The human papillomaviruses (HPV) are DNA viruses that infect the basal cells or the undifferentiated stem cells of the epidermis. It is the most common sexually transmitted infection in the United States. There are many different types of HPV and some are known to cause health problems including cervical pre-cancers, cervical cancer, head and neck cancer, and other anogenital cancers. It is known that HPV types 16 and 18 cause approximately 70% of cervical cancers and precancerous cervical lesions. Transmission can happen with any kind of genital contact. Infection may not present any signs or symptoms and some HPV go away on its own. High-risk HPVs, however, can cause cancer.
Preventive vaccines are effective at protecting against virus infection. These are however, ineffective at treating existing infections. There is currently no medical treatment for persistent HPV infections. There is no marketed therapeutic vaccine to treat HPV or cervical pre-cancers (cervical dysplasia) or cancers caused by HPV and therefore a significant unmet need exists for a therapeutic HPV vaccine.
Cervical dysplasia, also called cervical intraepithelial neoplasia (CIN), is a pre-cancerous lesion in which abnormal cell growth or change occurs on the surface of the cervix or endocervical canal. It is strongly associated with human papillomavirus (HPV) infection. Persistent infection with high-risk HPV type such as HPV 16 or HPV 18 is the most important risk factor, especially for moderate-to-severe dysplasia. Cervical dysplasia can develop at any age, but is most common in woman ages 25 to 35.
Cervical dysplasia usually causes no symptoms, and is often discovered by a routine Pap test. It can range from mild to severe, depending on the appearance of the abnormal cells. Although a Pap test alone can identify mild, moderate, or severe cervical dysplasia, further tests are often required to determine appropriate follow-up and treatment.
The treatment of cervical dysplasia depends on various factors including the severity of the condition and the age of the patient. Mild cervical dysplasia sometimes regress without treatment, and may only require careful observation with Pap tests every three or six months. But moderate-to-severe cervical dysplasia, and mild cervical dysplasia that persists for two years, usually requires treatment to remove the abnormal cells and reduce the risk of cervical cancer.
Because all forms of treatment are associated with risks such as heavy bleeding and possible complications affecting pregnancy, it’s important for patients to discuss these risks with their doctor prior to treatment. After treatment, all patients require follow-up testing, which may involve Pap tests in every 6 and 12 months or an HPV DNA test. After follow-up, regular Pap tests are necessary.
Cervical cancer begins in the cervix, or the lower, narrow end of the uterus. It is the second leading cause of cancer death in women worldwide. Long-lasting infections with high-risk HPV (type 16 and 18) cause most cases of cervical cancer. Severe forms of cervical dysplasia, if left untreated, can become cancer cells and spread deeper into cervix or to surrounding areas. While prophylactic vaccines can reduce the risk of cervical cancer, it is not effective at treating existing HPV infection. Early stage of cervical cancer shows no signs or symptoms but it can be detected early with regular check-ups. Regular Pap test can check for abnormal cells and HPV testing can find cells that could become cervical cancer. Cervical cancer can be cured if found and treated in the early stages.
There are several treatment options available to patients. Invasive cervical cancers are typically treated with surgery or radiation combined with chemotherapy. For women with metastatic, recurrent or persistent cervical cancer, targeted drug bevacizumab (Avastin) has been added to standard chemotherapy. Treatment should be decided on the basis of the stage and type cancer stage, patient’s desire to have children, and patient’s age. Patients should consult with their team of doctor to decide on the best treatment course.
Head and neck cancer (HNC) is the sixth most common cancer worldwide and it includes cancers that originate in the oral cavity, salivary glands, sinuses, and throat. Approximately 90% of cases have an epithelial origin and are typed as squamous cell carcinomas (SCCHN). Squamous cells are the flat cells that line the tracks and hollow organs. Risk factors for HNCs include tobacco smoking, alcohol consumption and HPV prevalence.
Recent years have seen a rise in the case of HNCs that are associated with HPV infections. Type of HNC that is associated with HPV infection mainly includes oropharyngeal cancers. Affecting the oropharynx region, the area at the back of the throat including the base of the tongue and tonsils, oropharyngeal cancers are caused by the high risk HPV types (mostly by type 16). The types of HPV that infect the genital areas can thus also infect the mouth and throat. Infection by the low risk types cause warts in the mouth or throat. Commonly known as “oral HPV”, the oral HPV infection does resolve on its own in most cases. However, in about 1% of cases, oral HPV infections are caused by high-risk cancer-causing HPV subtypes. Center for Disease Control reports that about 72% of oropharyngeal cancers are caused by HPV and that 2,370 new cases in women and 9,356 new cases in men are reported each year in the United States.
Symptoms of oropharyngeal cancer include persistent sore throat, ear pain, hoarseness, enlarged lymph nodes, pain when swallowing, unexplained weight loss, and coughing up blood. If you experience any of these symptoms, please visit your doctor. While there is no FDA-approved test to diagnose HPV in the mouth or throat, physical exam, PET-CT scan, MRI, biopsy, and HPV laboratory test can be performed for properly diagnosis.
Treatment for oropharyngeal tumors vary depending on the stage of the cancer and general health of the patients. There are four types of standard treatment including surgery, radiation therapy, chemotherapy and targeting therapy. Patients can also participate in a clinical trial for testing of new treatment. Patients should consult with a team of doctors with expertise in treating head and neck cancer to decide on the treatment course. While HPV prophylactic vaccines on the market can prevent cervical and other genital cancers, studies have not been conducted to determine its effectiveness in preventing oropharyngeal cancers.