Follicular lymphoma transformation experience

Hi all,

I am posting this as a response to a request in a different thread instead of hijackin that one.
The request was for me to share my experience with transformed FL and treatment etc.

Some bullet points for background knowledge:

• Male, 56
• Lives in Denmark
• Kidney cancer survivor since 2010
• Diagnosed with FL in 2019. Stage III
• Transformed to DLBCL with new diagnosis in April 2021

The transformation was confirmed/detected via new biopsies in March 2021. Until then I had been a "watchful waiting" FL patient with a pretty standard course of events as well as slow progression. I had bloodworks done and was clinically examined every two months.

But from, roughly, the autumn 2020 my bloodworks was starting to act out a bit. LDH increasing at an accellerated rate, increased leucocyt counts now exceeding the normal ranges etc. Increased CRP as well. As this persisted my hematologist assigned a pet-ct as well as a MRI.
MRI showed nothing. But the pet-ct showed that I had progressed to stage IV now with multiple organ involvement, spleen, lungs, stomach.

Biopsies from my groin and stomach was taken.

Histology showed transformation to classic DLBCL with a high proliferation rate (95%+, very agressive). No double or triple hit gene re-arrangements thank God.

I was deemed fit to start R-CHOEP asap (for some reason in the US its named R-EPOCH). 6 cycles with 2 week intervals plus 2 HD chemo rounds of ARA-C to prevent/lower the risk of CNS involvement.

Now. As most FL patients probably know, the risk of transformation is 3% per year. However that rate is cumulative in terms of individual probability. That means that in a 10 year time frame the individual patient has a 30% risk of transformation.
Transformed FL is, I am sorry to say, the main cause of death for those FL patients that do not live the average 15 year from diagnosis.

As for the prognosis after transformation there is one major factor that influences this:

Did you already have first line treatment or not for your FL?

If no, then your are treated as a de novo case DLBCL. And if cured for the DLBCL component, which is very likely as the treatment for standard DLBCL (no re-arrangements etc) is very effective if you can tolerate the treatment, then your prognosis moving forward as actually the same as a "normal" FL patient (a number of studies done on this over the years).
The FL component is still there but can become dormant (as in my case, 3 years from R-CHOEP now and no progression).

If you however already had first line treatment for your FL the outlook is not as bright. The short reason for this is that the first line treatment for FL and DLBCL is basically the same.
That means that transformation to DLBCL ocurring after you had first line treatment for FL is viewed as a relapse and not a de novo disease.
Moving forward that means in most cases the treatment is either stem cell transplant or CAR-T or similar. And these have, Im sorry to say, much lower curative success rates than de novo DLBCL treated with R-CHOP/R-CHOEP.

@ShadyGuy I hope this was informative, if not, just ask away in this thread.