Precancerous conditions of the cervix

Precancerous conditions of the cervix are changes to cells that make them more likely to develop into cancer. These conditions are not yet cancer. But if they are not treated, there is a chance that these abnormal changes will become cervical cancer.

Untreated precancerous conditions of the cervix can take at least 10 years to turn into cervical cancer. But in rare cases this can happen sooner.

Precancerous conditions of the cervix happen in an area called the squamo-columnar junction. This area is also called the transformation zone because it’s where columnar cells (a type of glandular cell) are constantly being changed into squamous cells. The transformation of columnar cells into squamous cells is a normal process, but it makes the cervix vulnerable to abnormal changes caused by an infection with the human papillomavirus (HPV). Infection with HPV increases the risk of cervical cancer.

Abnormal changes to cervical cells are the most common precancerous condition of the cervix. These are also known as precancerous changes. Doctors use many terms to describe these changes, including cervical intraepithelial neoplasia (CIN), squamous intraepithelial lesion (SIL) and dysplasia.

Precancerous conditions of the cervix are described based on how abnormal the cells look under a microscope and how severe the cell changes are. They are grouped together based on the type of cell that is abnormal.

Precancerous changes in the cervix are quite common. Minor changes may return to normal on their own without any treatment. Moderate to severe changes can be treated and don’t always become cancer.

Most doctors describe abnormal changes to squamous cells in the cervix using the Bethesda reporting system, which refers only to squamous intraepithelial lesion (SIL). Other reporting systems refer to cervical intraepithelial neoplasia (CIN) and cervical dysplasia.

SILs are divided into low grade and high grade. CIN is graded as 1, 2 or 3.

Low-grade SIL (LSIL) is the same classification as CIN 1. LSIL affects only the cells on the surface of the cervical lining or close to it. The cervical dysplasia is mild, with changes to the cells looking only slightly different from normal cells.

High-grade SIL (HSIL) is the same classification as CIN 2, CIN 3 or carcinoma in situ. There are changes to cells deeper in the cervical lining. The cervical dysplasia is moderate or severe (the cells are more abnormal). HSIL has a higher risk of becoming cancer than LSIL.

Atypical glandular cells (AGC) and adenocarcinoma in situ (AIS) are changes to glandular cells in the cervix. Glandular cell abnormalities are not graded.

AGC means the cells don’t look normal. Changes to cells are linked with a higher risk of becoming cancer or may mean that there is an underlying cancer.

AIS means precancerous cells are found, but they haven’t spread into the deeper tissues of the cervix or surrounding tissue.

An HPV infection is the main risk for precancerous changes in the cervix.

Smoking tobacco or having a weakened immune system increases the chance that an HPV infection will not go away on its own and will develop into a precancerous condition of the cervix.

Precancerous changes in the cervix usually don’t cause any signs or symptoms. An abnormal Pap test result is often the first sign that some cells in the cervix are abnormal. Talk to your doctor about getting regular Pap tests.

If a Pap test result is abnormal, you will have more tests to rule out or diagnose a precancerous condition or cervical cancer. Tests may include:

• another Pap test after a few months (usually 6 months) if there are mild changes
• an HPV test, which can sometimes be done on a sample of cervical cells taken during a Pap test
• a colposcopy and biopsy of any abnormal-looking areas
• endocervical curettage, which removes cells from the endocervical canal and is usually done at the same time as a colposcopy

Most people who are treated for a precancerous condition of the cervix have an excellent outcome and the condition doesn’t develop into cervical cancer.

Mild changes to the cervix often return to normal on their own without any treatment.

More severe changes to the cervix are more likely to develop into cervical cancer, especially if they aren’t treated for a long time. They are usually treated as soon as they are diagnosed.

Treatment options for precancerous changes in the cervix may include:

• a loop electrosurgical excision procedure (LEEP) or other cone biopsy procedure
• cryosurgery
• laser surgery
• a hysterectomy