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Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

A systematic review and meta-analysis of oncologic outcomes of pre- versus postoperative radiation in localized resectable soft-tissue sarcoma

E Al-Absi, F Farrokhyar, R Sharma, K Whelan, T Corbett, M Patel, and M Ghert.

Review published: 2010.

Link to full article: [Journal publisher]

CRD summary

The review concluded that the delay in surgical resection necessary to complete pre-operative radiation did not seem to increase the risk of lethal metastatic spread in soft-tissue sarcoma; risk of local recurrence may have been lower after pre-operative radiation. The authors urged caution when interpreting the results due to heterogeneity and bias in the studies; these conclusions appear appropriate.

Authors' objectives

To determine the oncologic outcomes in localised resectable soft-tissue sarcoma after pre- versus postoperative radiation.

Searching

MEDLINE, CANCERLIT, EMBASE and Cochrane Database of Systematic Reviews were searched without date restrictions for articles published in English. Search terms were reported.

Study selection

Randomised controlled trials (RCTs) and cohort studies that compared pre-operative radiotherapy with postoperative radiotherapy in localised resectable soft-tissue sarcoma were eligible for inclusion. Studies had to report local recurrence and overall survival. Studies were excluded if the patient population had advanced disease and if the outcome measures were related to wound healing and/or dose of radiotherapy.

The included studies compared pre-operative radiotherapy (mean dose range 48Gy to 52Gy) with postoperative radiotherapy (mean dose range 60Gy to 66Gy) in patients with soft-tissue sarcoma. Mean tumour size more than 10cm ranged from 35% to 43% in the pre-operative group and 18% to 33% in the postoperative group, where reported.

The authors did not state how many reviewers were involved in study selection.

Assessment of study quality

Quality assessment was undertaken by two reviewers using the Detsky Quality Assessment scale for RCTs and the Newcastle-Ottawa Quality Assessment scale for observational studies. Disagreements were resolved by discussion.

Data extraction

Data were extracted on the local recurrence rate and used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Data on overall survival were extracted.

The authors did not state how many reviewers extracted data.

Methods of synthesis

Fixed-effect and a random-effects meta-analysis were undertaken to calculate pooled odds ratios. Statistical heterogeneity was assessed using the I2 statistic. Publication bias was examined using funnel plot analysis.

Results of the review

Five studies were included in the review (n=1,098 patients): one RCT and four retrospective cohort studies. Study sample size ranged from 112 to 517 patients. The authors reported that Cohort studies averaged 8 out of 9 on the Newcastle-Ottawa scale and the RCT scored 19 out of 21 on the Detsky scale.

Using a fixed-effects model, the risk of local recurrence was statistically significantly lower in the pre-operative radiotherapy group compared with the postoperative group (OR 0.61, 95% CI 0.42 to 0.89). However, when a random-effects model was used, the results were no longer statistically significant (OR 0.67, 95% CI 0.39 to 1.15). Average survival rate was 76% (range 62% to 88%) in the pre-operative radiotherapy group and 67% (range 41% to 83%) in the postoperative group.

There was evidence of moderate statistical heterogeneity (I2=25%). There was evidence of publication bias.

Authors' conclusions

The delay in surgical resection necessary to complete pre-operative radiation did not seem to increase the risk of lethal metastatic spread; the risk of local recurrence may be lower after pre-operative radiation. Caution was warranted due to heterogeneity and bias in the available studies.

CRD commentary

Inclusion criteria for the review were clearly defined. Four relevant databases were searched without date restrictions. There was potential for language bias as only English-language studies were included. Publication bias was assessed and was found to be present, but assessment of publication bias may not have been meaningful given the small number of studies included. Attempts were made to reduce reviewer error and bias during quality assessment; it was unclear whether similar attempts were made for study selection and data extraction. Quality assessment was based on standard checklists, which indicated that the included studies were high quality. Most trials had small sample sizes (acknowledged by the authors). There appeared to be baseline differences in tumour size between the pre-operative and postoperative groups in the cohort studies, which may have introduced bias to the analysis. Trials were pooled using meta-analysis. Statistical heterogeneity was assessed. The authors acknowledged that their meta-analysis was underpowered and the results may have been prone to biases.

Overall, the authors’ conclusions were suitably cautious and appear appropriate.

Implications of the review for practice and research

Practice: The authors did not state any implications for practice.

Research: The authors stated that further prospective randomised trials were needed to determine the benefits of pre-operative versus postoperative radiotherapy in soft-tissue sarcoma.

Funding

Not stated.

Bibliographic details

Al-Absi E, Farrokhyar F, Sharma R, Whelan K, Corbett T, Patel M, Ghert M. A systematic review and meta-analysis of oncologic outcomes of pre- versus postoperative radiation in localized resectable soft-tissue sarcoma. Annals of Surgical Oncology 2010; 17(5): 1367-1374. [PubMed: 20217260]

Indexing Status

Subject indexing assigned by NLM

MeSH

Humans; Postoperative Period; Sarcoma /radiotherapy; Treatment Outcome

AccessionNumber

12010003956

Database entry date

23/03/2011

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 20217260

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