Outcome in patients with idiopathic retroperitoneal fibrosis treated with corticosteroid or tamoxifen monotherapy

BACKGROUND: Although corticosteroids (CS) are used primarily in idiopathic retroperitoneal fibrosis (iRPF), tamoxifen (TMX) may be a suitable alternative. We compared outcome with CS or TMX monotherapy for first presentation in a large group of patients with iRPF disease. METHODS: Of all patients with iRPF disease who were seen at our tertiary care referral centre from February 1999 to December 2011, 118 patients were eligible for this retrospective study. Treatment success was defined as the composite of (i) amelioration of symptoms, (ii) computed tomography (CT)-documented mass regression and, if applicable, (iii) definitive removal of ureteral stent or nephrostomy tube. Recurrence was defined as recurrence of signs and symptoms and/or CT-documented mass increase after initial treatment success with primary treatment. RESULTS: Presenting signs and symptoms did not differ between patients treated with CS (n = 50) or TMX (n = 68). Time to amelioration of symptoms after treatment initiation was shorter in CS-treated patients [CS, 2.0 (0.8–3.8) weeks versus TMX, 4.0 (2.0–6.0) weeks; P < 0.01]. Short-term percentual decrease in acute-phase reactant levels (P < 0.001 for both erythrocyte sedimentation rate and C-reactive protein) and serum creatinine level (P < 0.01) following treatment initiation was greater in CS-treated patients compared with that in TMX-treated patients. Mass regression at first follow-up CT scan was observed more frequently in CS-treated patients (CS, 84.0% versus TMX, 68.3%; P = 0.05) with no difference in time interval from treatment initiation to first follow-up CT between groups [CS, 5 (2–7) months versus TMX, 4 (4–5) months; P = 0.34]. Definite treatment success was non-significantly higher in CS-treated patients (CS, 72.7% versus TMX, 58.3%; P = 0.15). In patients with initial treatment success with primary treatment, recurrence rate was lower in TMX-treated patients (CS, 62.5% versus TMX, 21.4%; P < 0.01). CONCLUSIONS: CS are superior to TMX in treating iRPF disease. However, in patients with initial treatment success with primary treatment, recurrence rate was lower in TMX-treated patients.