Researchers found that the addition of cancer drug bevacizumab to chemotherapy or biological therapy may increase the risk of treatment-related mortality.
Bevacizumab inhibits the activity of the vascular endothelial growth factor, which is involved in the development of blood vessels.
A study by a team from Stony Brook University Medical Center in New York conducted a meta-analysis using data from 16 studies covering 10,217 patients with advanced tumours.
In total, 5,589 patients received bevacizumab while 4,628 were given a control drug.
Researchers found 148 fatal adverse events (FAE) occurred. The overall incidence of mortality with bevacizumab was 2.5 per cent, compared with 1.7 per cent in the control group.
Compared with chemotherapy alone, the addition of bevacizumab increased the risk of mortality by 46 per cent.
The association between bevacizumab and mortality during treatment varied significantly with chemotherapeutic agents but not with tumour type or bevacizumab dose.
The researchers concluded: 'Given that the absolute risk of treatment-related mortality appears low, the use of bevacizumab should be considered in the context of overall survival benefits.'
They added: 'Further efforts are needed to reduce FAEs due to haemorrhage, neutropenia and gastrointestinal perforation in association with bevacizumab therapy.
'It is very important for physicians and patients to recognise the risks as well as the benefits associated with bevacizumab treatment and to monitor closely to identify and treat serious adverse effects.'