Long-term immunosuppressive therapy of ulcerative colitis. Continuation of a personal series

Meta-analysis of risk of malignancy with immunosuppressive drugs in inflammatory bowel disease

BACKGROUND

There is a concern as to whether long-term administration of immunosuppressants in patients with inflammatory bowel disease (IBD) would increase the risk of malignancy.

OBJECTIVE

To compare the risks of developing malignancy between patients with IBD treated with immunosuppressive agents and patients with IBD not receiving these agents.

METHODS

A systematic literature review was conducted, and a meta-analysis was performed on data retrieved from cohort studies that followed patients with IBD who received immunosuppressive agents for more than a year and documented the incidence of newly developed malignancy. An electronic search was conducted using MEDLINE (1966-September 2006), the Cochrane Library (issue 3, 2006), and Japana Centra Revuo Medicina (1981-September 2006). Medical subject headings used in the searches were azathioprine, 6-mercaptopurine, cyclosporine, methotrexate, tacrolimus, inflammatory bowel disease, and neoplasms. We imposed no language limitation in the searches. Additionally, a manual search of reference listings from all articles retrieved from the electronic databases was performed. Using data obtained from control groups or population-based studies, the incidence of newly developed malignancy in patients with IBD treated with immunosuppressive agents was compared with that of patients with IBD who were not receiving immunosuppressive agents. Statistical analysis for the change in risk of developing malignancy was performed using the weighted mean difference (WMD) normalized to per person-year and its 95% confidence interval.

RESULTS

Nine cohort studies met the inclusion criteria for this meta-analysis. Analysis of these studies showed no discernible difference (WMD -0.3 x 10(-3)/person-year; 95% CI -1.2 x 10(-3) to 0.7 x 10(-3)) in the incidence of any kind of malignancy in patients with IBD who received immunosuppressants compared with those who did not receive immunosuppressants. No significant difference in WMD was observed when the data from patients with either Crohn's disease (CD) or ulcerative colitis (UC) were analyzed separately.

CONCLUSIONS

Our findings suggest that the administration of immunosuppressive agents in patients with either CD or UC probably does not confer a significantly increased risk of malignancy compared with patients with IBD who are not receiving these agents.

A search for the optimal duration of treatment with 6-mercaptopurine for ulcerative colitis

BACKGROUND AND AIMS

6-mercaptopurine has proven to be effective in the treatment and maintenance of remission of ulcerative colitis (UC). The optimal duration of treatment with 6-MP is unknown. The intention of this study was to determine the best duration of treatment with 6-MP in terms of maintenance efficacy once remission has been achieved.

METHODS

We reviewed the records from the inflammatory bowel disease (IBD) center at Lenox Hill Hospital and one large IBD practice in New York City of 334 patients treated with 6-MP for UC. These patients were followed from 4 months to 28.7 yr. Sixty-one patients were treated with 6-MP for at least 6 months and had at least a 3-month disease-free interval off steroids while on the medication. These patients were divided into two groups: Group 1 continued 6-MP and group 2 discontinued the drug at various times for reasons other than relapse. Time to relapse was calculated for both groups.

RESULTS

A Kaplan-Meier survival analysis was employed and differences between the two groups were analyzed using the log-rank test. The median time to relapse in group 2 was 24 wk and in group 1 was 58 wk (p < 0.05). There were no significant differences between the two groups in age, gender, extent of disease, use of concomitant 5-ASA products, dose of 6-MP during remission, duration of UC, and duration of treatment with 6-MP before remission was achieved.

CONCLUSION

Discontinuation of treatment with 6-MP while UC is in remission leads to a higher relapse rate than maintenance on 6-MP. Therefore, we favor the indefinite treatment with 6-MP in most patients.

Malignant neoplasms subsequent to treatment of inflammatory bowel disease with 6-mercaptopurine

OBJECTIVE

Most complications of 6-mercaptopurine (6MP) used in the treatment of inflammatory bowel disease (IBD) occur early, whereas neoplasms occur late in the course. Concern persists that the risk is increased when 6MP is used. We report our experience with malignant tumors developing over 27 yr of treating IBD patients with 6MP.

