How Cervical Cancer Is Diagnosed

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Cervical cancer is typically diagnosed with a Pap smear, which is a routine screening test. According to the American College of Obstetricians and Gynecologists, women ages 20 to 29 should have a Pap test every three years, and women between ages 30 and 65 should have one every five years. There are other tests that can also identify cervical cancer, particularly in the more advanced stages.

cervical cancer diagnosis
Illustration by Verywell

Self-Checks

Cervical cancer symptoms do not usually appear until cancer has progressed to a fairly advanced stage. And HPV, the most common cause of cervical cancer, does not usually cause symptoms—which is why it's so important to have your regularly scheduled Pap smears. 

Nevertheless, there are a few things you can look for. Noting these will not enable you to diagnose cervical cancer. Rather, they are simply signs you should see a doctor:

  • Genital warts, which may be raised, painless, and skin-colored
  • Vaginal discharge
  • Abnormal uterine bleeding
  • Increased urinary frequency
  • Pelvic pain, especially during intercourse

Labs and Tests

Abnormal changes in the cervix typically develop over several years. Since cervical cells go through a series of alterations before becoming cancer cells, it is possible to screen for evidence of HPV or for pre-cancerous changes with diagnostic tests.

The two simplest methods include:

Pap Smear

A Pap smear plays a vital role in diagnosing cervical cancer. It is how most women discover that they have cervical dysplasia or cervical cancer. It is a simple test that can reveal abnormalities of the cervix long before they progress into cancer.

A Pap smear is usually done in an exam room during a routine gynecological checkup. During a Pap smear, your doctor removes a tiny amount of tissue from the cervix. This is done by gently swabbing the cervix with a small, mascara-wand-like brush or cotton swab. It only takes seconds to collect a sample. Some women experience a mild cramping sensation similar to menstrual cramps after this, but usually there is no pain.

The cells are examined under a microscope and abnormal cells are referred to as cervical dysplasia

Cervical dysplasia is classified as follows:

  • ASCUS (atypical cells of undetermined significance) describes any changes that are mildly abnormal. The cause could be a result of anything from an infection to the development of precancerous cells. ASCUS is not an indication of cervical dysplasia until further confirmatory testing is performed.
  • AGUS (atypical glandular cells of undetermined significance) refers to an abnormality in the glandular cells that produce mucus. Although not technically classified as cervical dysplasia, AGUS can be an indication of an underlying serious condition. AGUS results are considered rare, occurring in less than one percent of all Pap smear results.
  • LGSIL (low-grade squamous intraepithelial lesion) means that the test has detected mild dysplasia. It is the most common finding and, in most cases, will clear up on its own within two years.
  • HGSIL (high-grade squamous intraepithelial lesion) is a more serious classification which, if left untreated, could lead to the development of cervical cancer.

If you have an abnormal Pap smear it is extremely important that you follow up on recommendations from your doctor, whether that be a colposcopy, a cervical biopsy, or a repeat Pap smear in a year. 

HPV Testing

HPV testing is another important test that may be done at the same time as a Pap smear or following an abnormal result, using a second or the same swab. The sample collected is sent to a lab to identify the virus. 

While there are over 100 strains of the virus, not all of these cause cancer. Around 70 percent of cervical cancers are caused by HPV 16 and HPV 18, with another 20 percent of cervical cancers being related to infection with HPV 31, 33, 34, 45, 52, and 58.

Procedures

If your Pap smear reveals cervical abnormalities, a colposcopy may be scheduled. A colposcopy is an in-office exam that allows the doctor to view the cervix more closely with a colposcope, a lighted instrument that magnifies the cervix. It is placed outside the vagina during the exam. The images seen from the colposcope may be projected onto a screen for a more detailed view and biopsy planning.

A doctor may perform a biopsy during this exam, or perhaps separate from it, so that a sample of cervical tissue can be examined by a pathologist.

Punch Biopsy

During the colposcopy, the doctor may perform a cervical biopsy depending on what is found during the exam. This involves removing a small amount of cervical tissue to be examined under a microscope.

