Toxicity of bevacizumab in combination with chemotherapy in older patients

BACKGROUND

Bevacizumab leads to improved survival for patients with metastatic colorectal cancer (CRC) or non-small cell lung cancer (NSCLC) when added to chemotherapy. Little is known about factors associated with receipt of bevacizumab, or whether bevacizamab is associated with increased toxicity when added to chemotherapy.

PATIENTS AND METHODS

We conducted a prospective study of patients aged ≥65 years, which evaluated the association between geriatric assessment (GA) metrics and chemotherapy toxicity. We examined differences in characteristics and outcomes of patients with CRC and NSCLC cancers who received bevacizumab with chemotherapy versus chemotherapy alone.

RESULTS

From a total of 207 patients, 27 (13%) received bevacizumab plus chemotherapy and 180 (87%) received chemotherapy alone. Groups were similar in sociodemographic and cancer characteristics. There were no baseline differences in GA domains except that patients with heart disease were less likely to receive bevacizumab (4% vs. 26%, p = .01). Seventy-eight percent of patients who had bevacizumab had grade 3-5 toxicity compared to only 57% who received chemotherapy alone (p = .06). Patients receiving bevacizumab were more likely to develop grade 3 hypertension than those who received chemotherapy alone (15% vs. 2%, p < .01). In multivariable analysis, factors associated with grade 3 or more toxicity included: bevacizumab (OR: 2.86, p = .04), CRC (OR: 2.54, p < .01), and baseline anemia (OR: 2.58, p = .03).

CONCLUSION

Heart disease was more common in those who did not receive bevacizumab. Older patients who receive bevacizumab with chemotherapy have a higher odds of developing a grade 3-5 toxicity compared with those who receive chemotherapy alone.

Anti-angiogenic therapies for metastatic colorectal cancer

BACKGROUND

Angiogenesis inhibitors have been developed to block tumour angiogenesis and target vascular endothelial cells. While some of them have already been approved by the health authorities and are successfully integrated into patient care, many others are still under development, and the clinical value of this approach has to be established.

OBJECTIVES

To assess the efficacy and toxicity of targeted anti-angiogenic therapies, in addition to chemotherapy, in patients with metastatic colorectal cancer. Primary endpoints are both progression-free and overall survival. Response rates, toxicity and secondary resectability were secondary endpoints. Comparisons were first-line chemotherapy in combination with angiogenesis inhibitor, to the same chemotherapy without angiogenesis inhibitor; and second-line chemotherapy, to the same chemotherapy without angiogenesis inhibitor.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, as well as proceedings from ECCO, ESMO and ASCO until November 2008. In addition, reference lists from trials were scanned, experts in the field and drug manufacturers were contacted to obtain further information.

SELECTION CRITERIA

Randomized controlled trials on targeted anti-angiogenic drugs in metastatic colorectal cancer (MCRC).

DATA COLLECTION AND ANALYSIS

Data collection and analysis was performed, according to a previously published protocol. Because individual patient data was not provided, aggregate data had to be used for the analysis. Summary statistics for the primary endpoints were hazard ratios (HR's) and their 95% confidence intervals.

MAIN RESULTS

At present, eligible first line trials for this meta-analysis were available for bevacizumab (5 trials including 3101 patients) and vatalanib (1 trial which included 1168 patients). The overall HR s for PFS (0.61, 95% CI 0.45 - 0.83) and OS (0.81, 95% 0.73 - 0.90) for the comparison of first-line chemotherapy, with or without bevacizumab, confirms significant benefits in favour of the patients treated with bevacizumab. However, the effect on PFS shows significant heterogeneity. For second-line chemotherapy, with or without bevacizumab, a benefit in both PFS (HR 0.61, 95% CI 0.51 - 0.73) and OS (HR 0.75, 95% CI 0.63-0.89) was demonstrated in a single, randomized trial. While differences in treatment-related deaths and 60-day mortality were not significant, higher incidences in grade III/IV hypertension, arterial thrombembolic events and gastrointestinal perforations were observed in the patients treated with bevacizumab. For valatanib, currently available data showed a non-significant benefit in PFS and OS.

AUTHORS' CONCLUSIONS

The addition of bevacizumab to chemotherapy of metastatic colorectal cancer prolongs both PFS and OS in first-and second-line therapy.