International Prognostic Index for aggressive non-Hodgkin's lymphoma is valid for all malignancy grades.

An International Prognostic Index (IPI) for patients with aggressive non-Hodgkin's lymphoma (NHL) has recently been published. The IPI is based on pretreatment clinical characteristics and developed on clinical trial patients, classified as intermediate grade according to the Working Formulation (WF). We applied this IPI in a population-based registry of NHL patients. This registry does not have the restrictions that usually hold for patients in clinical trials, eg, with respect to age and performance status. Moreover, it covers all the three WF classes (low, intermediate, and high). The IPI turned out to be of prognostic value for response rate and survival in our unselected cohort of 744 patients, as well. In each of the three WF classes separately, the four IPI classes showed going from low to high substantially decreasing response rates and survival percentages. For our cohort of WF intermediate grade patients 5-year survival levels were lower in all four IPI classes (59%, 34%, 14%, and 10%, respectively), probably reflecting the selection of clinical trial patients in the original study (73%, 51%, 43%, and 26%).