SAN ANTONIO — Stellate ganglion block may be an option for severe, treatment-refractory hot flashes and sleep disturbances in breast cancer patients.
In a prospective study, stellate ganglion block procedures led to significant improvements in 17 of 24 breast cancer patients with severe hot flashes despite pharmacotherapy with venlafaxine (Effexor) and/or clonidine, Dr. Patrick Neven reported at the San Antonio Breast Cancer Symposium.
The ganglion block is performed as an outpatient procedure and takes about 5 minutes. An anesthetist uses fluoroscopic guidance to inject 10 cc of anesthetic at the anterolateral aspect of the C-6 vertebra.
Benefits endured 12 or more weeks in 12 of the 17 responders. A single right-sided stellate ganglion block was effective in five patients. Following a second block placed on the opposite side, 5 of 10 patients had responses. Benefits also were seen in two of three patients who got a third block 2-3 months after the first, according to Dr. Neven of the University of Leuven (Belgium).
Stellate ganglion block was associated with no side effects other than the temporary Horner syndrome, which merely indicates the block has been successful. Horner syndrome involves pupillary changes, a droopy eyelid, and a one-sided decrease in facial sweating, typically lasting for about 20 minutes. The syndrome is “scary,” according to Dr. Neven, but patients are informed about it in advance.
Stellate ganglion blocks have been used for at least 6 decades to treat a variety of pain conditions, including chronic regional pain syndrome, migraine, and angina. The notion of using the procedure to treat severe hot flashes in postmenopausal women and in breast cancer patients is credited to Dr. Eugene G. Lipov, director of pain research at Northwest Community Hospital, Arlington Heights, Ill. In his 13-patient pilot study, the mean number of hot flashes per week plummeted from 79 at baseline to 7 at 42 weeks of follow-up. Ten patients needed additional blocks after a mean of 11 weeks (Lancet Oncology 2008;9:819-20).
Dr. Lipov demonstrated that the stellate ganglion has second- and third-order neuronal connections to key areas of the brain involved in temperature regulation and other functions. His proposed mechanism of benefit is that stellate ganglion block causes a prolonged reduction in brain nerve growth factor levels, resulting in decreased brain norepinephrine (Med. Hypotheses 2009;72:657-61).
Dr. Neven reported that sleep quality improved significantly in 14 of the 24 Belgian breast cancer patients, although the effect was temporary in 2 of them.
Session chair Dr. Charles L. Loprinzi said he found the Belgian study particularly interesting because, after speaking with Dr. Lipov, he too has undertaken a prospective pilot study of stellate ganglion block for hot flashes, with data available on eight breast cancer patients.
“Let me just say that similar results are being observed. We gave only one block, and we've seen a drastic decrease in hot flashes in the first 1-3 weeks. With follow-up out to 6 weeks, some women have their hot flashes come back, others don't,” commented Dr. Loprinzi, professor of oncology at the Mayo Clinic, Rochester, Minn.
A parallel improvement in sleep disturbances was seen. “Sleep problems in patients with hot flashes are often due to night sweats. Get rid of the hot flashes and the patients often sleep better,” he said.
Stellate ganglion block “might well work” for severe hot flashes, according to Dr. Loprinzi, but he'll reserve judgment pending the results of an ongoing randomized, double-blind clinical trial involving placebo injections of saline.
'We gave only one [stellate ganglion] block, and we've seen a drastic decrease in hot flashes in the first 1-3 weeks.'
Source DR. LOPRINZI
Stellate ganglion block improved symptoms in 17 of 24 breast cancer patients with severe hot flashes.
Source DR. NEVEN