Combination of local tumor invasiveness (LTI) and International Prognostic Index (IPI) provides better predictive value in extranodal NK/T-cell lymphoma, nasal type (NTCL)

17503 Background: In contrast to B-cell lymphomas, NK/T-cell lymphomas have unique clinical pattern (local invasiveness; Blood. 2005;106:3785). Prognostic factors were evaluated according to IPI as well as LTI and compared with the other prognostic model (Lee J, et al JCO 2006). Methods: 176 patients diagnosed with NTCL between 1992 and 2004 were analyzed. Overall survival (OS) and progression-free survival (PFS) were compared according to IPI, IPI combined with LTI, and the other model. LTI was briefly defined as follows: bony invasion or perforation or skin invasion (upper aerodigestive tract); serosal invasion or perforation (gastrointestinal tract); tumor more than 5cm or invasion of deep extradermal structures (skin); and neurovascular or bony invasion (muscle). Results: After a median follow-up period of 80 months, 5-year (y) OS and PFS were 33% and 25%, respectively. The IPI risk group was predictive of OS and PFS (5-y OS 52%, 23%, 10%, and 4%, respectively, P < .0001; 2-y PFS 47%, 31%, 5%, and 4%,...