Idiopathic Multicentric Castleman Disease-TAFRO: A Potentially Curable Disease?

Idiopathic multicentric Castleman disease (iMCD)-TAFRO (Thrombocytopenia, Anasarca, Fever, Reticulin fibrosis/renal dysfunction, Organomegaly) is the most severe clinical subtype of iMCD characterized by a catastrophic cytokine storm. Currently, iMCD-TAFRO is regarded as incurable which needs "indefinite" treatment. However, long-term data are sparse, and treatment discontinuation may be possible in a subset of patients. This multicenter, retrospective study analyzed 27 patients who discontinued treatment. All patients had biochemical complete response (CR) at the time of drug discontinuation. Most patients were treated with myeloma-like treatment (59.3%) and only 11.1% received anti-IL-6 therapy. With a median follow-up of 31 months (range, 12-108) after treatment discontinuation, only four patients (14.8%) suffered from progression of disease (PD) and the others (85.2%) maintained biochemical CR. Patients who suffered from PD had a significantly lower pretreatment CRP level than patients maintaining responses (43.7 ± 39.3 vs. 126.4 ± 62.5 mg/L, p = 0.018). No significant impacts of different treatment approaches or duration of treatment on the likelihood of achieving long-term remission were observed. The median time between drug discontinuation to PD (n = 4) was 9.5 months (range, 5-12). These patients all achieved treatment responses again with the same or similar treatment approaches. The estimated PFS at 6 months, 1 year, and 3 years were 96.3%, 85.2%, and 85.2%, respectively. All patients remained alive with a median of 31 months follow-up after drug discontinuation. This study suggests that some iMCD-TAFRO patients might maintain long-term remission after treatment discontinuation. For patients who achieved biochemical CR, an attempt at treatment discontinuation could be considered.