The staging of cervical cancer refers to the extent of the disease.
Doctors stage the disease according to the size of the tumor and whether it has spread to nearby tissues or other organs of the body.
Stage Zero is not considered invasive because the cancer cells are found only in the top layer of cells of the cervix.
Stage One-A is considered invasive cancer because the microscopic tumor grows through the top layer of cells into the underlying cervical tissue,
and is three to five millimeters deep by seven millimeters wide. Stage One-B cervical cancer has two scenarios.
One, where the tumor still can only be seen with a microscope, but is larger than five millimeters deep and seven millimeters wide.
In the second scenario for Stage One-B, the cancer can be seen without a microscope and is larger than four centimeters in diameter.
In Stage Two-A, the tumor spreads beyond the cervix to the upper two thirds of the vagina, but not to the tissues around the uterus.
In Stage Two-B, the cancer spreads to the tissues around the uterus.
In Stage Three-A, the tumor spreads to the lower third of the vagina.
In Stage Three-B, the cancer spreads to the pelvic wall, the lining of the body wall cavity between the hips.
Or, it may spread to the ureters, tubes that carry urine away from the kidneys to the bladder.
If the flow of urine is blocked, the kidneys can become enlarged or stop working.
In Stage Four-A, the tumor invades nearby pelvic organs, such as the bladder or rectum, and may spread to the pelvic lymph nodes.
In Stage Four-B, the cancer spreads past the pelvic lymph nodes to other places in the body, such as the liver, intestines or lungs.