HPV Vaccine Prevents Cervical Pre-Cancer - New Report

By Hank Dart

An important new report further confirms that the HPV vaccine is both safe and extremely effective at preventing cervical pre-cancers that could develop into cervical cancer.

The report, published Wednesday in the Cochrane Library, reviewed the results of 26 HPV vaccine clinical trials that included over 73,000 girls and women ages 15 - 45 followed for between six months and eight years.

Human papillomavirus (HPV) is a common sexually transmitted infection, with up to half or more of adults -- men and women -- getting infected at some point in their lives.  Most of these infections clear up on their own.  Some, however, can persist.  And if they are of a high-risk type of HPV, they can increase the risk of certain cancers -- particularly cervical cancer.  Around 70 percent of cervical cancers are linked to HPV16 and HPV18. This new review assessed the potential benefits and risks of HPV vaccines that target these two high-risk types.

The researchers found the HPV vaccine to be very effective at preventing cervical pre-cancers -- abnormal changes in cervical cells that can develop into cancer.

In females aged 15 - 25 who did not have a high-risk HPV infection at the beginning of the study, those who received the HPV vaccine had a 99% lower risk of developing HPV16/18-linked cervical pre-cancer (CIN2+) compared to those who did not receive the vaccine (see figure).  And even when including those who may have had an HPV infection at the beginning of the study, those who were vaccinated had a 54 percent lower risk of HPV16/18-linked cervical pre-cancer (CIN2+) than those were weren't.

The researchers also found no difference in rates of serious side effects between those who were vaccinated and those who weren't. But they also noted that more extensive data are likely needed to fully explore any impact on such rare health events.

Our very first post in Cancer News in Context way back in 2003 was on the potential benefits of the, then new, HPV vaccine - "A Shot in the Arm for Cancer Prevention."  Now in 2018, this new report in the Cochrane Library demonstrates further the true prevention benefits of the vaccine.

In a prepared statement, Dr. Jo Morrison, Consultant in Gynaecological Oncology at the Musgrove Park Hospital in the United Kingdom, said:

"These data show that immunizing against HPV infection protects against cervical pre-cancer, and it is very likely that this will reduce cervical cancer rates in the future."

Yet, rates of vaccination in the United States lag.

Current guidelines recommend a 2-dose series of the vaccine for both boys and girls at age 11 or 12. In 2016, however, only 44 percent of boys and 55 percent of girls ages 13-17 had had 2 or more doses.  Rates of other childhood vaccinations, by comparison, are often around 90 percent or higher.

To bring rates of HPV vaccination up, we need to effectively communicate to parents the importance of the vaccine and its demonstrated safety, train physicians to recommend it, and implement policies that promote and sustain its use.

Compared to many other steps to lower cancer risk, HPV vaccination is relatively quick and simple. And it potential benefits are huge.  To realize these benefits, we just need more shots in the arm.

Protect Your Children with the HPV Vaccine

by Dr. Lindsay Kuroki

Parents grow up wanting their kids to be healthy and happy. And taking control of your child’s health may be easier than you think with evolving research. We know that with healthy eating, encouraging exercise, staying safe in the sun, and getting scheduled vaccinations your child is on the right path to having a lower cancer risk later in life.

What’s even better news is that within the past decade, a specific vaccine has also been created to protect against at least five different types of cancers. This vaccine, the Human Papillomavirus (HPV) vaccine, is now recommended for all girls and boys during their annual check-ups. 

HPV is a common sexually transmitted infection with over 100 different types of strands in existence. In fact, HPV is so common that an estimated nine out of 10 sexually active people will at some point be infected with HPV. Often times, HPV does not present with symptoms, which makes it hard to know when someone may be infected. For this reason, it is important to protect your child against HPV, as some forms of HPV can cause multiple cancers. At least two strands of the HPV virus have been shown to cause cervical, vagina, and vulva cancers in women, penile cancer in men, and head and neck cancer in both men and women. HPV can live for a long time in a person’s body, so someone may not know they have HPV, or an associated cancer, until years after being intimate with someone who carried the HPV virus. Sadly, HPV contributes to over 31,000 new cases of cancer each year, but we can reduce that number by protecting our children with the HPV vaccine.

Unfortunately, nationwide only 65 percent of girls initiate the HPV vaccination series and 49 percent receive the two recommended doses, while only 56 percent of boys initiate and 37 percent complete the series.

The good news is now the HPV vaccine is available for boys and girls to protect thems before they become sexually active. It’s also safe and over 90 percent effective. This success rate could prevent over 90 percent of HPV cases, or eliminate 29,000 new cancer diagnoses each year.

