How Is Cervical Cancer Staged?
Cervical cancer affects the cervix, which connects the uterus and vagina. The endocervix is the part of the cervix that is closest to the uterus, while an ectocervix is nearer to the vagina. Most cases of cervical cancer begin in the cell at the transformation zone. This zone is where the two main types of cells in the cervix (squamous and glandular cells) meet.
The cells surrounding the cervix do not suddenly become cancer cells. These cells gradually develop into precancerous cells that will then become cancer cells. These abnormal changes can be seen through a Pap test. Women can also be treated to prevent the development of cervical cancer.
Although cervical cancer begins as a precancerous condition, not all women develop the disease. It could take several years for the change to happen from a precancerous to a cancerous condition, but it could also develop in less than a year. For most women, the pre-cancer cells would either go away on their own even without treatment or would remain unchanged. Unfortunately, in some women, most pre-cancer cells develop into true cancer cells.
The Cancer Stage
An important aspect of diagnosing cancer is its stage. Staging is the process of determining the extent of cancer – how far has it spread. It also serves as a guide to arrive at the appropriate treatment for cancer. Diagnostic tests and examinations are used to determine the tumor size, the invasion of cancer into the tissue, and the spread of cancer cells to nearby lymph nodes and other parts of the body.
There are two systems used for staging cervical cancer:
- AJCC (American Joint Committee on Cancer) TNM staging system
- FIGO (International Federation of Gynecology and Obstetrics) system
Both systems are very similar. Based on the AJCC system, cervical cancer is categorized into three factors:
- the extent of the tumor (T)
- whether cancer has spread to the lymph nodes (N)
- whether cancer has spread to the distant sites (M)
The FIGO system makes use of the same information.
Stage grouping involves the information about the tumor, lymph nodes, and the spread of cancer. The stages are classified using the number 0 and Roman numerals I to IV. Theses stages are then subdivided into letters and numbers. The FIGO stages do not include the lymph nodes until stage III and there is no stage 0 in the FIGO system.
The AJCC system classifies cervical cancer in stages 0 through IV. The clinical findings are the basis of staging, not the surgical findings. The extent of cervical cancer is assessed by the physician after conducting a physical examination and a few diagnostic procedures.
During surgery, cancer cells might have spread to other parts of the body, exceeding the expectation and estimation of the doctor. This development can then change the treatment plan for cancer but not the stage of cancer.
The TNM Staging System
Tumor Extent (T)
This is the first factor considered in the AJCC system.
- T1: Indicates that cancer has penetrated deeper into the tissues from the surface layer of the cervix. Cancer cells can also develop within the uterus.
- T1a: The cancer is so small that it can only be seen through a microscope.
- T1b: Includes visible cancer without the use of a microscope.There is also a cancerous substance that is not visible to the naked eye.
- T2: The cervix and uterus are already affected by cancer. However, cancer hasn’t yet spread to the pelvic cavity walls and the lower portion of the vaginal canal.
- T3: Cancer has already affected the lower portion of the vagina.
- T4: Cancer grows out of the pelvis and has spread to neighboring organs such as the urinary bladder or rectum.
Lymph Node Spread (N)
This is the second factor in the AJCC system.
- NX: The lymph nodes that are nearby cannot be evaluated.
- N0: Cancer has not spread to nearby lymph nodes.
- N1: Cancer has already affected the nearby lymph nodes.
Distant Spread (M)
- M0: Cancer has not yet affected the distant lymph nodes, organs, or tissues in the body.
- M1: Cancer has already affected the distant organs in the body such as the liver, lungs, or lymph nodes in the neck and chest.
FIGO Staging
- Stage 0: Also called as carcinoma in situ (CIS), where the cancer cells stay in place, particularly on the surface of the cervix.
- Stage I: Cancer in this stage has developed inside the cervix. However, there are still no cancer cells developing outside of the womb.
- Stage IA: This is an early form of stage I, where cancer can only be seen through a microscope in small amounts.
- Stage II: Cancer has spread outside the cervical walls and womb, but it still hasn’t affected the pelvic walls or the lower portion of the vagina.
- Stage III: In this stage, cancer has already affected the lower portion of the vagina or the pelvic walls.
- Stage IV: This stage is called as metastatic cervical cancer, where cancer has already spread to neighboring organs or other distant parts of the body.
Abnormal cells are contained within the cervical surface layer. These abnormal cells may not develop into cancer cells, but in some women, they can testify that the cancer cells will still develop after a few years.
Survival Rates for Cervical Cancer
The following is the recent statistics of cervical cancer survival rates based on the collected data by the National Cancer Database:
- Stage 0 - 93%
- Stage IA - 93%
- Stage IB - 80%
- Stage IIA - 63%
- Stage IIB - 58%
- Stage IIIA - 35%
- Stage IIIB - 32%
- Stage IVA - 16%
- Stage IVB - 15%
Presenting cervical cancer survival rates is usually the standard way of discussing the prognosis of a patient. The five-year survival rate refers to the percentage of patients who live at least five years after their cancer diagnosis. There can be a number of women who will survive, and for more than five years, many are cured. However, people with cancer die of many other reasons, too.
Cervical Cancer Survival by Age
A five-year survival for cervical cancer is highest in young women but also decreases with an increasing age. A five-year net survival ranges from 90 percent in 15 to 39-year-olds to 25 percent in 80 to 99-year-olds.
