Understanding High-Risk HPV Types 16 and 18 and Their Link to Cancer

What Are HPV 16 and 18?

HPV 16 and 18 are strains of the human papillomavirus that are transmitted through intimate skin-to-skin contact. According to the Centers for Disease Control and Prevention (CDC), they are responsible for around 70% of cervical cancer cases as well as a significant proportion of vaginal, vulvar, penile, anal, and oropharyngeal cancers.

These high-risk HPV types can be passed between partners during vaginal, anal, and oral sex. Using condoms reduces, but does not eliminate, the risk of transmission. Many people contract high-risk HPV at some point in their lives, but most infections clear up on their own without causing cancer.

When high-risk HPV lingers in the body, it may cause precancerous cell changes that can develop into cancer over time if left untreated. HPV 16 is the strain most likely to progress to cancer, while HPV 18 is the second most carcinogenic.

Key Facts About HPV 16 and 18

• Extremely common sexually transmitted infections
• Classified as high-risk or oncogenic HPV types
• Persistent infections can lead to cancer
• Responsible for most HPV-related cancers
• Can be prevented with vaccination

HPV 16 and 18 and Cervical Cancer

HPV 16 and 18 account for over 70% of all cervical cancer cases worldwide. Cervical cancer develops in the cervix, which is the narrow lower part of the uterus. It often takes years or even decades for cancer to develop after an initial high-risk HPV infection.

According to the American Cancer Society, over 14,000 new cases of invasive cervical cancer are diagnosed yearly in the United States. Thanks to screening and early treatment, cervical cancer rates have decreased dramatically over the past 40 years.

However, it remains a leading cause of cancer deaths in women in many low-income countries that lack access to routine Pap tests and HPV vaccination. The WHO reports that it is responsible for over 300,000 deaths per year globally, with around 90% occurring in less developed regions.

Key Facts About HPV 16/18 and Cervical Cancer

• HPV 16 causes over 60% of cervical cancer cases
• HPV 18 accounts for 10-15% of cases
• High-grade precancerous cervical lesions are also linked to HPV 16/18
• Cervical cancer usually takes years to develop after initial HPV infection
• Routine Pap screening is critical for early detection

Association With Other Cancers in Men and Women

In addition to cervical cancer, HPV 16 and 18 can lead to cancer in other parts of the body for both men and women. Cancers linked to high-risk HPV include:

• Oropharyngeal cancer - cancers of the throat, tonsils, tongue, or back of the mouth. HPV 16 causes over 60% of oropharyngeal cancers.
• Anal cancer - over 90% are linked to HPV 16 and 18.
• Vulvar and vaginal cancers - high-risk HPV is responsible for over 70% of cases.
• Penile cancer - HPV 16 and 18 account for 40-70% of penile cancer cases.

The incidence of HPV-related oropharyngeal and anal cancer is increasing in the United States, especially among men. Oral HPV infections have become particularly prevalent in recent years.

Thankfully, cervical and oropharyngeal cancer are highly preventable through HPV vaccination. There are currently three HPV vaccines approved for use - Gardasil, Gardasil 9, and Cervarix. All provide excellent protection against persistent HPV 16/18 infections that can lead to precancerous lesions and cancer.

Reducing Your Risk of HPV 16 and 18

While many people will contract HPV at some point, the good news is that most infections resolve without treatment and never progress to cancer. However, it's important to reduce behaviors that increase your risk of persistent HPV 16 and 18 infections. Here are some tips:

Get Vaccinated

The CDC recommends routine HPV vaccination at age 11-12 for both boys and girls, but it can be started as early as age 9. Young adults up to age 26 should also get vaccinated if not previously immunized. The vaccine provides close to 100% protection against persistent infections and precancerous lesions from HPV 16 and 18.

Practice Safe Sex

Use condoms correctly every time you have sex to help prevent transmission of HPV. Limit your number of sexual partners and avoid high-risk sexual behaviors.

Don't Smoke

Smoking weakens your immune system and makes it harder for your body to clear an HPV infection. According to the CDC, smoking doubles the risk of HPV-related cancers.

Get Screened

Women should have regular Pap tests to screen for cervical cancer and precancerous changes. HPV testing may also be recommended. There are currently no recommended routine screening tests for other HPV-related cancers.

Treatment of HPV 16 and 18 Infections

There is no specific treatment for HPV infections - most resolve spontaneously within 1-2 years. However, abnormalities detected on Pap tests or HPV DNA tests require further evaluation and treatment as needed. This may include:

• Colposcopy - detailed exam of the cervix using magnification and staining dyes.
• Cone biopsy - removal of precancerous cervical tissue.
• LEEP - loop electrosurgical excision procedure to remove abnormal cervical cells.
• Cryotherapy - freezing precancerous cervical cells.

Treatment of HPV-related cancers depends on the location, stage, and aggressiveness of the cancer. Common options include surgery, chemotherapy, radiation, immunotherapy, or targeted drug therapy. The prognosis is excellent when HPV-linked cancers are detected and treated early.

The Future of HPV Prevention

Widespread HPV vaccination holds promise for drastically reducing cervical, oral, and other cancers caused by high-risk HPV strains like types 16 and 18. However, vaccination rates remain low - only half of teens are up to date on recommended HPV shots.

Improving awareness and access to this cancer-preventing vaccine should be a top public health priority. Researchers are also working on next-generation HPV vaccines, enhanced screening tools, and novel treatment approaches to further minimize the impact of high-risk HPV infections.

The Bottom Line

HPV 16 and 18 are high-risk strains responsible for the majority of HPV-related cancers. Although common, most infections resolve without causing health problems. Get vaccinated at the recommended age, follow safe sex practices, don't smoke, and get regular screenings for the best protection against cancers linked to these potent oncogenic HPV types.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.