The Centers for Disease Control and Prevention (CDC) recommends that both girls and boys be vaccinated with a two-shot vaccine around ages 11 – 12. The second vaccine will be administered within one year after the first dose. The vaccine can be given until age 26, and being vaccinated after exposure to HPV will help reduce their risk of contracting future HPV infections. Adolescents and young adults, starting at age 15, who receive the HPV vaccine will require a three-dose vaccination series.

Protect your family against cancer, as it’s never too early to reduce your child’s risk. Talk with your pediatrician to schedule your child’s HPV vaccination.

Back to School Vaccinations: Don't Forget the HPV Vaccine

by Katy Henke

With Labor Day weekend bringing summer vacation to a close, parents are putting the finishing touches on preparation for the impending school year. In addition to school supplies and new clothing, parents should also be vaccinating their children prior to school starting. Vaccinations help prevent possible future infections and diseases. Prevention through vaccines is one of the best ways to help your child stay healthy during their lifetime and is recommended by multiple health organizations, such as the Centers for Disease Control and Prevention, the World Health Organization, and the National Cancer Institute.

Some of the more common vaccines parents may have heard of, and that some schools in the United States require, include Tdap, which protects against diphtheria and tetanus; IPV, which protects against polio; and MMR, which protects against measles, mumps, and rubella. These diseases have decreased in children and young adults throughout the years thanks to the use of vaccines. Influenza (flu) is another common virus that can help be reduced and infection prevented when children, teens, and adults receive the flu vaccine. Research continues to show that vaccines are important, safe, and effective for children and teens, and should be administered at appropriate ages. The CDC offers a quick vaccine guide for parents based on a child’s age.

A more recent vaccine, and one that’s often overlooked by many parents and doctors, is the human papillomavirus (HPV) vaccine. This vaccine protects against a specific strand of viruses that can cause cancer. The HPV virus affects one in four people. It’s estimated that 14 million people each year contract the HPV virus, which can lead to cervical and vaginal cancer in women, and penile cancer in men. More than 90 percent of sexually active men and 80 percent of sexually active women will contract a form of HPV at some point in their lives. Most HPV infections do go away on their own, but some don’t. The HPV vaccine helps protect and reduce these infection rates

The HPV vaccine series is recommended to both preteen boys and girls beginning around age 11 or 12, prior to when they would contract the HPV virus. This vaccine is a three-part series for both girls and boys, with the second shot given at one to two months after the first shot, and the final third shot given around six months after the first shot. Teenagers and young adults can also receive the vaccine up until age 26, so talk with your doctor today. The HPV vaccine will be most effective when the person being vaccinated receives all three shots.

Research continues to show that the HPV vaccine should very successfully prevent later adult cancers in preteens and young adults. Close to 100 percent of people who receive the vaccine will be protected against the types of HPV targeted by the vaccine. And studies have found that vaccination cuts the risk of cervical pre-cancer in about half.

The HPV vaccine is a safe and effective way to reduce the risk of cancer, yet vaccination rates are still low due in part to lack of knowledge and other barriers. Talk with your child’s doctor or your doctor today to learn if the HPV vaccine may help reduce their risk for cancer in the future.

Benefits TODAY from the HPV Vaccine (Infographic)

While the ultimate goal of the HPV vaccine is to prevent cancer, that benefit can feel very far off in the future, especially since vaccination ideally takes place in eleven and twelve-year-old girls and boys.  But studies looking at the five to six years after the vaccine was approved and became widely available show that it has real - and it seems impressively big - benefits over the short term.  For more details on the HPV vaccine and recommended vaccination schedule, visit the CDC's HPV page.

(PDF version)

Big Drop in Cancer-Causing HPV Following Vaccination, But Rates of Vaccination in US Lag

by Hank Dart

Thirteen years ago, in an earlier incarnation of Cancer News in Context, we wrote our very first post about the potential of the HPV vaccine following the release of a promising study in the New England Journal of Medicine. That post - "A Shot in the Arm for Cervical Cancer Prevention" -  concluded:

"While much work remains before there is any sort of widespread cervical cancer vaccination program in the U.S. or abroad, the results of this initial study spawn a realistic hope that over the next decade or so great strides will be made in preventing cervical cancer the world over."

Well here we are, that decade or so on from the original post, and the latest news on the HPV vaccine - as reported in today's New York Times - is quite positive, but with a number of important caveats.

HPV (human papillomavirus) is a common sexually transmitted infection, and certain types of HPV are a primary cause of cervical cancer. It's estimated that nearly all adults - men and women - are infected with HPV at some point in their lives. While the body naturally clears most of these infections, some can persist, increasing the risk of cervical (and a number of other) cancers.

