progression free survival and overall survival

Anonymous

progression free survival and overall survival

Jojo71

Can someone help me understand this?

I read that most hormone treatments contribute to progression free survival, but not overall survival. Is that true? It doesn't make sense to me.

When I was diagnosed stage 4, I had extensive mets to liver, lungs, and bone. I had lost my appetite, had shortness of breath, had abdominal pain and nausea. The doctor told me I had maybe 6 months to a year without treatment.

I went on Ibrance and letrozole, and a year and a half later, I am NED.

How is this not longer overall survival?

Joellen

Sadiesservant

Hi Joellen,

I am sure others with more knowledge than I have will chime in but I'll give it a whirl. Progression free survival is usually reported as the median time before the cancer progresses whereas overall survival is the median time until death. I recently read that while Ibrance doubled the progression free period it had no impact on overall survival and must admit that I also did a bit of a double take. Huh? But I think what we need to keep in mind is that the stats are based on the entire population in the study and not individuals. It does not mean that, in your case, your life has not been extended through the use of the drugs. I also believe that it is a bit early for the researchers to report on overall survival as, in theory, in order to be accurate, 100% of the patients would need to be deceased. We know that is not the case. Finally, I have typically seen these stats reported against another drug or combination, not in the absence of treatment. (I believe the stat for Ibrance was stated as Ibrance/Femara or Femara alone.)

Hopefully Bestbird will comment. She's a whiz at this stuff.

Jojo71

Oh ok, I kind of see what you're saying. But, why don't people who have longer progression free time live longer?

Does the cancer progress faster when it comes back?

illimae

Here's how I thought it worked. Let's say we have a stage 3er on these meds and they work for 4 yrs before the person has progression to stage 4, then they pass a year later. We also have a stage 4er on these meds, which work well for 4 yrs, then stop working and they pass a year later. The overall survival is the same (5yrs) but I think "progression" is only considered in the earlier stage since those of us dxd as stage IV basically had our progression from the beginning. I might be totally wrong though.

Sadiesservant

Hi Ladies,

Bumping this in the hopes that someone else will chime in. Illimae, I do know that we talk about progression as stage IV. We can go many months/years on a treatment with either a regression in the cancer or no change. Once the cancer spreads to a new location or starts to grow it is considered progression at which point our oncologists will move us to another treatment option.

Heidihill

Survival statistics for treatments compare different treatments and not survival without treatment.  Hypothetically, if too many people are dying of other non-bc causes while on one drug, overall survival statistics from another drug may be higher even if progression-free survival is lower.  Hypothetically, if you have progression on one drug and move on to another which allows you to be NED or stable again for a long time, and there are enough people doing the same, the overall survival statistics taking into account only a single line of treatment is no longer as meaningful.

These issues and more are discussed here:

http://ascopubs.org/doi/full/10.1200/JCO.2011.38.6359

PFS may be an attractive end point because it is available earlier than OS, less influenced than OS by competing causes of death, and not influenced by treatments administered after progression.