Tuesday, September 2, 2014

Hormonal IUDs and Breast Cancer: Is There a Link?


by Sarah Cortez

It certainly goes without saying that birth control has been a major news story the past couple of months. Much of this coverage, of course, has revolved around the recent Supreme Court ruling and reactions to it. Outside of that media storm, there have been some other health-related birth control stories as well, a number of which have focused on the potential of a specific type of IUD - the levonorgestrel IUD - to increase breast cancer risk. 

Photo: Flickr/Theilr
So what do the data actually say about this link? Let’s take a look.

In case you are unfamiliar with the levonorgestrel IUD (brand name Mirena or Skyla), it is a small, plastic, T-shaped device that is inserted into your uterus by a healthcare provider, usually your gynecologist. It prevents pregnancy by releasing a hormone called levonorgestrel and can be left in your uterus for up to five years.

Much of this recent interest in levonorgestrel-releasing IUDs was sparked by a study published in Obstetrics & Gynecology that looked at the records of all 30-49 year old women in Finland who used a levonorgestrel IUD to treat menorrhagia (heavy periods).

The study reports finding that the Finnish women who used the levonorgestrel IUD for 5 years had a 19% increased rate of breast cancer compared to the general Finnish population. That’s bad, right? Well, hold on.

The study also reports that, for these women, ovarian cancer was decreased by 40% and endometrial (uterine) cancer was decreased by 54%. Seeing if the IUD could decrease the risk for, or prevent, endometrial (uterine) cancer was the actual goal of the study.

Remember, these women were receiving a levonogrestrel IUD to treat very heavy periods. Periods, which if caused by endometrial hyperplasia (overgrowth of the uterine lining), put them at increased risk for endometrial cancer. So the study showed that it helped prevent endometrial (uterine) cancer in women who used it to treat very heavy periods.

But, what about the increase in breast cancer?

The authors of the study advised not being too quick to assume that this increase in breast cancer is real. Prior studies have never found an association between levonogrestrel IUD use and breast cancer. So, the finding could just be an outlier or something else could be going on. We don’t know, for example, whether a group of women with very heavy periods has the same breast cancer risk as the general population.

Exactly how this finding translates from Finnish women to American women is also unclear, since the IUDs available in Finland are not exactly the same as those available in the United States

So before you decide to get rid of your IUD because of concerns about breast cancer risk, have an in-depth talk to your doctor. Discuss your family-planning goals, your family history, and your personal risk for breast, endometrial, and ovarian cancer. If your overall risk for breast cancer is low, the levonogrestrel IUD isn’t likely to put you in the high-risk category.

The three most important things women of child-bearing age can do to prevent breast cancer are: be physically active, stay at a healthy weight, and drink only moderate amounts of alcohol – if at all.


Reference

Soini T, Hurskainen R, Grenman S, Maenpaa J, Paavonen J, Pukkala E. Cancer Risk in Women Using the Levonorgestrel-Releasing Intrauterine System in Finland. Obstet Gynecol 2014;124:292-299.

Friday, August 15, 2014

New Study Confirms Weight is a Major Cancer Risk Factor

Photo: Flickr/Kizette
The subjects of weight gain, the obesity epidemic, and their major impact on health are brought up so much these days that they're easy to tune out.  So, if a few articles and news reports here and there pass you by - on accident or on purpose - we understand.  But we won't let that keep us from continuing to write regularly about the topic because it's something we're passionate about here at CNiC.

Why?

That's simple.  Overweight really is one of the most important health issues of our time, and much like tobacco in the middle part of the last century - unless we make some big strides against today's weight problem, generations will experience a greatly decreased quality of life and greatly increased rates of conditions like heart disease, diabetes, stroke, and cancer.  By keeping the issue upfront in articles, journals, and on social media, we can help push for policy changes and shifts in public attitude that will help address the obesity epidemic - much like we did with tobacco.  We've seen some very small positive steps recently on the obesity front, but we need to keep up - and expand on - these efforts.  

A study out today further confirms why.  Building on results from previous studies, researchers with the London School of Hygiene and Tropical Medicine published an analysis in The Lancet showing that increases in weight raise the risk of 11 different cancer, including esophageal, colon, liver, gallbladder, pancreatic, breast (post-menopause), cervical, uterine, ovarian, and kidney cancers, as well as leukemia.  Even for those in the healthy weight range (BMI of 18.5 - 24.9; or someone 5' 9" weighing 125 - 168 pounds), an increase of just one BMI point, say from 23 up to 24, was linked to an increased risk of cancer.

