Recent advances in the management of gastrointestinal stromal tumor

Table 3 American Joint Committee on Cancer tumor node metastasis system for gastric and omental gastrointestinal stromal tumor

Stage	TNM	Mitotic rate	Stage description
IA	T1 or T2; N0; M0	Low (G1): mitotic rate 5/50 per HPF or less	T1: Tumor ≤ 2 cm; T2: Tumor > 2 cm but ≤ 5 cm; N0: no regional lymph node metastasis; M0: No distant metastasis
IB	T3; N0; M0	Low (G1)	T3: Tumor > 5 cm but ≤ 10 cm; N0: no regional lymph node metastasis; M0: No distant metastasis
II	T1; N0; M0 or T2; N0; M0 or T4; N0; M0	High (G2): mitotic rate > 5/50 HPF; High (G2); or Low (G1)	T1: Tumor ≤ 2 cm; T2: Tumor > 2 cm but ≤ 5 cm; T4: Tumor > 10 cm in greatest dimension; N0: no regional lymph node metastasis; M0: No distant metastasis
IIIA	T3; N0; M0	High (G2)	T3: Tumor > 5 cm but ≤ 10 cm; N0: no regional lymph node metastasis; M0: No distant metastasis
IIIB	T4; N0; M0	High (G2)	T4: Tumor > 10 cm in greatest dimension; N0: no regional lymph node metastasis; M0: No distant metastasis
IV	Any T; N1; M0 or Any T; Any N; M1	Any rate or Any rate	N1: Regional lymph node metastasis; M1: Distant metastasis

TNM: Tumor node metastasis; HPF: High power field.