Stage I includes: IA: (T1 or T2, N0, M0, Low Mitotic Rate); IB: (T3, N0, M0, Low Mitotic Rate). T1: Tumor measuring 2 cm or less. T2: Tumor measuring more than 2 cm but not more than 5 cm. T3: Tumor measuring more than 5 cm but not more than 10 cm. N0: No regional lymph node metastasis or unknown lymph node status. M0: No distant metastasis. Low Mitotic Rate: Five or fewer mitoses per 5 square millimeters, or per 50 HPF. (AJCC 8th ed.) [from NCI]