The uterine cervix is the lowest portion of a woman’s uterus (womb), connecting the uterus with the vagina. Cervical cancer occurs when the cells of the cervix grow abnormally and invade other tissues and organs of the body. When it is invasive, this cancer affects the deeper tissues of the cervix and may have spread to other parts of the body (metastasis), most notably the lungs, liver, bladder, vagina, and rectum. However, cervical cancer is slow-growing, so its progression through precancerous changes provides opportunities for prevention, early detection, and treatment.
CAUSES OF CERVICAL CANCER
Cervical cancer begins with abnormal changes in the cervical tissue. The risk of developing these abnormal changes is associated with infection with human papillomavirus (HPV). In addition, early sexual contact, multiple sexual partners, and taking oral contraceptives (birth control pills) increase the risk of cervical cancer because they lead to greater exposure to HPV.
Forms of HPV, a virus whose different types cause skin warts, genital warts, and other abnormal skin disorders, have been shown to lead to many of the changes in cervical cells that may eventually lead to cancer. Certain types of HPV have also been linked to cancers involving the vulva, vagina, penis, anus, tongue, and tonsils. Genetic material that comes from certain forms of HPV (high-risk subtypes) has been found in cervical tissues that show cancerous or precancerous changes.
In addition, women who have been diagnosed with HPV are more likely to develop a cervical cancer. Girls who begin sexual activity before age 16 or within a year of starting their menstrual periods are at high risk of developing cervical cancer.
Cigarette smoking is another risk factor for the development of cervical cancer. The chemicals in cigarette smoke interact with the cells of the cervix, causing precancerous changes that may over time progress to cancer. The risk of cervical cancer in cigarette smokers is two to five times that of the general population
SYMPTOMS OF CERVICAL CANCER
As in many cancers, you may have no signs or symptoms of cervical cancer until it has progressed to a dangerous stage. They may include:
- Pain, when the cancer is advanced
- Abnormal vaginal bleeding (other than during menstruation)
- Abnormal vaginal discharge
- Pelvic pain
- Kidney failure due to a urinary tract or bowel obstruction, when the cancer is advanced
DIAGNOSING CERVICAL CANCER
As with all cancers, an early diagnosis of cervical cancer is key to successful treatment and cure. Treating precancerous changes that affect only the surface of a small part of the cervix is much more likely to be successful than treating invasive cancer that affects a large portion of the cervix and has spread to other tissues.
There are various diagnostic tools that can be used to identify changes in the cervix. They include:
Colposcopy is a procedure similar to a pelvic exam. It is usually used for a patient who had an abnormal Pap smear result but a normal physical exam. The examination uses a type of microscope called a colposcope to inspect the cervix. The entire area of the cervix is stained with a harmless dye or acetic acid to make abnormal cells easier to see. These areas are then biopsied. The colposcope magnifies the cervix by eight to 15 (depends on the colposcope) times, allowing easier identification of any abnormal-appearing tissue that may need biopsy. This procedure can usually be done in your gynecologist’s office. If a biopsy under colposcopy suggests an invasive cancer, a larger biopsy is needed to fully evaluate your condition. Treatment will depend on stage of the cancer.
The loop electrosurgical excision procedure (LEEP) technique uses an electrified loop of wire to take a sample of tissue from the cervix. This procedure can often be performed in your gynecologist’s office.
A conization (removal of a portion of the cervix) is performed in the operating room while you are under anesthesia. It can performed with a LEEP, with a scalpel (cold knife conization) or a laser. In this procedure, a small cone-shaped portion of your cervix is removed for examination.
If abnormal cells spread deeper into the cervix or to other tissues or organs, the disease is then called cervical cancer, invasive cervical cancer, or metastatic cancer. Cervical cancer occurs most often in women aged 40 years or older.
If the biopsy results show invasive cancer, a series of tests may be performed, all designed to see whether the cancer has spread and, if so, how far. They include:
- A chest X-ray to see if the cancer has spread to the lungs
- Blood tests can indicate whether the liver is involved; a CT scan may be necessary if results are not definitive.
- Special X-rays known as an IVP or a CT scan can be used to look at the urinary tract; the bladder and urethra are evaluated by cystoscopy.
- The vagina is examined by colposcopy; the rectum is evaluated by a procto signoidoscopy and barium enema.
- Lymph nodes are evaluated by CT scans, MRI scans, or PET scans; the MRI is superior to the CT scan and the PET scan is superior to both.
The most widely used treatments for invasive cervical cancer are surgery and radiation therapy. Chemotherapy or biological therapy also is sometimes used.
If a biopsy shows that cancerous cells have invaded through a layer called the basement membrane, which separates the surface layers of the cervix from other underlying layers, surgery is usually required. The extent of the surgery varies, depending on the stage of the cancer.
If the cancer is only on the surface of the cervix, the cancerous cells may be removed or destroyed by using methods similar to those used to treat precancerous lesions, such as the LEEP or a cold knife conization.
If the disease has invaded deeper layers of the cervix but has not spread beyond the cervix, an operation may remove the tumor but leave the uterus and the ovaries.
If the disease has spread into the uterus, hysterectomy — removal of the uterus and cervix — is usually necessary. Sometimes, the ovaries and fallopian tubes also are removed. In addition, lymph nodes near the uterus may be removed to check for spread of the cancer. Hysterectomy is also sometimes done to prevent spread of the cancer.
Radiation therapy (or radiotherapy) is also used to treat cervical cancer at some stages. Radiation therapy uses high-energy rays to damage cancer cells and stop their growth. Like surgery, radiation therapy is local therapy; the radiation affects cancer cells only in the treated area. Radiation may be applied externally or internally. Some women receive both kinds.
External radiation comes from a large machine, which aims a beam of radiation at your pelvis. Treatments, which take only a few minutes, usually are given five days a week for five to six weeks. At the end of that time, an extra dose of radiation called a “boost” may be applied to the tumor site.
Because of safety concerns and expense of equipment, radiation therapy generally is offered only at certain large medical centers or hospitals.
Internal or implant radiation comes from a capsule containing radioactive material which is placed directly in the cervix. The implant puts cancer-killing rays close to the tumor while sparing most of the healthy tissue around it.
There are two types of implant radiation, also called brachytherapy. With low dose rate brachytherapy the implant is usually left in place for one to three days. The treatment may be repeated several times over the course of 1-2 weeks. You stay in the hospital while the implants are in place.
Another type is high dose rate brachytherapy. This form may be performed as an outpatient. During this treatment the implant is inserted for several minutes then removed. The therapy is performed several times over a series of weeks, each treatment usually at least a week apart.
Chemotherapy is the use of powerful drugs to kill cancer cells. In cervical cancer, it is used most often when the cancer is locally advanced or has spread to other parts of the body. Just one drug or a combination of drugs may be given. Anticancer drugs used to treat cervical cancer may be given via an IV line or by mouth. Either way, chemotherapy is systemic treatment, meaning that the drugs flow through the body in the bloodstream. They can kill cancer cells anywhere in the body.
FOLLOW-UP AFTER CERVICAL CANCER TREATMENT
Regular pelvic exams and Pap smears are important for every woman. These tests are no less important for a woman who has been treated for precancerous changes or for cancer of the cervix.
Follow-up care should include a full pelvic exam, Pap smear, and other tests as indicated on a regular schedule recommended by your gynecologist. These precautions are necessary to allow early detection should the cancer return.
Cervical cancer treatment may cause side effects many years later. For this reason, you should continue to have regular checkups and should report any health problems that appear.