Haest, K., Kumar, A., Van Calster, B., Leunen, K., Smeets, A., Amant, F., . . . Neven, P. (2012). Stellate ganglion block for the management of hot flashes and sleep disturbances in breast cancer survivors: an uncontrolled experimental study with 24 weeks of follow-up. Annals of Oncology, 23, 1449–1454.

Researchers studied the long-term efficacy of stellate ganglion block (SGB) treatment in reducing hot flashes (HF) and improving sleep disturbances in breast cancer survivors.  

Female breast cancer survivors who were experiencing HF and sleep disturbances were enrolled to undergo SGB treatment. A pilot study was conducted on nine patients before the main study enrolled 25 patients for the SGB treatment. In the pilot study, patient assessments occurred at baseline (one week before SGB) and four weeks after treatment. In the main study, patients were assessed at baseline and at weeks 1, 4, 12, and 24 after treatment.

• The pilot study enrolled nine women, and the main study enrolled 25.
• Median age was 53 years (range 34–69).
• Patients were included if they
  • Were women
  • Had nonrecurrent, early stage, postmenopausal breast cancer diagnosed more than five years prior
  • Had a Karnofsky Performance Scale score (KPS) greater than 80%
  • Had severe treatment-resistant HF.
• Patients were excluded if they had a change of antihormonal therapy for breast cancer within eight weeks of the first SGB, blood clotting disorders, use of anticoagulatants (other than low-dose aspirin), any acute infections, cardiac disorders, and an American Society of Anesthesiologists (ASA) classification score greater than three, as determined by an anesthetist.
• Previous use of systemic therapy for climacteric symptoms was recorded, but simultaneous use of these agents was not allowed.

• Single site   
• Outpatient
• University Hospital, Leuven, Belgium

• Patients were undergoing the transition phase of care after initial treatment.
• The study has clinical applicability for late effects and survivorship.

This was a prospective, single-arm, nonrandomized trial.

The Climacteric Symptom Form, HF diary, and Pittsburgh Sleep Quality Index (PSQI) were used to assess the efficacy of SGB on HF and sleep quality. 

This study was divided into two parts:  a pilot study of nine patients and the main study of 25 patients. All patients completed the treatment intervention (SGB) and the assessment to week 24.

• Pilot study:  Five of nine patients had a unilateral SCB; the remaining four had the block bilaterally. Three patients reported no change in HF or sleep quality. Six reported improvement in either the severity of their HF or in sleep quality. All patients required a bilateral SGB to maintain the improvement. 
• Main study: This study showed a decrease in the HF score of 64% (95% confidence interval [CI] [49, 74]) at week 1 and 47% at week 24 (95% CI [27, 62]). The odds ratio for improved sleep quality at week 24 compared with baseline was 4.26 (95% CI [1.86, 9.77]). Thus, SGB seemed to maintain its positive effect on sleep quality over time.

SGB appears to be effective in reducing the number of HF and improving sleep quality in women with early stage breast cancer who are experiencing HF and are resistant to other therapies. The HF gradually returned over time, whereas the improvement in the sleep quality was maintained over 24 weeks. The study demonstrated excellent patient compliance and noted very few side effects other than treatment-induced Horner’s syndrome (ptosis, miosis, anhidrosis, and enophthalmos) that lasted less than six hours.

• The study lacked an appropriate control group.
• The study had a small sample size. The article contains both the data from the pilot study of nine patients and the main study of 25 patients.
• Terminology used in this article was difficult to interpret, and statistical applications for results were confusing.
• There was no consistency to performing a unilateral versus bilateral SGB or to the timing of the second SBG.

The treatment was reported to be safe and very well tolerated, and the side effects were minimal. Further investigation is warranted to identify feasibility in community practices as well as further identification of the appropriate patient population for this intervention.