Nerve block cuts hot flashes after breast cancer

NEW YORK (Reuters Health) - Blocking parts of the nervous system that regulate body temperature can reduce hot flashes and improve sleep in survivors of breast cancer, researchers reported on Thursday.

With the experimental nerve blocker therapy, the average number of hot flashes per week fell from about 80 to just 8. Very severe hot flashes were almost totally abolished and a marked drop in nighttime awakenings was also seen, according to a report in the online issue of the Lancet Oncology.

Hot flashes and sleep dysfunction are common in breast cancer survivors, particularly those who use anti-estrogen agents like tamoxifen. Conventional treatments, such as hormone therapy or herbal remedies, have proven either ineffective or have been linked to important side effects.

Blocking the function of "stellate cells" -- star-shaped nerve cell bodies found at the base of the neck -- has been used to treat various conditions for more than 60 years. Dr. Eugene G. Lipov, from Advanced Pain Centers in Hoffman Estates, Illinois, and colleagues hypothesized that this treatment may provide a safe and effective alternative to current therapies used to treat hot flashes and sleep dysfunction in breast cancer survivors.

The new study involved 13 survivors of breast cancer with severe hot flashes and night awakenings who received targeted delivery of a stellate cell blocker. Women were given one block, but during the course of the study they were permitted to have another if they thought that the beneficial effects were waning. Five women had one block and eight had two blocks. Symptoms were assessed one week before treatment and then every week after treatment for 12 weeks.

With treatment, the average number of hot flashes per week fell from 80 to 8, as mentioned, and severe hot flashes virtually disappeared. Night awakenings dropped from 19.5 per week prior to treatment to just 1.4 per week.

The findings of this study suggest that this type of nerve blockade can provide survivors of breast cancer with relief from hot flashes and sleep dysfunction "with few or no side-effects," the investigators conclude.

"Long-term relief of symptoms has the potential to improve overall quality of life and increase compliance with anti-estrogen medications for breast cancer," they say.

SOURCE: The Lancet Oncology, May 15, 2008.