METHODS

A total of 591 patients with IBD treated with 6MP between 1969 and 1997 were followed or traced until present to identify all malignant tumors and blood dyscrasias that had developed to determine the type, distribution, and duration of the IBD, the dose and duration of 6MP therapy, the concurrent versus previous use of 6MP, the incidence and probable relationship of 6MP to specific neoplasms, and whether the 6MP had been effective in treatment.

RESULTS

A total of 550 patients (93%) fulfilled the criteria for follow-up; these included 380 with Crohn's disease (CD) and 170 with ulcerative colitis (UC). Twenty-five patients had developed neoplasms (16 of 380 CD and nine of 170 UC) (p = 0.66). In half of the cases, the goal of therapy had been achieved with 6MP. In 10 patients, the neoplasm was diagnosed while the patients were taking 6MP (40%) and in 15, many years after the 6MP had been terminated (60%). The incidence of neoplasms (25 of 550) was 2.7/1000 patient-years of follow-up. The most common neoplasms were found in the bowel (eight of 550, 1.6%; five CD, and three UC), and breast (three, 0.5%; two CD, and one UC). Non-Hodgkins lymphomas occurred in two patients with CD; one was cerebral and the other abdominal. One patient with CD developed leukemia. The duration of 6MP therapy ranged from 5 months to 22 yr, with a mean of 5 yr. The dose of 6MP ranged from a quarter of a tablet/day (12.5 mg) to 100 mg/day, with the majority in a range from 50 to 75 mg/day.

CONCLUSION

In no instance could a neoplasm be attributed to the use of 6MP. The incidence of colon cancer is not greater than that with long standing colitis. Suspicion of a relationship between 6MP and leukemia/lymphoma persists, but the incidence is low. This must be weighed against the improved quality of life due to 6MP for patients with IBD.

Experiences with 6-mercaptopurine and azathioprine therapy in pediatric patients with severe ulcerative colitis

BACKGROUND

The effectiveness of 6-mercaptopurine combined with azathioprine in treating severe ulcerative colitis has been shown in several adult studies. Reported pediatric experiences are rare. The purpose of this study was to investigate the safety and the potential efficacy of 6-mercaptopurine and azathioprine in the treatment of active ulcerative colitis in a pediatric population.

METHODS

The medical records of patients with active ulcerative colitis who were under observation at The Children's Hospital of Philadelphia and its satellite clinics from January 1984 through December 1997 were retrospectively reviewed. Patients were included who had received a diagnosis of ulcerative colitis, who met no criteria for Crohn's colitis, and who had received treatment with 6-mercaptopurine and azathioprine. They were then analyzed for the development of side effects, the indication to use 6-mercaptopurine and azathioprine, and the ability to discontinue corticosteroid use in those patients taking 5-acetylsalicylic acid products who were corticosteroid-dependent or whose disease was refractory to treatment. Excluded from the corticosteroid analyses were patients who underwent surgery for their disease and patients treated with 5-acetylsalicylic acid only. Statistical analysis was performed by the Kaplan-Meier survival curve and paired Student's t-test.

RESULTS

In a review of 200 medical records of patients with active ulcerative colitis, 20 patients met the criteria. The patients' average age at the initiation of treatment with 6-mercaptopurine and azathioprine was 13.8 years. Sixteen patients (80%) were corticosteroid dependent and 3 (15%) had ulcerative colitis refractory to corticosteroid treatment. One patient had severe colitis treated with 5-acetylsalicylic acid only. Discontinuation of corticosteroid was accomplished in 12 (75%) of 16 patients. The median time to discontinuation of corticosteroid after initiation of 6-mercaptopurine and azathioprine therapy was 8.4 months. Eight patients (67%), observed from 3 months to 65 months, have continued without corticosteroid therapy. Side effects included pancreatitis and shingles that resulted in discontinuation of 5-acetylsalicylic acid, leukopenia corrected by withholding 6-mercaptopurine, and self-resolved hepatitis.

