Hot flashes: Risk Factors

Mature woman white smiling

Over the next several issues, I’ll turn to hot flashes: What are the risk factors, what is the pathophysiology, and management. Today, we begin with factors associated with hot flashes for patients with or without cancer.

Risk Factors: Both men and women can get hot flashes due to hormonal changes that occur during the natural aging process, although hot flashes are more common among midlife women. Age, race, ethnicity, educational level (equivocal), smoking, genetics, and body mass index can play roles. Some of  my patients see exacerbations with alcohol, exposure to heat, stress, spicy foods, and caffeine.

Race: Some studies point to African Americans having a greater risk for hot flashes (in addition to greater severity) as compared to other races. Here are the results from the Study of Women’s Health Across the Nation for combined hot flash and night sweat prevalence: Japanese 18%; Chinese-Americans 21%; whites 31%; Latinas 21%, and blacks 46%.

Smoking: The few studies that address the issue suggest a link between smoking and hot flashes. Smoking can alter estrogen metabolism in at least 4 ways.

Heart: Women who have hot flashes for 6 days or more over 2 weeks (especially those who are overweight or obese) have a higher cardiovascular risk. The role of weight and body mass index is less clear.

Genes: Research into the link between genetics (estrogen metabolism and receptor genes) and hot flashes appears promising. For example, women with a change (polymorphism) in a gene spot called CYP1B1 are at a 1/3 greater risk of reporting more severe and persistent hot flashes.

Cancer-related risk factors: These are predominantly related to the rapidity of hormone withdrawal. Among women, this is most commonly a drop in internal estrogen levels; with men, it is a drop in testosterone. For women, this may be linked to stopping hormone replacement therapy (HRT) when hormone-dependent breast cancer is diagnosed, the start of anti-estrogen therapies for treatment, chemotherapy-induced disruption of ovarian function, or damage to the ovaries (for example removal or radiation). Younger women are less likely than midlife women to have menopause induced by chemotherapy. In men, hot flashes are most commonly associated with anti-testosterone treatments for prostate cancer.

Certain cancers can be due to secretion of hormones by the cancer itself. Examples include some carcinoid tumors, medullary thyroid cancer, pancreas cancer, and kidney cancer.

I’m Dr. Michael Hunter. In my next blog, I’ll look at the physiology of hot flashes: Why do they occur?

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Coming Soon for iPad  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minutes. Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Thank you.

No Cancer Rise from Japan’s Nuclear Disaster


As you know, our Japanese friends suffered a magnitude 9 earthquake (and subsequent tsunami) on March 11, 2011. Nearly 19,000 people died, and the Fukushima Daiichi nuclear plant was devastated, spewing radiation and leading to the evacuation of 160,000 from their homes. Now, the United Nations offers tat evacuation and sheltering significantly reduced the exposure to radioactive substances. The chair of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) explained that while a few individuals received extraordinarily high doses of radiation, there were no radiation-related deaths of acute effects among nearly 25,000 workers. Unlike Fukushima, people close to the then-Soviet plant were exposed to radioactive iodine in milk. The thyroid is the most exposed organ, as radioactive iodine concentrated there (children are especially vulnerable). For the Japanese, the UN committee offers that “the radiation dose levels were so low, that we don’t expect to see any increase in cancer in the future in the population.” Good news for the Japanese people, and for the world. I’m Dr. Michael Hunter.

The small print: Anything stated here is for general use only, and should not be construed as medical advice for an individual. Please check with your health care provider with any questions or concerns.