What is cervical cancer?

Cervical cancer is when abnormal cells in the lining of the cervix grow uncontrollably and eventually form a growth (tumour).

If not caught early, cancer cells gradually grow into the surrounding tissues and may spread to other body areas.

The cervix

The cervix is the lower part of the womb (uterus), also called the neck of the womb. It is a small round organ and a strong muscle. It has an opening called the os. The womb and the cervix are part of the female reproductive system.

The reproductive system is made up of the:

  • vulva
  • vagina
  • womb (uterus), including the cervix
  • fallopian tubes
  • ovaries

The diagram shows the position of these organs in the body.

Diagram showing the parts of the female reproductive system

The cervix forms a canal that connects the top of the vagina to the lower part of the womb. This is called the endocervical canal.

The cervix has 2 parts:

  • ectocervix – the outer surface of the cervix
  • endocervix – the inside (the canal) of the cervix
Diagram showing the structures of the cervix

This video shows more detail about the female reproductive system. 

Where cervical cancer starts

Cell types

A layer of skin-like cells covers the ectocervix on its outer surface. These cells are called squamous cells.

Glandular cells that produce mucus cover the endocervix.  

The skin-like cells of the ectocervix can become cancerous, leading to squamous cell cervical cancer. This is the most common type of cervical cancer.

The glandular cells of the endocervix can also become cancerous, leading to adenocarcinoma of the cervix.

Transformation zone

The transformation zone is where the area of glandular and squamous cells meets. Most cervical cancers start here.

Diagram showing the transformation zone on the cervix

Cervical screening

The transformation zone is the area your doctor or nurse checks during cervical screening.

Cervical screening is not a test for cancer. It is a test to look for HPV. If HPV is found (HPV positive), further tests look for abnormal cervical cells. If left untreated, the abnormal cells might develop into cancer.

Lymph nodes

Like all other body areas, there are lymph nodes around the womb and cervix. Lymph nodes (lymph glands) are part of the lymphatic system. They: 

  • help to protect the body against infections
  • filter, drain and circulate the tissue fluid around all body cells and tissues. This fluid is called lymph fluid

Lymph nodes are also important in cancer. The lymph fluid around the cancer drains to the nearest lymph nodes. So, if any cancer cells break away from the tumour, the first place they can go is to the nearest lymph nodes.

When you have surgery for cervical cancer, your surgeon usually takes out some lymph nodes. They send them to the laboratory to check for cancer cells.

Diagram of the lymph nodes in the pelvis with para-aortic lymph nodes

Who gets cervical cancer?

Cervical cancer is most common in women in their early 30’s.

Trans men and non-binary people assigned female at birth can also develop cervical cancer. This can happen when they haven't had an operation to remove their womb and cervix (total hysterectomy).

The main cause of cervical cancer is long lasting (persistent) infection of certain types of the human papillomavirus (HPV). HPV is a common virus. In most people, the immune system clears the infection without any problems.

How common is cervical cancer?

Around 3,200 women are diagnosed with cervical cancer in the UK each year. That’s nearly 9 cases diagnosed every day.

  • Cancer Incidence from Cancer Intelligence Statistical Information Team at Cancer Research UK  (2016 - 2018 UK average) 
    Accessed September 2023

  • Cancer: Principles and Practice of Oncology (12th edition)
    VT DeVita, TS Lawrence, SA Rosenberg
    Wolters Kluwer, 2023

  • Cervical Cancer Guidelines: Recommendations for Practice (May 2020)

    British Gynaecological Cancer Society (BGCS)

    Accessed September 2023

  • Ross and Wilson Anatomy and Physiology in Health and Illness (14th edition)

    A Waugh and A Grant

    Elsevier Ltd, 2023

  • Cervical Transformation Zone Segmentation and Classification based on Improved Inception-ResNet-V2 Using Colposcopy Images

    S Dash and others

    Cancer Inform, 2023 March 29. Volume 22, Page: 11769351231161477

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact patientinformation@cancer.org.uk with details of the particular risk or cause you are interested in.

Last reviewed: 
05 Sep 2023
Next review due: 
05 Sep 2026

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