Tuesday, April 19, 2016

For Marie: Survival and Statistics

A few weeks ago, a reader named Marie left a comment on a post from last October. I responded to it, and said I'd try to leave a longer response in a few days. I'm late with the longer response, but here it is.


I have just been diagnosed with follicular lymphoma two weeks ago and I am losing my mind. I will be having another biopsy, blood tests, the bone marrow stuff (sorry I haven't yet learned the proper vocabulary),the scans etc. Then I will be waiting for reults... hmmm. I have found your blog on the internet and it keeps me from losing my mind completely. But I have noticed that most people affected by FL who comment on your blog (and seem to be doing quite well) are between 40 and 50. Any thoughts for us oldies (I'm 61) whose OS rates are always scary.

Best regards,

Hi Marie. I'm guessing that the results from your tests are back now, and I hope they brought you some comfort -- as much comfort as you can get from hearing the details of your cancer. If you'd like to share the details, please do.

You are right -- Overall Survival rates are scary, for all of us, not just you "oldies." As I've said in this blog a bunch of times, the times that my cancer have made me truly sad have been when I looked at statistics. There's something about numbers that seems very definite and final. Numbers don't lie, right? Well, sure, except those times when they do lie.

It's not that numbers lie. They're just easy to read as something that isn't necessarily true. It's always more complex than the numbers make it seem. The one truth to looking at statistics is this: a number that says something about a large group of people is in no way a predication about your own life. Don't forget that. Ever.

Let's start with the idea that "OS rates for oldies are always scary."

There aren't many breakdowns of OS by age, and the one that I have seen that gave me the most encouragement (as a youngster) came from an ASH presentation from 2011. That makes it a little bit old (a whole lot has happened in 5 years), but it's about the best I have seen. While it focuses particularly on patients under 40, it does give statistics for OS for three age groups:

Under 40 have a median OS of 24 years.
41-59 year olds have a median OS of 16 years.
Over 60 have a median OS of 6 years.

Now, comparing those two groups (us youngsters with the 24 year OS -- I was diagnosed at 40 -- and you oldies with your OS of 6 years), and things look grim for the oldies. No wonder you're scared. Yikes!

But compared to us youngsters, you actually might be better off. Assuming the median OS, someone diagnosed at 61 would live to 67. But someone diagnosed  at 40? I'd only have until 64. So you have 3 years on me. (Don't brag about it.)

Now, before I start panicking anyone else (youngsters, oldies, or tweeners), let's remind ourselves of what median Overall Survival means. And let's remember, too, that a number that says something about a large group of people is in no way a predication about your own life. I told you not to forget that. Ever.

So let's assume that it is accurate that Follicular Lymphoma patients over 60 have a median OS of 6 years. But before we assume that it is accurate, remember that this number is more than 5 years old, and was calculated from patients from the 25 years prior, from 1986 to 2011, so a bunch of them never heard of Rituxan -- in other words, that number could very well be higher than 6 for a patient today.

But let's assume that it's accurate. The first thing to look at is the word "median." In statistical analysis, "median" means that half of the group is below that number, and half is above. So while there will be some people who have an OS of less than 6 years, the other half will have an OS of more than 6. How many more? Maybe 7, or 8, or 9, or 10, or 20, or 50. There's a lot that determines how long that will be, much of it having to do with the nature of your lymphoma (and maybe all of those tests you took shed some light on that). But the important thing to remember is, someone else's OS doesn't determine your lifespan.

Now, about that "Overall Survival" statistic. OS doesn't measure cause-specific survival, or death from cancer. It measures death from anything -- that's what "overall" means. It means that people with Follicular Lymphoma might have died within 6 years because of heart attack, being hit by a bus, whatever. Because FL is a slow-growing disease, the cause-specific survival is actually higher than it is for Overall Survival -- 9 years. You'd be more likely to die from something other than FL than you would from FL.

But none of those statistics really matters. Why? Because a number that says something about a large group of people is in no way a predication about your own life. I keep telling you that.

Again, all of this is based on patients who were diagnosed between 1986 and 2011. We've made advances since even then.

