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!

Should doctors prescribe exercise?

young woman running city park

“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!

Low Sunlight Exposure and Higher Risk for Pancreatic Cancer

What You Need to Know: People living in countries with low levels of sunlight have a substantially increased risk for pancreatic cancer, even after taking into account a number of factors associated with the disease. Researchers found that low exposure to ultraviolet B (UVB) irradiance, which is related to both latitude and the degree of cloud cover, was associated with a six-fold increased risk for pancreatic cancer.

The Study: Investigators obtained age-standardized pancreatic cancer incidence rates for 172 countries from the International Agency for Research on Cancer’s GLOBOCAN 2008 database.

  • Data on energy intake from animal sources and alcohol consumption were obtained from the United Nations Food and Agriculture Organization, and the World Health Organization provided information on the prevalence of obesity, the sex-specific smoking prevalence, and per capita health expenditure.
  • Crucially, data from the NASAs International Satellite Cloud Climatology Project, which pertain to geographical variations in solar irradiance, allowed estimated UVB irradiance levels to be corrected for percentage cloud cover, inasmuch as heavy cloud cover does not transmit UVB.

Results: Overall, there was a higher incidence rate of pancreatic cancer with lower cloud-adjusted UVB irradiance, such that residents of countries with low UVB irradiance were approximately six times more likely to have incident pancreatic cancer than those living in countries with high UVB irradiance (P < .0001 for males and females).

The associations remained significant after taking into account per capita health expenditure, the geographical distribution, and factors known to be associated with pancreatic cancer, such as diabetes, obesity, alcohol consumption, and smoking. Interestingly, consumption of animal protein was positively associated pancreatic cancer in both sexes (P = .0190 in males; P = .0156 in females).

My Take: Given the strong association between UVB irradiance and pancreatic cancer risk, what about using vitamin D in an attempt to prevent or even treat pancreatic e cancer? There are a number of ongoing studies in both animal and human models on whether pancreatic cancer can be treated with vitamin D. Moderate doses of vitamin D seem reasonable as both a potential risk-reduction agent for a dreadful disease, and for consideration among those with pancreas cancer. 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.

Reference: American Society of Breast Surgeons (ASBS) 16th Annual Meeting. Presented April 30, 2015.

Can Green Tea Reduce Your Risk of Pancreas Cancer?

What You Need to Know: Green tea can change the metabolism of pancreatic cancer cells. While green tea has been thought to have potential anti-cancer activity, scientists have struggled to explain how it may work to reduce cancer risk, or to slow the growth of cancer. A recent study points to EGCG (a biologic constituent of green tea), as it changes the metabolism of pancreatic cancer cells by suppressing the expression of an enzyme associated with cancer (LDHA).

Details, details: Using sophisticated metabolic profiling methods, researchers found EGCG disrupts the balance of “flux” throughout the cellular metabolic network. Flux is the rate of turnover of molecules through a metabolic pathway. The researchers found EGCG disrupts this balance (as does another known LDHA inhibitor, oxalate).

My Take: This represents a new way to look at metabolism. Hopefully, we can use this increasing understanding of how cancer cell metabolism can be disrupted to try to prevent cancer, or to alter its course. 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: Qing-Yi Lu, et al. Metabolic consequences of LDHA inhibition by epigallocatechin gallate and oxalate in MIA PaCa-2 pancreatic cancer cells. Metabolomics, 2014; DOI:10.1007/s11306-014-0672-8.

Four in 10 Pancreatic Cancers Could Be Prevented by Lifestyle Changes

 What You Need to Know: Almost 40 per cent of pancreatic cancers — one of the deadliest forms of cancer — could be avoided through maintaining a healthy weight and not smoking according to research, in a call to arms against the disease. While more research is needed to find better ways of diagnosing and treating the disease, there is evidence to suggest that some pancreatic cancers are linked to being overweight and to smoking — and almost four in 10 could be prevented by lifestyle changes to address this.

“Survival for this disease remains shockingly low and this has to change. There’s an urgent need to tackle pancreatic cancer head on by building up an armoury of effective new treatments — and developing ways to diagnose this disease sooner, when surgery is more effective.”At the same time it’s important to remember that people can take steps to reduce their risk of developing pancreatic and other cancers, by not smoking and by keeping a healthy weight — especially if you are prone to carrying too much around your middle. Keeping physically active and cutting down on red meat may also help reduce the risk.”

– Professor Jeff Evans, a clinician and researcher at Cancer Research UK’s Beatson Institute in Glasgow

My Take: Pancreas cancer is rarely in the spotlight, unlike breast or prostate cancer. Pancreas cancer is challenging to manage, and I like that we are reminding folks that there are things you can do to reduce your risk of this often deadly disease. 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.

Does Aspirin Cut Your Risk of Pancreatic Cancer?

aspirin What You Need to Know: A new study adds to growing evidence suggesting that low-dose aspirin (known to reduce the risk for heart disease) may also reduce the risk for pancreatic cancer.  Background: Pancreas cancer has a 93 percent fatality rate. In the USA, there will be about 46,000 new cases annually, with 40,000 dying of the disease. The Study: Researchers from the Yale School of Public Health (USA) compared aspirin use among 362 pancreatic cancer patients and 690 randomly chose controls. Participants were asked about past and present use of aspirin, defined as at least once a week for three months. The authors controlled for age, sex, race, smoking, diabetes and other variables.

The Evidence: Regular aspirin use lowered the risk for pancreatic cancer by nearly half (48 percent).

  • Patients who used aspirin regularly for 1-3 years reduced their risk by 43 percent;
  • Patients who had been taking it for 7 to 20 years reduced risk by 56 percent.

My Take: We do not know why aspirin may reduce your risk of getting this often deadly cancer. Perhaps aspirin prevents the formation of new tumors. Alternatively, it may help the immune system fight cancer. As for you, ask your health care provide if a low dose aspirin might be for you. One needs to balance risks such as stomach ulcers against potential benefits (such as a reduction in heart attacks and maybe even cancer). While a baby aspirin (81mg) is not for everyone, your should ask if it is good for you personally. 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: Cancer Epidemiology, Biomarkers & Prevention. Published online June 26, 2014.; 23(7); 1-10 AACR (American Association for Cancer Research).