***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: Our search strategies led to 699 potentially relevant references. Of these, one RCT involving 79 patients was included. We judged the quality of the trial as moderate. The study was reported as a randomised open-label study and published as a full-text article. Even though PFS was statistically significantly improved for patients treated with HD-MTX plus cytarabine (HR 0.54; 95% CI 0.31 to 0.92; P = 0.01), this did not translate to a statistical significant OS benefit (HR 0.65; 95% CI 0.38 to 1.13; P = 0.07). AEs, especially infective complications, hepatotoxicity and haematological toxicities, were assessed more often in patients undergoing HD-MTX therapy combined with cytarabine. However, there were no statistically significant differences in terms of TRM (RR 3.08; 95% CI 0.33 to 28.32; P = 0.35). Owing to the small number of included trials and patients, the findings in this review remain uncertain. In summary, the presently available evidence (one small trial) showed a benefit in terms of PFS, ORR and CRR but no statistically significant difference regarding OS for patients with PCNSL treated with HD-MTX plus cytarabine compared to HD-MTX alone. However, the risk of severe infections and toxicity was significantly higher in patients treated with combined chemotherapy. More RCTs with additional chemotherapy to HD-MTX therapy with higher numbers of patients and longer follow-up periods are needed to confirm the results of this review and determine whether the PFS benefit will translate into an OS advantage. At least the one included study shows that RCTs of moderate quality and with valuable outcomes for this malignant disease are feasible.
Output:

In this systematic review we summarised and analysed the evidence from randomised controlled trials (RCTs) on efficacy and safety of methotrexate combined with additional chemotherapy in the treatment of adult, immunocompetent PCNSL patients regarding overall survival, progression-free survival, response rate, adverse events, treatment-related mortality and quality of life. We searched several important medical databases such as CENTRAL and MEDLINE and found one RCT with 79 patients that fulfilled our inclusion criteria. As a result, this review shows that patients treated with methotrexate plus cytarabine compared to high-dose methotrexate alone have a statistically significant improvement in progression-free survival and response rate. No statistically significant difference is shown for overall survival. Adverse events, especially infections, hepatotoxicity and haematological toxicities are more common in patients undergoing therapy with methotrexate plus cytarabine, although there are no differences in terms of treatment-related mortality. Owing to the small number of included trials and patients, the findings in this review remain uncertain and more RCTs with enlarged numbers of patients and longer follow-up periods are needed. However, the one analysed study demonstrated that RCTs are feasible on patients with this rare disease and should concentrate on overall survival.