A retrospective study of patients with non-small cell lung cancer (NSCLC) who had received radiotherapy found that those who had been taking beta-blockers survived 22% longer than those who did not.  The patients, who had been taking the beta-blockers for conditions other than cancer, also had lower rates of cancer recurrence and metastasis (cancer spread to other parts of the body). Further studies are required to confirm any possible beneficial effects of beta-blockers on lung cancer survival.

Primary source: http://annonc.oxfordjournals.org/content/early/2013/01/01/annonc.mds616.full