HPV and Breast Cancer: Is There a Link?

Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States, affecting at least 43 million people in their late teens and 20s. It's a silent disease, meaning there may be no symptoms, and for many, their immune system clears the infection. The carrier may not know they had it or if they have passed it to a sexual partner.

There are more than 100 strains of HPV, and types that do not clear up on their own can eventually lead to cancer. It's well known that HPV can cause cervical cancer, but research also shows that HPV can cause other types of cancer, which may possibly include breast cancer.

Breast cancer affects one in eight women in the United States. Most breast cancers are invasive, meaning they spread into surrounding healthy tissue. Noninvasive cancers stay within the milk ducts or lobules in the breast and do not grow into normal, healthy tissue within or around the breast.

It's not clear what exactly causes all the different types of breast cancer, but genetics play a role, and many breast cancers are linked to gene mutations.

People who carry the BRCA1, BRCA2, or PALB2 genes may be at higher risk. Other risk factors include age, diet, alcohol use, obesity, and environmental exposures.

HPV and Breast Cancer: Is There a Link?

There may possibly be a link between HPV and breast cancer, but this controversial area requires more research.

A 2017 study found high-risk HPV DNA and proteins in 42% of the breast cancer tissues they examined. The researchers hypothesized that the entry point for HPV is the exposure of the mammary duct via the areola. Most breast cancers originate from mammary duct epithelia (sheets of cells with more than one layer).

In an older study from 2009, researchers found high-risk HPV gene sequences (analysis of DNA sample taken from blood) in breast cancer specimens and cell lines.

In both studies, healthy breast tissues also showed evidence of high-risk HPV, suggesting this connection is worthy of further investigation and research.

What Is High-Risk HPV?

High-risk HPV causes different types of cancer. There are approximately 14 high-risk HPV strains (types), but HPV16 and HPV18 cause most HPV-related cancers.

Cervical cancer is the fourth most common cancer among women worldwide.

What Kinds of Cancers Do High-Risk HPV Types Cause?

Having HPV exposure doesn't necessarily mean you are at risk for cancer, but it can cause normal cells to become cancerous if they aren't removed or if your system doesn't clear them.

Of the 43 million people who have the HPV infection, approximately 36,000 of those will be diagnosed with a cancer every year.

These cancer types include:

• Cervical cancer: Affects the lower part of the uterus that connects to the vagina
• Anal cancer: Affects the area between the rectum and the outside of the body
• Rectal cancer: Affects the rectum, the last six inches of the large intestine
• Oropharyngeal cancer: Affects the soft palate, tongue, throat, and tonsils
• Penile cancer: Affects the tissues of the penis
• Vaginal cancer: Affects the lining of the vagina
• Vulvar cancer: Affects the outer part of the female genitals

Screening for HPV-Related Cancers

Early detection of cancer helps people see the best outcomes. Screening plays an important role in prevention and early detection.

Current screening guidelines include:

• Breast cancer: Screening includes mammograms (X-rays of the breast) or breast magnetic resonance imaging (MRIs). Mammograms are recommended for people ages 50 and older, or people between 40 and 49 years old if recommend by their healthcare provider. Self-checks of the breasts can be administered to feel for lumps.
• Cervical cancer: Screening includes HPV tests, Pap tests, and HPV/Pap combined tests. A gynecologist takes a swab of the cervix with what looks like a long Q-tip to collect a sample to test.
• Anal cancer: Screening may include an anal Pap test. A gynecologist or a gastroenterologist swabs the anal area for infection.
• Oral cancer: An exam is not yet a standard of care, although most dentists look at the tongue and inside of the mouth and throat during a routine dental cleaning or exam.
  

Treatment for HPV-Related Cancers

Several treatment options are available to remove precancerous cells.

For a cervical HPV infection, the loop electrosurgical excision procedure (LEEP) is a common procedure. After numbing the cervix, a healthcare provider inserts a thin wire loop into the vagina. Once it reaches the cervix, an electric current is passed through the wire loop to cut away and remove a thin layer of abnormal cervical tissue.

Anal, penile, vaginal, vulvar lesions, and genital warts have other treatment options, including:

• Topical medicines: These can include Aldara (imiquimod), an immune response cream applied to the infected area, or Condylox (podophyllin and podofilox), a plant-based medicine that destroys genital wart tissue. Trichloroacetic acid, which burns the genital wart away, may also be used, or the chemotherapy drug fluorouracil (5-FU).
• Surgical excision: Also called shaved excision, this is conducted to remove genital warts.
• Cryosurgery: This procedure freezes abnormal tissue.
• Laser therapy: Also called laser ablation, a laser burns away the abnormal cells.
• Immunotherapy: Harnesses the power of the immune system. Targeted therapies (custom tailored to each person) are being studied for oropharyngeal cancers.

HPV and Breast Cancer: Risk Factors

HPV is not currently considered a risk factor for breast cancer. However, there are proven risk factors for breast cancer, including:

• Aging: Most breast cancers are identified after the age of 50.
• Gene mutations: Certain gene mutations, such as BRCA1 and BRCA2, can increase the risk of developing breast cancer.
• Alcohol use: The risk goes up with increased alcohol consumption.
• Early menarche: Someone who gets their period very young (before age 12) has a longer lifetime exposure to estrogen, which increases their risk.
• Late menopause: Similar to early menarche, late menopause increases a woman's lifetime exposure to estrogen.
• Breast density: Denser breast tissue makes it more challenging for tumors to show up on a mammogram.
• Family history of breast or ovarian cancer: Mothers, sisters, and aunts may provide insight into a person's risk.
• Lack of pregnancy: Not having children or having children later in life poses a higher risk for developing breast cancer.
• Obesity: Women who are overweight or who do not regularly exercise are more at risk.
• Radiation exposure: Women who have been exposed to radiation therapy in the chest area have a higher risk of developing breast cancer.

The greatest risk for HPV is being sexually active.

HPV and Breast Cancer: Prevention

Although there is no known way to prevent breast cancer, people can focus on risk reduction through lifestyle changes, including:

• Not using tobacco products (including vaping)
• Eating lots of fruits and veggies and other plant-based foods, like nuts and seeds

Ways you can help prevent acquiring HPV include:

• Getting the HPV vaccine, currently approved for children and adults ages 9 through 45
• Using a latex barrier (condom) during sex
• Knowing your partners, their history, and practicing safe sex
  

A Word From Verywell

If you want to know more about a possible link between HPV and breast cancer, speak with your healthcare provider or an oncologist for more information. HPV is preventable through vaccination, and many people who are exposed to HPV clear the infection without intervention. If you are concerned about your HPV status, it's recommended that you get tested and vaccinated if possible.