A Prognostic Model of 114 Patients with Castleman’s Disease.

Background: Castleman Disease (angiofollicular hyperplasia) is a rare, lymphoproliferative disease. There has been no large study describing the natural history of this disease.

Hypothesis: A retrospective analysis of clinical, pathologic, and laboratory factors predictive of outcome should be identifiable.

Methods: During the period from 3/30/48 to 6/18/2002, 114 patients with Castleman Disease were seen at the Mayo Clinic (Rochester, 56; Jacksonville, 19; Arizona, 13) and at the University of Nebraska (26). Pathology, laboratory and clinical characteristics analyzed included: the presence of unicentric or multicentric disease, the pathologic variant (hyaline vascular versus plasma cell variant), co-existing POEMS syndrome, age, serum albumin, alkaline phosphatase, AST, sedimentation rate, the presence of cytopenias, organomegaly (hepatomegaly or splenomegaly), papilledema, peripheral neuropathy, sclerotic bone lesions, renal disease, B-symptoms or respiratory symptoms. The impact of these variables on overall survival from time of diagnosis was evaluated using univariate analyses, where their significance was determined based on the logrank statistic. To derive the multivariable model, the score-based model-building method was used. Based on this approach, a 3-variable model was designed, adjusting for age at diagnosis. Patients were then assigned a risk score corresponding to how many of these risk factors they possessed. A final proportional hazards model was constructed based on this risk score.

Results: The median age at diagnosis was 43 (range: 5 – 78), and 48% of patients were male. Fifty-five patients had multicentric disease. Median follow-up of living patients was 5.8 years (range: 0.02 – 27). On univariate analysis, factors that predicted for overall survival included: age at diagnosis, presence of multicentric disease, presence of a monoclonal protein in the urine, co-existing POEMS syndrome, serum albumin, presence of cytopenias, organomegaly, neuropathy, thrombocytosis, and respiratory symptoms. The final multivariable model included 98 patients. Adjusting for age, the model included organomegaly, respiratory symptoms, and thrombocytosis. Patients were assigned 1 point for each risk factor they possessed based on clinical relevance and similarity of the hazard ratios for each of these 3 variables (ranging from 3.1 to 4). A final prognostic survival model was constructed using this assigned risk score. These scores were collapsed further based on observed similarities (0 factors vs. 1 or more factors). This final model yielded a hazards ratio of 5.5 (95% CI 2.3–13.4). The 10 year survival rates were 80% (95% CI: 65–98%) and 41% (95% CI: 28–59%) for the 0 factor and 1+ factor groups, respectively. The 20 year survival rates were 71% (95% CI: 52–87%) and 31% (95% CI: 19–51%), respectively.

Conclusion: The most distinguishing prognostic clinical, laboratory, and pathological characteristics of Castleman’s Disease are orgnaomegaly, respiratory symptoms, and thrombocytosis. This prognostic scoring system should aid in individual cases and in assessing results of therapeutic interventions.