Median Survival Time

Median survival time is a number to help you understand your dog’s prognosis. In mathematics, the median number is the midway number in any group of numbers.  It’s the number right in the middle. The way it’s used in cancer is to describe the “halfway” point or even 50/50 point. It’s the point at which half of the patients with a given cancer are expected to be alive, and half will have passed. For example, the CHOP protocol for lymphoma has a median survival time of fourteen months. That means that for any group of dogs with lymphoma who get CHOP, your veterinarian expects half of them to be alive at the fourteen-month mark and half to have passed away. It doesn’t predict which group your dog will be in. It also doesn’t tell you anything about “when” something will happen to your dog. If your dog lives to the median survival time, your veterinarian will not be able to predict how much time he has left. It’s useful to know the median survival time for your dog’s cancer treatments, so you have a rough idea of your “50/50” date. However, like all statistics, it never applies to your dog directly. When your veterinarian says “fourteen months” they do not mean that your dog will live to that day, or that she won’t. It’s not a date to circle on your calendar. It’s more of a mile marker on your dog’s cancer journey. You may also hear the words “median overall survival” or “median survival.”