Most often this is a punch biopsy, in which the doctor removes a small sample of tissue with a device similar to a paper punch. It takes only seconds for the doctor to collect a tissue sample and discomfort is fleeting. Depending on the findings during the colposcopy, a few areas of the cervix may be biopsied.

Abnormal cells found during a colposcopy and biopsy may be described as cervical intraepithelial neoplasia (CIN).

Endocervical Curettage

Endocervical curettage (ECC) is another type of cervical biopsy that may be done during a colposcopy exam. During an ECC, the doctor uses a small brush to remove tissue from the endocervical canal, the narrow area between the uterus and cervix. As with a punch biopsy, the tissue is then examined by a pathologist. 

An ECC can be moderately painful, like bad menstrual cramps.

Before arriving for the procedure, there are a number of things you are asked to do. Among them:

  • Avoid taking aspirin or blood thinners before the procedure.
  • Do not douche or use tampons for at least three days before the procedure.
  • Avoid sexual intercourse for at least three days before the procedure.

Women can expect to experience mild symptoms in the days following the procedure, including localized pain and cramping. An over-the-counter pain reliever can usually help alleviate some of the discomfort.

In addition to pain, there may be vaginal bleeding or a dark discharge, so be sure to wear a sanitary pad. You will need to limit your activities for a day or two and avoid sexual intercourse, tampons, or douching until you have fully healed.

Cone Biopsy

There are times when a larger biopsy needs to be done to diagnose cervical cancer or remove tissue so that it does not become cancerous. In these cases, a cone biopsy may be performed.

During a cone biopsy, a cone-shaped piece of tissue is removed. This procedure is done under general anesthesia. A cone biopsy is also used to remove precancerous tissue from the cervix.

You may experience pain or bleeding for a few days after the procedure. While it is not common, after a cone biopsy, some women experience menstrual pain, decreased fertility, or an incompetent cervix, which can lead to premature vaginal delivery if you become pregnant. Discuss these concerns and risks with your doctor, as the extent of these effects is related to the exact location and size of your biopsy, as well as how well you heal. 

LEEP

An alternative to cone biopsy, a loop electrosurgical excision procedure (LEEP) is a procedure done under local anesthesia to remove tissue from the cervix. A LEEP uses an electrically charged wire loop to remove a tissue sample. This method is more commonly used to treat high-grade cervical dysplasia, rather than diagnose cervical cancer.  

As with a cone biopsy, women can experience pain and bleeding for a few days after a LEEP procedure. It also may result in long-term consequences such as menstrual pain, decreased fertility, or incompetent cervix. 

Stages

Once the biopsy results return, cervical cancer can either be ruled out or diagnosed. If a cervical cancer diagnosis is made, the next step is to determine the stage of cervical cancer. There are five cervical cancer stages, each of which represents how far advanced cancer has spread.

Stage 0: This stage of cancer is considered non-invasive (carcinoma in situ), based on a biopsy or a Pap smear, and any stage beyond stage 0 is considered invasive. There has been much debate over whether this is truly cancer or a ​precancerous stage.​

Stage I: These tumors are generally only seen with a microscope, but in advanced stage I, cancer may be seen without a microscope. The cancerous cells have invaded the cervix and cells are no longer just at the surface. This stage is broken down into:

    • Stage IA1: The invasion area is no more than 3 mm deep and no more than 7 mm wide.
    • Stage IA2: The invasion area is greater than 3 mm but no more than 5 mm deep, and no more than 7 mm wide.
  • Stage IA: This is the earliest stage of invasive cervical cancer. The cancer cannot yet be visualized with the naked eye and can only be identified under the microscope. This stage is further broken down by size into:
    • Stage IB1: These tumors can only be seen under the microscope and are less than 4 cm in size.
    • Stage IB2: These tumors can be seen without a microscope and are larger than 4 cm in size.
  • Stage IB: This stage includes tumors that are slightly larger than stage IA and may or not be visible without a microscope.

