Cervical cancer develops when cells in the cervix, the lower part of the uterus that connects to the vagina, grow uncontrollably. Squamous cell cervical cancer is the most common form of this disease, accounting for about 80% to 90% of all cases. This type of cancer originates from specific cells that line the outer surface of the cervix. Understanding its nature, causes, and available interventions is important for public health.
Understanding Squamous Cell Cervical Cancer
Squamous cells are thin, flat cells that naturally line the ectocervix, the part of the cervix visible during a pelvic exam. Squamous cell cervical cancer begins when these cells undergo abnormal changes and multiply uncontrollably.
The transformation zone, where the squamous cells of the ectocervix meet the glandular cells of the endocervix, is where most cervical cancers, including squamous cell carcinomas, originate. This area is particularly susceptible to cellular changes that can lead to precancerous conditions. This specific origin distinguishes it from rarer forms of cervical cancer, such as adenocarcinomas, which arise from glandular cells.
Causes and Risk Factors
The primary cause of squamous cell cervical cancer is a persistent infection with high-risk types of the Human Papillomavirus (HPV). HPV is a very common virus, and many infections clear on their own. However, persistent infection with certain high-risk types can lead to changes in cervical cells over time.
These high-risk HPV types introduce specific genetic material into the cervical cells, which can disrupt normal cell growth regulation. This can cause cells to become abnormal, leading to precancerous lesions that may eventually develop into cancer. While HPV infection is necessary for almost all cervical cancers, other factors can increase the likelihood of developing the disease once infected.
Other contributing risk factors include a weakened immune system, which can make it harder for the body to clear HPV infections. Smoking also increases risk, as chemicals in tobacco can damage cervical cell DNA. Long-term use of oral contraceptives and having multiple full-term pregnancies are also associated with an elevated risk.
Detection and Diagnosis
Routine screening tests detect squamous cell cervical cancer or precancerous changes. The Pap test, also known as a Pap smear, collects cells from the cervix to examine them under a microscope for abnormalities. This test identifies changes in squamous cells.
The HPV test identifies the presence of high-risk types of HPV in cervical cells. This test can be performed alongside a Pap test or as a primary screening method. A positive HPV test indicates increased risk and prompts further investigation.
If abnormal results appear, follow-up diagnostic procedures are performed. A colposcopy uses a magnifying instrument to examine the cervix for suspicious areas. During a colposcopy, a biopsy may be taken. Different types of biopsies include punch biopsies for visible lesions or a cone biopsy, which removes a cone-shaped piece of tissue from the cervix. Imaging tests such as MRI or CT scans may be used to determine the extent of the cancer, known as staging.
Treatment Approaches
Treatment for squamous cell cervical cancer depends on the cancer’s stage. For precancerous lesions or very early-stage cancers, surgical options are used. Procedures like conization remove the abnormal tissue while preserving the rest of the cervix, which may be suitable for those who wish to maintain fertility.
For more invasive cancers, a hysterectomy, the surgical removal of the uterus and cervix, may be performed. In some cases, nearby lymph nodes may also be removed to check for cancer spread. After surgery, or as a primary treatment for more advanced stages, radiation therapy is used.
Radiation therapy uses high-energy rays to destroy cancer cells. This can be delivered externally, known as external beam radiation, or internally through brachytherapy, where radioactive sources are placed inside the body near the tumor. Chemotherapy may be administered alongside radiation for advanced or recurrent cancers.
Prevention Strategies
Preventing squamous cell cervical cancer relies on HPV vaccination and regular cervical cancer screening. The HPV vaccine protects against high-risk types of HPV. Vaccination is recommended for adolescents, and can be given up to age 26.
The vaccine works by preventing infection if exposed to the virus. Vaccinating before sexual activity provides the most effective protection. This vaccine represents a significant advancement in cancer prevention.
Regular cervical cancer screenings, including Pap tests and HPV tests, are important for early detection. These screenings can identify precancerous changes before they develop into invasive cancer. Following recommended screening schedules helps prevent the progression of cervical disease.