Stage IIIA includes: (T1-T2, N1/N1c, M0); (T1, N2a, M0). T1: Tumor invades the submucosa (through the muscularis mucosa but not into the muscularis propria). T2: Tumor invades the muscularis propria. N1: One to three regional lymph nodes are positive (tumor in lymph nodes measuring 0.2 mm or more), or any number of tumor deposits are present and all identifiable lymph nodes are negative. N1c: No regional lymph nodes are positive, but there are tumor deposits in the subserosa, mesentery, or nonperitonealized pericolic, or perirectal/mesorectal tissues. N2a: Four to six regional lymph nodes are positive. M0: No distant metastasis. (AJCC 8th ed.) [from NCI]