Should doctors prescribe exercise?

“Although the data vary by different cancer types, there is a consistent trend suggesting that moderate daily exercise has a beneficial effect on preventing certain cancers. If you are a reasonably healthy adult, your should exercise regularly.” 

Let’s look at the relationship of exercise and selected cancers. The American Society of Clinical Oncology (ASCO) has done a nice job of summarizing:

Breast Cancer

While the amount of risk reduction varies among studies (20-80%), most suggest that 30 to 60 minutes of moderate to high-intensity exercise per day lowers breast cancer risk. Women who are physically active throughout their life appear to benefit the most, but those who increase physical activity after menopause also fare better than inactive women.1

Colon Cancer

Research suggests that people who increase their physical activity can lower the chance of developing colon cancer by 30 to 40% relative to sedentary adults.1,2 A decrease in colon cancer risk can be achieved regardless of body mass index (BMI) and people who are most active benefit the most. There is insufficient evidence of a protective effect of physical activity on the risk of rectal cancer (a protective effect was seen in some case-control studies, but not in cohort studies).3

Endometrial, Lung and Ovarian Cancer

A handful of studies have suggested that women who are physically active have a 20-40% reduced risk of endometrial cancer compared to those who don’t exercise.1 Higher levels of physical activity seem to also protect against lung cancer (up to 20% reduction in risk), particularly among men.1Although less consistent, research suggests that physical activity possibly reduces the risk of ovarian and prostate cancer.

What about Other Cancers?

While observational data on the benefits of exercise for prevention of the types of cancers listed above are fairly consistent, evidence of the effects of exercise on prevention of any other type of cancer either is either insufficient or inconsistent.2,4

Prostate Cancer

Prostate cancer is one disease in which the data are not consistent, however prostate cancer is a heterogeneous disease and risk factor associations for total non-aggressive disease are different from aggressive / lethal disease. Most population based studies show similar findings, with little effect of exercise on overall incidence of prostate cancer but lower risk of aggressive prostate cancers for those with the highest levels of VIGOROUS activity (rather than any type of activity). In the Health Professionals Follow-up Study men 65 years or older who engaged in vigorous physical activity, such as running, jogging, biking, swimming or tennis at least three hours per week  had a 67% lower risk of advanced prostate cancer and 74% lower risk of fatal prostate cancer.5

Conflicting data for other malignancies

For example, one recent study found no association between physical activity and risk of developing gastric, rectal, pancreatic, bladder, testicular, kidney and hematological cancers.4 In contrast, a pooled analysis of data from prospective trials with 1.4 million participants found that physical activity was linked to lower risk of 13 cancers: esophageal, lung, kidney, gastric, endometrial, myeloid leukemia, myeloma, colon, head and neck, rectal, bladder, and breast.6Interestingly, leisure-time physical activity was associated with a higher risk of melanoma (presumably due to time spent outdoors) and prostate cancer, although it is not clear from these data whether that association was with nonaggressive or aggressive prostate cancer.

While we wait for confirmation and clarity on the role of exercise in preventing all the 200+ types of cancer – should doctors prescribe exercise? The answer is simple: yes, because evidence of the protective role of exercise is already strong for some of the most common cancers.

References

  1. Lee I, Oguma Y. Physical activity. In: Schottenfeld D, Fraumeni JF, editors. Cancer Epidemiology and Prevention. 3rd ed. New York: Oxford University Press, 2006.
  2. Slattery, ML. Physical activity and colorectal cancer. Sports Medicine 2004; 34(4): 239–252.
  3. Pham NM, et al. Physical activity and colorectal cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population. Jpn J Clin Oncol. 2012 Jan;42(1):2-13.
  4. Friedenreich CM, Neilson HK, Lynch BM. Eur J Cancer. State of the epidemiological evidence on physical activity and cancer prevention. 2010 Sep;46(14):2593-604.
  5. Giovannucci E, Liu Y, Leitzmann MF, et al. A prospective study of physical activity and incident and fatal prostate cancer. Arch Intern Med. 2005; 165(9):1005-1010.
  6. Moore SC, Lee IM, Weiderpass E, et al. Association of Leisure-Time Physical Activity With Risk of 26 Types of Cancer in 1.44 Million Adults. JAMA Intern Med. 2016 Jun 1;176(6):816-25.
  7. http://www.asco.org/about-asco/press-center/asco-resources-media/cancer-perspectives/should-cancer-doctors-prescribe?et_cid=38723632&et_rid=463715101&linkid=Read+more

I’m Dr. Michael Hunter. Of course, the disclaimer: Do not begin an exercise program without input from an appropriate medical professional. Many can simply start with a brisk walk for 30 minutes daily, 5 days per week. Have a wonderful day!

