***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: We identified 14 eligible studies which randomised a total of 5,500 women. Median follow-up ranged from 18 to 124 months. Eight studies described a satisfactory method of randomisation. Data, based on 1139 estimated deaths in 4620 women available for analysis, show equivalent overall survival rates with a HR of 0.98 (95% CI, 0.87 to 1.09; p, 0.67; no heterogeneity). Preoperative chemotherapy increases breast conservation rates, yet at the associated cost of increased loco regional recurrence rates. However, this rate was not increased as long as surgery remains part of the treatment even after complete tumour regression (HR, 1.12; 95% CI, 0.92 to 1.37; p, 0.25; no heterogeneity. Preoperative chemotherapy was associated with fewer adverse effects. Pathological complete response is associated with better survival than residual disease (HR, 0.48; 95% CI, 0.33 to 0.69; p, < 10-4). This review suggests safe application of preoperative chemotherapy in the treatment of women with early stage breast cancer in order to down-stage surgical requirement, to evaluate chemosensitivity and to facilitate translational research.
Output:

This review identified 14 randomised controlled trials involving 5,500 women addressing this question. The analyses revealed no difference in overall survival and disease-free survival for women who received either preoperative or postoperative chemotherapy. Preoperative treatment makes more breast-conserving surgery possible because of shrinkage of the tumour before surgical intervention (relative risk, 0.82; 95% confidence interval, 0.76 to 0.89). However, this also results in a increase of loco-regional recurrence (recurrence in the same area) rate (hazard ratio, 1.12; 95% confidence interval, 0.92 to 1.37). Preoperative chemotherapy provides the possibility of monitoring tumour response and making appropriate regimen changes once the tumour appears to be resistant to the primary therapy. Adverse effects, which were reported in only half of the studies, were fewer in women receiving preoperative chemotherapy. Although, postoperative complications, nausea and vomiting, and alopecia were equally distributed, events of cardiotoxicity were less likely (relative risk, 0.74; 95% confidence interval, 0.53 to 1.04) in women receiving preoperative chemotherapy. Also, serious infection (analysed in 2799 women) was less likely to occur in women receiving preoperative chemotherapy (relative risk, 0.69; 95% confidence interval, 0.56 to 0.84).