Cancer is found in the cervix only. Stage I is divided into stages IA and IB, based on the amount of cancer that is found. In stage IA, a very small amount of cancer that can only be seen with a microscope is found in the tissues of the cervix. Stage IA is divided into stages IA1 and IA2, based on the size of the tumor. In stage IA1, the cancer is not more than 3 millimeters deep and not more than 7 millimeters wide. In stage IA2, the cancer is more than 3 but not more than 5 millimeters deep, and not more than 7 millimeters wide. Stage IB is divided into stages IB1 and IB2, based on the size of the tumor. In stage IB1, (1) the cancer can only be seen with a microscope and is more than 5 millimeters deep and more than 7 millimeters wide; or (2) the cancer can be seen without a microscope and is not more than 4 centimeters. In stage IB2, the cancer can be seen without a microscope and is more than 4 centimeters.