Cervical Dysplasia - The Precursor to Cervical Cancer

Cervical cancer​ is one of the most frequent gynecological cancer worldwide. It is a slow growing cancer and luckily, it can be prevented by appropriate screening that begins at age 21. The Pap Test is the most commonly used screening test to detect cervical dysplasia, which is the earliest change that occurs in the development of cervical cancer. 

To understand how cervical cancer can develop, we need to know about the anatomy of the cervix and the term cervical dysplasia. 

The cervix is divided into 2 parts: The Ectocervix (outside part) and The Endocervix (inside part).

The junction where these 2 parts meet is known as the ‘transformation zone’. When the transformation zone is exposed to cancer-causing substances (carcinogens), it can lead to abnormal overgrowth of cells in this zone. This abnormal overgrowth of cells in the transformation zone of the cervix is known as cervical dysplasia. 

Cervical dysplasia​ is pre-cancerous cells, that is, it hasn’t yet transformed into cancerous cells, but it has the potential to. The goal of cervical cancer screening is to detect and treat cervical dysplasia early on,  to prevent the development of cervical cancer. If no abnormal cells are detected by the Pap Test, then screening is carried out every 3 years. But if abnormal cells are detected by the Pap Test, your doctor may ask you to undergo colposcopy.


What is Colposcopy?

Colposcopy​ is an in-office procedure in which your doctor will use a large microscope to look at your cervix. A solution is applied to the insides of the cervix, and the area where cervical dysplasia is present will turn white. The doctor will then take a small sample of tissue from this area to classify the extent of dysplasia and for further evaluation. 

There are 3 stages of cervical dysplasia (also known as Cervical Intraepithelial Neoplasia, CIN): 

CIN 1: mild dysplasia - the abnormals cells are present in the outer one-third of the lining of the cervix

CIN 2: moderate dysplasia - the abnormal cells are present within two-third of the lining of the cervix 

CIN 3: severe dysplasia - the abnormal cells are present in more than two-thirds of the lining or occupy the full thickness of the cervix 

The treatment for cervical dysplasia varies according to the stage it is in. 

CIN 1 requires no treatment, but yearly follow-ups are recommended to assess progression. 

Depending upon the severity of dysplasia, CIN 2 and 3 can be treated with either ablation or excision. 

Ablation​ uses heat or cold to destroy abnormal tissue. It is usually done when dysplasia is minimally invasive. Cryotherapy (freezing the tissue using gas or probe) and thermoablation (uses heat from electricity) are the two main modalities of ablation. 

Excision​ is a procedure in which the abnormal area along with the normal margins are removed. This procedure is most commonly used as it removes all of the abnormal tissue and provides an adequate sample with clearer margins for pathologists to review. 

Conization and LEEP are the two main excisional procedures. Conization can be performed with a scalpel (cold-knife conization) or laser, to remove a cone-shaped abnormal tissue from the cervix. Loop electrosurgical excision procedure (LEEP) uses a loop shaped electrical wire to remove abnormal tissue from the transformation zone. 

Routine follow-ups after the procedure are required to monitor recovery and for continuation of screening. Adequate treatment of cervical dysplasia is known to ​reduce the frequency of cervical cancer. However, it is also important to minimize the risk factors for cervical cancer. Such as using condoms during intercourse, receiving HPV vaccination, complete treatment of HPV infection, and regular check-ups with your doctor.

Reference

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