Circadian rhythm of hot flashes and activity levels among prostate cancer patients on androgen deprivation therapy

Abstract

Objective. Altered circadian rhythms have been identified in untreated prostate cancer patients. Findings of restored rhythmicity following cancer treatment may have relevance for cancer control and symptom management. This study assessed and compared the cyclic patterns of hot flashes and activity levels in treated prostate cancer patients.

Methods. Data were collected during two 24-h periods among 47 prostate patients undergoing androgen deprivation therapy (ADT). Hot flashes were detected objectively through sternal skin conductance and by patients via electronic event marking. Activity levels were recorded on a wrist actigraphy device.

Results. The mean frequency of objectively measured and patient-reported hot flashes was 13.6 (SD = 14.3) and 12.6 (SD = 9.6), respectively. There were significant 24-h circadian rhythms of both hot flashes and activity levels. The peak of the rhythms occurred in early afternoon. There was no significant cross correlation between hot flashes and activity levels.

Conclusions. The acrophases of hot flashes and elevated activity levels in this study may represent a normalisation of circadian rhythms following ADT, pointing to the need for more research, including controlled, prospective chronobiologic studies. Future research may have important implications for the survival of prostate cancer patients and the identification of new and safe hot flash treatments.

Keywords:

• Circadian rhythm
• hot flashes
• actigraphy
• prostate cancer

Acknowledgement

The authors thank Nalaka Gooneratne, MD, for his contributions to this study.

Declaration of interest: The authors report no conflicts of interest. This work was supported by the Department of Defense [grant number DAMD17-02-1-0125]. The content of this publication does not necessarily reflect the views or policies of the Department of Defense.