PALIATIVE RADIOTHERAPY FOR GASTRIC CANCER: IS THERE A RELATIONSHIP BETWEEN DOSE AND BLEEDING STOP?

Objective: To evaluate if there is a relationship between radiotherapy dose and response to bleeding in palliative patients with local relapse or disease progression in gastric cancer. Methodology: It was conducted a systematic meta-analysis review of observational studies evaluating bleeding response in a gastric cancer (GC) patient with local relapse or disease progression. A meta-regression was performed between biological effective dose (BED) and complete bleeding response (CBR). A subgroup analysis was performed stratifying studies by BED level and radiotherapy technique (RT). A value of p <0.05 was significant. Results: Ten noncomparative retrospective studies and one prospective study were included. Overall, RT was an effective treatment for CBR, the CBR rate was 0.77 (95% CI 0.73- 0.81). The meta-regression showed a linear relationship between BED Gy 10 and CBR (p = 0 <0001). Studies using conformational RT obtained a significant difference in the rate of CBR when compared to RT2D (0.79 CI95% 0.74 -0.84 vs 0.65 CI95% 0.56 – 0.75, p = 0.021). In subgroup analysis dividing the studies into 3 levels of BED and assessing the CBR rate, a higher response was obtained in studies with BED> = 30Gy10; BED Gy 10 ≥40 (0.79 CI95% 0.7-0.8), BED Gy10 30-39 (0.79 CI95% 0.71- 0.86) and BED Gy10 <30 (0.64 CI95% 0.5-0.7, p = 0.0001). The median survival was 3.31 months (95% CI 2.73 – 3.9), and response to treatment had a significant increase in survival compared to non-response 2.5 months (95% CI 1.7 – 3.3, p <0.0001). Conclusion: Palliative RT is effective in controlling bleeding by local control / local progression of gastric cancer. There is a relationship between CBR and BED. Our data show that BED <30Gy 10 should not be recommended, and for best results the 3D technique should be indicated.