Updated: September 28, 2019
Cervical cancer is a type of cancer that occurs in the cells of the cervix. Cervix is the the lower part of the uterus that connects to the vagina.
Various strains of the human papillomavirus (HPV), a sexually transmitted infection, smoking, taking birth control pills can play a role in causing most cervical cancer.
The immune system of a women typically prevents the virus from doing harm when exposed to HPV. However, the virus survives for years in some women, contributing to the process that causes some cells on the surface of the cervix to become cancer cells. HPV infection may cause cervical dysplasia, or abnormal growth of cervical cells. The risk of developing cervical cancer can be reduced by having screening tests and receiving a vaccine that protects against HPV infection.
Regular pelvic exams and Pap testing can detect precancerous changes in the cervix. Precancerous changes in the cervix may be treated with cryosurgery, cauterization, or laser surgery.
Abnormal vaginal bleeding, increased vaginal discharge, bleeding after going through menopause, pain during sex, and pelvic pain are the most common symptoms of this type of cancer. Cervical cancer can be diagnosed using a Pap smear or other procedures that sample the cervix tissue. Chest X-rays, CT scan, MRI, and a PET scan may be used to determine the stage of cervical cancer.
Treatment options for cervical cancer include radiation therapy, surgery, and chemotherapy.The prognosis of cervical cancer depends upon the stage and type of cervical cancer as well as the tumor size. Cervical cancer is different from cancer that begins in other regions of the uterus (uterine or endometrial cancer). If detected early, cervical cancer has a very high cure rate.
Cervical cancer generally produces no signs or symptoms in its early stage.
Signs and symptoms of more-advanced cervical cancer include:
Normally, an orderly process of growth, division, and death is followed by our body cells. Healthy cells grow and divide in an orderly way to keep your body functioning normally. Cancer happens when these cells grow and divide uncontrollably, without dying. This is because cells continue to divide when DNA of a cell is damaged and becomes cancerous. They grow even when new cells aren't needed. As the cells accumulate, they form a tumor. Cancerous cells may spread from malignant tumors to other parts of the body through the blood and lymph systems.
Overtime, the cancer cells can grow to invade and destroy normal tissue nearby and cancerous cells can travel to other parts of the body to form deposits there which is called as metastasis. This condition is more serious and less treatable.
The exact causes are unknown, but cervical cancer has several potential risk factors. Almost all cervical cancers are caused by longstanding infection with one of the HPV strain. HPV infection is very common, and most people with HPV infection do not develop cancer. There are over 100 types of HPVs. Only certain types of HPV have been linked to cancers. Other HPV types cause benign warts on the skin or genitals.
HPVs can also cause cancers of the mouth, throat, and anus in people of both sexes. HPV infection is spread through sexual contact or skin to skin contact.
HPV infection is common and a majority of people will be infected with HPV at some point in life. However, mostly the infection resolves on its own. But in some women, the HPV infection persists and causes precancerous changes in the cells of the cervix. These changes can be detected by regular cervical cancer screening known as Pap testing.
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.
Determining the type of cervical cancer helps in your prognosis and treatment. The main types of cervical cancer are:
This type of cervical cancer begins in the thin, flat cells called squamous cells lining the outer part of the cervix, which projects into the vagina. Most cervical cancers are squamous cell carcinomas.
This type of cervical cancer begins in the column shaped glandular cells that line the cervical canal.
Sometimes, both types of cells are involved in cervical cancer. Cancer that occurs in other cells in the cervix are very rare.
Risk factors for cervical cancer include:
Like other 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.
The widespread use of the Papanicolaou test (Pap smear) and high-risk HPV testing can be useful in early detection of cervical cancer. A Pap smear is done as part of a regular examination. During the procedure, cells from the surface of the cervix are collected and examined for abnormalities. If abnormal cells are detected on the Pap smear, diagnosis of cervical cancer requires a biopsy where a sample of cervical tissue be taken and analyzed under a microscope.
There are various diagnostic tools and procedure that can be used to identify changes in the cervix. They include:
Colposcopy is a procedure similar to a pelvic exam. It is usually done when the Pap smear result is abnormal inspite of a normal physical exam. It uses a lighted microscope to examine the external surface of the cervix during a pelvic examination. 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 to look for precancerous changes or cancer.
The colposcope magnifies the cervix by 8 to 15 times, allowing easier identification of any abnormal appearing tissue that may need biopsy. Colposcopy requires no special anesthesia and is similar to having a Pap smear in terms of discomfort. A larger biopsy is needed to fully evaluate your condition if a biopsy under colposcopy suggests an invasive cancer.
The transformation zone of the cervix (see above) cannot always be visualized well during colposcopy. In this case, a sample of cells may be taken from the interior canal of the cervix, known as an endocervical curettage or scraping. LEEP technique uses an electrified loop of wire to take a sample of tissue from the cervix. A thin loop of wire is heated by an electrical current. This is also known as also called a large loop excision of the transformation zone (LLETZ). LEEP is performed in the doctor's office with a local anesthetic.
Another option is conization, or removal of a cone shaped portion of the cervix around the cervical canal. It is performed in the operating room while you are under anesthesia. It can be 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.
After a conization or biopsy procedure, the tissue are studied by the pathologist to determine if precancerous changes or cancer are present.
They can be used to diagnose problems or to treat known problems.
The abnormal changes in the cells are most often called squamous intraepithelial lesion (SIL). Intraepithelial means that the abnormal cells are present only in the surface layer of cells and lesion refers to an area of abnormal tissue. Changes in these cells can be divided into two categories:
Early, subtle changes in the size and shape of cells that form on the surface of the cervix are considered low grade. These lesions may go away on their own. However, they may become more abnormal, eventually becoming a high-grade lesion over time. LGSIL is also called mild dysplasia or cervical intraepithelial neoplasia 1 (CIN 1). Most often these early changes in the cervix occur in women ages 25 to 35 years, but can appear in women of any age.
A large number of precancerous cells, which look very different from normal cells, are considered as a high grade lesion. Like low grade SIL, these precancerous changes involve only cells on the surface of the cervix. These lesions are also called moderate or severe dysplasia, CIN 2 or 3, or carcinoma in situ. Most often they develop in women ages 30 to 40 years, but can occur at any age.
Usually precancerous cells, even high grade lesions do not become cancerous and invade deeper layers of the cervix for many years.
If abnormal cells spread deeper into the cervix or to other tissues or organs, it is then called cervical cancer, invasive cervical cancer, or metastatic cancer. Most often it occurs in women aged 40 years or older. If cancer is present, depending on the size and extent of the tumor, other tests might be done to help determine the extent to which the tumor has spread. These additional tests can include:
These tests are used to stage the cancer which helps determine the doctor your prognosis and the kind of treatment you will need. Staging is based on size and depth of the cancerous lesion, as well as degree of spread. Usually cervical cancer is staged from stage 0 that is least severe) to stage IV which is metastatic disease, the most severe.