Cervical Cancer and HPV

What a relief that the weather for yesterday’s periodic commute to New York for chemotherapy was much warmer than the bone-chilling, windy backdrop of the past several days. Even more pleasant was a punctual public transportation commute, which got me to my appointment at Memorial Sloan-Kettering Cancer Center (MSKCC) on time. Work on the signals and tracks at NY Penn Station frequently delayed my trains in recent weeks, so I never know quite what to expect these days.

My blood counts were amenable to the scheduled dose of chemotherapy, which was infused as planned. My positive transportation karma continued, and I was back home resting in Pennsylvania by mid-afternoon. No more treatment until after my CT scan later this month for an update on my disease status (queue “scanxiety”).

Traveling alone, I took time during my commute to listen to music on my headphones and catch up on news events. Scrolling through my Twitter feed, I came across the fact that January is Cervical Cancer Awareness Month. It caught my eye, as cervical cancer and oropharyngeal cancer (tongue, throat, and tonsil – as in my particular diagnosis) collectively account for more than two-thirds of the cancer cases caused by high-risk human papillomavirus (HPV) infection. According to the CDC, more than 30,000 new cancers attributable to HPV infection are diagnosed each year.

HPV is the most common sexually transmitted infection in the United States. Nearly 80 million people — about one in four Americans — are currently infected, and about 14 million people become infected with HPV each year. Almost all sexually active people get infected with HPV at some point in their lives.

For most people exposed to HPV, the virus goes away on its own, but a small group of people will experience health problems — sometimes even 20 or 30 years after the initial contact — and go on to develop cancer. In these individuals, HPV can cause changes in the body that can lead to the development of:

  • Cervical, vaginal and vulvar cancer in women;
  • Penile cancer in men; and
  • Oropharyngeal (the tongue, tonsils, and back of the throat), anal, and rectal cancer in both women and men.

The good news is that HPV infections and the seven cancers attributed to them are highly preventable with available vaccines that protect against the high-risk HPV 16 and HPV 18 types responsible for 90 percent of HPV-related cancers. The bad news is that despite reliable data showing the safety and benefits of the vaccines, the rate of vaccination in both sexes is disappointing. Across America, only 49.5 percent of girls and 37.5 percent of boys were up to date with the recommended HPV vaccination series, according to a 2017 CDC report. Interestingly, around 80 percent of adolescents receive two other recommended vaccines—a vaccine to prevent meningococcus, which causes bloodstream infections and meningitis, and the Tdap vaccine to prevent tetanus, diphtheria, and pertussis.

So, with PLENTY of room for progress in vaccinating both girls and boys against HPV, please schedule a time to talk to your pediatrician now to eradicate this cancer-causing virus.

PS – There is undoubtedly a role for gender-specific cancer awareness activities, such as Cervical Cancer Awareness Month. From pink ribbons to professional sports apparel, breast cancer awareness advocates have done a fantastic job spreading the word that October is National Breast Cancer Awareness Month. But each September, during National Prostate Cancer Awareness Month, the color blue doesn’t consume the country with the same vigor. And reduced awareness correlates with less money*, as prostate cancer research receives less than half of the funding as breast cancer research from the American Cancer Society. On this note, perhaps it is time to at least consider “HPV-Related Cancer Awareness Month” or something gender neutral?

* Of course, correlation does not imply causation

New Study Highlights Importance of HPV Prevention

A new study published in the journal Cancer represents the largest population-based study of survival for human papillomavirus (HPV)-associated cancers in the United States, covering 59% of the population. The study covered 220,211 histologically-confirmed cases diagnosed during 2001 through 2011 (see Figure 1).

HPV is the most common sexually transmitted infection in the United States. Nearly 80 million people — about one in four Americans — are currently infected and about 14 million people become infected with HPV each year. Nearly all sexually active people get infected with HPV at some point in their lives.

For most people exposed to HPV, the virus goes away on its own, but a small group of people will experience health problems — sometimes even 20 or 30 years after the initial contact — and go on to develop cancer. In these people, HPV can cause changes in the body that can lead to the development of seven different types of cancer:

  • Cervical, vaginal and vulvar cancer in women;
  • Penile cancer in men; and
  • Oropharyngeal (the tongue, tonsils and back of the throat), anal, and rectal cancer in both women and men.

