If you specified a Z-test interval on the Parameters tab, your Survival results matrix will contain a page with Z-statistics for your analysis.

On this page, the statistic in each cell is the Z-statistic resulting from the comparison of the two survival curves. Survival curve comparisons are made for each combination of the innermost survival table variable.

For a detailed description of the Z-test methodology, please refer to:

Brown CC. The statistical comparison of relative survival rates. *Biometrics* 1983;39:941-8.