Myeloma Rocket Scientist: Conditional Luck
As multiple myeloma patients, we rapidly become familiar with many concepts from probability and statistics. There are measures such as the probability of a given treatment leading to a complete response, the probability of that treatment producing undesirable side effects, and of course numbers like median progression-free survival and median overall survival.
It can sometimes be difficult to remember that statistical measures such as these usually only apply to an entire population, not to any single individual. They are therefore useful for drawing general conclusions, but not for predicting the outcome that any one person will experience.
When I was diagnosed in 2006, the median overall survival for multiple myeloma was pretty much always quoted as being three years. I therefore expected it to be my future. Fortunately, it was clearly not the case. It is important not to take probability measures as precise values.
Even so, these measures can sometimes be useful for guiding treatment decisions. For instance, when I was about to have my stem cell transplant, a clinical trial involving stem cell transplants was running that my myeloma specialist mentioned to me. Patients in the trial would have tandem transplants, the first always autologous (using the patient’s own stem cells), but the second randomly selected to be either autologous or allogeneic (using stem cells from a donor). This trial was set up to investigate whether the potential benefits of the graft versus myeloma effect that can result from an allogeneic transplant would outweigh the associated risk of complications from graft versus host disease.
Eventually, after weighing the trial’s pros and cons, I decided against it. Only then did my oncologist say that he agreed, for two reasons: I was doing so well already (I liked this reason), and I was too old to take full advantage of it (I didn’t care for this one quite so much!).
Another key concept in statistics is the idea of “conditional probability.” This concept is based on the fact that two events (call them A and B) may not be independent from one another; the probability of B happening at all can be very different from the probability that B happens, given that A has already taken place.
For instance, for most readers of this column, the probability that the next person you meet will be a fluent Hungarian speaker is quite low. However, the probability that they will speak Hungarian, given that you are in Budapest, is extremely high.
It often seems to me that there is also a similar concept that should be called “conditional luck.” I remember being struck by this concept back in the 1980s, when a British newspaper front page headline announced “Luckiest man alive: he fell off a cliff and lived!” (Headlines based on someone being the luckiest man alive are pretty much a staple of British tabloids.)
The really striking point was the contrast between the “lucky” in the headline and the large photo under it, which showed the man in his hospital bed, casts covering him virtually from head to toe. Unquestionably, his “conditional luck” of surviving, given that he had fallen off a cliff, was extremely good. However, measured against the entire population, the vast majority of whom did not fall off cliffs, he was extremely unlucky to end up in hospital with such severe injuries.
Dealing with multiple myeloma brings up similar issues. Anyone with myeloma has had really bad luck compared to the general population. After all, only about 0.02 percent of the population has multiple myeloma, and it is still an incurable disease. On the other hand, an increasing number of myeloma survivors these days have treatments that go very well, putting them into extended periods of near-complete remission.
I am one of these people, and often think of how lucky I have been to be able to continue leading a basically normal life, seeing our boys grow up, and working at something that I really enjoy. However, whenever a new set of blood test results comes in and I get so nervous before looking at them, or I think of “regular” people who can worry about such things as “outliving their money”, or I remember that myeloma almost always eventually returns, it reminds me that this “luckiness” is really conditional.
I am indeed lucky, but only given that I have multiple myeloma. However, that is still pretty good.
Trevor Williams is a multiple myeloma patient and columnist at The Myeloma Beacon. You can view a list of his columns here.
If you are interested in writing a regular column for The Myeloma Beacon, please contact the Beacon team at .
Kind of like when my husband's oncologist told him it was a "good" time to have myeloma.
Trevor - What a great column. You put into terms what the average person can understand when it comes to statistical measures, which are so much a part of life for those of us afflicted with multiple myeloma. I enjoy reading your columns because you so often relate to your profession with rocket science.
I enjoyed reading this column as well. I have an MS in statistics and a husband diagnosed in 2010. It is very hard to separate statistics the doctors give you with your personal situation. To me, most of it is even simpler than that – it is binary: you either made the group that contributes to statistical probability of 20, 30, 40 percent of whatever it is you are measuring, or you did not. Additionally, the new treatments that were approved in the last 5-10 years are immediately put to use, and that makes the probability obtained based on the old treatment data less reliable.
Trevor, thank you for your time and thoughts in this article. I appreciate it and needed to hear it! Thank you!
Thanks for your article, Trevor. The multiple myeloma statistics can be overwhelming to someone like me - English teacher - (so much to understand) that I really appreciated your "take" on them. I like to think "lucky."
My story might be a reverse image, though I hope not. I was told in November 2013, one month after diagnosis, that I was in the "good risk for long-term survival" population, but my autologous stem cell transplant resulted, after 8 months, in zero indication of cancer in blood or marrow, only to have it reappear after just 3 months. That was August 2014. Since then, I have gone through different 4 chemo based treatments, just starting my 5th this week, with M-spike readings going from 0.3 g/dL to 0.7, 1.5, 1.9, 1.7 (hooray), 1.9, 2.2, 3.1. In the meantime, this year, it finally broke into the bones big time, with a tumor in left pelvis (radiation starts today), and 6 fractured vertebrae, and an inability to hold head higher than 45 degrees from straight down, and that only with great effort. Generally my head wants to point straight down. I considered myself blessed until this year, with too many problems to face and deal with at once. I now wonder If I will make 3 years, let alone the projected 5. But I am glad to hear of the many success stories. Onward and upward.
Trevor,
Great article! My son has a degree in statistics, so I leave all of this stuff to him! I also have a cousin who is a math professor. Suffice it to say, with a degree in English Lit, my eyes glaze over in their company!
Tell more stories about Gemini, Apollo and the space program! That, I understand! I loved watching those take offs and landings on the grainy footage of that time. To me, it was so magical. The moon walk in 1969 was probably the most incredible thing I have ever seen. Even to this day. Maybe it reminds me of a time when I thought anything was possible, and youth was my mantle.
I always enjoy your columns, Trevor. You have the mind of a scientist but the pen of a writer!
I’m just back from a couple weeks in England trying (with some success) to find cooler, wetter weather, so am finally getting caught up on replies.
Marianna - Yes, “a good time to have myeloma” is a good one! Doctors don’t always think carefully about how they say things…
Steve - Thanks very much for the encouragement. I’m really grateful that I haven’t had to retire yet: I find orbits work fun, plus it is definitely good for taking my mind off myeloma! I do sometimes wonder about when I should retire (as discussed in your column “My Three R’s”), but hope it won’t have to be for a while yet. My wife figures that, when I retire, I’ll go crazy and then drive her crazy too!
Connie - Thanks. I’m glad you liked it.
Ella - You definitely have much more expertise in statistics than I do. I really liked your point about the binary nature of any individual’s response, as well as the point about any new treatments that have come along in the last 5 years necessarily not being reflected in such things as the 5-year survival statistics. It somehow always makes me think of testing for metal fatigue of aircraft in a ground test rig: you can simulate at faster than real-time by, for instance, applying takeoff and landing loads in quick succession, or perhaps testing at high temperatures, etc. This doesn’t work so well for patients though! Results can only come in at one year per year ...
Sylvia – Thanks very much.
Paul – I’m very sorry to hear that things are not going well for you at the moment. Myeloma is such a difficult, complicated disease. I hope the radiation treatment helps with your bones. As for other treatment options, I suppose you’ve already had a second opinion on how to proceed? I have to admit that I’ve never gone for a second opinion myself, but people always say that it’s a good idea. Good luck: I hope things start to improve!
Ellen – Thanks for your comment: I really appreciated it. I feel the same as you about Gemini and Apollo: it was such an exciting time to be growing up. I got hooked on space then, and still am. Also, I’d never heard of myeloma back then and, if I had, I would never have imagined that I would ever get it: the mantle of youth indeed. I’ve got a few ideas for some more space-related columns, but they still need some work ...
Trevor, thank you for writing this column. I appreciate all that I have read. My world changed suddenly on a beautiful April day when I received a call that my sister, who is 55, was in the ER. She sustained a 4th vertebra fracture (more like disintegration) from a tumor. That was the first time I have ever heard of multiple myeloma. She endured a 10+ hour surgery to build a new vertebra and save her from paralysis. Thankfully, it worked, and she can still walk!
Our world quickly became filled with many more words that were unfamiliar to both of us. I basically left my family and moved in with her to care of her. Her husband had had a stroke and fell down a flight of stairs and received head trauma and was currently undergoing life saving surgeries from a flesh eating bacteria.
At this time, she has gone through 3 cycles of her chemo. We are preparing for her stem cell transplant at the beginning of September.
Thank you to all of you who are a voice in the cancer community. May the Lord bless you!
Donna: I had never heard of myeloma before my diagnosis either; in fact, I have never yet met anyone who had. What sort of chemo has she had so far? I hope her stem cell transplant goes well, and that her husband does well also. They certainly have a lot to deal with. It’s fortunate that you were able to help out so much!
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