According to the new study, HPV-related oropharyngeal cancer surpassed the incidence of cervical cancer during the period (80,151 versus 79,425 patients, respectively). Of the 80,151 oropharyngeal patients, nearly 80 percent (63,457) were male. Collectively, these two cancers accounted for more than two-thirds of the cases in the study.

Figure 1 (adapted from Cancer Volume 124, Issue 1, January 1, 2018, Pages 203–211)

For women diagnosed with cervical cancer, the 5-year relative survival rate was high (64.2 percent), which may reflect the availability of screening tools and early detection. Patients diagnosed at the localized stage (only in the part of the body where it started) generally have a better prognosis compared with those diagnosed at regional or distant stages. In this regard, nearly one-half of cervical cancers in the study were detected at the localized stage.

The 5-year survival rate for patients with HPV-related oropharyngeal cancer (51.2 percent), was the second lowest among HPV-associated cancers. Study researchers observed that more than 60 percent of HPV-associated oropharyngeal cancers were diagnosed at the regional stage (spread to adjacent organs, structures, or regional lymph nodes) compared with less than 40 percent for other HPV-associated cancers. Only 15.9 percent of HPV-related oropharyngeal cancers were diagnosed at the localized stage.

The authors conclude that in the absence of routine screening, with the exception of cervical cancer, primary prevention through HPV vaccination is essential—especially for oropharyngeal cancer, which is expected to become the most common HPV-associated cancer by 2020. HPV vaccines are approved and recommended for use among both boys and girls.

Sadly, only 49.5 percent of girls and 37.5 percent of boys in the United States were up to date with the HPV vaccination series, according to a 2017 CDC report. In sharp contrast, around 80 percent of adolescents receive two other recommended vaccines—a vaccine to prevent meningococcus, which causes bloodstream infections and meningitis, and the Tdap vaccine to prevent tetanus, diphtheria, and pertussis.

Please talk to your pediatrician about vaccinating your 11-year-old boys and girls against HPV today to eradicate this cancer-causing virus.

The Role of Social Media in Cancer Care

Possibly due to my early days of computer programming and/or work creating one of the first brokerage firm websites, I recognized very early on the power of the Internet to connect people. When I first started my cancer patient blog in December 2015, it was mainly an efficient tool for me to keep family and friends updated on my health. However, I quickly realized that social media (e.g., Twitter, Facebook, Instagram, blogging) also afforded me the opportunity to provide unprecedented access to my personal experience as a terminal cancer patient. In doing so, I felt that my insight could be beneficial to others dealing with a head/neck cancer diagnosis and the effects of treatment. Importantly, I hoped that sharing my story could also help create awareness for the cause of my cancer (human papillomavirus, or HPV) and how today’s vaccines can prevent it.

Writing about my cancer experience is cathartic and that alone made all of the blog posts, Tweets, Instagram images, and Facebook entries seem worthwhile. What I didn’t expect was how my social media activities actually helped me deal with my own cancer diagnosis. Accordingly, the purpose of this blog post is to highlight some of these interactions with the hope that other cancer survivors find similar ways to derive benefits from social media.

For example, some people have a talent for making new friends. Unfortunately, not everyone is born with the gift—including me (yes, it’s true). Some side-effects associated with cancer and its treatment make this situation even more difficult. Being fatigued and depressed can lead to a lot of time being secluded in one’s own home—not working and feeling isolated and alone. The ability to meet new people and establish relationships can be enhanced through social media and other Internet activities.

In this regard, I’ve been fortunate to have met several Twitter acquaintances during their visits to the East Coast from as far as Buenos Aires, Argentina (@BursatilBiotech), the Pacific Northwest (@SheffStation), and Lenexa, Kansas (@bradloncar). Meeting individuals in person was an unexpected yet pleasant surprise in view of today’s digital communication era. Of course, it doesn’t hurt that our family’s latest animal addition, a golden retriever puppy named Humphrey, has attracted his own cult following on social media.

Lorie and Michael Becker – click to enlarge (photograph by Paul Reitano)

In late September 2017, I received an unsolicited email from fellow head/neck cancer survivor Paul Reitano. His surgical oncologist had posted a story about me on Facebook that led him to both my book and blog. Beyond our shared cancer background, we both enjoy photography and Paul wanted to include me in his personal project regarding portraits of cancer survivors. We set a date for early October when he was in town and spent the better part of a beautiful autumn day talking about common interests as he clicked the shutter on his camera. By late afternoon, we were like old friends even though we had just met. Among many excellent captures, Paul took a beautiful photo of me and my wife, Lorie, that we treasure. Aside from an array of gorgeous photos, Paul and I keep in touch and it has been great to have another head/neck cancer survivor in my life.

