Anal cancer has fortunately been very rare (about half of a percent of all cancers in 2019), as screening for anal cancer has not been well-established, but its incidence is on the increase. Many of those who experience it will not talk about it, due to the stigmas surrounding this cancer. Years ago breast and prostate cancer were unmentionable; it took high-profile patients such as former First Lady Betty Ford to break this taboo. Farrah Fawcett's well-publicized anal cancer may have begun this process, but secrecy and shame are still part of the anal cancer experience for many. If you have been diagnosed with anal cancer, you must expect some of your friends and relatives to be squeamish about it, and you will have to work out how to deal with this reaction; see the tab on Reactions of Others for more on this topic. If you can be open about it, and even clarify for your friends and family that the underlying virus can be transmitted in a number of ways, and most of us have been infected at one time or another, you will help to remove the stigma. See this UK discussion about why we must talk more openly about this cancer. A good short article about anal cancer and its treatment is here. For a complete overview of the cancer and its treatment, see this guide from the National Comprehensive Cancer Network.
Incidence
The National Cancer Institute estimates that there will be 9440 new cases (about 0.5% of all new cancers) in the U.S. in 2022, most with a Squamous Cell Anal Carcinoma (SCAC), and 1,280 deaths from anal cancer in 2019; the American Cancer Society estimate is the same. The incidence of anal cancer is rising, especially among young and the proportion of women among those diagnosed is increasing - more women are reported with this cancer than men. In the past three decades reported cases have gone up some 60% for males and almost 80% for women. HPV vaccination could help prevent most of these cancers, but vaccination rates in the US are very low. Until a significant part of the population has been vaccinated, increasing numbers for this cancer diagnosis can be expected. Anal cancer is an issue for gay men - see this article.
Screening and Diagnosis
Anal cancer and hemorrhoids often have the same symptoms. See these medical sites for further information - the National Cancer Institute, the American Cancer Society and/or the Mayo Clinic; this Australian site. the Cancer Council, also offers useful information. The professional society of colon and rectal surgeons, ASCRS, has extensive information on its site. And the HPV and Anal Cancer Foundation has a good short summary. Even experienced doctors have mistakenly diagnosed hemorrhoids when the problem was anal cancer. Some doctors never examine the anal area, even though a “digital rectal exam” (DRE) requires no special equipment and not much training. Many if not most patients either do not know about this kind of examination or are reluctant to ask for it. The American Cancer Society itself dropped the recommendation for an annual DRE after 1997, in favor of examinations such as a colonoscopy or sigmoidoscopy that are only done every 5 or every 10 years —arguably increasing the probability of missed anal cancer signs: Chronological History of ACS Recommendations for the Early Detection of Cancer in Asymptomatic People. Fortunately, there is research underway demonstrating that early detection and treatment of anal precancer can have major benefit in preventing progression to cancer. https://www.analcancerfoundation.org/news/anchor-trial-q-a/
Symptoms such as rectal bleeding or pain, sensitivity in the groin, changes in bowel habits, and excessive gas or bloating, may be ignored or attributed to hemorrhoids. The result, recounted by numerous anal cancer patients and confirmed in medical literature, is delayed diagnosis.
If you are reading this and have not been diagnosed with an anal cancer, but have been told over time you have hemorrhoids – consider consulting a colorectal doctor or an oncologist soon!! This is especially true if you have any of the symptoms mentioned above. A DRE and if possible an anoscopy, or proctoscopy, a simple exam with a small instrument that enables a magnified look at the area under a light, determine if there is any cause for concern. For more information on this procedure, see the National Institutes of Health website. An online search will also bring up videos of the procedure in action; you may not want to view them before you have one! Please note that an anoscopy is very different from a colonoscopy or flexible sigmoidoscopy, neither of which can adequately exam the anal canal for signs of anal dysplasia or tumors. The risk factors for anal canal are not the same as those for colon cancer, and there is no evidence that anal cancer patients are more likely to have colon cancer. Talk to your oncologist and your colorectal surgeon or gastroenterologist about these screening or followup procedures. If you are at all uncertain about the diagnostic terms that you read here or that your doctors use, a helpful guides is here. If you believe that you have not been diagnosed correctly, seek other help!
