The Trend is Our Friend: Living with Uncertainty with my CLL (chronic lymphocytic leukemia)
After a gradual but steady improvement in my tumor burden visit after visit at Ohio State University (OSU) during my last three years on ibrutinib (when I started it was then called PCI-32765), on my last visit my ALC (absolute lymphocyte count) rose the tiniest amount to about 2, but I didn't worry as it still was well within normal limits. It was just an unusual result for me. It hadn't been over 1.4 in a couple of years, now it was >2.
The rest of the CBC and the chemistry panel was all normal.
The next day back in California I was due for my IVIG and my repeat ALC was back down to around 1 again so I didn't think much of it.
The fancy flow cytometry that checks for the small population of my clonal B cells, my CLL cells, is the test that really counts. That measures how many cancer cells that I still have and every test had shown fewer than the last. Both Dr. Byrd and I had predicted that already small number would continue to fall, but I would not yet be MRD negative.
When those results were not forthcoming in the weeks following my visit, I calmed my catastrophic flights of imaginations with reminders that when counts are too low, sometimes it hard to get an accurate result.
Then I got the news that I had a "small number of B cells" on the flow, within the expected variation seen from test to test.
That is "doctor talk" for the fact that my count had bumped up a little, but the number was still within the expected margins of error of the test, or not significant different than the prior result.
I still haven't seen my flow report nor do I know my absolute number. I will need to know that number at some point, but knowing it would make absolutely no difference today in what I do now, so I will try to be patient (not my best trait).
What I do know is that if the count had gone down, even just a little "within the expected margins of error" I would have been told and cheered on.
As we know that the only major group where we have seen a higher rate of relapse of their CLL on ibrutinib are previously treated patients with deletion 17p such as myself. They are the only group where < 1/2 are still progression free after less than 2 1/2 years. I have enjoyed being part of the happy minority on the Kaplan Meyer graphs.
But is this my personal start of a bad trend, the first stirrings of a tiny resistant clone that will only grow over time to become dominant? Is this the beginning of the end of my super duper run with ibrutinib?
Honestly I doubt it.
Here's why I am honestly not worried.
A week later I received the wonderful news that my BTK and PLCG2 mutation test was negative and since nearly all CLL resistance to ibrutinib is related to a growing clone with either the BTK and PLCG2 mutation that prevents the ibrutinib from blocking signaling, odds are excellent that my lab result is nothing but a meaningless blip. Richter's Transformation (RT), the other common and more sinister cause of relapse on ibrutinib, tends to occur early in treatment and three years out is not early. I don't have RT. No signs or symptoms.
So although I won't rest completely easy until I see my next flow cytometry results sometime after my next OSU clinic visit in August, odds are really with me on this one.
The trend is our friend, and as I have coached so many others, I now must heed my own advice: One lab test means nothing.
I will be traveling for a couple of weeks in Poland on a Jewish Heritage trip with my rabbi. One purpose of the trip is to forget all about CLL and our nonprofit CLL Society for a few days, but I will be busy in the evenings in Eastern Europe writing for the CLL Society website (some great stuff from the CLL Research Consortium or CRC Patient Empowerment and Education Meeting and from EHA coming soon) and more critically, for a peer reviewed medical journal on CLL due the beginning of August.
I am alright with that crazy balancing act though I do worry what I will eat in Poland, not exactly a vegan's paradise.