In order to get FDA approval, drugs must first go through a clinical trial that demonstrates that they offer a better treatment result than the current standard of care. In some instances the better result can be a demonstration that the investigational drug provides an advantage which is only palliative (as Mitoxantrone does for advance prostate cancer), but the best treatment result is survival. Survival is the gold standard of positive results; extending life is the ultimate goal.

The pivotal clinical trial for prostate cancer chemotherapy using taxotere showed that it provide a median of 2.5 months additional survival over the then standard of care, Mitoxantrone. Cabazitaxel, which was just approved by the FDA to treat men who have failed chemotherapy with taxotere, provides a 2.4 month additional survival time and Provenge adds an additional 4.1 months of survival.

Recent debates have rocketed into the public debate about the economic value of these survival advantages as the median survival advantages are measured only in months while all these treatments come with extra side effects and significant additional economic costs. The big question is are these extra months of survival really worth the possible negative effects on your quality of life and are they worth the economic burden they place on your family and on society in general?

My opinion is a very clear and very strong YES.

Why do I feel this way, let me explain my opinion?

Survival advantages are expressed in statistics and statistics are just a way to express general group trends. Statistics do not imply any guarantee, or even useful information, at the individual, personal level. The simplest way I can explain this is by sharing what my statistics 101 teacher said on the first day of class, “Ten women are in a room and one is pregnant. He then stated that from a statistical point of view it is possible to state that each woman is 10% pregnant.” We all know the absurdity of this statistically correct statement. Statistics are excellent in a large group trend analysis, but statistics are worthless when it comes to understanding the individual situation. Statistics do not provide you with any insight into what you can personally expect; they don’t even accurately express your individual situation. A statistical analysis of a trial will not give you any insight into what your personal experience might be if you take a drug or treatment.

Statistics are constantly being misunderstood, often leading to the detriment of understanding the potential upside of a drug or treatment for an individual. Survival statistics are expressed as a median and the median is the number that lies in the middle. If a trial evaluated survival time one half of the people in a trial lived longer than the median and one half survived less than the median number. The median does not take into account how long the men on the right side of the curve, the side that expresses a longer survival advantage, lived. It is theoretically possible that all the men on the right side of the curve could have lived for 50 more years while all the men on the left side died the day after receiving the treatment. Survival statistics do not attempt to explain what actually happened to the individual person, neither to the person who was on the left side or the right side of the curve.

Anyone of us, actually one half of us, will be on the right side of the curve and live longer while the other half will have died. By taking a treatment you have a 50% chance of being in the better responding group, you have the hope of being a person who lives much longer, maybe 50 years longer!

The way most clinical trials are conducted the median number often becomes blurred and contaminated. The studies that were conducted for the drugs, taxotere, Provenge and Cabazitaxel all allowed men in the placebo group to crossover to the treatment arm once they showed signs of disease progression. This means that men in the placebo group, the group that did not receive the investigational drug, were allowed to receive the treatment, but their survival time was still calculated as if they never received the investigational treatment. Since receiving the treatment extends life, then the survival statistics for the control placebo group might also have been extended beyond what it otherwise would have been.

Since the investigational drug did extend life, the fact that men in the placebo group were allowed to received the treatment probably added to their actual survival time, statistically shrinking the difference in the survival differences between the two groups. The bottom line is that the survival time of the placebo arm was probably inflated, reducing the survival advantage of the treatment arm.

So, are these treatments worth it? My unabashed answer is yes, they certainly provide hope and they do provide life extension, possibly well beyond the statistical survival advantage we see from the clinical trials.

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Joel T Nowak, MA, MSW