Figure 4

Funnel plots to examine the possibility of publication bias in the data for overall survival (A) and that for disease-free survival (B).

The standard error of log HR (S.E. of log HR) was plotted against log HR for each individual study as represented in a circle. Egger's tests showed that the funnel plots were asymmetric (P < 0.001 for Figure 4(A); P = 0.002 for Figure 4(B)), which could be due to potential publication bias among other reasons.