Hormone Replacement Therapy Increases Ovarian Cancer Risk

What You Need to Know: Taking hormone replacement therapy (HRT) for menopause, even for just a few years, is associated with a small increased risk of developing the two most common types of ovarian cancer, according to a detailed re-analysis of all the available evidence.

The Evidence: The findings from a meta-analysis (a study of a collection of studies) of 52 epidemiological studies, involving a total of 21488 women with ovarian cancer, almost all from North America, Europe and Australia, indicate that women who use HRT for just a few years are about 40% more likely to develop ovarian cancer than women who have never taken HRT.

“For women who take HRT for 5 years from around age 50, there will be about one extra ovarian cancer for every 1000 users and one extra ovarian cancer death for every 1700 users”, explains study co-author Professor Sir Richard Peto from the University of Oxford in the UK.

The effect of HRT on the risk of developing ovarian cancer was the same for the two main types of HRT (preparations containing oestrogen only, or oestrogen together with a progestagen). Likewise, the proportional increase in risk was not materially affected by the age at which HRT began, body size, past use of oral contraceptives, hysterectomy, alcohol use, tobacco use, or family history of breast or ovarian cancer.

There are, however, four main types of ovarian cancer, and an increase in risk was seen only for the two most common types (serous and endometrioid ovarian cancers), and not for the two less common types (mucinous and clear cell ovarian cancers).

My Take: While hormone replacement therapy can provide benefits for selected individuals, this study reminds us to be prudent: If you must use HRT (for example, for hot flashes not controlled by acupuncture, exercise, and attention to triggers such as heat, caffeine, alcohol, stress, and spicy foods), use the lowest dose of HRT that you can, for as short a duration as possible. HRT can also increase the risks of breast cancer and cardiovascular events (but may lower your risk of colon cancer, and help with hot flashes (among other symptoms of menopause). I’m Dr. Michael Hunter.

References: 

  1. Collaborative Group on Epidemiological Studies of Ovarian Cancer. Menopausal hormone use and ovarian cancer risk: individual participant meta-analysis of 52 epidemiological studies. The Lancet, 2015 DOI: 10.1016/S0140-6736(14)61687-1
  2. The Lancet. “Short-term use of hormone replacement therapy associated with increased ovarian cancer risk.” ScienceDaily. ScienceDaily, 12 February 2015. <www.sciencedaily.com/releases/2015/02/150212211945.htm>.

Some Cancers More Likely Among Taller Women

What You Need to Know:  A new study has found an increased risk for certain types of cancers in taller women.

Background: While obesity has long been named as a risk factor for cancer, a new study published in Cancer Epidemiology, Biomarkers & Prevention that adjusts for various factors including age and weight, has found an increased risk for certain types of cancers in taller women.

The Evidence: The study, which included 20,298 postmenopausal women, found that for every 10-centimeter (3.94 inches) increase in height, there was a 13% increase in the risk of developing certain cancers, including, breast, colon, endometrium, kidney, ovary, rectum, thyroid, multiple myeloma and melanoma. The most surprising finding for researchers was that weight seems to be a lower risk factor than previously assumed.

“We did examine variation in risk and there was no variation of levels of risk by weight,” says senior author Thomas Rohan, PhD, MD, chairman and professor of the department of epidemiology and population health at Albert Einstein College of Medicine.

Since you can’t really do anything about your height, what does this mean to tall women? Nothing specifically, says Dr. Rohan. He says the purpose of the study was not to make clinical recommendations and there was no thought of cancer screening or diagnosis implied in the study. Rather, the researchers were merely to try to add to the existing research into the biology of cancer development.