Stage II: These tumors have spread beyond the cervix. 

    • Stage IIA1: The tumor can be seen without a microscope but is no more than 4 cm in size.
    • Stage IIA2: The tumor can be seen without a microscope and is more than 4 cm in size.
  • Stage IIA: These cancers have spread beyond the cervix to the upper two-thirds of the vagina, but have not spread around the uterus. This is further broken down by size into:
  • Stage IIB: The cancer has spread to the tissues around the uterus and the upper two-thirds of the vagina, but not to the pelvic wall.

Stage III: In this stage, cervical cancer spreads to the nearby uterus and vagina or pelvic wall. 

  • Stage IIIA: These cancers may have spread to the lower third of the vagina, but not to the pelvic wall.
  • Stage IIIB: There are a few reasons why cervical cancer would be classified as stage IIIB. One is if it has invaded the pelvic wall. The other is if it has blocked one or both ureters (the tubes that travel from the kidney to the bladder), such that it has caused the kidneys to become enlarged or stop working as well as usual.

Stage IV: In this stage, the cancer spreads beyond adjacent regions to other areas of the body. 

  • Stage IV: These cancers have spread so that they have invaded either the bladder or rectum or both (spread to adjacent pelvic organs.)
  • Stage IVB: These cancers have spread to distant regions of the body, for example, lymph nodes in a distant region of the body, the lungs, liver, or bones.
cervical cancer: stage at diagnosis
Illustration by Verywell

Imaging

Cervical cancer that spreads is considered invasive cancer. Imaging tests can help identify areas of metastasis.

In general, imaging tests are used for staging. So, if you have non-invasive cervical cancer removed, and no signs or symptoms of metastasis, these tests are likely not necessary. If your doctor suspects local spread or distant metastasis, due to your symptoms or to the appearance of the tumor (on physical examination or under a microscope), then imaging tests will be used to assess the regions of the body that there is concern about.

  • Ultrasound: An ultrasound can look at the cervix, the bladder, and the whole pelvic region to determine the cause of symptoms. It can also be used to view other areas of the body if there is a concern about metastasis.  
  • X-ray: An X-ray, such as a chest X-ray, can identify metastatic cervical cancer that has spread to the lungs or the ribs, for example. Rarely, an abnormality seen on a routine X-ray could be the first sign of metastatic cervical cancer. 
  • MRI: An MRI scan can be used to visualize the area of the cervix and pelvis. An MRI is especially useful for evaluating the spine and the spinal cord, where late-stage cervical cancer may spread. 
  • CT Scan: A CT scan, like an MRI, can visualize the area of the cervix and pelvis, as well as other regions of the body where cervical cancer could have metastasized. 

Differential Diagnoses

There are a few other conditions that may initially appear similar to cervical cancer or HPV infection. Your doctor may suspect them initially, but testing will quickly rule them in or out.

  • Endometrial cancer: Endometrial cancer is cancer of the uterus. The cervix is the passageway between the vagina and the uterus, so sometimes, the two diseases can appear similar if either one has spread to the other location. In general, a biopsy is a good method of distinguishing between the two. 
  • Vaginal cancer: Vaginal cancer is not common, and, because the vagina is so closely attached to the cervix, the conditions can appear similar. However, as with endometrial cancer, a biopsy can differentiate between these types of cancer. 
  • Herpes: Herpes is a sexually transmitted disease (STD) that causes vaginal sores, and you or your partner might confuse herpes lesions with genital warts. The lesions may look different from each other on a pelvic examination in the doctor's office. And, because both types of infections can be diagnosed with a sample taken during a medical examination, your doctor can test you to determine which of them you have if it is difficult to distinguish the lesions.  
  • Syphilis: Another STD that causes visible vaginal lesions, the sores of syphilis look like open wounds and are often reddish, in contrast to the colorless warts that HPV can cause. Nevertheless, it is common to confuse the conditions if you aren't trained in recognizing them, and a medical visit can help clear up the difference with a pelvic exam and lab testing. 
How Cervical Cancer Is Treated
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