Definition

Cancer is found in the cervix only. Stage I is divided into stages IA and IB, based on the size of the tumor and the deepest point of tumor invasion. Stage IA is divided into stages IA1 and IA2, based on the deepest point of tumor invasion. In stage IA1, a very small amount of cancer that can only be seen with a microscope is found in the tissues of the cervix. The deepest point of tumor invasion is 3 millimeters or less. In stage IA2, a very small amount of cancer that can only be seen with a microscope is found in the tissues of the cervix. The deepest point of tumor invasion is more than 3 millimeters but not more than 5 millimeters. Stage IB is divided into stages IB1, IB2, and IB3, based on the size of the tumor and the deepest point of tumor invasion. In stage IB1, the tumor is 2 centimeters or smaller and the deepest point of tumor invasion is more than 5 millimeters. In stage IB2, the tumor is larger than 2 centimeters but not larger than 4 centimeters. In stage IB3, the tumor is larger than 4 centimeters.