More recently, I had the pleasure of connecting with another head/neck cancer survivor, Jason Mendelsohn, through social media. Jason was recently the subject of a NBC news segment reporting on the silent epidemic of HPV-related cancers among men. Like me, Jason is determined to help others by sharing his story and experience through his blog.

Another unexpected benefit from social media is the support from reporters and related contacts I’ve developed throughout my career or who have recently covered my cancer story. One of the more memorable experiences was when @adamfeuerstein dedicated his 2017 Pan-Mass Challenge (PMC) ride to me as a token of his support over the summer. PMC raises money for life-saving cancer research and treatment at Dana-Farber Cancer Institute through an annual bike-a-thon that crosses the Commonwealth of Massachusetts. Through social media, I’ve also been fortunate to make several new media connections, such as @BiotechSusan, editor of BioCentury, and @JohnCendpts, co-founder of Endpoints News, among many others.

Social media can also be a means for health education and public messaging. Through Tweets and sharing articles, I’ve enjoyed being able to help correct the popular misconception that HPV vaccination is only for girls and cervical cancer. Creating awareness about HPV’s link to six different cancers and the proven safety/benefits of HPV vaccination for both boys and girls is one of my personal goals, which has been enhanced through my participation in social media.

The role for social media in cancer care is embryonic and evolving, but my experience thus far suggests that there are many potential benefits. There are, of course, certain challenges, not the least of which includes the potential for sharing inaccurate medical information and the lack of privacy and confidentiality when discussing deeply personal situations.

As an example of both, one need look no further than Michael Douglas’ revelation in 2013 that his cancer may have been caused by performing oral sex has and the resulting embarrassment caused to his wife, Catherine Zeta-Jones. In fact, only a few studies have looked at how people get oral HPV, and some show conflicting results. Some studies suggest that oral HPV may be passed on during oral sex (from mouth-to-genital or mouth-to-anus contact) or open-mouthed kissing; others do not. The likelihood of getting HPV from kissing or having oral sex with someone who has HPV is not known. According to the Centers for Disease Control and Prevention (CDC), more research is needed to understand exactly how people get and give oral HPV infections.

Perhaps the world just wasn’t ready to hear about the links between oral sex, HPV and head/neck cancer at the time, but fast forward to today and Michael Douglas’ story may have helped create greater awareness and a sense of urgency to better treat and prevent what is becoming the one type of oral cancer whose numbers are climbing, especially among men in the prime of their lives. The world could use more support from celebrities affected by HPV and cancer to further increase awareness and/or raise research funds for new treatments and diagnostics.

In view of growing use, researching and defining the role for social media in cancer care represents an important area of unmet need. Certainly, this is a subject that merits further investigation and could be an interesting workshop at an upcoming major medical conference, such as the American Society of Clinical Oncology (ASCO) annual meeting. In the meantime, thank you to ALL of my social media connections who help make the world seem a bit smaller and a whole lot brighter!

No Such Thing as “Risk-Free”

In a recent guest editorial that I penned for BioCentury, I referenced that a parent’s choice whether or not to vaccinate their child against the human papillomavirus (HPV) isn’t a “risk-free” choice. Every drug has risks – consider the following statement by the U.S. Food and Drug Administration (FDA): “although medicines can make you feel better and help you get well, it’s important to know that all medicines, both prescription and over-the-counter, have risks as well as benefits.” I would also point out that there are risks in forgoing a medication.

Let’s take a look at the HPV vaccine’s side-effects according to the prescribing information for Gardasil® 9 (Human Papillomavirus 9-valent Vaccine, Recombinant). The most common side effects include pain, swelling, redness, itching, bruising, bleeding, and a lump where your child got the shot, headache, fever, nausea, dizziness, tiredness, diarrhea, abdominal pain, and sore throat. These are adverse events disclosed by the sponsor (Merck & Co., Inc.) to the FDA from completed clinical trials of Gardasil 9. Since licensure in 2006, over 270 million doses of HPV vaccines have been distributed and the sponsors are obligated to report any new side effects to the FDA.

