Red Meat and Cancer: What’s The Beef?

Roast beef cooked under high heat
Roast beef cooked under high heat (Photo credit: Wikipedia)

With a nod to Oprah, I’ll say it: Please (beef industry), don’t sue me! Today, let’s take a brief look at the relationship between red meat and various cancers.

Prostate cancer: Positive association between prostate cancer and high intake of red meat cooked at high temperatures, pan-fried, or well-done.

Pancreas cancer: No link to red or processed meat or fish; possible link to high consumption of poultry.

Bladder cancer: Processed meats may raise risk.

Esophagus cancer: Studies of studies (meta-analyses) appear to increase risk. Higher fish intake lowers risk.

Lung cancer: High red meat intake increases risk (by 35%).

Hepatocellular carcinoma (liver cancer): Fish reduces risk.

Kidney cancer: Red meat increases risk for renal cell carcinoma.

Breast cancer: Not consistently linked to meat intake.

Uterus cancer: Modest association between heme iron, total iron, and liver intake (not with red or processed meats). Other studies have not linked red or processed meat with uterus cancer.

In summary, red meat is one dietary factor that can increase your risk of getting certain cancers. In future blogs, we’ll dive a bit deeper to better understand the association, and what you can do to lower risk. I’m Dr. Michael Hunter.

Reference: http://www.medcape.com/viewarticle/806573

Prostate Cancer: Surgery and Radiation Have Similar Long-term Toxicities

Photo of linear accelerator
Linear accelerator for radiation therapy                         (Photo credit: Wikipedia)

A recent student represents the first large-scale comparison of long-term quality of life among patients treated with radical prostatectomy versus external beam radiation therapy (EBRT) for prostate cancer. Today, we turn to this important research.

Study: Dr. Matthew Resnick and colleagues used data from the Prostate Cancer Outcomes Study, a population-based cohort of patients whose prostate cancer had been treated in the mid 1990s and who had been prospectively followed for 15 years. The goal? To compare urinary, bowel, and sexual function after prostatectomy or radiation therapy for localized prostate cancer. Included were 1,655 men between the ages of 55 and 74. Of these 1,164 had surgery and 491 had radiation therapy. Researchers examined functional status at baseline and again at 2, 5, and 15 years after diagnosis. Full results may be found in the New England Journal of Medicine 2013;368:436-334.

Results:

Pro-radiation: Patients who had surgery were more likely to not be able to control their urine (urinary incontinence) compared to radiation therapy (at 2 years: over 6x more likely; at 5 years, over 5x more likely. By 15 years, however, there were no differences between radiation therapy and surgery in terms of urinary incontinence. Surgery also led to more impotence at 2 years (3.5x more likely) and 5 years (2x more likely), but the treatment groups were similar by 15 years. By 15 years, the impotence chance was around 80% if you started out with good function, and nearly 90% if you did not!

Pro-surgery: Patients undergoing prostatectomy were less likely to have bowel urgency at 2 years (radiation therapy 2.5x more likely to cause it) and 5 years (double the risk with radiation therapy). The % that dropped bowel function was about 10% for radiation, and 5% for surgery by 15 years.

My take: Give that the median survival following treatment for prostate cancer approaches 14 years, it is important to look at long-term quality of life among men living with a diagnosis of prostate cancer. This study hints at potential compromises in quality of life with either radiation therapy or surgery. However, it is not a randomized trial, and the study loses power over time as the number of men followed shrinks (for example, due to death from other causes). At 15 years, there were no significant relative differences in disease-specific functional outcomes comparing surgery versus radiation therapy. Still, caveat emptor: Men treated for localized prostate cancer commonly had declines in all functional domains during 15 years of follow-up. If you are contemplating treatment for low-risk prostate cancer, ask carefully about side effects. And ask if you might be a candidate for active surveillance. 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.

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

Nuts: Can They Lower the Risk of Diabetes?

English: a walnut and a walnut core

First of all, I should state what may be obvious: There is an epidemic of type 2 diabetes in the USA and in the world. Fortunately, lifestyle and diet are key drivers of the phenomenon, so there is hope that we can change the incidence of the disease. Research suggests that the type of fat eaten may play a role. Higher intake of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs – don’t say it like Sam Jackson) and lower consumption of saturated fat and trans fat lowers the risk of type 2 diabetes.

Recent study: A prospective study done as part of the Nurses’ Health Study (NHS)and the NHS II looked at walnuts and other nuts. The goal? To better understand the nut-diabetes reduction link. They also tracked body mass index.

The results: Tree nut and peanut consumption are linked to lower rates of the development of diabetes, but not when adjusted for body mass index. On the other hand, walnuts appear to be independently associated with a lower rate of development of type 2 diabetes, even when adjusted for body mass index. More than 2 servings per week reduced risk by about a third!

My take: We probably should eat nuts, especially walnuts. In moderation, of course. Watch out for the caloric density of the nuts, and remember to aim for a health body mass index of 20-25. But… maybe the consumers of walnuts in the study also ate more health foods. There was no subgroup analysis to remove confounding variables like that. Still, I personally eat half a dozen walnuts 2 to 3 times per week.

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. All can be found at the Apple Ibooks store. Thank you.

Hot Flashes: Management Options

Full of Soy Lunch
Full of Soy Lunch (Photo credit: Bunches and Bits {Karina})

Long blog warning: I wish I could be more like the Dadaist Marcel Duchamp, who once offered: I shall be so brief that I am now done!

There are a wide variety of options for those with hot flashes. These may be conveniently divided into pharmaceuticals, neutraceuticals, surgical ones (stellate ganglion blacked). Complementary/behavioral therapies include acupuncture, exercise, yoga, and others. In today’s blog, we will look at neutraceuticals. Neutraceuticals include herbal remedies, vitamins, and phytoestrogens.

Herbals: Black cohosh is an herb made from a North American perennial plant, and has been well-studied among women with menopausal symptoms (bit not for men with prostate cancer). Black cohosh is not estrogenic, instead acting on serotonin receptors. A study of studies (meta-analysis) showed that in 6 of 9 randomized trials, black cohosh as the potential to reduce hot flashes. But, more recent trials show no effectiveness among women without cancer. Potential side effects include mild gastrointestinal upset, headaches, vomiting, and dizziness at higher doses.

St. John’s Wort is a perennial herb from Europe, and has been reported to have anti-depressant properties. Most of the studies regarding hot flashes have been limited to women experiencing natural or surgical menopause. The data is mixed on its efficacy. Because it can activate certain enzymes (called cytochrome P450 enzymes), you must check with your health care provider before taking it.

Vitamins: Vitamin E has been investigated for hot flashes: There have been 3 randomized trials, and to me it seems that vitamin E has minimal efficacy. It appears to reduce the number of hot flashes per day by only 1 to 2. A study of studies (meta-analysis) of 57 trials showed no relationship between death rates (all-cause mortality) and vitamin E. Those with heart disease, diabetes, and high blood pressure should take heed. And there is some concern about a possible increase in cancer incidence. Multivitamins with minerals may help hot flashes improve for a few months, but the advantage over placebo disappears by the 3 month mark. Folic acid is under investigation, but there are some hints that it may reduce hot flashes by reducing levels of a byproduct of norepinephrine.

Phytoestrogens: Soy products have been analyzed in a meta-analysis of 19 randomized controlled trials of soy isoflavones. Soy did appear to reduce hot flashes, when compared to a placebo. The median dose across the studies was 54 mg. The effects on men are not clear, but at least one report has not shown a benefit among men with prostate cancer. And the safety for men has not been established.

Similar to soy, red clover results have not been especially impressive. A recent randomized trial of black cohosh, red clover, placebo, and hormone therapy showed red clover didn’t work (at a dose of 398 mg per day). Among men, it has not been well-studied. Flax seed is a rich source of lignans. Three randomized trials have shown no benefit for hot flashes (women). It has not been well-investigated among men.

My take: For these interventions, differences in information about product purity, dosing, and side effects makes comparisons across studies difficult. Unfortunately, there is a lack of standardization (the US Food and Drug Administration) has minimal oversight. Multivitamins with minerals may temporarily improve symptoms, and soy seems to have some activity against hot flashes in women. For many, neutraceutical do not have the desired reduction in hot flash frequency or severity. Next, we’ll turn to surgical therapies such as a stellate ganglion block. Hint: It may work(!), but the data is limited.

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. All can be found at the Apple Ibooks store. Thank you.

Reference: Fisher WI et al. CA: A Journal for Clinicians, vol 63 (3).

Hot Flashes: Physiology

hot flashes

Don’t blame the messenger! The physiological mechanisms of hot flashes are unknown. However, we have some clues that they are linked to 1) thermoregulatory disruption; and 2) neurochemical disruption.

Thermoregulatory Disruption: Hot flashes have been described to be an exaggerated response to changes in the thermoregulatory system. What does that mean? Thermoregulation maintains your body temperature. Did you know that the threshold point between sweating and shivering can occur with a 0.4 degree (C) change in internal temperature: Sweating happens at higher-than threshold temperatures, with shivering at lower temperatures. In individuals with hot flashes, this thermoregulatory system is disrupted. This disruption may be due to changes in neurochemicals such as estrogen, norepinephrine, serotonin, glucose, and others.

Neurochemical Disruption: Estrogen is a strong suspect neurochemical linked to hot flashes. Unfortunately, while estrogen is the most effective drug intervention for hot flashes, we cannot offer it is your cancer is hormone-dependent. Estrogen appears to stabilize thermoregulatory disruption. It may reduce spontaneous fluctuations in core boy temperature after ovary removal. Estrogen therapy raises the sweating threshold.

But could it be that estrogen works via other chemicals? For example, changes in estrogen levels alter levels of the brain chemicals norepinephrine and serotonin. Drugs (such as clonidine) that activate norepinephrine can alleviate hot flashes. Drugs (such as  yohimbine) that block norepinephrine can exacerbate the symptoms. Around menopause, serotonin levels are positively correlated to hot flashes. Low blood sugar levels (hypoglycemia) may trigger hot flashes. Eating may provide an average of 90 minutes free from hot flashes.

We will turn to the management of hot flashes in the next blog. Thanks for hanging in there through the biochemistry-speak! 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.

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.

Reference: Fisher WI et al. CA: A Journal for Clinicians, vol 63 (3).

The Worst Time to Have a Colonoscopy (And Other Procedures)

colonoscopy cartoonYou have probably heard that July is not a great time to have elective surgery, as this is the month that all the new doctors have their first day in the USA. Actually, the data is mixed. Still, there are some times that are more dangerous than others:

  1. Public holidays: If you are admitted to the hospital on an emergency basis on a public holiday, you are nearly 1.5x more likely to be dead a week later!
  2. Late in the day: Colonoscopies are less likely to find polyps, as compared to earlier in the day. With each hour of the day that passes, the average gastroenterologist is 4.6% less likely to find a polyp. And a Duke study showed that the likelihood of anesthesia problems increases over the course of the day: 1% at 9 am, rising to 4.2% for those starting at 4 pm.

Conclusion: Early to bed, early to get the best colonoscopy and surgeries, and stay safely in your home, motionless, on public holidays.

Atlantic Monthly, June 19, 2013

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. Thanks!

 Interested in cancer? Check out my e-books for IPad at the ibooks store. Available now: Understand Col

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.