Vitamin D Associated with Higher Survival Rates Among Cancer Patients

Vitamin D graphic

What You Need to Know: Cancer patients who have higher levels of vitamin D when they are diagnosed tend to have better survival rates and remain in remission longer than patients who are vitamin D-deficient.

Background: The body naturally produces vitamin D after exposure to sunlight and absorbs it from certain foods. In addition to helping the body absorb the calcium and phosphorus needed for healthy bones, vitamin D affects a variety of biological processes by binding to a protein called a vitamin D receptor. This receptor is present in nearly every cell in the body.

“By reviewing studies that collectively examined vitamin D levels in 17,332 cancer patients, our analysis demonstrated that vitamin D levels are linked to better outcomes in several types of cancer,” said one of the study’s authors, Hui Wang, MD, PhD, Professor of the Institute for Nutritional Sciences at the Shanghai Institutes for Biological Sciences at the Chinese Academy of Sciences in Shanghai, China. “The results suggest vitamin D may influence the prognosis for people with breast cancer, colorectal cancer and lymphoma, in particular.”

The Evidence: The meta-analysis (study of studies) looked at the results of 25 separate studies that measured vitamin D levels in cancer patients at the time of diagnosis and tracked survival rates. In most of the research, patients had their vitamin D levels tested before they underwent any treatment for cancer. The study found a 10 nmol/L increase in vitamin D levels was tied to a 4 percent increase in survival among people with cancer.
Researchers found the strongest link between vitamin D levels and survival in breast cancer, lymphoma and colorectal cancer. There was less evidence of a connection in people with lung cancer, gastric cancer, prostate cancer, leukemia, melanoma or Merkel cell carcinoma, but the available data were positive.

“Considering that vitamin D deficiency is a widespread issue all over the world, it is important to ensure that everyone has sufficient levels of this important nutrient,” Wang said. “Physicians need to pay close attention to vitamin D levels in people who have been diagnosed with cancer.”

My Take: Many studies have established an association between low levels of vitamin D and a myriad of illnesses (for example, multiple sclerosis, macular degeneration, colon cancer, breast cancer, rheumatoid arthritis, heart disease, and more. Those closer to the equator appear to have lower incidences and death rates for certain cancers. Because exposure to ultraviolet light from sunlight leads to vitamin D production, researchers have wondered whether variation in vitamin D levels might be responsible for this association.

However, causality has not been established. Whether you can lower your risk of these diseases by increasing your vitamin D intake remains unknown. I am not enthusiastic about across-the-board recommendations regarding amounts for intake, since your blood vitamin D levels may depend on your weight, skin color, sun exposure, diet, genetics, and other factors. I do not think it is unreasonable to consider checking your blood level of vitamin D. With vigorous supplementation, your blood vitamin D levels may become toxic (too much vitamin D raises calcium levels, which can cause calcinosis – calcium is deposited in soft tissues such as the kidneys, heart, and lungs). On the other hand, many have levels that are too low. The safe upper intake level of vitamin D for adults is around 4000 IU daily (some patients are placed on higher doses, but only temporarily, and with monitoring of blood levels). Finally, excessive exposure to sunlight can increase your risk of skin 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.

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: Endocrine Society. “Vitamin D may raise survival rates among cancer patients.” ScienceDaily. ScienceDaily, 29 April 2014. <www.sciencedaily.com/releases/2014/04/140429133456.htm>; Mian Li, Peizhan Chen, Jingquan Li, Ruiai Chu, Dong Xie, Hui Wang. Review:The Impacts of Circulating 25-Hydroxyvitamin D Levels on Cancer Patient Outcomes: A Systematic Review and Meta-Analysis. The Journal of Clinical Endocrinology & Metabolism, 2014; jc.2013-4320 DOI: 10.1210/jc.2013-4320

Stethoscope: Should You Ask Your Health Care Provider to Clean It?

stethoscope doctor

Background: Although healthcare workers’ hands are the main source of bacterial transmission in hospitals, physicians’ stethoscopes appear to play a role. To explore this question, investigators at the University of Geneva Hospitals assessed the level of bacterial contamination on physicians’ hands and stethoscopes following a single physical examination. The study appears in the March issue of Mayo Clinic Proceedings.

Didier Pittet, MD, MS: By considering that stethoscopes are used repeatedly over the course of a day, come directly into contact with patients’ skin, and may harbor several thousands of bacteria (including MRSA) collected during a previous physical examination, we consider them as potentially significant vectors of transmission,” said lead investigator Dr. Didier Pittet, Director of the Infection Control Program and WHO Collaborating Centre on Patient Safety at the University of Geneva Hospitals. “From infection control and patient safety perspectives, the stethoscope should be regarded as an extension of the physician’s hands and be disinfected after every patient contact.”

