The impact of radiotherapy on survival in resectable gastric carcinoma: a meta-analysis of literature data.

BACKGROUND

The benefit of external radiotherapy for gastric carcinoma has been extensively studied, but data on survival are still equivocal.

OBJECTIVE

To assess the effectiveness of surgery combined with preoperative radiotherapy or postoperative chemoradiotherapy in the reduction of all-cause mortality in patients with resectable gastric carcinoma.

METHODS

Computerised bibliographic searches of MEDLINE and CANCERLIT (1970-2006) were supplemented with hand searches of reference lists.

STUDY SELECTION

Studies were included if they were randomised controlled trials (RCTs) comparing mortality of surgery combined with preoperative radiotherapy or postoperative chemoradiotherapy to surgery alone, and if they included patients with histologically-proven gastric adenocarcinoma without metastases. Nine eligible RCTs, 4 of preoperative radiotherapy (832 patients) and 5 of postoperative chemoradiotherapy (869 patients), were identified and included in the meta-analysis.

DATA EXTRACTION

Data on study populations, interventions, and outcomes were extracted from each RCT according to the intention to treat method by three independent observers and combined using the DerSimonian and Laird method.

RESULTS

Surgery combined with preoperative radiotherapy compared to surgery alone significantly reduced the 3-year (OR 0.57; 95% CI 0.43-0.76: p=0.0001) and 5-year (OR 0.62; 95% CI 0.46-0.84; p=0.002) mortality rate. A significant reduction of the 5-year (OR 0.45; 95% CI 0.32-0.64; p<0.00001) mortality rate was observed when surgery followed by chemoradiotherapy was compared to surgery alone.

CONCLUSIONS

In patients with resectable gastric carcinoma, adjuvant radiotherapy significantly reduces 3-year and 5-year all-cause mortality, but the magnitude of the benefit is relatively small. Available evidence is inadequate to determine whether postoperative chemoradiotherapy is superior to preoperative radiotherapy.