“We have been aware of some reports in the literature about the link between cancer and height, and we thought we could make a contribution to that research,” says Dr. Rohan.

In other words, don’t try to stunt your daughter’s growth so that her cancer risk is reduced when she is in her 70s.

Lead researcher Geoffrey Kabat, PhD, MS, a senior epidemiologist at Albert Einstein College of Medicine, noted that cancer is a result of processes having to do with growth, so hormones or other growth factors that influence height may also influence long-term cancer risk. The study also notes that height should not be thought of as a risk factor, but rather as a marker for exposures that may influence cancer risk. In other words, there are so many things that effect growth, that it’s almost beyond anyone’s ability to control.

The take-home message is not to panic, but to just appreciate one more small step in the ongoing quest to try to figure out exactly what makes cancer tick. I’m Dr. Michael Hunter.

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.

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

Reference: http://www.prevention.com/health/health-concerns/scary-link-between-height-and-cancer-risk

 

 

Sleep Apnea Linked to Cancer and Stroke Risk

CPAP sleep apnea

What You Need to Know: Moderate to severe obstructive sleep apnea isassociated with an increased risk of stroke, cancer and death.

Background: Sleep apnea is a serious sleep disorder that occurs when a person’s breathing is interrupted during sleep. People with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times. This means the brain — and the rest of the body — may not get enough oxygen.  There are two types of sleep apnea:

  • Obstructive sleep apnea (OSA): The more common of the two forms of apnea, it is caused by a blockage of the airway, usually when the soft tissue in the back of the throat collapses during sleep.
  • Central sleep apnea: Unlike OSA, the airway is not blocked, but the brain fails to signal the muscles to breathe due to instability in the respiratory control center.

The American Academy of Sleep Medicine reports that obstructive sleep apnea is a common sleep disorder that affects up to seven percent of men and five percent of women. It involves repetitive episodes of complete or partial upper airway obstruction occurring during sleep despite an ongoing effort to breathe. The most effective treatment option for OSA is continuous positive airway pressure (CPAP) therapy, which helps to keep the airway open by providing a stream of air through a mask that is worn during sleep.

 The Study: The study involved 397 adults who are participating in the ongoing Busselton Health Study. Objective sleep data were gathered in 1990 using a portable home sleep testing device. Participants with a history of stroke or cancer were excluded from selected analyses.

The Evidence: Results of a 20-year follow-up study show that people with moderate to severe obstructive sleep apnea are

  • four times more likely to die (hazard ratio = 4.2), nearly four times more likely to have a stroke (HR = 3.7),
  • three times more likely to die from cancer (HR = 3.4), and
  • 2.5 times more likely to develop cancer.

Results were adjusted for potential confounding factors such as body mass index, smoking status, total cholesterol and blood pressure.

My Take: If you think you may have sleep apnea, get evaluated. You may need medical intervention. Are you at risk for having sleep apnea? Sleep apnea can affect anyone at any age, even children. Risk factors for sleep apnea include:

  • Being male
  • Being overweight
  • Being over age 40
  • Having a large neck size (17 inches or greater in men and 16 inches or greater in women)
  • Having large tonsils, a large tongue, or a small jaw bone
  • Having a family history of sleep apnea
  • Gastroesophageal reflux, or GERD
  • Nasal obstruction due to a deviated septum, allergies, or sinus problems

 I’m Dr. Michael Hunter.

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.

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

 References: Nathaniel S. Marshall, Keith K.H. Wong, Stewart R.J. Cullen, Matthew W. Knuiman, Ronald R. Grunstein. Sleep Apnea and 20-Year Follow-Up for All-Cause Mortality, Stroke, and Cancer Incidence and Mortality in the Busselton Health Study Cohort. Journal of Clinical Sleep Medicine, 2014; DOI: 10.5664/jcsm.3600; http://www.webmd.com/sleep-disorders/sleep-apnea/sleep-apnea

Want To Stay Young? Start Moving.

women walking exercise

A new study finds that exercise among older adults helps ward off depressiondementia and other health problems, such as heart diseasecancer and diabetes. Exercise increased the odds of healthy aging as much as sevenfold, the researchers found. And apparently it’s never too late to start: Even adults who don’t begin exercising until they’re older could increase their odds of healthy aging threefold, the researchers said.

