Value of International Prognostic Score (IPS) in predicting need for bone marrow biopsy (BMB) in Hodgkin's lymphoma (HL)

Abstract

e19531 Background: BMB is frequently performed during the staging of patients (pts) with HL. Previous data suggested routine use of this procedure may be unnecessary. The Ann Arbor classification is currently used to detect pts requiring BMB. Despite sensitivity (sen) of 100%, specificity (spec) is only 40%. We sought to determine whether IPS [as developed by Hasenclever and Diehl (1998)] would yield greater spec while maintaining good sen. Methods: We retrospectively reviewed charts of 1215 histologically proven HL pts from Jan 2000-Dec 2008 at Cleveland Clinic Taussig and Fairview Moll Cancer Centers. Of 1215 pts, 1089 had BMB (90%). 876 pts were included in our study. 213 were excluded due to un-interpretable BMB or missing data. The IPS is calculated as the number of poor risk features present based on male sex, age ≥45, albumin (alb) <4 g/dL, hemoglobin (hem) <10.5 g/dL, stage IV, white blood cell (WBC) ≥15,000/mm3, lymphocyte (lymph) <600/mm3 and/or <8% of total WBC. Multivariable logistic regression was initially used to assess the association between BMI and each factor in the IPS. All 7 factors were significant (p<.001 for sex, age, albu, hem, stage and lymph; .07 for WBC); and therefore recursive partioning algorithm was used to identify a cutoff for determining bone marrow involvement (BMI). Results: 88 pts (10%) had BMI. Using an IPS of >3 to predict BMI, sen was 97% and spec 87%. BMI by histology was 4% lymphocyte-rich, 5% nodular sclerosis, 20% mixed-cellularity and 21% lymphocyte-depleted. Using the IPS>3 cutoff sen and spec were similar across all types of histologies; ranging from 94–100% and 86–89% respectively. Conclusions: using an IPS of >3 for predicting BMI in HL doubled the spec associated with Ann Arbor classification with little loss of sen. The implementation of IPS is a practical and reliable tool that will allow physicians to predict BMI in HL pts. It may, therefore eliminate painful BMB in many Pts. No significant financial relationships to disclose.