The Evidence: 71 patients were examined by one of three physicians using sterile gloves and a sterile stethoscope. After they completed the examination, two parts of the stethoscope (the tube and diaphragm) and four regions of the physician’s hands (back, fingertips, and thenar and hypothenar eminences) were measured for the total number of bacteria present.

The stethoscope’s diaphragm was more contaminated than all regions of the physician’s hand except the fingertips. Further, the tube of the stethoscope was more heavily contaminated than the back of the physician’s hand. Similar results were observed when contamination was due to methicillin-resistant S.aureus (MRSA) after examining MRSA-colonized patients.

My Take: Contamination levels of a stethoscope are substantial after a single physical examination, and comparable to the contamination of parts of the physician’s dominant hand. Ask your healthcare provider to wipe down her stethoscope with an alcohol wipe. 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.

 

Chemotherapy for Breast Cancer and Aging

 woman white with wrinkles

What You Need to Know: Adjuvant chemotherapy for breast cancer is gerontogenic, defined as accelerating the pace of physiologic aging, a new study reported.

Background: Loss of organ function, characterized by an increase in cellular senescence, is one physiological part of aging. Markers of cellular senescence have been identified as leukocyte telomere length, expression of senescence-associated cytokines including interleukin-6, and expression of p16INK4a, and ARF in peripheral blood T lymphocytes (PBTLs).

The authors previously showed p16INK4a is a marker of accelerated molecular age in PBTLs associated with smoking, physical inactivity, and chronic human immunodeficiency virus infection. To date, reports have not explored how long-term effect of cytotoxic chemotherapy given with curative intent affects molecular aging.

The Study: Hanna K. Sanoff, MD, Norman E. Sharpless, MD, and Hyman B. Muss, MD, of the Lineberger Comprehensive Cancer Center in Chapel Hill, North Carolina, and their colleagues prospectively collected blood and clinical data from 33 women with stage I-III breast cancer before, immediately after, 3 months after, and 12 months after anthracycline-based chemotherapy. Blood was analyzed for markers of cellular senescence.

The Evidence: They observed increased expression of the senescence markers p16INK4a and ARF in PBLTs immediately after chemotherapy, and these remained elevated for at least 1 year after treatment. In an independent cohort of 176 breast cancer survivors, prior chemotherapy was associated with a persistent increase in p16INK4a at an average of 3.4 years after treatment. These results suggest the age-promoting effects of chemotherapy last for several years after treatment and may be permanent.

The authors concluded, “We have shown that cytotoxic chemotherapy potently induces the expression of markers of cellular senescence in the hematologic compartment in vivo, comparable with the effects of 10 to 15 years of chronologic aging in independent cohorts of healthy donors.” Further studies are underway.

I’m Dr. Michael Hunter, and I do wonder how much of this aging can be “undone” with physical activity such as exercise.

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: Journal of the National Cancer Institute (2014; doi:10.1093/jnci/dju057).

Breast Cancer: Does Saturated Fat Consumption Matter?

grilled meat steak diet french fries dinner

What You Need To Know: High intake of saturated fats may be associated with an increased risk of certain subtypes of breast cancer.

The Evidence: Sabina Sieri, Ph.D., of the Fondazione IRCCS Istituto Nazionale dei Tumori in Milan, and colleagues analyzed data from a prospective cohort of 337,327 women to assess the association between fat intake and development of breast cancer subtypes.

The researchers found that

  • High intake of fat was associated with increased risk of estrogen receptor (ER)-positive, progesterone receptor (PR)-positive disease, but not ER-negative or PR-negative disease, for the highest versus lowest quintiles of total fat (hazard ratio [HR], 1.20; 95 percent confidence interval [CI], 1.00 to 1.45) and saturated fat (HR, 1.28; 95 percent CI, 1.09 to 1.52).
  • High intake of saturated fat was associated with significantly greater risk of human epidermal growth factor 2 receptor (HER2)-negative disease.

“High saturated fat intake particularly increases risk of receptor-positive disease, suggesting saturated fat involvement in the etiology of this breast cancer subtype,” the authors write.

