We know that sexually transmitted infections (STIs) can lead to many health complications, especially if they’re undiagnosed or untreated for a long time. But did you know that some types of cancer can also be a consequence of untreated STIs? It’s important to know just what STIs can lead to cancer so you can protect your sexual and reproductive health.

Read on to learn which STI is a common cause of cancer, and what you can do to stay protected.

Can STDs cause cancer?

Yes, but it’s not as simple as that. In some cases, people can get cancer from sexually transmitted diseases that are left untreated. You can’t get directly sexually transmitted cancers — instead, these types of cancer happen as a long-term complication of untreated STDs.

That’s another reason why it’s so important to practice safe sex, get tested for STIs regularly, and get vaccines against these diseases if available. These safe sex strategies can greatly reduce your risk of getting a sexual transmitted cancer by keeping you protected from the STI itself.

According to the World Health Organization (WHO), vaccines are only available for two STDs: hepatitis B and HPV. But both of these infections are important causes of STD-related cancers, and they can help prevent a significant number of complications.

Which STI is a common cause of cancer?

Human papillomavirus (HPV)

Human papillomavirus, or HPV, is one of the most common STDs around the world and it’s also the most common association between STDs and cancer.

Fortunately, most cases of HPV-cancer can be prevented through HPV vaccination. The HPV vaccine is very effective at protecting both men and women against different strains of HPV which can cause warts and cancer.

Additionally, it’s very important to get tested for HPV regularly once you become sexually active. According to the CDC, HPV-related cancer typically takes years or decades to develop, and catching it early can greatly improve the prognosis.

According to Cancer.net by the American Society of Clinical Oncology (ASCO), HPV can cause different types of cancer, including:

Cervical cancer: HPV is responsible for practically all cases of cervical cancer, which is an important cause of female mortality. It has been estimated that approximately 70% of cases of cervical cancer are caused by just two strains of HPV: HPV-16 and HPV-18. According to the WHO, cervical cancer is the fourth most common cancer among women around the world.
Oral cancer: HPV can cause cancer of the mouth, tongue, and the oropharynx. These cancer cases are usually related to HPV infections due to giving oral sex to an infected partner, and their incidence has increased significantly in recent years.
Other types of cancer:
- Anal cancer
- Penile cancer
- Vaginal cancer
- Vulvar cancer

Hepatitis

According to the Department of Health of New York State, the hepatitis B virus (HBV) is mainly transmitted through:

Unprotected vaginal or anal sex
Sharing needles or drug paraphernalia
From mother to baby during childbirth

Most cases of hepatitis B are acute and resolve on their own, but some people go on to develop chronic hepatitis. According to University of Michigan Health, chronic hepatitis B can lead to cirrhosis, and eventually, a type of liver cancer called hepatocellular carcinoma. However, patients with chronic HBV can develop liver cancer even if they never have cirrhosis. Taking antiviral therapy to manage HBV can reduce the risk of these complications.

There’s another STD which may lead to cancer of the liver: hepatitis D. The hepatitis delta virus (HDV) is not as well-known as other types of viral hepatitis. According to the National Organization for Rare Disorders, the hepatitis D virus is also known as a “satellite virus”, because it can’t cause infection unless the person is also infected with hepatitis B.

Chronic hepatitis D is one of the most severe forms of hepatitis, and it significantly increases the risk of developing cirrhosis, liver failure, liver cancer, and early development of liver disease complications.

HIV/AIDS

HIV doesn’t cause cancer by itself, but it can increase the risk of developing some types of cancer. According to Cancer.net by the American Society of Clinical Oncology (ASCO), HIV/AIDS-related cancers include:

Kaposi sarcoma: this is a type of soft-tissue sarcoma that can affect the skin, lymph nodes, liver, spleen, lungs, and digestive tract.
Non-Hodgkin lymphoma (NHL): this is a cancer of the lymphatic system, and the most common types of NHL associated with HIV/AIDS include aggressive B-cell lymphomas, primary central nervous system lymphoma, and primary effusion lymphoma.
Cervical cancer: people with HIV/AIDS have a higher risk of developing cervical cancer when they’re co-infected with HPV.

Keep in mind that not all STIs have the potential to cause cancer — however, that doesn’t mean that you shouldn’t take them seriously. Only a few STIs can lead to certain types of cancer, but other STIs can still cause significant health problems and even death if they’re left untreated. Additionally, untreated STIs greatly increase the risk of transmitting an infection to your sexual partner(s) — even if you’re asymptomatic.

The best way to prevent complications from STDs is to use condoms properly and get tested regularly so you can catch any infections early and receive treatment. You can learn the benefits of at-home STD testing at STDWatch.com.