OS of patients with AITL. OS according to IPI (A) and PIT (B) are shown. Both IPI and PIT could stratify the prognosis of AITL. IPI categorized patients as follows: L (n = 18), LI (n = 42), HI (n = 74), and H (n = 64). L, low risk; LI, low-intermediate risk; HI, high-intermediate risk; H, high risk. PIT categorized as follows: group 1 (n = 8), group 2 (n = 42), group 3 (n = 80), and group 4 (n = 71).