Objective To investigate the prognostic stratification value of an enhanced international prognostic index (NCCN-IPI) in patients with diffuse large B-cell lymphoma (DLBCL) who are negative at the end of treatment with positron emission tomography computed tomography (PET/CT).

Methods A retrospective analysis was conducted on 60 patients with DLBCL from April 2013 to August 2017 in the first affiliated hospital of Soochow university. There were 28 males and 32 females, with a median age of 51 years (16−81 years). Baseline characteristics were collected from all the patients who underwent six- to eight-cycle R-CHOP regimen chemotherapy and were negative by ¹⁸F-FDG PET/CT. The risk stratification was performed by NCCN-IPI, Log-rank test was used for comparison of the differences in progression-free survival (PFS) and overall survival (OS) between groups.

Results The patients featured a median follow-up of 34 months (14–69 months). The two-year PFS and OS rates reached 83.33% (50/60) and 96.67% (58/60), respectively. On the basis of NCCN-IPI risk categorization, 35.0% (21/60), 41.7% (25/60), 18.3% (11/60) and 5.0% (3/60) patients belonged to the low-, low–intermediate-, high–intermediate-, and high-risk subgroups, respectively. A statistically significant difference was observed in the PFS between the low-risk group and the other groups (P=0.0272, 0.0143, <0.0001) and in the OS between the high-risk group and the other groups (P=0.0098, 0.0166, 0.0045). The difference between the PFS and OS of other components showed no statistical significance (all P>0.05).

Conclusion Further prognostic stratification can be performed by NCCN-IPI in patients with DLBCL who are negative at the end of treatment by PET/CT.