What’s that you say? You don’t trust the pharmaceutical industry? The Global Advisory Committee on Vaccine Safety (GACVS), an independent expert clinical and scientific advisory body that provides the World Health Organization (WHO) with scientifically rigorous advice on vaccine safety issues of potential global importance, first reviewed the safety data for HPV vaccines in 2007 and subsequently in 2008, 2009, 2013, 2014, 2015, and 2017. In each period, the GACVS examined various vaccine specific safety issues, such as links to Guillain-Barré syndrome (GBS) and other autoimmune safety issues. No other adverse reactions have been identified and GACVS considers HPV vaccines to be extremely safe. According to the WHO, there are now accumulated safety studies that include several million persons and which compare the risks for a wide range of health outcomes in vaccinated and unvaccinated subjects.

Early on, the GACVS was presented with signals related to anaphylaxis and syncope related to the HPV vaccines. According to the GACVS, the risk of anaphylaxis from HPV vaccines has been characterized as less than 2 cases per 1,000,000 doses, and syncope was established as a common anxiety or stress- related reaction to the injection. Anaphylaxis is a severe allergic reaction that needs to be treated right away with an epinephrine (adrenaline) shot. Anaphylaxis is rare, and most people recover from it. Syncope, also known as fainting, is a loss of consciousness and muscle strength characterized by a fast onset, short duration, and spontaneous recovery. It is caused by a decrease in blood flow to the brain, usually from low blood pressure. For these reasons, the prescribing information for Gardasil 9 recommends observation of the individual for 15 minutes after administration.

Next, let’s consider the risks of not getting vaccinated against HPV. Again, according to the prescribing information for Gardasil 9, the vaccine helps protect girls and women ages 9 to 26 against cervical, vaginal, vulvar, and anal cancers and genital warts caused by 9 types of HPV. Gardasil 9 also helps protect boys and men ages 9 to 26 against anal cancer and genital warts caused by those same HPV types. Accordingly, individuals who do not get vaccinated against HPV are at risk for the aforementioned cancers and genital warts.

In addition, the 9 types of HPV that infect the genital areas can also infect the mouth and throat (called oropharyngeal cancers). HPV is thought to cause 70% of oropharyngeal cancers in the United States, with HPV type 16 causing 60% of all oropharyngeal cancers. The HPV vaccine was originally developed to prevent cervical and other less-common genital cancers and has been shown in clinical studies to prevent cervical and other precancers. However, HPV vaccines could also prevent oropharyngeal cancers because the vaccines prevent infection with HPV types that can cause oropharyngeal cancers.

HPV vaccines were not available until I was age 38, which is well-beyond the upper age limit of 26 when the vaccines are considered effective. In late 2015, I was diagnosed with poorly differentiated, oropharyngeal squamous cell carcinoma, HPV type 16 related. My three treatment regimens thus far have included: chemoradiation, immunotherapy and currently chemotherapy.

Side-effects that Michael Becker has experienced from cancer and its treatment (click image to enlarge)

My diagnosis is terminal, so “death” would be the primary side effect from the disease that I would gladly forgo in favor of any of the aforementioned HPV vaccine side effects. Setting my grim humor aside for the moment, there are more than a dozen other side-effects that I have personally experienced to date from either cancer or its treatment (see accompanying image for details). And these side-effects don’t include others that I haven’t personally experienced, such as kidney damage.

I’m an advocate of HPV vaccination and strongly encourage parents to speak with a physician when it comes to deciding whether or not to vaccinate a child. The purpose of this blog post is to underscore that deciding not to vaccinate against HPV isn’t a risk-free decision. In my experience, the diagnosis of any one of the six cancers resulting from HPV infection is associated with plenty of important risks for parents to also consider.

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Calm

It’s been a few weeks since my last blog post, so I wanted to provide a brief update. The good news is that life has been rather uneventful – no trips to the emergency room, no new side effects, etc. Let’s face it, we were due for a break!

Last week was not only the Labor Day Holiday but also a scheduled break from chemotherapy to allow my blood counts, etc. to recover. As a result, as of Monday morning I was feeling better than any time in recent memory. My appetite has been good and my energy level afforded us an opportunity to take our puppy Humphrey with us to walk around a local art fair this past weekend.

