Because of treatment effects on hormones, women with breast cancer and men with prostate cancer have an increased risk of frequent and severe hot flashes after treatment. As many as 80% of patients across both genders experience the symptom, which can have an impact on sleep, mood, energy, and sexual function.

The ONS GuidelinesTM for Cancer Treatment-Related Hot Flashes in Women With Breast Cancer and Men With Prostate Cancer provide evidence-based recommendations for practitioners to manage the symptom among their patients. The full guideline by Kaplan et al. was published in the July 2020 issue of the Oncology Nursing Forum.

Hot Flashes Related to Cancer Treatment

Women receiving treatment for hormone-dependent breast cancer can experience an abrupt depletion of estrogen from chemotherapy-induced premature menopause, discontinuation of menopausal hormone therapy, or prolonged use of estrogen suppression therapies (e.g., tamoxifen, aromatase inhibitors), Kaplan et al. reported. The hormones are involved in thermoregulation, and replacement therapies typically used for menopausal women in the general population are contraindicated in women with hormone-dependent breast cancer. Use of androgen deprivation therapy to manage prostate cancer results in a similar depletion of testosterone, leading men to experience hot flashes, Kaplan et al. explained.

The ONS Guidelines share evidence-based pharmacologic and nonpharmacologic alternatives to manage hot flashes in either population of patients with cancer.

Pharmacologic Interventions

Women with breast cancer: Drug- or surgery-induced hot flashes in women with breast cancer may be managed with venlafaxine, paroxetine, or clonidine, which the guidelines classified as a conditional recommendation with a low certainty of evidence. Other choices include sertraline, fluoxetine, escitalopram, or duloxetine, which are also classified as conditional but with a very low certainty of evidence. Kaplan et al. said that the first set of recommended drugs is preferred over the second set, with particular emphasis on venlafaxine or paroxetine. If those agents are ineffective, try clonidine, then the other antidepressants.

The panel drew attention to the harms that the study reports associated with antidepressants, such as nausea, constipation, loss of sexual desire, fatigue, and dry mouth. Because many antidepressants are metabolized through the CYP450 enzyme pathway, they may interact with other medication for cancer or comorbidities. Additionally, paroxetine and fluoxetine inhibit the CYP2D6 pathway, which tamoxifen uses to develop active metabolites, so the medications are contraindicated in women with tamoxifen-induced hot flashes.

Men with prostate cancer: Drug- or surgery-induced hot flashes in men with prostate cancer may be managed with paroxetine or clonidine, which are classified as a conditional with a low certainty of evidence. Other choices include sertraline, fluoxetine, escitalopram, or duloxetine, which the guidelines classified as conditional with a very low certainty of evidence. Again, Kaplan et al. recommended that the first set of drugs is preferred over the second set.

The harms associated with antidepressants in women with breast cancer are similar for men with prostate cancer. The panel found that most of the identified harms in men were extrapolated from studies in women with breast cancer.

Nonpharmacologic Interventions

Physical activity with exercise programs or yoga has advantages over no treatment in the management of cancer-related hot flashes in both men and women. The guidelines classified the recommendation as conditional with a low certainty of evidence. None of the study reports noted any serious harms, although adherence rates were low.

ONS has tools and resources for oncology nurses to use to recommend exercise to their patients. The toolkit provides patient education information, staff education resources, and links to teaching videos. Learn more at ons.org/make-a-difference/quality-improvement/get-up-get-moving.

Additional podcast episodes discuss how experts incorporate physical activity conversations into care.

Interventions Lacking Evidence or Not Recommended

Insufficient evidence: The ONS Guidelines panel could not provide a recommendation for venlafaxine for hot flashes in men with prostate cancer because the drug has only been studied in women with breast cancer, Kaplan et al. explained.

Many nonpharmacologic interventions have only limited evidence that could not provide enough information to meet the rigor of the ONS Guidelines, including hypnosis, relaxation therapy, cognitive behavioral therapy, and acupuncture. Kaplan et al. recommended them only for use in well-designed clinical trials that are intended to build the body of evidence for interventions in men with prostate cancer or women with breast cancer.

Not recommended: When reviewing the evidence, the ONS Guidelines panel found reports of serious side effects related to use of gabapentinoids in patients with comorbidities or who were taking medications such as opioids. Because of the risk, the panel did not recommend use of gabapentinoids for hot flashes in women with breast cancer or men with prostate cancer.

Studies of dietary supplements such as soy, black cohosh, St. John’s wort, melatonin, and vitamin E are limited and many demonstrate no benefit or potential harms, so the guidelines panel did not recommend use of supplements for cancer-related hot flashes.

For more information about the ONS Guidelines for Hot Flashes Related to Breast and Prostate Cancer Treatment, including an overview of the methods used to develop the guidelines, refer to the full article by Kaplan et al.

Listen to a discussion about the hot flashes guideline on the Oncology Nursing Podcast, Episode 113: Manage Cancer-Related Hot Flashes With ONS Guidelines.