Yet a new study shows that anal cancer cases — and the number of people dying from the disease — has been increasing. A well-known virus, as well as changing cultural norms, are likely to blame.
Recently published in the Journal of the National Cancer Institute, the study examined trends in anal cancer cases over 15 years, including 69,000 cases and more than 12,000 deaths. Researchers found that the number of squamous cell carcinoma diagnoses went up 2.7% each year, and deaths had increased 3% every year.
This doesn’t come as a surprise to Dr. Joseph Pizzolato, who specializes in gastrointestinal and genitourinary cancers at the Sylvester Comprehensive Cancer Center. He’s noticed a steady uptick in his practice.
“Where we used to get a couple of cases a month, we now get several,” he says. “And we’re seeing them presented at more advanced stages.”
While the demographics of his anal cancer patients haven’t changed, Dr. Pizzolato finds the increase in diagnoses among certain groups on the national level especially worrisome. According to the study, distant stage squamous cell carcinoma (when the malignancy spreads) has tripled among men during the 15-year period. Young black men and older men appeared to be most at risk. But so are middle-age and older women. In fact, the study reported “statistically significant” spikes in death rates for the 50-and-over set.
Dr. Pizzolato attributes the increases to two factors. “Anal cancer really isn’t on anybody’s radar,” he says. People aren’t necessarily as aware of it as, say, colon or breast cancer, both of which have been showered with public campaigns. What’s more, many of the symptoms of anal cancer — rectal bleeding and a strange sensation in the anus — are often mistaken for hemorrhoids. Add to this the fact that the cancer shows up in an area we don’t pay much attention to. “For many,” adds Dr. Pizzolato, “it’s embarrassing to even talk about it.”
The study’s researchers, as well as other oncologists, are concerned that, at this rate of growth, anal cancer may be one of the fastest-growing cancers in the U.S. both in incidence and mortality. Yet, historically, anal cancer is one of the rarest forms of cancer. About 6,530 people are diagnosed with anal cancer each year, according to the Centers for Disease Control and Prevention.
Of those cases, more than 90% are caused by the human papillomavirus, or HPV.
HPV is a collection of a couple of hundred related viruses, some of which are spread directly through sexual contact. An estimated 79 million Americans are currently infected with HPV. And while this is a shockingly high number, most HPV cases clear up on their own. However, not all cases disappear, and the results can be particularly vicious. HPV is blamed for about 35,000 cases of cancer, namely cervical, penile, vulvar, vaginal, and head and neck.
Now here’s the catch: HPV is largely preventable. A vaccine, under the trade name of Gardasil, has been around since 2006. It protects against 80% of HPV-caused cervical cancers and another five types of cancer. It even prevents 90% of genital wart cases.
The HPV vaccine, which comes in a series of shots, is recommended for people ages 15 to 45. But the rate of compliance is, frankly, embarrassing. Just over half of adolescents were up-to-date on the vaccine series, according to the Centers for Disease Control and Prevention, and the U.S. Food and Drug Administration only expanded the age range guidelines for immunization in 2018.
“Our society has experienced pushback on vaccines in general,” Dr. Pizzolato says. “And the HPV vaccine is certainly a victim of that.”
In addition to HPV, he also cites “changing societal norms” on sex for the increase in cancers of the anus. Common risk factors for the disease include multiple sexual partners and having anal sex.
Dr. Pizzolato hopes that this study will draw attention to this rare cancer, both among the general public and with healthcare providers. It might convince people to get the proper series of HPV vaccinations — and to not dismiss any strange sensation or symptoms in the anus. While 20 percent of anal cancer patients may be asymptomatic, warning signs should be addressed with a doctor.
Like other cancers, “early detection is crucial,” Dr. Pizzolato says. “Found early, it’s highly treatable.”
What are symptoms of anal cancer?
- Rectal bleeding
- Rectal itching
- A lump or mass at the anal opening
- Pain or a feeling of fullness in the anal area
- Narrowing of stool
- Changes in bowel habits (like having more or fewer bowel movements)
- Abnormal discharge, mucus, or pus from the anus
- Swollen lymph nodes in the anal or groin areas
If you experience any - or a combination - of these symptoms, contact your doctor.
HPV is a group of more than 150 similar viruses, some of which can cause a variety of cancers. In women, HPV infections can cause cervical, vaginal, and vulvar HPV cancers. Men may get penile HPV cancer. Both men and women are at risk for HPV-caused cancers of the mouth, throat, anus and rectum. Read more.