In a large study from MD Anderson Cancer Center, patients with non-small cell lung cancer (NSCLC) survived longer if they took beta-blockers while receiving treatment that included radiotherapy. Results were published online January 8 in the Annals of Oncology.
An analysis of 722 patients with locally advanced disease showed that those who took beta-blockers had improved disease-free and overall survival compared to those who did not take the drugs. The patients receiving beta-blockers also had better distant metastasis-free survival. The beta-blockers (predominantly metoprolol and atenolol) did not affect locoregional progression-free survival, however.
The researchers conducted the retrospective analysis to test their hypothesis that beta-blocker use could lower rates of disease progression and improve overall survival for locally advanced NSCLC. They identified patients who had been treated between 1998 and 2010 at the cancer center (Ann Oncol, January 8, 2013).
Some patients received chemotherapy and some did not, but all received a radiation dose of 60 Gy to 87.4 Gy during treatments delivered with 3D conformal radiotherapy (48%), intensity-modulated radiation therapy (42%), or proton beam therapy (10%).
The patients ranged in age from 34 to 95 years. Of the 722, 155 (21.5%) took beta-blockers for conditions such as heart disease and/or high blood pressure. Those taking beta-blockers tended to be older, have hypertension, have poorer Karnofsky Performance Status scores, and have less advanced disease. All patients were followed for a median of 44 months.
The patients in the beta-blocker group survived for an average of 23.7 months, compared with 18.6 months for the other 567 patients. After adjusting for other factors, the improvement in overall survival for the beta-blocker group was 22%, according to lead author Dr. H. M. Wang, from the department of radiation oncology, and colleagues.
The mechanism underlying the development of metastases is complex, but it may involve chronic stress conditions and prolonged exposure to stress hormones. Norepinephrine, for example, has been shown to stimulate the migration of tumor cells to other parts of the body. Receptors on the surface of cells, which beta-blockers are designed to inhibit, are involved in this process.
"Our findings agree with results from previous studies suggesting that beta-blockers have a specific effect on the cascade of events that lead to metastases," said co-author Dr. Zhongxing Liao, professor of radiation oncology, in a statement. "The fact that their use did not affect locoregional progression-free survival suggests that the drugs affect this metastatic cascade rather than the primary tumor."