CONCLUSIONS

The data support the safety of 6-mercaptopurine and azathioprine use in the treatment of pediatric patients with ulcerative colitis; side effects were minimal and reversible. Eighteen (90%) of 20 patients tolerated the therapy well. The results also show that 12 (75%) of 16 pediatric patients with ulcerative colitis will benefit from the use of 6-mercaptopurine and azathioprine after initial discontinuation of corticosteroid therapy. Although 6-mercaptopurine and azathioprine may not prevent further relapses, medical management of these flares may be less intense and may not require long-term corticosteroid use. Prospective clinical trials in pediatric patients are necessary to delineate further the role of 6-mercaptopurine and azathioprine in pediatric ulcerative colitis.

Treatment of Crohn's disease with 6-mercaptopurine. A long-term, randomized, double-blind study

To test the effectiveness of 6-mercaptopurine (6-MP) in the treatment of Crohn's disease, we entered 83 chronically ill patients into a two-year double-blind study comparing 6-MP with placebo. Crossover data showed that improvement occurred in 26 of 39 courses of 6-MP (67%) as compared with three of 39 courses of placebo (8%) (P less than 0.001). Non-crossover data likewise confirmed the superiority of 6-MP. The drug was more effective than placebo in closing fistulas (31 vs 6%) and in permitting discontinuation or reduction of steroid dosage (75 vs. 36%) (P less than 0.001). The onset of response to 6-MP was often delayed, with 32% of patients taking longer than three months to respond, and 19% taking longer than four months. Adverse side effects to 6-MP occurred in 10% of patients and were uniformly reversible. We conclude that 6-MP is an effective and useful agent in the management of Crohn's disease.

Clinical use of immunosuppressive drugs: part II

In haematological diseases, insufficient data has been accumulated to evaluate the efficacy of immunosuppressive drug treatment in patients with erythroid aplasia or sideroblastic anaemia. Cyclophosphamide may be efficacious in inhibiting circulating anticoagulants in patients who need continued replacement of clotting factors. Azathioprine, 6-mercaptopurine, cyclophosphamide and vincristine have been used successfully in treating patients with idiopathic thrombocytopenic purpura, and some patients with auto-immune haemolytic anaemia may benefit from the addition of purine analogues. However, the use of immunosuppressive therapy seems to accelerate the presence of haematological malignancies in patients with macroglobulinaemia. In gastro-intestinal diseases, uncontrolled studies have shown nitrogen mustard, 6-mercaptopurine and azathioprine to be of modest benefit to patients with ulcerative colitis and Crohn's disease. In a controlled trial azathioprine plus prednisone proved more effective than prednisone alone in sustaining remission in patients with Crohn's disease. In patients with either chronic active hepatitis or primary biliary cirrhosis, however, there seems to be no benefit from immunosuppressive therapy for primary treatment of these diseases. Cyclophosphamide, azathioprine and methotrexate have all been used with some success in treating patient with uveitis, and in a controlled trial cytarabine has been shown to be beneficial to patients with herpes ophthalmicus. However, no benefit has been shown to patients with the eye changes of Graves' disease with either azathioprine or methotrexate. Patients with Paget's disease appear to be helped by mithramycin. Cyclophosphamide, chlorambucil and azathioprine are ineffective in treating patients with multiple sclerosis. 6-Mercaptopurine, azathioprine, methotrexate and cyclophosphamide have all produced some benefit in patients with myasthenia gravis, and some patients with idiopathic pulmonary haemosiderosis have responded to azathioprine, 6-mercaptopurine and cyclophosphamide. Alkylating agents have proved useful in treating some patients with asthma and in treating frequent relapsers among children with the nephrotic syndrome. In adults with membrano-proliferative glomerulonephritis some patients have responded to combination therapy with cyclophosphamide, azathioprine and corticosteroids. Immunosuppressive therapy is also indicated in prolonging graft survivals in patients receiving organ transplants. Drug toxicities of immunosuppressive agents are discussed. Their long-term effects, including mutagenic potential, have as yet not been fully elucidated.