New national data, as reported in the Times and published in the journal Pediatrics today, show that in the six years after 2006, when the HPV vaccine became available for girls, rates of infection with four main cancer-causing types of HPV(6, 11, 16, and 18) have dropped dramatically - as much as 64 percent in younger females (age 14 - 19), the age group that had been the most widely vaccinated.

Though only time, and data, will tell for sure, such findings seem likely to translate to significantly lower future rates of cervical cancer in today's groups of vaccinated girls and young women.

Alongside such positive news, however, is the fact that the HPV vaccine remains frustratingly underused in the United States.  As we wrote about in 2014, vaccination rates for the HPV vaccine are much below those of other childhood vaccines.  The most recent numbers show that only 38 percent of girls in the United States receive the complete 3-shot series of the HPV vaccine.  Boys' numbers are even lower - at 14 percent.  And low as these are, they are modest improvements from pervious years.

In comparison, in Australia, where the vaccine is offered for free at schools as part of its national immunization program, rates of full 3-dose HPV vaccination in girls is over 70 percent by age 15.

No such integration into systems has happened in the United States, and HPV vaccination remains in many ways on the fringe.  Though it has huge potential to prevent cervical cancer - as well as to lower the risk of anal, throat, and penis cancers, as well as genital warts - many physicians aren't proactive in suggesting vaccination, many parents don't know to request it,  and both groups may not be perfectly clear on its safety, effectiveness, and ultimate purpose of preventing cancer.

Clearly, there has been a lot of progress since our post in 2003 but perhaps not surprisingly it has been at a pace slower than hoped.  To be sure, there have been some "great strides" in further developing the vaccine, in documenting its safety and effectiveness, and - in certain countries - developing model vaccination programs.

But there is still a great deal of work to do before we tap the HPV vaccine's full potential in the United States - as well as worldwide.  This latest study shows the likely benefits of developing a better-integrated HPV vaccination program.  Let's use it to spur on coordinated efforts toward that important end.

HPV Vaccination Programs Shown Effective in Australia

Photo: Flickr/PAHOWHO

by Sarah Cortez

When given before the start of sexual activity, the HPV (human papillomavirus) vaccine prevents most cases of cervical cancer and genital warts. It can also lower the risk of oropharyngeal, penile and anal cancer.

HPV is a sexually transmitted infection, and we target the vaccine to 11-12 olds, as we expect children at this age to not be sexually active. This allows immunity to build up before any exposure to HPV occurs.

Though girls were the initial focus of the vaccine, it is now recommended that boys get vaccinated, too. Boys do not have cervices and, therefore, can’t get cervical cancer, but they certainly can get genital warts and the other rarer cancers linked to HPV. Importantly, males can also spread the cancer-causing virus to females.

As we have covered in previous posts, the use of the HPV vaccine has been slow to build in the US. But this is not the case in other countries.

A new study published in the open access journal PLOS ONE, details the effect of the Australian government’s national HPV vaccination program, using the Gardasil vaccine. Starting in 2007, the Australian government offered the HPV vaccine for free at school to all 11-12 year old girls on the standard schedule:

1. 1st dose at start
2. 2nd dose 1-2 months after 1st dose
3. 3rd dose 6 months after 1st dose

The Australian government also offered older schoolgirls (13-18 years old) and young adult women (18-26 year old) the vaccine for free through their general practitioners and community health clinics. This was referred to as the catch-up program due to the increased likelihood that patients were more likely to already be sexually active.

Preliminary results showed that by 2012, over 70% of all Australian girls had received the full 3 dose vaccine by age 15 and over 85% were vaccinated by the last year of high school. As a comparison, in 2012, the rates of 3-dose vaccination among adolescent girls in the US were only 35% by age 15 and 45% by age 17. 

So what resulted from this Australian vaccination program? Following its onset, the diagnosis of genital warts decreased by 93% among young women seen in the sexual health clinics. Additionally, the diagnoses of genital warts decreased by 82% among young heterosexual men. Remember, the vaccine was only free for girls, so the decrease in genital wart diagnoses for men who have sex with women was possibly due to something called “herd immunity,” where vaccination of a large percentage of a population (the “herd”) benefits even those who were not vaccinated.

The decrease in genital warts seen in the sexual health clinic is great, but the sexual health clinics see many fewer patients than general practitioners. So was the decrease in genital wart diagnoses also found in the general population?

To find out, the new study used data collected from over 11,000 Australian general practitioners who saw at least some Medicaid patients. Once a year since 1998, each general practitioner recorded 100 patient encounters. This method logged over 1 million patient encounters between 2000 and 2012.