An improvement in followup of an abnormal Pap smear has been developed and approved for use in Canada and the UK but prospects for approval by the US FDA in the US are uncertain. (Research is underway in the US to review anal cancer screening for women during regular visits to the gynecologist.) This website author wonders if biophotonics might be applied to anal cancer scans; in the meantime, a periodic DRE and anoscopy is essential in the presence of persistent hemorrhoids or rectal bleeding. If you hear "don't worry about it," regarding your hemorrhoids, that may be the time to head for a colorectal surgeon. Listen to your body and your instincts! (My oncologist recommended seeing a different cancer center for a second opinion, and that in itself increased my confidence in him. No one is error-free, and it's your body being treated - make yourself responsible for understanding what will be done.)
The long-range goal of many cancer researchers now is improving detection methods so that cancers are detected far earlier than they are now. Our canine friends may someday show that DOG scans are better than CAT scans! Here, for example, issues about HPV and anal cancer in older women are discussed. in the meantime, improvement of treatment - increasing effectiveness and reducing toxicity - is a key part of the story. While research on anal cancer is limited to some extent by its rarity, there are some new avenues being explored. The HPV and Anal Cancer Foundation helped to sponsor the Inaugural Annual Scientific Meeting of the International Anal Neoplasia Society (IANS) in 2013, and the following yearly conferences will help develop more research.
Following any initial diagnosis for anal cancer, your medical team will order scans to determine if the cancer has spread to any distant sites; the same tests may be part of your follow-up program. Many patients experience a period of nervousness before these follow-up tests, known to some of us as “scanxiety!” You may have encountered some of these scans as diagnostic tools for other medical problems; I did not have a clear understanding of the PET scan until I had to have one! Find a good explanation of current technology here. As you prepare for treatment, here are some suggestions for "taking control" of what is happening to you. If you have any concerns about your treatment or your medical team, don't be afraid to seek a second opinion.
Treatment
Before the 1970s, most anal cancer was generally treated by a rather brutal operation that removed the anus and lower rectum, leaving the patient with a permanent colostomy (feces bag), and survival rates after 5 years as low as 40%. In 1974 Dr. Norman D. Nigro, of Wayne State University School of Medicine, published a review of patients who had been treated with combined radiation and chemotherapy – first to reduce the tumor prior to surgery, but later only with the combined regime, when it was realized this was as successful as the surgery. This combined regime has been studied and tested over the years, and improved with better-targeted radiation; but it remains the standard treatment for anal cancer, known now as the Nigro Protocol. (Dr. Nigro retired to Arizona, where he passed away in 2009.) A colostomy may become necessary if the tumor recurs in the anal area; no one of course wants to contemplate this, but recent reports from vibrant survivors show that life is well worth living post-colostomy. See this, for example, about a young model who was not afraid to be photographed in a bikini with her colostomy bag, this uncoverostomy.org YouTube, and this fascinating CNN report.
When caught early, this treatment is highly effective, with an 80% five-year cancer-free survival rate. Survival rates when the cancer is not diagnosed until a later stage drop to to 60%. (The National Cancer Institute, the American Cancer Society, and the Cancer Guide site all offer information for patients about staging.) These are still better survival rates than many of the other cancers related to HPV, such as cervical cancer (see below).
See the National Comprehensive Cancer Network site Clinical Practices Guidelines for anal carcinoma. Registration for the Clinical Practices material is required - you do not have to be a physician to register. The guidelines are updated periodically; the guidelines for 2017 are now posted.
The Cancer Network (Journal of Oncology) discusses anal cancer management here and here. https://www.eurekalert.org/pub_releases/2018-10/trmn-nta101918.php
A short summary is provided by the American Society of Colon and Rectal Surgeons on their website. A very basic summary is available from the Lifescript site.
