Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Idiopathic Retroperitoneal Fibrosis: Treatment-Related Outcomes and Predictors of Clinical Response.

Kermani1,  Tanaz A., Crowson2,  Cynthia S., Achenbach2,  Sara, Luthra1,  Harvinder S.

Mayo Clinic, Rochester, MN
Mayo Clinic

Purpose:

1) To compare outcomes by treatment type, and 2) to determine baseline variables associated with treatment response, in 151 patients with retroperitoneal fibrosis (RF) followed at a single tertiary-care center.

Methods:

In this retrospective study, incident cases of RF diagnosed between 1/1/1996 and 12/31/2006 were included. RF was defined by compatible imaging findings. Medical records were reviewed and treatment and outcomes were abstracted.

We defined 4 response types: partial response (stabilization/improvement in imaging findings on stable medical regimen for 1 year), complete response (stabilization/improvement in imaging findings on a stable medical regimen with discontinuation of prednisone for 1 year), remission (stabilization/improvement in imaging findings off all therapy for 1 year), and relapse (worsening imaging findings 1 year after an initial response). Patients were followed until last contact, death or December 31, 2009. Kaplan-Meier methods were used to compare outcomes by treatment group. Cox proportional hazard models were used to evaluate the association between baseline variables and treatment response.

Results:

We identified 185 patients with RF, mean age at diagnosis 57.6 (±11.8) years. Follow-up was available in 151 patients which included 87 men (58%) and 64 women (42%); median length of follow-up 4.0 years (total 671 person-years).

Forty-seven patients (31%) were treated with medications only (Group 1), 67 patients (44%) received medications and ureteral stenting (Group 2) and 20 patients (13%) were treated with medications and ureterolysis (Group 3). Commonly prescribed medications were prednisone (96 patients), tamoxifen (107 patients) and methotrexate (46 patients). Five patients (3%) who received no treatment and 12 patients (8%) treated only with stenting or ureterolysis were not analyzed due to small numbers.

At baseline, all 3 treatment groups were similar in age at diagnosis, ethnicity, sex, smoking status, anemia, ESR and CRP (p>0.05). However, baseline creatinine (Cr) was elevated in 2 patients (4.4%) in Group 1 compared to 39 patients (62%) in Group 2 and 11 patients (55%) in Group 3 (p<0.001). Also, more patients in Groups 2 and 3 had hydronephrosis compared to Group 1 (p<0.001).

Kaplan-Meier curves for the 3 groups were similar for all response types (p>0.05). At 2 years from diagnosis, 59% of all patients achieved at least partial response. Relapses occurred in 18 patients. There were no differences in relapse rates by treatment group (p=0.198). Age at diagnosis, ethnicity, sex, smoking status, anemia, ESR, CRP, elevated Cr, or hydronephrosis did not predict any response type.

Conclusions:

This is the largest series to systematically evaluate treatment outcomes and predictors of response in RF. We defined 4 response types. While patients with baseline renal insufficiency or hydronephrosis were more likely to undergo a urologic procedure, the outcomes for all treatment groups analyzed were similar. No baseline variables were associated any response type. Our findings suggest that regardless of baseline Cr, with close follow-up and appropriate treatment (medical and surgical), the overall outcomes were good.

To cite this abstract, please use the following information:
Kermani, Tanaz A., Crowson, Cynthia S., Achenbach, Sara, Luthra, Harvinder S.; Idiopathic Retroperitoneal Fibrosis: Treatment-Related Outcomes and Predictors of Clinical Response. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :705
DOI: 10.1002/art.28473

Abstract Supplement

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