Zhou et al. Journal of Experimental & Clinical Cancer Research 2011, 30:72 http://www.jeccr.com/content/30/1/72 Page 4 of 7 Figure 1 Forest plot for meta-analysis of arthralgia of patients treated with zoledronic acid (ZOL) versus no ZOL. Figure 2 Forest plot for meta-analysis of bone pain of patients treated with zoledronic acid (ZOL) versus no ZOL.