The researchers also calculated the percent of specific cancers likely caused by being obese or overweight (figure).  Five percent of all breast cancers diagnosed after menopause were linked to weight, as well as 11 percent of all colon cancers.  Each of these cancers is quite common.  Less common - but still very important - cancers had much greater percentages linked to weight.

In an accompanying editorial, titled Obesity: a certain and avoidable cause of cancer, Peter Campbell of the American Cancer Society concludes:
"We have sufficient evidence that obesity is an important cause of unnecessary suffering and death from many forms of cancer, in addition to the well recognised increased risks of mortality and morbidity from many other causes. More research is not needed to justify, or even demand, policy changes aimed at curbing overweight and obesity."
We certainly agree.  It's time to act more forcefully for prevention.  Yet, even though disease prevention is increasingly listed as a public health priority, funding and political backing for prevention programs still often lag behind fields like treatment and diagnosis. If we are to truly make headway in the fight against obesity and other key risk factors, prevention needs funding and political will commensurate with its large potential to reduce future disease burden.

Tuesday, August 12, 2014

Evolution of the Science on Aspirin Use and Colon Cancer Prevention

Yesterday, we posted about a new analysis suggesting that long term aspirin use is likely to have an overall health benefit in the general population even when its side effects are taken into account.  At risk of being wonky, we wanted to follow up on that with a figure that shows the general evolution of the science on aspirin use and colon cancer prevention.  

Though it's the cardiovascular benefits that come to most people's minds when they think of reasons to take a daily aspirin, the Cuzick et al analysis shows that most of the benefits from regular aspirin use don't come from the prevention of heart attack and ischemic stroke, they actually come from the prevention of cancer - including colorectal, esophageal, and stomach cancer, and possibly breast, prostate, and lung cancer.  Of these, colorectal cancer is the most important, making up about a third of the total cancer and cardiovascular disease benefits of aspirin use.  

The figure below (full size PDF) shows the evolution of the evidence on aspirin and colon cancer prevention.  Though the science has taken a while to develop, the findings of a number of early positive studies have been confirmed in later studies, and it seems we're finally reaching a point where broad recommendations for daily aspirin use to prevent cardiovascular disease as well as cancer may become a reality.




Monday, August 11, 2014

An Aspirin a Day...May Have Overall Health Benefits

Photo: Flickr/JenR
The writing was on the wall a few years ago, but it seems that we may have finally reached a point
where the scientific evidence points pretty convincingly to the potential health benefits of long-term regular aspirin use outweighing the potential risks for most people. That's the conclusion of a new analysis appearing last week in the Annals of Oncology

While the heart attack and stroke benefits of aspirin use, especially in those at high risk of such events, has been accepted for years, the cancer prevention benefits have been slower to catch on - even though the evidence for colon cancer prevention alone has been quite convincing.

This new analysis confirms the cardiovascular benefits of aspirin use while solidifying its benefits in both preventing and lowering mortality for colorectal, esophageal, and stomach cancer - and possibly for breast, prostate, and lung cancer.

Bleeding is the main concern with regular aspirin use, and the analysis found - not surprisingly - that the risks of events such as bleeding strokes (hemorrhagic strokes) and GI (gastrointestinal) bleeding go up with regular use.

However, after looking at all the benefits and risks together, the researchers found that use of a daily 75 - 325 mg aspirin for 5 or more years starting between ages 50 - 65 years had overall positive benefits.

After 10 years of use, risk of cancer, heart attack, and stroke was 9 percent lower in men and 7 percent lower in women after 15 years. Lower rates of cancer made up the large majority of this benefit, with colon cancer by itself making up about a third of the total benefit from aspirin use. Taking the risks of bleeding events into account, the overall health benefit dropped to about 6 percent for men and women. Lower but still overall positive.

Of course there are still many unanswered questions about the best approach to aspirin use. Because risk of bleeding goes up with age, it's unclear at what age people should stop taking aspirin because the risks outweigh the benefits. Figuring out the best way to identify people at risk of bleeding issues is another important topic, as is the best dose to use. While there's good evidence that a low-dose baby aspirin provides most if not all the benefits of, and likely has fewer risks than, a higher dose 325 mg aspirin, there are not yet definitive studies that have looked at the issue.

While anyone interested in starting on daily aspirin should first talk with his or her doctor, the data are now clearer than they've ever been that such use is likely to have real and lasting health benefits for most people.

