Comparison of the prognostic impact of IPI and PIT in peripheral T-cell lymphoma in real-world practice with a large elderly population.

We compared the predictive ability of the International Prognostic Index (IPI), a frequently used prognostic model for peripheral T-cell lymphoma (PTCL), with that of a type-specific prognostic model, the Prognostic Index for PTCL-U (PIT). We retrospectively analyzed 113 patients diagnosed with PTCL. The median age was 67 years (range, 16-88 years), 75 patients (66%) were male, and the most common disease type was PTCL, not otherwise specified (69%). With a median follow-up of 6.8 years (interquartile range, 2.7-9.9 years), 5-year survival rates for the four groups in IPI were 85%, 62%, 49%, and 13%, respectively. Similarly, 5-year survival rates for the four groups in PIT were 83%, 64%, 49%, and 19%, respectively. The area under the receiving operating characteristic curve for predicting mortality from PIT (0.725) was not significantly different from that from the IPI (0.685, P = 0.134). Multivariable analysis showed that performance status ≥ 2 (P < 0.0001) and extranodal lesions ≥ 2 (P = 0.029) were significantly associated with lower overall survival. The present study found no significant difference in prognostic ability between the IPI and PIT for PTCL, and both models appear useful as predictive models.