Many cancer treatment sites now provide advice or access to "complementary treatment," such as meditation or nutrition counseling, help with sleep disorders, and the like. See the National Cancer Institute "CAM" page for information on these treatments. This may be referred to as "integrative medicine;" these are aids to the standard treatment, to ease difficulties or improve emotional health. There is no known alternative treatment for anal cancer that eliminates the chemoradiation of the Nigro Protocol, although there is some research being pursued to improve the basic treatment. If you have been diagnosed with anal cancer, pursue acupunture, meditation, a better diet, or anything else that helps you with the treatment; but please do not try to substitute these for the treatment that you need to beat this cancer! See the Cancer Guide site for a discussion of this. You may also want to consider a clinical trial - a discussion on how to find and enter such a trial, with your physician's help, is here in the Cure magazine. Brown University, for example, is conducting trials of immunotherapy for HPV-related anal cancer (virtually all anal cancer); A discussion about this is here. European oncologists have also expressed interest in having more clinical trials for possible new treatments, and one clinic in Canada is experimenting with use of targeted viruses to attack cancer cells. Some other clincal trials are underway, and In a few years there may be new options for treatment. Here is one example from Advaxis for persistent or metastatic anal cancer.
Additionally, see this report by doctors from the 21st Century Oncology Group about colostomy-free results from "treatment in a community setting."
Less damaging treatments may be available in the future. Check out this discussion by Dr. Trimble of the Farrah Fawcett Foundation. Research and use of immunotherapy treatment is making rapid strides, and other work is being done on how to combat metastases. The HPV and Anal Cancer Foundation reported in late 2018 on encouraging results of clinical trials in the UK for a new treatment for advanced anal cancer.
Post-Treatment
The National Comprehensive Cancer Network Guidelines also discuss the post-treatment followup, and the options depending on the results of the treatment. They include a periodic examination of the anal area, with an anoscopy rather than a colonoscopy as the recommendation. Most of us do not get even a digital rectal exam (DRE) in our standard physical or gynecological exams, much less an anoscopy, but either of these would certainly help reduce the incidence of anal cancer. Colonoscopies are designed to detect problems higher up in the digestive tract, and are not the best means for checking the anal area after the Nigro treatment is over. They also do not require extensive preparation or anesthesia, which itself has risks.
HPV and Cancer
The Centers for Disease Control and Prevention (CDC) reports that approximately 85% of anal cancers are considered to arise from infection with the Human Papillomavirus, often abbreviated as HPV. (The Papillomavirus family is named from the Latin word papilla for bud, after the budding habit of these viruses.) Papillomaviruses have been identified in humans, rabbits, cows, birds and reptiles; some researchers have posited that the first land vertebrates, ancestors of today’s reptiles, birds and mammals, were already hosting this virus three hundred million years ago. Genital cancers have become widespread in marine mammals, and many of them are associated with a papilloma virus. As human beings evolved the Human Papillomavirus evolved with them; over 200 strains of this family have been identified. Various studies done after the virus was isolated in the 20th century have shown that the majority of us, perhaps 80% or more, are either infected or carry antibodies, indicating a past infection. In most cases the virus co-existed with the human in a kind of balance, not growing in ways that threatened the life of the host. For a small, but growing, number the balance breaks down and cancer develops. This may be the result of stress, smoking, or other health problems that suppress the immune system. While medical science is aware of risk factors, exactly who will develop a cancer or other health problem* as the result of HPV infection is not known.
HPV is associated with anal, cervical, vaginal and vulvar, and penile cancers, and more recently with head and neck cancers. Researchers are also finding evidence of HPV infection in breast cancers, and prostate cancers. Michael Douglas talks about his throat cancer in terms of HPV and oral sex, with surprising frankness, here. And check this site created in Australia about penile cancer. The HPV Alliance is dedicated to fighting this virus.
For more information on this virus family:
A Planet of Viruses, by Carl Zimmer, and What your Doctor May Not Tell You about HPV and Abnormal Pap Smears, by Joel Palefsky, M.D., with Jody Handley.
The Centers for Disease Control and Prevention website covers HPV in detail at What is HPV.
WebMD has a good article here. And see this link for a personal story focused on HPV infection.
The International Papillovirus Society holds an international conference each year to share research information and increase public understanding of the virus and its role in cancers. Organizations such as the HPV and Anal Concer Foundation (see Key Websites) participate and report.
THe US National Institutes of Health report on non-sexual transmission is here.