Tuesday, July 29, 2014

Missed Opportunities to Prevent Cervical Cancer: Use of HPV Vaccine Still Low

Photo: Flickr/Melissa Wiese 
To work in the field of cancer prevention one has to be an optimist at heart.  In the science, in the statistics, and in the news, you see not only the broad burden of cancer but also the vast opportunities that exist to lower risk and prevent the disease.

At the same time, we understand that shifting environments, attitudes, and behaviors in positive directions can take years, and most likely decades.  We didn't overnight become a nation where two-thirds of us are overweight/obese and half of us get little or no activity.  So it follows that shifting the pendulum in the other direction won't happen overnight either.  Such issues take daily efforts year after year to address both on a personal level and on a societal level.  There are no magic bullets.

Yet, however optimistic, there are two issues that leave many in the public health and medical professions scratching their heads over: the underuse of two relatively simple medical strategies that have vast potential for preventing cancer.

We've written at length about both of these strategies here in CNiC: the use of medications to prevent breast cancer in those at high risk of the disease (posts), and the use of the HPV vaccine to prevent cervical cancer (posts).

Of these two, the low use of the medications tamoxifen and raloxifene is perhaps the hardest to understand, given the large demonstrated benefits they have in preventing breast cancer in high risk women and the yawning gap between the number of women who likely stand to benefit from taking them (well over 2 million) and the number who actually do take them (just 117,000).

While new data on the HPV vaccine show there's been some progress in its use, the numbers also fall well short of what should be possible based on the use of other standard childhood vaccines. The vaccine is recommended for all girls and boys ages 11 or 12, given in a three dose course.  Its safety has been well-documented. Yet, only 57% of girls and 35% of girls get one or more doses of the vaccine.  Count only those who've received the full three doses, and the numbers fall to 38% for girls and 14% for boys.  Based on the number of children in this age-group cohort who receive other vaccines at their standard health care visits, and these percentages could realistically be as high as 91%.

The primary reasons parents give for not vaccinating their children were similar for both girls and boys, including the vaccine not being recommended by the health care provider, concerns about safety, and lack of knowledge of the vaccine or feeling it wasn't needed.

Both of these cases -  low use of the HPV vaccine and of tamoxifen/raloxifene - demonstrate just how important broad-based efforts at education are. It is not enough to demonstrate cancer prevention benefits - even benefits from activities as relatively simple as getting a vaccine or taking a pill.  Concerns of patients, parents, and health care providers must be appropriately addressed while we also move ahead fostering knowledge of, and demand for, the benefits the vaccine and preventive medications provide.

The trend in HPV vaccination show's we're making some progress on that front.  We have to be happy with that, but as usually, we'll keep striving for more.

Thursday, July 3, 2014

Alcohol and Health: Three New Studies and What They Mean for Youth and Young Adults

Photo: Flickr/Tim RT
It's been a big week in the news for alcohol and health. Three separate studies were released that helped shed light on a key issue we often discuss here at Cancer News in Context: the important impact that drinking has on cancer risk - particularly when started early in life.

The first report, which appeared in the online journal Preventing Chronic Disease, details the impact that drinking has on both disease risk and lifespan.  In the overall population, excessive drinking was found to cause over 87,000 deaths each year, resulting in 2.5 million years of life lost.  Acute causes - like car crashes, suicide/homicide, and falls - accounted for a little over half of these deaths, while chronic diseases - like stroke, cancer, and liver diseases - accounted for the rest.  Among working age adults (20 - 64 years), 10 percent of all deaths each year could be attributed to alcohol.

In those under age 21, alcohol accounted for about 4,300 deaths each year and a total of 249,727 years of life lost.  Not surprisingly, the most important contributors to these deaths were more immediate causes - car crashes and suicides/homicides -  rather than chronic diseases.  

Yet, just because the full chronic disease effect of excessive drinking doesn't show itself until later in life, this doesn't mean that drinking in youth doesn't have an important impact on later risk.  This seems especially so for breast cancer, where there is now good evidence that drinking in youth and young adulthood has a pronounced influence on later-life breast cancer risk.  Unlike most other organs in the body, the breasts continue to develop until a woman has her first child, and up until then, breast tissue appears more susceptible to harmful risk factors, like alcohol.  

