***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: The five trials that met our criteria included 698 patients: data from 499 (71.5%) were available for analysis of relapse frequency at one year's, from 488 (70%) at two years' and from 415 (59.5%) at three years' follow-up. Azathioprine reduced the number of patients who had relapses during the first year of treatment (relative risk reduction [RRR] =20%; 95% CI = 5% to 33%), at two years' (RRR =23%; 95% CI = 12% to 33%) and three years' (RRR =18%; 95% CI = 7% to 27%) follow-up. These results were consistent in sensitivity analysis. There was no heterogeneity among the studies.  Data from only three small trials with a total of 87 patients were available to calculate the number of patients who progressed during the first two to three years. There was a statistically significant benefit (RRR = 42%; 95% CI = 7% to 64%) of azathioprine therapy at three years' follow-up; this result was robust after sensitivity analyses and there was no heterogeneity among the trials.  Gastrointestinal disturbances, bone marrow suppression and hepatic toxicity were greater in the azathioprine group rather than in the placebo group; they were anticipated, and, by monitoring and dosage adjustment, were easily managed. Withdrawals due to adverse effects were few, occurring mostly during the first year of azathioprine treatment and mainly due to gastrointestinal intolerance (5%).  Data from the trials and from cohort and case controls studies available in the literature did not show an increase in risk of malignancy from azathioprine. A possible long-term risk of cancer from azathioprine may be related to a treatment duration above ten years and cumulative doses above 600 g. Azathioprine is an appropriate maintenance treatment for patients with MS who frequently relapse and require steroids. Cumulative doses of 600 g should not be exceeded in relation to a possible increased risk of malignancy. Considering the trade off between the benefits and harms, azathioprine is a fair alternative to interferon beta for treating MS. A logical next step for future trials would seem the direct comparison of azathioprine and interferon beta. In fact the direct comparison between these two widely used treatments in MS has not been made.
Output:

Two studies had deaths reported, comprising of four persons in the control group, and eight in the AZA group. These small numbers do not allow a statistical analysis.  Conflicting conclusions on potential risk of cancer in MS patients with long-term AZA treatment have been reported in eight published papers, not considered in the present review because they came from sources other than clinical trials. The presence of patients who developed cancer ( three in the AZA and 1 the placebo group) was reported in two out of five studies considered in this review. Numerous studies of AZA treated patient populations other than MS patients are also available. The whole data, however, does not show an increase in risk of malignancy from AZA. Possible long-term risks may be related to a treatment duration above ten years and cumulative doses above 600 g.