Add-on targeted therapies boost stereotactic radiosurgery efficacy in brain metastasis

The combination of stereotactic radiosurgery (SRS) with targeted chemotherapy treatments appears to improve disease outcomes in cancer patients with brain metastasis, reports a recent study.

Researchers conducted a systematic review and meta-analysis of 18 eligible studies, corresponding to 1,800 patients of whom 701 had been treated with SRS and targeted therapies. Most primary cancers were nonsmall cell lung cancer, melanoma, and breast cancer. The most commonly used targeted drugs were inhibitors of pro-cancer proteins BRAF, mTOR, and VEGF.

Pooled analysis found that using targeted therapies with SRS significantly improved OS, reducing the risk of death by more than 40 percent (hazard ratio [HR], 0.59, 95 percent confidence interval [CI], 0.49–0.71; p<0.01).

Similarly, such a combination approach statistically cut the risk of local recurrence by nearly 60 percent (HR, 0.43, 95 percent CI, 0.32–0.58; p<0.01), and of distant brain recurrence by almost 30 precent (HR, 0.72, 95 percent CI, 0.56–0.93; p<0.01).

Subgroup analyses showed that HR estimates for OS was even smaller in participants aged ≥60 years. Such an effect was significantly greater than in younger comparators, suggesting that combining SRS with targeted approaches might be even more effective for older patients. Survival and recurrence outcomes did not differ according to the primary tumour.

In terms of safety, researchers reported that radiation necrosis and haemorrhage were the most common adverse events. Patients with melanoma brain metastases tended to show higher rates of side effects.