This makes the results of another study released this week particularly concerning.  This study, released in the Journal of the American Medical Association - Psychiatry, found that younger generations of Australian women now drink much more excessively than did their mothers when they were the same age.  One primary reason for this is, simply, that women today are more likely to delay childbirth, deciding to have children later in life than their mothers did.  Without obligations of children and family there is greater opportunity for, and fewer drawbacks to, drinking.  

This new pattern  - which is likely mimicked across multiple nations - can have important implications for breast cancer for the reasons discussed above related to breast development.  Not only are women drinking more, they're doing so during the key period in breast development between first having a period and having a first child.   

Finding effective ways to help adolescents and college-aged women understand these risks and avoid alcohol - or at a minimum avoid excessive amounts of alcohol - will be a challenge for health professionals moving forward.  

Another paper released in the journal Nature this week could eventually help with this (related NPR story).  Researchers looked at various characteristics of 700 European 14 year olds - from family history, to personality traits, to brain anatomy - to see if any patterns emerged that predicted drinking at age 16.  They found that life experiences, personality, and certain aspects of brain anatomy could predict with decent accuracy who would go on to become problem drinkers.  While using such an algorithm is a long way off from practical application, it does show that it may be possible in the future to identify in the health care setting which youth may be more likely to put their health at risk with early life drinking.  Interventions could then be better targeted and would hopefully be more effective at curbing youth drinking.

Despite the depictions in magazine, TV, and website ads, drinking is a major minefield for adolescents and young adults.  There's the very immediate dangers of car crashes, injuries, and unsafe sex, and the longer-term dangers of alcoholism, cancer, and other chronic diseases.  Forming effective channels to reach out to youth with such messages needs to be a continued priority for public health.

Friday, June 27, 2014

Time on the Side: New Analysis Finds That to Eat Less - Eat Slower

Photo: Flickr/thomashawk

It probably comes as no surprise, but mom was right: We really shouldn't eat so fast.

Apart from the noise and the mess and the ill-effects on dinner table conversation, wolfing down food may have ill-effects on health as well.

A detailed new analysis in the American Journal of Clinical Nutrition shows that taking your time when you eat can substantially cut down on how much you eat.  And in today's world, where at least two thirds of the nation struggles with weight, this can have important implications.

The researchers performing the analysis combined the results from 22 separate studies looking at speed of eating and the amount of food eaten.  What they found was that those who ate their food slower ate less overall than those who ate their food faster, and apparently without feeling deprived.  Eating speed - fast or slow - had no effect on feelings of hunger, either right after a meal or three and half hours later.

We live in a society that often works against us when it comes to choosing healthy food and getting physical activity.  This can make it tough to lose weight, or even stay at the same weight. Yet, there are some simple steps we've promoted for a long time that can help with cutting back on calories and burning more calories through exercise.  Eating more slowly is one of these.  It may take some re-training of eating habits but in the end, its a pretty simple step  - just sit back, enjoy your food, and let time do the hard work.  In the end, we're likely to have eaten less - and to feel just as satisfied.

Try this and other tips to help keep weight in check: 

Choose smaller portions, and eat more slowly.  At the most basic level, eating slowly gives our stomachs time to tell our brain when we’ve had enough food.  As competitors at the Nathan’s Hot Dog eating contest will tell you, it takes about 8 minutes or so for the brain to register when the stomach’s full.  If you eat too quickly, you can down a plate of food, grab more, and then down that before your brain knows what hit it.  By then, you may have had twice as much food as you needed or even really wanted.  So why not slow down and enjoy your food.  You won’t even miss the extra food you’re not eating and that you didn’t even really want.

Fit physical activity and movement into your life each day.  Regular activity is one of the best ways to keep weight in check.  Choose things you enjoy that get you moving and shoot for at least 30 minutes a day.  And studies show that 60 minutes or more is even better for weight loss. 

Limit time in front of the TV and computer.  Screen time – the phrase given to time spent with our TVs, computers, phones, and tablets – is a double whammy when it comes to weight and health. Not only does it up the amount of time we spend each day in complete inactivity, but it also makes it more likely that we’ll overeat (especially unhealthy foods) while we’re sitting in front of those screens.  Shoot for under two hours of non-work screen time each day.  Less is even better.  Zero is ideal.  

Eat a diet rich in fruits, vegetables, and whole grains.  Eating a lot of plant-based foods can help keep appetite and weight in check.  Not only are they very filling but they also keep at bay wild swings in blood sugar that make you want to eat – even if you’ve just had a big meal.  Shoot for at least 3 servings of whole grains a day, 5 serving of fruits and vegetables, and keep red meat to a minimum.