MEDIAN SURVIVAL TIME
When a population is evaluated statistically, there are a number of ways the central tendency of the group can be evaluated. The median is the value at which 50% of the group falls above and 50% of the group falls below. This is a little different from the average of the group, though more people are familiar with this term. When one evaluates median survival times one is looking at a 50% chance of surviving longer than the median (and a 50% chance of surviving less than the median).