My Take: A definite link between dietary fat intake and breast cancer has not been clearly established. However, I think that there may be a very modest effect when comparing extremism of fat intake. We may better understand the relationship between dietary elements and breast cancer risk as we better stratify by specific breast cancer subtype. For now, I would take a prudent approach to dietary fat intake. You may get a benefit in terms of cardiovascular risk, if not more. 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: JNCI J Natl Cancer Inst (2014) dju068 doi: 10.1093/jnci/dju068; First published online: April 9, 2014

Triclosan: Does This Antimicrobial (In some Soaps and Toothpastes) Spur Breast Cancer Growth?

liquid soap

What You Need to Know: Don’t panic just yet (unless you are a mouse who uses certain soaps and toothpastes), as the research is only in lab dishes and mice. Still, some manufacturers are turning away from using tricolsan as an antimicrobial ingredient in soaps, toothpastes, and other products. New evidence suggests that tricosan and octylphenol promote the growth of human breast cancer cells in lab dishes and breast cancer tumors in mice.

Background: Hormonal imbalances seem o play a role in the development of some breast cancers. In this context, researchers are investigating whether endocrine-disrupting chemicals (EDCs) – which are compounds that act like hormones – might spur breast cancer growth. Research has found that two EDCs (triclosan, an antimicrobial ingredient in many products, including soaps, cosmetics, and cutting boards; and octylphenol, which is in some paints, pesticides, and plastics) have accumulated in the environment. Triclosan has been reported to be in the urine of 75 percent of Americans.

The Evidence: Kyung-Chul Choi’s team found that both agents interfered with genes involved with breast cancer cell growth resulting in more cancer cells. Mice exposed to these compounds had larger and denser breast tumors, compared to controls.

My Take: This research proves little, at least with respect to breast cancer among living humans. Still, the laboratory and mice data are consistent with the view that endocrine disruptors may be linked to breast cancer. Might be reasonable to avoid these compounds, even if we do not have high level evidence to do so. In addition, I typically recommend potential risk-reducing maneuvers such as: Exercise (such as 30 minutes, 5 days per week), for example  a brisk walk. Watch the weight, don’t drink too much alcohol (might be wise to have no more than one standard drink of alcohol daily, and keep 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: Mia M. Gaudet, Brian D. Carter, Alpa V. Patel, Lauren R. Teras, Eric J. Jacobs, Susan M. Gapstur. Waist circumference, body mass index, and postmenopausal breast cancer incidence in the Cancer Prevention Study-II Nutrition Cohort. Cancer Causes & Control, 2014; DOI: 10.1007/s10552-014-0376-4

 

 

 

 

Breast Cancer Risk: BMI Matters (Shape, Not So Much)

obese white woman

Summary: A study of predominantly white women finds a larger waist circumference is associated with higher risk of postmenopausal breast cancer, but not beyond its contribution to Body Mass Index (BMI). The study, by American Cancer Society researchers, fails to confirm previous findings that body shape itself is an independent risk factor for breast cancer. The current study appears in the April 2014 issue of Cancer Causes, and Control.

Background: Abdominal obesity is linked to a number of conditions, including heart disease, type II diabetes, and breast and other cancers. Those studies have led to the theory that having an “apple shaped” body, with weight concentrated in the chest and torso, is riskier than having a “pear-shaped” body, with fat concentrated in the hips, thighs and buttocks.

The Evidence: To explore the theory, researchers led by Mia Gadet, PhD, analyzed data from 28,965 women participating in the Cancer Prevention Study II. Among those women there were 1,088 invasive breast cancer cases diagnosed during a median 11.58 years of follow-up. They found a statistically significant positive association between waist circumference and postmenopausal breast cancer risk; however, when they adjusted for BMI, the association disappeared.

“Iif you have a high BMI, regardless if you are pear or apple shaped, you are at higher risk of breast cancer,” said Dr. Gaudet. “Most prior studies on this issue looked at BMI or at waist circumference, but had not looked at them together. This study brings some clarity to the association between obesity and risk of breast cancer.”

Dr. Gaudet says the data could help women focus on what’s important in what has been a confusing array of potential risk factors for breast cancer. “We know being overweight, particularly when the weight gain happened during adulthood, is one of the important modifiable risk factors for breast cancer in post-menopausal women. This new data indicates it’s not what shape you are, it’s what kind of shape you are in that probably ought to be their focus.” 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: Mia M. Gaudet, Brian D. Carter, Alpa V. Patel, Lauren R. Teras, Eric J. Jacobs, Susan M. Gapstur. Waist circumference, body mass index, and postmenopausal breast cancer incidence in the Cancer Prevention Study-II Nutrition Cohort. Cancer Causes & Control, 2014; DOI: 10.1007/s10552-014-0376-4


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