A new prognostic model for PTCL?

“Of course, this isn’t a pre-treatment variable, but we did add it as sort of an exploratory analysis,” Dr Petrich said. “And regardless of disease stage, [radiation] seems to be associated with improved survival. But when we include it in a multivariate analysis, it’s also highly associated with protection from 5-year mortality (P<0.0001).”

Creating, validating the prognostic model

Dr Petrich and his colleagues created a prognostic model based on some of the aforementioned factors. They assigned points according to hazard ratios (HRs).

Patients received 1 point for each of the following factors: age 55 or older (HR 1.51), black race (HR 1.43), distant-stage disease (HR 1.79), PTCL-NOS (reference), AITL (HR 1.19), ALCL (HR 0.88), and ATLL (HR 1.34).

Patients received 2 points for each of the following histologies: HSTL (HR 1.76), EATL (HR 2.32), ENKTL (HR 1.50), and T-PLL (HR couldn’t be calculated). And they received 0 points for SCPTL (HR 0.71) and T-LGL (HR 0.43).

The researchers then applied the model to the population of 8802 patients and evaluated survival. The median OS was more than 120 months for patients with a score of 0-1, 36 months for those with a score of 2, 14 months for those with a score of 3, and 9 months for those with score of 4 or 5.

“We have good discrimination of outcome based on this scoring system, with patients with the most favorable prognosis having median survival that’s out over 10 years,” Dr Petrich said.

The researchers also obtained good discrimination when they tested the model in a validation cohort of 112 patients, Dr Petrich said. He noted, however, that validating the model with a larger patient population would provide better results.

He also pointed out that this study had its limitations, such as missing data and a lack of uniformity with regard to treatment. But the research does reveal factors that are likely important prognostic indicators in PTCL.