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 boys 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.