Response to the letter Re: Carvedilol blocks neural regulation of breast cancer progression in vivo and is associated with reduced breast cancer mortality in patients

We thank De Sanctis et al. for their interest in the findings reported in ‘Carvedilol blocks neural regulation of breast cancer progression in vivo and is associated with reduced breast cancer mortality in patients’ [ [1] ]. They raise the interesting suggestion that other conditions linked to elevated sympathetic nervous system (SNS) activity, such as pain and migraine, may influence cancer progression. De Sanctis et al's. comments about migraine are especially interesting given that beta-blockers are commonly taken long term and as a prophylactic treatment to reduce the frequency of migraines. It must be remembered however that migraine-pain (being episodic, with long periods of normality between) is likely to give a very different pattern of SNS activation than a more chronic pain associated with, for example, arthritis.