Cervix cancer is one among the top gynecologic cancers worldwide. According to current data, it is the fourth ranked cancer among women that results in over 3,00,000 deaths worldwide. It is mainly caused by certain strains of human papillomavirus (HPV).
Research showed that 90% of cervical cancers occur in low-income and middle-income countries that fail to organize proper screening and HPV vaccination programs. As per Globocan 2018, cervical cancer is the second most common cancer among Indian women.
About cervical cancer
The cervix is the lower part of the uterus that connects the vagina (birth canal) and uterus. It acts as a passage for menstrual blood and secretes mucus to lubricate the female reproductive tract.
Cervical cancer occurs when the normal cells of the cervix undergo mutations and begin to grow out of control. These abnormal changes in the cells can initially lead to a pre-cancerous stage. In some cases, these pre-cancerous cells of the cervix turn into invasive cancers that may spread to other parts of the body and can be fatal.
Types of cervical cancer:
The main types of cervical cancers are:
- Squamous cell carcinoma: It accounts for 85 to 90 percent of cervical cancers. This cancer begins in the squamous cell lining the outer part of the cervix (exocervix).
- Adenocarcinomas: These cancers develop from glandular cells of the endocervix (cervical opening that leads to uterus).
- Adenosquamous carcinomas: These cancers are rare and have features of both squamous cell carcinomas and adenocarcinomas.
Signs and symptoms of cervical cancer
Cervical cancer is usually asymptomatic during the early stage. As the cancer begins to grow then the woman might experience the following symptoms:
- Unusual bleeding, such as in between periods, after sex, or after menopause
- An unusual discharge from the vagina
- Pain in the pelvic region
- Pain during sexual intercourse
- Pain during urination
Advanced stage cervical cancer may cause the following symptoms:
- Swelling of the legs
- Problem while urinating or during a bowel movement
- Blood in the urine
Causes/ Risk Factors
Most cervical cancers are caused by human papillomavirus (HPV). However, not all HPV infections lead to cervical cancer.
HPV viruses are usually transmitted between people through skin-to-skin contact. It can be passed through sexual contact and can affect cells on the surface of the mucus membrane lining the genitals, anus, mouth, and throat. They manifest with visible warts on the genitals or surrounding skin.
Factors that might increase the risk of cervical cancer include the following:
- Exposure to the drug diethylstilbestrol (DES) while in the mother's womb
- Having three or more children
- Oral contraceptive use for a long time
- Multiple sexual partners
- A weak immune system
- Past or current history of sexually transmitted infections (STIs)
- Sexual activity and/or pregnancy at a young age
- Family history of cervical cancer
Regular screening is the only way to detect cervical cancer. Cervical screening can be done by HPV test and the Pap test.
- HPV test: This test involves collecting and examining cells from the cervix to identify the HPV strains that are most likely to cause cervical cancer.
- Pap test: This test involves inserting a brush or spatula inside the cervix to collect a sample of cells from the cervix. The sample is examined in a laboratory to check for any abnormalities.
Some more tests are recommended if the results of HPV test and Pap test are abnormal. Initially, the signs and symptoms, medical history, and family history of the patient is reviewed. A complete physical examination is performed to evaluate the overall health of the patient followed by a detailed pelvic examination. If cervical cancer is suspected, a colposcopy may be scheduled.
- Colposcopy: In this procedure, a small colposcope (a thin flexible tube with a video camera at an end) is inserted through the wall of vagina. The camera would then transmit the real-time images of the vagina and cervix on the monitor. During the colposcopic examination, the doctor may perform a cervical biopsy for a detailed diagnosis.
- Biopsy: It is performed along with colposcopy. The procedure involves inserting special tools through the colposcope to collect the sample of tissue. These tissues are further examined in the laboratory to check for any abnormalities.
Stages of cervical cancer
Staging of cancer helps in describing the extent of the cancer in the body. The FIGO (International Federation of Gynecology and Obstetrics) staging system is used most for gynecological cancers.
The staging for cervical cancer include:
- Stage I: The cells have grown from the surface of the cervix into deeper tissues of the cervix. It has not spread to nearby lymph nodes or distant sites.
- Stage II: The cancer has spread beyond the cervix and uterus, but is still inside the pelvic area. It has not spread to nearby lymph nodes or distant sites.
- Stage III: The cancer has spread to lower third of the vagina, and/or has spread to the pelvic wall. It may cause kidney problems and involves regional lymph nodes.
- Stage IV: The cancer has spread to distant parts of the body, such as lung.
Treatment for cervical cancer
Based on the stage of cervical cancer, the following treatment modalities may be recommended:
Surgery: It is the mainstay of treatment for cervical cancer. Depending upon the size and stage of the cancer, the surgeon may recommend any of the following surgeries:
- Cryosurgery: It is a type of ablation to destroy the cancerous cervical tissues with cold temperature. During the procedure, a very cold metal probe is placed directly on the cervix to kill the abnormal cells by freezing them.
- Laser ablation: It is a type of ablation method that uses laser beam to destroy the cancerous tissues. It is performed under local anesthesia. In this procedure, an intense laser beam is passed through the vagina to vaporize abnormal cells.
- Conization: It is recommended both as a diagnostic tool and treatment modality. Here, a cone-shaped piece of tissue from the cervix and cervical canal is removed.
- Hysterectomy: It is recommended during early stage cervical cancer. This procedure involves removal of the cervix and uterus. Hysterectomy can either be simple or radical. A simple hysterectomy involves removal of the uterus and cervix while the radical hysterectomy involves the removal of the uterus, cervix, upper vagina, and the tissue around the cervix.
- Trachelectomy: It involves the removal of whole cervix to completely remove the cancer.
Radiation therapy: It involves usage of high-energy X-ray beams to kill the cancer cells. Depending on the stage, radiation therapy can be given alone or combined with chemotherapy, or might be administered after the surgery. Radiation therapy can be given externally through an external machine or it can be delivered internally by placing a radiation source near the vagina or cervix.
Chemotherapy: It involves the use of drugs to kill or stop the growth of cancer cells. The drugs are usually taken orally or injected into the vein or muscles. In cervical cancer, chemotherapy is administered in combination with radiation therapy to enhance its effect.
Common drugs used for chemotherapy include:
Targeted therapy: It involves use of specific drugs or other substances to identify and destroy the cancer cells without harming the normal cells. Drugs approved for the treatment of cervical cancer include bevacizumab.
Immunotherapy: It involves the use of certain medicines to boost a person’s immune system to find and destroy the cancer cells. It is used to treat advanced stage cervical cancer and to prevent its recurrence. The drug approved for the treatment of cervical cancer is pembrolizumab.
Prevention of cervical cancer
In addition to getting screened regularly and receiving HPV vaccination follow these steps to prevent cervical cancer:
- Delaying first sexual intercourse until the late teens or older
- Avoiding sexual intercourse with multiple partner
- Practicing safe sex by using condoms
- Smoking cessation
Cervical cancer is one of the most preventable and treatable cancers. When diagnosed at an early stage, the five-year survival rate is 92%, while it drops to 56% when diagnosed at an advanced stage. Additionally, routine screening and HPV vaccination improves the prognosis of women with cervical cancer. Cancer diagnosed at late stages can also be controlled with appropriate treatment and palliative care.
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