HPV transmission
HPV is transmitted by skin contact. This is frequently by sexual activity, and HPV infection is described as a sexually transmitted disease, or STD, which may explain why doctors may be reluctant to want to talk about it. But sex need not be involved in this transmission. Newly diagnosed patients may be embarrassed to learn that anal cancer is characterized as an STD; it is important to understand that the infection is extremely common, and can occur without anal sex, or any sexual contact at all. Recent research has shown that HPV can be transmitted by equipment used in medical procedures such as colonoscopies or gynecological exams; see this report, and this summary from the National Institutes of Health. And it appears to be related to stress. And now there is some evidence that the long-recommended wiping from front to back may be a means of transmitting HPV to the anal area! As the doctor in the story says, “just dab!”
Anal cancer affects more women than men, but the highest risk for this disease is among gay men, men having sex with men (MSM in the literature). “Main-stream” reporting on this cancer often leaves the impression that anal cancer results only from anal sex. Such inaccurate reporting overlooks the other risk factors for anal cancer, such as smoking, and perpetuates a stereotype that contributes to the shame that many such patients sense about this diagnosis.
Anal cancer has been associated with HPV strains 16 and 18. These two HPV strains are also associated with cervical, vaginal and vulvar cancers (and HPV strains are also causative agents in penile, mouth and throat cancers.) HPV-related cancers are on the rise among heterosexual men, despite the association with gay men for anal cancer.
The Vaccine
A vaccine now exists that offers protection against HPV 16 and 18, and two other strains that cause genital warts; and it is approved by the FDA for both young women and young men. For more information the New York Times has a very informative article, A Vaccine May Shield Boys Too, see also the online Oncology Journal, Cancer Network here. In October 2011 the Centers for Disease Control's Advisory Committee on Immunization Practices recommended the vaccine for boys and young men (Panel Endorses HPV Vaccine for Boys of 11), and spoke to concerns that the vaccine had adverse effects. The National Cancer Institute presents information here. Another study indicates that young women who receive this vaccination are not more likely to engage in risky sexual behavior - e.g., be promiscuous. A good discussion of this issue appeared in the Boston Globe M.D.Mama column. In late June 2013 a CDC study was published showing a substantial drop in HPV infections in girls, even with a relatively low rate of vaccination, and there is evidence that the vaccine helps prevent cervical cancer. The recent study showing that HPV infection can occur in medical procedures makes the vaccine even more important! A Conservative MP in Canada announced support of the vaccine for boys after going through his own agonizing treatment for throat cancer. The M.D.Anderson Center has joined 68 other cancer centers in calling for vaccination. Regretably, the application of the vaccine in the US is still very low. Perhaps this piece in Teen Vogue, or this one in Glamour, will help reassure! The HPV and Anal Cancer Foundation provides good information here. And M.D.Anderson reports that vaccination is slowly improving “herd immunity" statistics.
Charlotte Haug, M.D., discusses the risks and benefits of this vaccine in the Journal of the American Medical Assciation. For a view from the British Medical Journal, see this. Unfortunately, the CDC reports that vaccination is proceeding very slowly in the US, in part because doctors do not actively recommend it to teenagers - and few if any school programs include it. See the HPV and Anal Cancer Foundation report. Fortunately the vaccine is reported to be working among those who have received it.
Vaccination can help prevent disease even among those who have had severe HPV-related disease such as cancer. (Canada has raised their upper age limit to 45, while the US CDC keeps the limit at 26 - why?) For more details on this research and the implications for those of us who've had an HPV-related cancer, see this Science Daily story, and the summary from the British Medical Journal where the research was published. The US Department of Defense has endorsed the vaccination for patients within its system; see the report here. While this news is important, recent studies conducted in Sweden indicate that the protective effect of the vaccine is enhanced by receipt of the shots at younger ages.
There are promising indications that an experiemental vaccine might serve as treatment for pre-cancerous cervical lesions; these are caused by the same HPV strains that can cause anal cancer, so the hope must be that early discovery might lead to prevention of a cancer. And Australia researchers report that a new vaccine might completely eliminate cervical cancer.
While vaccination is currently restricted to the young, there is no medical reason to prevent adult vaccination.
On the HPV test:
Can you get HPV through oral sex?
Risk factors and incidence of anal cancer:
For additional detailed information on anal cancer, see the Key Websites Page.
*Recent research suggests that an HPV infection in women may raise the risk of heart attack or stroke.
General information on HPV from M.D.Anderson