So what will our OS be, when someone calculates it 25 years from now? No idea. But, as a group, I can almost guarantee it will be higher than what we have now. The stuff we've learned about cancer, and especially Follicular Lymphoma, in just 5 years, is astounding. Stuff in the treatment pipeline now will only increase our OS in the future. And there is stuff that hasn't even been talked about yet at ASH or ASCO that will have an impact on our lives in the near future.

My advice is to stay away from statistics. But if you have to look at them, be sure to take a step back and think about what they really mean, and especially what they don't mean.

Marie, I hope your test results were as good as they could be, and you have created a plan with your oncologist and started on it. If you have something you'd like to share, I hope you will.

I wish you all some peace.


Mark Sutter said...

Thanks for the post Bob.
On a personal note, my mother was diagnosed in 2010 with Follicular Lymphoma at the age of 89. She received Rituxan upon diagnosis and did quite well with it.She'll celebrate her 95th birthday next week and has no symptoms/problems associated with the lymphoma. So, I'm pretty certain she will be one of the majority that does not die from their FL.

I was also diagnosed with FL, just two years ago (age 54). I'm optimistic that I'll have many years to come (though doubt I'll reach my mother's age!)

Anonymous said...

I was DX 1 & 1/2 years ago at age 56, I'm now 58
I was a real basket case at first. How could I, the only healthy person in my family, the only one who exercises and eats well and doesn't smoke, be diagnosed with cancer? Stage 4, in my BONE MARROW?
Having researched and read a lot and gained information, I'm hoping my watching and waiting goes on for years before I need any treatment! I'm hoping more new, better treatments come down the pike!
Thank you for this blog!
I'm going to live to 100 with FNHL!

cricket said...

Having FL today is in no way comparable to the "C" word we were taught to be terrified about years ago. Do all you can to get the following question about YOUR disease answered: Am I more likely to die WITH my disease or OF my disease? Then, realize what used to be true about cancer when we were young is NOT now-especially as to diseases like FL. I was diagnosed in Oct 2012. Almost had a breakdown over the very IDEA of having cancer. Today- it's nearly an after thought on a daily basis. All the best to you from one 61 year old to another!

Mark said...

Although you mention it, it's worth repeating that this was a retrospective study done in 2011 and going back 25 years for those patients diagnosed between 1986 and 2011. Rituximab wasn't approved until 1997 and since 1997, there is a long list of other treatments that extend the lives of those with follicular lymphoma. Your 61-year-old reader, Marie, can be certain that today, median survival for those diagnosed at 60+ year is far more than the 6 years reported in the retrospective study. Also, the study shows that cause specific survival (i.e., those that died of follicular lymphoma and not something else) is 9 years. So if Marie eats healthy, exercises, doesn't smoke, and maintains a healthy body weight, her life would be extended even longer - much more than a decade. And by the time Marie reaches 70 years old in 2025, there will be other, novel treatments that will extend her life even longer and she is likely to reach her actuarial age of 85-years old (see government actuarial table of life expectancy based on age: https://www.ssa.gov/oact/STATS/table4c6.html)

I hope Marie sees this comment so she realizes that there is a far lower than a 50% probability that her life will end at 67.

One more thing that follicular lymphoma patients should consider is that a bone marrow biopsy is often not necessary. I was diagnosed in 2011 at the age of 46 and am being treated at Memorial Sloan Kettering. I originally went to a local oncologist who had scheduled me for a bone marrow biopsy which involved drilling a hole into my hip bone and removing some bone marrow. I went to Sloan Kettering for a second opinion and my oncologist said that the only difference bone marrow involvement makes is defining whether you have stage III or stage IV disease. If a follicular lymphoma patient is stage III or stage IV, the treatment options is the same – so why do a bone marrow biopsy? I’ve been on watch-and-wait for the past 5 years and my medical chart diagnosis shows “Stage III/IV Follicular Lymphoma (BMBx deferred), grade 2, FLIPI-2 (stage and nodal sites)”

Marie Smith said...

Hi Bob, Mark, Cricket and Anonymous,

Your comments are quite encouraging.THANK YOU!!! Epecially hearing from Mark's 95 years old mom.Hope we all reach that age and have quality of life also.I still haven't all of my test results, I was told I was a stage 3,but I don't know what grade just yet. My FLIPI though is quite depresing... ouch! I'm still trying to wrap my head around the fact that I have cancer but reading Bob's blog and your generous comments has helped a lot.I'll keep coming back.