated with bevacizumab-containing chemotherapy.

Clinical Trial Registry: ClinicalTrials.gov Identifier: NCT01733628.