“In a growing elderly population, it is important to encourage healthy aging. Physical activity is effective in maintaining health in old age,” said lead researcher Mark Hamer, from the department of epidemiology and public health at University College London, in England.

For the study, Hamer and his colleagues collected data on nearly 3,500 people with an average age of 64 who took part in the English Longitudinal Study of Aging.

As part of the study, the participants reported their level of physical activity every two years between 2002-’03 and 2010-’11. The researchers categorized the participants by how much exercise they did each week. There were those who were inactive, those who did moderate exercise and those who exercised vigorously.

People who partook in moderate or vigorous physical activity at least once a week were three to four times more likely to be healthy agers, compared with those who remained inactive, the researchers found. Moreover, people who were active at the start of the study were seven times more likely to be healthy agers than people who were inactive and remained so, the researchers found.

My Take: Want to stay healthy? Get moving. I’m Dr. Michael Hunter.

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.

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

Reference: The report was published online Nov. 25 in the British Journal of Sports Medicine.

Depression Does Not Increase Cancer Risk

depression young woman depressed sad lonely

Does psychological depression increase your risk of getting cancer? We have long-suspected a link, but there is no good study to either confirm or reject this hypothesis. That is, until now.

The Study: The INSERM’s Mixed Research Unit 1018 “Epidemiology and Population Health Research Centre,” AP-HP, University of Versailles Saint-Quentin monitored 14203 people between 1994 and 2009, including 1119 who developed cancer. All of the absences from work for depression (certified by doctors) were recorded as well as many questionnaires measuring depressive moods. Five major types of cancer were monitored, including prostate, breast, colon, cancer associated with smoking, and cancer of the lymph nodes or blood (leukemias). THe mean (average) follow-up was 15.2 years.

The Results: Depression does not appear to increase the risk of getting cancer. Of course, a cancer diagnosis can cause symptoms of depression, so let your care team know if you feel down!

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.

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

Reference: C. Lemognem S,N, Consoli, M. Melchior et al. Depression and the Risk of Cancer: A 15-year Follow-up Study of the GAZEL Cohort. Am J of Epidemiology 2013.

Can Orange Juice Reduce Your Risk of Cancer?

orange juice splashing

Background: Who amongst us doesn’t love a nice, cold glass of orange juice at breakfast? Orange juice has many potential positive anti-cancer effects , particularly because it is high in antioxidants from flavonoids such as hesperitin and naringinin. Evidence from previous laboratory studies has indicated that orange juice might reduce the risk of leukemia in children, and may aid in chemoprevention against breast, liver, and colon cancers.

The Study: In a review article in Nutrition and Cancer: An International Journal, researchers review the available evidence that links orange juice with cancer chemoprevention. The review article, “Orange Juice and Cancer Chemoprevention” discusses the putative mechanisms involved in the process, the potential toxicity of orange juice, and the available data in terms of evidence-based medicine.

This review article summarizes several biological effects of orange juice that might contribute to chemoprevention, including antioxidant, anti-mutation,  and antigenotoxic, cell protective, hormonal, and cell signaling modulating effects. Orange juice has antimicrobial and antiviral action and modulates the absorption of xenobiotics. “Orange juice could contribute to chemoprevention at every stage of cancer initiation and progression,” the researchers explained.Among the most relevant biological effects of OJ is the juice’s antigenotoxic and antimutagenic potential, which was shown in cells in culture and in rodents and humans.”

My Take: This study is hypothesis -generating: Orange juice may have significant anti-cancer effects associated with it. It does not provide high-level evidence to prove it. The authors rightfully point out the dangers of too much of a good thing:  Consumed in excess amounts — especially for children, hypertensive, kidney-compromised, and diabetics – OJ can cause noxious effects, including hyperkalemia (blood levels of potassium that are too high), and has been associated with both food allergies and bacterial outbreaks in cases where the juice was unpasteurized. “Excessive intake of any food, even for the healthiest, can lead to oxidative status imbalance,” write the researchers. Still, OJ looks promising, and I really hope that additional research is done to determine the optimal amount of orange juice for cancer chemoprevention. As for me, I’m heading for my daily glass of OJ with breakfast!

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.

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