This week, however, I’m back to week #1 of my treatment schedule starting with a doublet of chemotherapies (paclitaxel and carboplatin). For me, the carboplatin results in greater side effects, particularly stomach upset, decreased appetite, and fatigue. My typical four week treatment “cycle” looks like this:

Week #1: paclitaxel + carboplatin
Week #2: paclitaxel only
Week #3: paclitaxel only
Week #4: holiday/break (no treatment)
Lather, rinse & repeat

Before this week’s chemo appointment, I had time and energy to visit with another one of my social media connections for the first time (@BursatilBiotech). She traveled from Argentina to New York with a relative for vacation and we had arranged a brief meeting in the morning while she was in town.

@BursatilBiotech and Michael Becker

My next chemo break falls during the first week of October. At that time, I’ll have my periodic imaging procedure to see if the cancer is continuing to respond favorably to the treatment. Based on improved air flow to my lungs, I’m hopeful for some continued good news.

In the meantime, I’ve been keeping busy with my mission to raise awareness for the human papillomavirus (HPV), its direct link to six cancers, and the available vaccines that can prevent HPV. For example, my guest editorial on the topic appears in this week’s issue of BioCentury and is freely available to view on their website by clicking here. In addition, last Thursday I did a television interview with CURE Today and you can view the first segment on their website by clicking here. I’m so very grateful to these and other media outlets that have provided me with a platform to advance my mission!

Most importantly, today is another gift that I will truly treasure…as I get to celebrate my youngest daughter’s birthday. Happy 17th birthday Megan!!

Help Eradicate Six Cancers Caused by HPV

As a sexually transmitted disease, discussions surrounding human papillomavirus (HPV) can understandably be uncomfortable and/or embarrassing. Interestingly, according to the Centers for Disease Control and Prevention (CDC), HPV is so common that nearly ALL sexually active men and women get the virus at some point in their lives. About 79 million Americans (~25% of the U.S. population) are currently infected with some type of HPV. About 14 million people in the United States become newly infected each year. Accordingly, I thought that a more detailed blog post on the subject was warranted.

HPV is a virus with the ability to infect skin and mucous membranes, or mucosa, that lines various cavities in the body and surrounds internal organs. It can cause normal cells in infected areas to turn abnormal. Most of the time, you cannot see or feel these cell changes. In the majority of cases, the body fights off the HPV infection naturally and infected cells then go back to normal.

There are approximately 179 distinct HPV genotypes, which can be divided into “low risk” and “high risk” groups based on their capacity to drive cancer transformation. Most people with HPV never develop symptoms or health problems; 9 out of 10 HPV infections go away by themselves within two years. Sometimes HPV infections will last longer and can cause certain cancers, warts, and other diseases. There is currently no test to find out a person’s “HPV status.”

The “high risk” HPV subtypes most clearly implicated in cancer are HPV16, 18, 31, 33, 35, 45, 51, 52, and 56, which are capable of causing cancers of the cervix, head and neck, anus, vagina, vulva, and penis. Every year in the United States, HPV causes 30,700 such cancers in men and women.

Most of the time, people get HPV from having vaginal and/or anal sex with an infected partner. In fact, “genital HPV” is the most common sexually transmitted infection (STI) in the U.S.

However, the same types of HPV that infect the genital areas can also infect the mouth and throat. HPV found in the mouth and throat is called “oral HPV.” Only a few studies have looked at how people get oral HPV, and some of these studies show conflicting results. Some studies suggest that oral HPV may be passed on during oral sex (from mouth-to-genital or mouth-to-anus contact) or simply open-mouthed (“French”) kissing, others have not. The likelihood of getting HPV from kissing or having oral sex with someone who has HPV is not known. According to the CDC, more research is needed to understand exactly how people get and give oral HPV infections.

Oral HPV is about three times more common in men than in women. Overall, HPV types 2, 4, 6, 11, 13 and 32 have been associated with benign oral lesions while HPV types 16 and 18 have been associated with malignant lesions, especially in cancers of the tonsils and elsewhere in the oropharynx. The most commonly implicated subtype in oropharyngeal cancer is HPV16, accounting for over 80% of HPV positive cases. Not surprisingly, my initial biopsy results showed that tumor cells were positive for HPV16.

