Effects of cyclophosphamide on the development of malignancy and on long-term survival of patients with rheumatoid arthritis. A 20-year followup study.

OBJECTIVE: To examine the effects of cyclophosphamide (CYC) on the development of malignancies and on the long-term survival of patients with rheumatoid arthritis (RA). METHODS: We used a longitudinal cohort design in which 119 patients (76 women and 43 men) with refractory RA who were treated with oral CYC between 1968 and 1973 were compared with 119 control patients with RA (matched for age, sex, disease duration, and functional class) who were evaluated during the same time period but did not receive CYC. RESULTS: There was increased risk of malignancy in the CYC-treated group, with 50 cancers found in 37 patients in the CYC group compared with 26 cancers in 25 of the control patients (P < 0.05). The relative risk of cancer for those treated with CYC was 1.5 (95% confidence interval 0.93-5.5). Nine of the malignancies in the CYC group were bladder cancers and 19 were skin cancers, compared with no bladder cancers and 6 skin cancers in the control group. The total dose of CYC was higher in those who developed cancer, particularly in those with bladder cancer. Three of the bladder cancers occurred 14, 16, and 17 years after CYC had been discontinued. CONCLUSION: The risk of malignancy, particularly bladder cancer, in RA patients treated with oral CYC continues even 17 years after discontinuation of the drug.

Recurrence of cervical spine instability in rheumatoid arthritis following previous fusion: can disease progression be prevented by early surgery?

In a retrospective study, 110 patients with rheumatoid arthritis who had cervical spine fusion were evaluated for recurrence of cervical spine instability and resultant need for further surgery. Recurrence of cervical instability was correlated with initial radiographic abnormality, primary surgical procedure and interval between the 2 surgeries. There were 55 patients who had atlantoaxial subluxation (AAS) and required C1-C2 fusion as primary surgery. Three of these patients (5.5%) developed subaxial subluxation (SAS) and had a second procedure after a mean interval of 9 years. Twenty-two patients had AAS with superior migration of the odontoid (AAS-SMO) and had initial surgery of occiput-C3 fusion. Eight of these patients (36%) developed SAS and had a second surgery after a mean interval of 2.6 years. Of the 19 patients with primary radiographic deformity of SAS, one required further surgery for subluxation of an adjacent superior vertebra after a period of 6 years. Fourteen patients had combined deformity of AAS-SMO-SAS, and one required further surgery for SAS after an interval of 22 months. Recurrence of cervical instability following a previous fusion occurred in 15% of these 110 patients. It was seen in 5.5% of patients with initial deformity of AAS vs 36% of patients with AAS-SMO. No patients with C1-C2 fusion for AAS progressed to develop superior migration of the odontoid. We conclude that early C1-C2 fusion for AAS before development of SMO decreases the risk of further progression of cervical spine instability. The pattern of progression of cervical spine involvement, as discussed in the literature, is reviewed.

Malignancy following treatment of rheumatoid arthritis with cyclophosphamide. Long-term case-control follow-up study.

A long-term retrospective case-control study was performed comparing 119 patients with rheumatoid arthritis treated with cyclophosphamide and 119 matched control patients with rheumatoid arthritis not treated with cyclophosphamide to determine the risk of subsequent malignancy. Thirty-seven malignancies were detected in 29 cyclophosphamide-treated patients, while 16 malignancies were found in 16 control patients (p less than 0.05) during a mean follow-up period of more than 11 years. Urinary bladder cancer (six cyclophosphamide-treated patients, no control patients) and skin cancer (eight cyclophosphamide-treated patients, no control patients) were identified as differing statistically between the groups, and hematologic malignancy (five cyclophosphamide-treated patients, one control patient) showed a similar trend. Survival analysis indicated that the rate of development of malignancy in the cyclophosphamide-treated patients was significantly greater than in the control patients at six years following drug initiation, and that this increased rate persisted even at 13 years (p less than 0.01). Of the many risk factors evaluated, mean total cyclophosphamide dose and duration and tobacco use were significantly increased in patients in whom cancer subsequently developed. These long-term complications must be considered seriously when cyclophosphamide or other cytotoxic drugs are initiated for the treatment of rheumatoid arthritis.