What was the result? Did the general practitioners find the same decrease in genital warts after the start of the HPV vaccination program?

The answer is yes. Genital warts were found most often in 15-27 year old males and females. Following the vaccination program, genital wart management decreased by 61% among 15-27 year old females. As a comparison, they tracked the rate of other STDs like genital herpes. As expected, the diagnoses of other STDs did not decrease following the vaccination program.

There was no change in males or the 27+ age group, which did not receive the vaccination.

All in all, this is great news. The HPV vaccine works. It decreases genital warts among those who are vaccinated, and hopefully, in the future, we can replicate here in the United States the success Australia has seen. As for us at CNiC, we will continue to report the findings and outcomes of this important preventative health tool. 

References

Harrison C, Britt H, Garland S, Conway L, Stein A, Pirotta M, Fairly C. Decreased management of genital warts in young women in Australian general practice post introduction of national HPV vaccination program: Results from a nationally representative cross-sectional general practice study. PlosOne 2014; 9(9): e105967.

"Genital HPV Infection - Fact Sheet." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 20 Mar. 2014. Web. 12 Oct. 2014.

"National and State Vaccination Coverage Among Adolescents Aged 13–17 Years — United States, 2012." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 30 Aug. 2013. Web. 13 Oct. 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.

Vaccination Against Hepatitis B Prevents Liver Cancer

As reported in the New York Times, San Francisco has launched an important public health campaign to promote vaccination against the hepatitis B virus which causes liver disease and liver cancer (story). This campaign is important for several reasons. Infection is usually silent and the impact on disease is many years after initial infection.

Prevention programs for cancer take different durations for the benefit to be observed. Vaccination programs offer one insight to the time frame of intervention and the ultimate reduction in cancer incidence. For cervical cancer prevention with human papilloma virus (HPV) vaccine, the current U.S. Center for Disease Control (CDC) recommends vaccination for women between ages 13 and 26; the benefit of this prevention will be observed many years hence. Hepatitis vaccination programs in Africa and Asia offer further illustration of these points. In the Gambia, a program launched in 1986 aims to evaluate the effectiveness of childhood vaccination with hepatitis B and current estimates are that the final outcome of reduced hepatocellular carcinoma in adults should be measurable from 2017 onwards. In Asia with nationwide hepatitis B vaccination implemented in Taiwan in 1984, results at 10 years show significant reduction in hepatocellular carcinoma in children. Clearly many years of follow-up are required to demonstrate protection of adults, though this outcome is implied by results to date.

The etiology of some 18 per cent of cancers worldwide can be linked to chronic infections due to agents such as Helicobacter pylori, human papillomaviruses (HPV), Hepatitis B, Hepatitis C, Epstein-Barr virus (EBV), human immunodeficiency virus (HIV), human herpes virus 8 (HHV-8), and Schistosoma haematobium, with the proportion of all cancer due to infections being much higher in developing countries (26 per cent, compared to 7.7 per cent in developed countries). The current burden of cancer in the developing world is dominated by infection, once smoking is accounted for. Of 10.8 million new cases of cancer worldwide (2002 figures), those caused by infectious agents are estimated as: H. pylori 5.5 per cent (mainly stomach, and lymphoma); HPV 5.2 per cent (mainly cervix, and ano-genital, mouth, pharynx); HBV and HBC 4.9 per cent (liver); EBV 1.0 per cent (nasopharynx, Hodgkin lymphoma and Burkitt lymphoma), HIV and HHV-8 0.9 per cent (Kaposi sarcoma, non-Hodgkin lymphoma) and other less common agents including schistosomes, HTLV-1, and liver flukes, less than 0.5 per cent. More than 25 per cent of cancer incidence in developing countries could be avoided if infectious causes of cancer were prevented. Successful vaccination programs have the potential to reduce cancer incidence and mortality; for example, Taiwan’s HBV vaccination program was initiated in 1984, and impressively high coverage rates (up to 97 per cent in 2004) have led to a consistent decline in hepatocellular cancer rates. However, a recent study by Chang et al. underscores the importance of a multi-pronged approach. Though Taiwan has seen a decrease in the incidence of hepatocellular cancer in children since initiation of the vaccination program (from 0.54 to 0.20 per 100,000 before and after the program), vertical transmission, vaccine failure, and the lack of hepatitis B immunoglobulin injection has affected program effectiveness and public health impact.

Given the burden of infection with the virus in Asian Americans in California, estimated at 10% it is not too early to begin a major campaign such as that instituted in San Francisco.