Part 2 of the statistical update

I’m so sorry, folks, to be behind.  I’ve received a number of terrific emails from the newly diagnosed to long-time fellow travelers and I want to thank all of you for writing to me.  I’m particularly thankful, always, to hear from patients who have found this blog to be helpful to them as the lead their own fight against this disease.   You inspire me and I’m thankful to play any part whatsoever in your battle.

So…where was I…

Ah yes, the lack of a plateau.

I sent BB a lengthy email explaining my concerns, and the basic math that I’d done on the back of an envelope to arrive at somewhere around 50-60% cure versus 87%.   He commented quickly in an email that the 87% figure had been updated as a result of longer follow-up, and that this is expected, but that the Blood article (from which I presented figures below) indicated that “cure is still there.”

It’s a question of what percent.

He told me, in his playful way that has a serious undercurrent, that I was “doing a lot of arithmetic that was not really getting anywhere” and that I was a bit of a “pain in the ass.”  :)    I know this is an endearing term from him so I relish it.

It is a huge testament to this doctor that, despite not having an appointment with me scheduled, he called me and spent 45 minutes not just discussing this data but also forwarding me articles, both published and unpublished, to help educate me.

He agrees that the final number will be somewhere better than TT2-Thal, but not the 87% that looked like could be the case.   The numbers for TT4, which include more extensive maintenance than TT3 (the beginning of TT3 used only one year of Velcade, for example), are better than TT3, so the current cohort can be expected to do marginally better.  BB has never in his career seen a decline in efficacy as therapies advance — recall that in all the studies for pediatric leukemia as well as the TT regimens, the curves move up the Y axis towards the top of the graph as they advance.

The real answer is, we won’t know until 10 years out where the final curve is.  He also reminded me, as did a couple of blog followers, that these curves include mortality from other causes so you have to take those out — doing so flattens the lines significantly, though they still don’t reach a plateau yet.

I was casting about for something that would give me slightly better news on this, and BB was kind enough to tell me that they have compared PET scans after the commencement of treatment with treatment outcome.  Before treatment begins, a PET scan is performed to identify the number and intensity of what are called “FDG-avid lesions” — thriving cancer tumors.  Then, after the first week of treatment, another PET scan is performed to see the impact of the treatment on patient biology.  These same tests are done with MRIs, as well.

I’ve got some data to share, but presenting it is going to take some time, so I’ll get back to that tomorrow.  I will say that the news is slightly more optimistic than the 60% figure.  Not 87%, but something.  :)