title: The International Prognostic Index predicts outcome after histological transformation of low-grade non-Hodgkin lymphoma.
abstract: Histological transformation of low-grade non-Hodgkin lymphoma (NHL) to diffuse large cell NHL is well recognized and is associated with a poor prognosis. We sought to determine the overall outcome and the factors that affect survival in patients with histological transformation of low-grade NHL. Between November 1979 and September 2000, 93 patients who developed transformed lymphoma were identified. The median time to transformation was 4.2 years from the original diagnosis. The median age at transformation was 63 years. Seventy-eight percent had stage III or IV disease. Fifty-seven percent had extranodal involvement, including bone marrow; 33% had an elevated lactate dehydrogenase. The International Prognostic Index (IPI) at transformation was termed the transformation IPI (tIPI); 29% had a tIPI of 0-1, 59% had a tIPI of 2-3 and 8% had a tIPI of 4-5. At a median follow-up of 15 months from histological transformation, 20 of 93 patients (22%) were alive. The median survival from transformation was 15 months (4 months to 19.7 years). On univariate analysis, the following factors at the time of histological transformation were associated with an improved survival: low tIPI (P = 0.009), time to transformation > 4 years (P = 0.02), age < or = 60 years (P = 0.02) and stage I or II disease (P = 0.04). On multivariate analysis, factors that remained significant included a low tIPI (P = 0.0001) and a time to transformation > 4 years (P = 0.004). tIPI correlated with overall survival (OS); IPI 0-1, median OS 38 months; IPI 2-3, median OS 12 months; IPI 4-5, median OS 4 months. In conclusion, tIPI at the time of histological transformation is an important predictor of OS. A time to transformation > 4 years from diagnosis is associated with better OS.
authors.affiliation: Divison of Hematology, Department of Internal Medicine, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA. micallef.ivana@mayo.edu
authors.forename: Ivana N M
authors.initials: IN
authors.lastname: Micallef
authors.forename: Ellen D
authors.initials: ED
authors.lastname: Remstein
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Ansell
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Colgan
authors.forename: David J
authors.initials: DJ
authors.lastname: Inwards
authors.forename: Patrick B
authors.initials: PB
authors.lastname: Johnston
authors.forename: Jason T
authors.initials: JT
authors.lastname: Lewis
authors.forename: Svetomir N
authors.initials: SN
authors.lastname: Markovic
authors.forename: Luis F
authors.initials: LF
authors.lastname: Porrata
authors.forename: William L
authors.initials: WL
authors.lastname: White
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Witzig
authors.forename: Kay
authors.initials: K
authors.lastname: Ristow
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Habermann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D005260:Female; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy / Q000473:pathology*; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate