Risks for anal cancer
Some things can affect your risk, or chance, of developing cancer. Certain behaviours, substances or conditions can increase or decrease the risk. Most cancers are the result of many risks. But sometimes cancer develops in people who donʼt have any risks.
Infection with human papillomavirus (HPV) is the main risk for anal cancer.
The risk of developing anal cancer increases with age. Anal cancer occurs most often in people older than 55. More women than men develop anal cancer.
Some of the things that increase the risk for anal cancer may also cause precancerous conditions. Anal intraepithelial neoplasia (AIN) is a precancerous condition of the anus. AIN isn’t cancer, but it can sometimes become anal cancer if it isnʼt treated. Find out more about precancerous conditions of the anus.
Some of these risks canʼt be changed. But in some cases, there are things you can do to lower your risk.
The following can increase your risk for anal cancer:
Infection with human papillomavirus (HPV)
Infection with human papillomavirus (HPV)
Human papillomavirus (HPV) is a group of more than 100 different types of related viruses. HPV can cause warts (called papillomas) on different parts of the body, including the genitals. HPV infections are very common because the virus is easily passed by skin-to-skin contact with any HPV-infected area of the body. It is mainly spread through sexual contact, including oral sex. HPV increases the risk for anal cancer.
The different types of HPV are usually given a number to identify them. HPV16 is most likely to cause anal cancer. HPV18 is also linked to anal cancer, but it is less common.
Learn more about human papillomavirus (HPV) and how to reduce your risk of HPV.
History of anal warts
Anal warts are the most common non-cancerous (benign) tumour of the anus. If you have a history of anal warts, you have a higher risk for anal cancer.
Anal warts and anal cancer are caused by different types of HPV. But being infected with the HPV types that cause warts increases your risk of getting the types that lead to anal cancer.
Find out more about non-cancerous tumours of the anus.
Sexual behaviour
Certain types of sexual behaviour increase the risk for anal cancer. These include having receptive anal intercourse (receiving anal sex) and having many sexual partners. This is likely because these behaviours increase a person’s risk of infection with HPV.
Men who have sex with men have a higher risk of anal cancer compared to the overall male population.
Weak immune system
Having a weak immune system (immunosuppression) increases your risk for anal cancer. You may have a weak immune system for different reasons, including if you have HIV (the virus that causes AIDS) or if you have had an organ transplant and must take medicines to suppress your immune system.
History of cervical, vaginal or vulvar cancer
If you have been diagnosed with cancer of the cervix, vagina or vulva, you have a higher risk of developing anal cancer. This may be because these cancers have similar risks as anal cancer, such as infection with HPV.
Find out more about cervical cancer, vaginal cancer and vulvar cancer.
Smoking tobacco
Smoking tobacco increases your risk for anal cancer.
The more you smoke and the longer you smoke, the greater your risk. The risk of developing anal cancer decreases with time after you quit smoking.
Learn more about how to live smoke-free.
Questions to ask your healthcare team
To make the decisions that are right for you, ask your healthcare team questions about risks.
Your trusted source for accurate cancer information
With support from readers like you, we can continue to provide the highest quality cancer information for over 100 types of cancer.
We’re here to ensure easy access to accurate cancer information for you and the millions of people who visit this website every year. But we can’t do it alone.
Every donation helps fund reliable cancer information, compassionate support services and the most promising research. Please give today because every contribution counts. Thank you.