Table of Contents

Chapter 1: What Does a Diagnosis of Prostate Cancer Mean?

b. Predicting Prognosis

Despite the best efforts of hundreds of prostate cancer researchers, there’s no way to know for certain exactly how your tumor will act and exactly how you will respond to any particular treatment or intervention. Our understanding of the way the disease behaves is getting better all the time. But, for now, we need to be able to predict, as best we can, what to expect so that we can determine the treatment that’s right for you.

Suppose you wanted to estimate how likely it is that a particular treatment will get rid of all of your disease. You would need to take into account a number of factors:

• Has the cancer already spread outside the prostate?

• How aggressive does the disease look (ie, what is the Gleason grade)?

• If surgery was used, was all of the cancer taken out?

Are some of these factors more important than others? Or do they all tell us the same thing?

Nomograms are simplified charts that have been specially constructed to weigh each of the necessary contributing factors and to provide a single assessment of the likelihood of remaining disease-free after treatment. The physician enters the relevant details from the case, and each factor is assigned a point value depending on how much it has been shown to contribute to the overall outcome.

For example, if a man’s PSA at diagnosis was 2 ng/mL, he might get 30 points, but if his PSA at diagnosis was 30 ng/mL, he might get 80 points. Why? Because, as we noted earlier, a higher PSA at diagnosis indicates that the disease has likely spread further, so that factor will contribute more to his overall outcome.

Once all of the points for the various factors are added, the nomogram shows us the chances that the disease will show up again five years after initial treatment. This is referred to as the five-year recurrence rate.

Let’s look at the two extremes. If the total score were 140, the chart would show a five-year recurrence-free probability of 0.05 or 5%, meaning that 5 men out of every 100 with a score of 140 will be free of disease in five years. On the opposite end of the spectrum, a total score of 20 would correspond with a five-year recurrence-free probability of 0.93 or 93%, meaning that 93 of every 100 men with a score of 20 will have no disease present at five years after initial treatment. Knowing how likely it is that you’ll be disease- free in five years can be reassuring, especially if you’re in the 20-point range. However, if you have any factors that indicate your tumor is aggressive, you might have a continued risk of recurrence even beyond the five years.

It is important to note that nomograms designed to predict the likelihood of recurrence are not predicting death from prostate cancer—a man can live for many years despite a recurrence. But they can play an important role in helping to decide whether to undergo additional treatments or whether to enroll in clinical trials assessing new therapeutic regimens or agents.