Chances are you either have received human papillomavirus or know someone who has it. At least 100 different types of human papillomavirus (HPV) exist. Almost 80 million people in the United States alone are infected right now. The Centers for Disease Control and Prevention predicts 14 million new diagnoses each year.

HPV is the most common sexually transmitted infection (STI) in the United States. Certain types of HPV can cause cervical cancer. But can HPV cause other types of cancer, like breast cancer?

Breast cancer occurs when cancer forms in the cells of the breasts. It’s the second most common cancer among women in the United States, and it can also occur in men. It has the highest death rate of any type of cancer in women.

Breast cancer usually starts in the milk-producing glands, called lobules, or the ducts that drain milk to the nipple. Noninvasive cancers, also known as carcinoma in situ, stay within the lobules or ducts. They don’t invade normal tissue around or beyond the breast. Invasive cancers grow out into and beyond surrounding healthy tissue. Most breast cancers are invasive.

Approximately 1 in 8 women in the United States will develop invasive breast cancer in their lifetime. In 2016, approximately 246,660 new diagnoses of invasive and 61,000 diagnoses of noninvasive breast cancer will occur in women in the United States.

Although researchers have connected HPV to cervical cancer, suggesting a link exists between breast cancer and HPV is controversial. In one study, researchers used 28 breast cancer specimens and 28 noncancerous breast cancer specimens to see if high-risk HPV was in the cells. Results showed high-risk HPV gene sequences in two of the cell lines.

The sample size was small, so it’s difficult to determine if there is a link. More research is necessary.

No one knows exactly why breast cancer occurs. The environment, hormones, or your lifestyle could all play a role in the development of breast cancer. It may also have genetic causes. Researchers link about 5 to 10 percent of breast cancers to genetic mutations.

High-risk HPV can cause cancer if your immune system doesn’t eliminate the cells it infects. These infected cells can then develop mutations, which can cause cancer. Because of this, it’s possible that HPV could cause breast cancer, but not enough research exists to support that theory.

HPV isn’t currently considered a risk factor for breast cancer. Women are more likely to develop breast cancer than men. Other risk factors include:

  • increasing age
  • obesity
  • radiation exposure
  • having a child at an older age
  • not giving birth to any children
  • starting your period at a young age
  • beginning menopause later in life
  • drinking alcohol

Breast cancer isn’t often inherited, but genetic factors may play a role for some people. Eighty-five percent of the cases occur in women who have no family history of breast cancer.

The greatest risk factor for HPV is sexual activity. You’re at an increased risk for HPV if you have sexual activity with multiple partners.

Breast cancer prevention

You can’t prevent breast cancer. Instead, you should perform self-exams and get screening exams. Recommendations about when you should start getting a mammogram or how frequently you get it vary. The U.S. Preventive Services Task Force recommends that women begin getting mammograms when they’re 50 years old. The American Cancer Society recommends that women start getting mammograms when they’re 45. They both say that starting screening at 40 years old may be appropriate for certain women. Talk to your doctor about when to begin screening and how frequently you should get it.

Catching breast cancer early can help stop it from spreading and increase your chances of recovery.

HPV prevention

You can help prevent HPV by doing the following:

Use latex condoms

You should use latex condoms every time you have sex. HPV is different than a typical STI in that you can contract it through areas that a condom doesn’t cover. Use as much caution as possible when engaging in sexual activity.

Get vaccinated

This is the best way to prevent cancer that’s due to HPV. The U.S. Food and Drug Administration has approved three vaccines to prevent HPV:

  • human papillomavirus bivalent vaccine (Cervarix)
  • human papillomavirus quadrivalent vaccine (Gardasil)
  • human papillomavirus 9-valent vaccine

You’ll receive three shots over a six-month period, and you need to get all of them for it to be effective. These vaccines are approved for females and males ages 11-26.

You should also follow these tips:

  • Know your sexual partners.
  • Try to stay in a monogamous relationship.
  • Ask your partner questions about their sexual activity and how often they get tested.
  • See your doctor to get screened for cancer if you’re a woman.

Current evidence doesn’t support a link between HPV and breast cancer. However, you can do the following:

  • Talk to your doctor about an HPV vaccine.
  • Always practice safe sex.
  • Talk to your sexual partners about their sexual history.
  • Follow your doctor’s recommendations for breast cancer screening.
  • If you’re concerned that you may have an increased risk of breast cancer, discuss your risk factors with your doctor.
  • Preventing cancer isn’t always possible. However, you can increase your chances of catching and treating cancer early if you’re proactive.