The very small study reviewed here suggests that nerve blocking may ease hot flashes and night sweats in post-menopausal women being treated for hormone-receptor-positive breast cancer. These results were presented at the 2009 San Antonio Breast Cancer Symposium.
Hot flashes, night sweats, and difficulty sleeping can be common side effect of hormonal therapy medicines used to reduce the risk of hormone-receptor-positive breast cancer coming back (recurrence). These side effects can severely affect the quality of life of some women being treated for breast cancer.
The stellate ganglion is a group of nerves on either side of the base of the neck. These nerves affect many sensations and functions, including sweating and blushing. Injecting the stellate nerves with a long-acting numbing medicine (similar to what's used during dental procedures) can ease certain conditions, including extreme facial sweating. So doctors wondered if a stellate ganglion block might ease hot flashes.
In this study, 24 post-menopausal women being treated for hormone-receptor-positive breast cancer were having troubling hot flashes, night sweats, and difficulty sleeping. Most of the women were taking either tamoxifen or an aromatase inhibitor. Nearly all of the women also were taking one or both of two prescription medicines -- Catapres (chemical name: clonidine) and Effexor (chemical name: venlafaxine) -- to ease these symptoms.
All of the women had a stellate ganglion block injection on one or both sides of their necks using a long-lasting numbing medicine (chirocaine). The women got one or more injections and the procedure was done in a doctor's office. While 11 women had one injection, some women had a second or third injection if they didn't get any relief after the first one. Ten women got a second injection, which was done 2 months after the first. Three women got a third injection that was done 1 month after the second. Most of the women (14) were followed for about 6 months and the rest of the women were followed for shorter periods of time.
The women kept a hot flash scoring diary that recorded the frequency and intensity of the hot flashes. Sleep quality was analyzed with a tool called the Pittsburgh Sleep Quality Index.
After the nerve block:
Because the stellate nerves control some eye movements, people who have a stellate ganglion block temporarily may have Horner's sign or Horner's syndrome. The symptoms of Horner's sign include drooping eyelids, narrowed pupils, and loss of the ability to sweat on the side of the face where the nerve block was given. Some of the women did have Horner's sign right after they got the nerve block, but the symptoms went away quickly. None of the women had any other side effects from the nerve block.
The results of this very small study are promising and other very small studies have shown similar, promising results. Still, it's important to remember that these studies are VERY preliminary. Stellate ganglion nerve blocks shouldn't be used routinely until more is known about the benefits and risks of the procedure. The researchers who did these small studies wanted to know if stellate ganglion block would help at all. Based on these positive results, stellate ganglion block will be studied in larger groups of women. Researchers also are looking at using different methods to block the stellate nerves.
If you're a post-menopausal woman having troublesome hot flashes and sleep disturbances because of breast cancer treatment, you might want to talk to your doctor about this study. Until more research is done, your doctor probably won't recommend a stellate ganglion block. Still, there are other techniques you can use to ease hot flashes. Visit the Breastcancer.org All About Hot Flashes page to learn more about hot flashes, how to avoid them, and how to manage them.
SAN ANTONIO (MedPage Today) -- In a new application of an old procedure, stellate ganglion block significantly relieved intractable hot flashes, night sweats and sleep disturbances in postmenopausal breast cancer patients, data from a small clinical trial showed.
Hot-flash frequency and intensity declined for 17 of 24 patients, and the improvement persisted at last follow-up for two thirds of those who benefited from the treatment. Additionally, 14 of the 24 patients (58%) had improved sleep quality.
"These results confirm that stellate ganglion block is a feasible and safe procedure for hot-flushes," Patrick Neven, MD, of University Hospitals in Leuven, Belgium, told attendees at the San Antonio Breast Cancer Symposium.
"There were neither short- nor long-term side effects. Stellate ganglion block was efficacious in the majority of cases but only after more than one procedure."
Endocrine therapy for postmenopausal breast cancer often causes severe hot flashes, night sweats, and associated sleep disturbance.
Though many patients get relief from various medical therapies, many researchers believe the symptoms play a role in the high rate of discontinuation from anti-estrogen therapy among breast cancer patients.
Last year a Chicago-area anesthesiologist reported a 90% improvement in treatment-induced vasomotor symptoms in 13 patients enrolled in a pilot study of stellate ganglion block (Lancet Oncol 2008; 9: 523-532). Neven's group followed with a report of positive results in a nine-patient study (Breast 2009; 18: S67).
Investigation of stellate ganglion block continued with a prospective study of postmenopausal breast cancer patients who had severe sleep disturbance caused by intense hot flashes and night sweats that did not respond to other treatment.
Performed as an outpatient procedure, stellate ganglion block consisted of a 10-cc injection of chirocaine 0.25% at the anterolateral aspect of the C6 vertebra.
A second (contralateral) or third block was permitted only when the initial procedure failed to relieve symptoms and improve sleep quality.
All patients will be followed for 24 weeks.
At the time of the stellate ganglion block procedure, 16 of the 24 patients were being treated with tamoxifen and four others were taking an aromatase inhibitor. Almost all patients were taking clonidine, venlafaxine (Effexor), or both drugs for hot flashes.
Neven reported that 14 of the 24 patients had completed 24 weeks of follow-up. Five others had completed 12 weeks, and the remaining five had just completed the first week of follow-up.
Eleven patients had a unilateral block; ten had bilateral procedures, and three underwent a third stellate ganglion block procedure. Among the patients who had more than one procedure, the second block was performed two months after the first and the third at three months.
Patients recorded hot flash frequency and intensity in a daily diary. Investigators used the Pittsburgh Sleep Quality Index to assess sleep disturbance.
Stellate ganglion block had no effect on symptoms or sleep disturbance in six of the 24 patients. Two of the six had a unilateral procedure and the remaining four had bilateral procedures.
Of the 17 patients who had improvement in hot-flash scores, the improvement was maintained at last follow-up in five patients who had unilateral blocks, five who had bilateral blocks, and two who had three procedures.
Of the 14 patients with improved sleep quality, 12 had a durable benefit as of last follow-up.
The only adverse effect associated with the procedure was occurrence of Horner's sign, which resolved in 30 minutes or less in all cases.
"Stellate ganglion block is not for every breast cancer patient who has hot flushes and night sweats," Neven said in an interview. "It is for patients for whom nothing else has worked. For that group of patients, stellate ganglion block can provide relief in a majority of cases."
Charles Loprinzi, MD, of the Mayo Clinic in Rochester, Minn., has begun an evaluation of stellate ganglion block in postmenopausal breast cancer patients.
When word of the study reached patients, the queue of would-be participants extended outside his office the first day of enrollment.
"I'm not saying that I have proof that it works," said Loprinzi, who was the moderator of the poster session where Neven presented the findings. "I think it looks quite interesting and it might well work as a therapy for patients. Sometimes it is cheaper to do something like this than to treat patients with long-term drug therapy."
Neven reported no disclosures.Primary source: San Antonio Breast Cancer Symposium Source reference: Haest K et al. "Does the stellate ganglion block reduce severe hot flushes and sleep disturbances in breast cancer patients?" SABCS 2009; Abstract 809.
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