Patients with oral HPV cancer present at a younger age and are less likely to partake in excess alcohol consumption or heavy tobacco use that are associated with corresponding HPV-negative cancers. Additionally, HPV-related tumors more frequently arise in the oropharynx – the part of the throat at the back of the mouth behind the oral cavity. It includes the back third of the tongue, the soft palate, the side and back walls of the throat, and the tonsils (where my cancer started). Smoking-related tumors arise more commonly in the oral cavity, larynx, or hypopharynx.

Oral HPV tumors are more likely to be smaller and poorly differentiated, with a higher incidence of advanced lymph node metastases in comparison to HPV negative tumors. Despite a more aggressive clinical presentation, HPV status is the best independent predictor of survival in these patients.

Signs and symptoms of oral HPV may include persistent sore throat, earaches, hoarseness, enlarged lymph nodes, pain when swallowing, and unexplained weight loss. In my case, the first sign of disease in November 2015 was an enlarged (3-4cm) lymph node on the right side of my neck where the cancer had spread from my right tonsil. Some people have no signs or symptoms.

While there is currently no cure for the virus, there are commercially available prophylactic vaccines against HPV available today: the bivalent (HPV16 and 18) Cervarix®, the tetravalent (HPV6, 11, 16 and 18) Gardasil®, and newer Gardasil 9 (HPV6, 11, 16, 18, 31, 33, 45, 52, 58). Since the HPV subtype 16 was included in each of these vaccines, and this subtype was found in my tumor cells, it is very likely that my cancer could have been prevented had such vaccines been available to me when I was younger.

The HPV vaccine was initially developed to prevent cervical and other less common genital cancers, which raised questions regarding the ability to also prevent oral cancers. In one of the first large studies to explore the possible impact of HPV vaccination on oral HPV infections, researchers found it may confer a high degree of protection. The study of young adults in the U.S. showed that the prevalence of high-risk HPV infection was 88% lower among those who reported getting at least one vaccine dose than among those who were not vaccinated. Researchers reported the results at the recent American Society of Clinical Oncology (ASCO) 2017 annual meeting.

To be an effective preventive strategy, HPV vaccination should start before “sexual puberty.” The CDC recommends routine HPV vaccination for girls and boys at age 11 or 12 (two doses six months apart, a 2016 revision of guidelines that previously recommended three doses). People who get vaccinated later (up to age 26 for young women and up to age 21 for young men) will need three.

The same research reported at ASCO 2017 found that from 2011 through 2014 fewer than 1 in 5 (18.3%) young adults in the U.S. reported receiving at least one dose of the HPV vaccine before age 26. The vaccination rate was much lower among men than women (6.9% vs. 29.2%) at this time.

“The HPV vaccine has the potential to be one of the most significant cancer prevention tools ever developed, and it’s already reducing the world’s burden of cervical cancers,” said ASCO President-Elect Bruce E. Johnson, MD, FASCO. “The hope is that vaccination will also curb rising rates of HPV-related oral and genital cancers, which are hard to treat. This study confirms that the HPV vaccine can prevent oral HPV infections, but we know it only works if it’s used.”

More research is needed to understand exactly how people get and give oral HPV infections that resulted in my oropharyngeal cancer. Recent studies confirm that the HPV vaccine can prevent such oral HPV infections, but only when they are used – and vaccination rates are extremely low. This is disappointing, as vaccination is widely considered one of the greatest medical achievements of modern civilization. Childhood diseases that were commonplace less than a generation ago are now increasingly rare because of vaccines (although the measles are making a comeback since elimination was first documented in the U.S. in 2000). In order to be effective at eliminating communicable diseases, vaccines must be administered to sufficient levels of persons in the community.

If you have a son or daughter, please talk to your doctor about the HPV vaccine. HPV has become a recognized driver of six cancers affecting more than 30,000 people each year, yet there are available vaccines to prevent the majority (about 28,000) of these cases from ever occurring.

 

Sources:

American Cancer Society. Cancer Facts & Figures 2017. Atlanta: American Cancer Society; 2017.

From HPV-positive towards HPV-driven oropharyngeal squamous cell carcinomas. Cancer Treat Rev. 2015 Oct 31.

Centers for Disease Control and Prevention: Human Papillomavirus (HPV) Statistics

J Clin Oncol 35, 2017 (suppl; abstr 6003)