Transformed Follicular Lymphoma

The current issue of the Journal of Clinical Oncology features a very interesting article called "Autologous and Allogeneic Stem-Cell Transplantation for Transformed Follicular Lymphoma: A Report of the Canadian Blood and Marrow Group." It offers what I think are some surprising results for the best way to treat transformed Follicular Lymphoma.

A little background (though, if you're reading this blog, my guess is that you already know a little something about transformation): FL is an indolent, slow-growing lymphoma. It can tale months or even years to progress  to something that needs to be treated. However, for some patients, their FL is particularly unstable genetically, and it transforms -- changes from fairly slow-growing cancer into an aggressive, fast-growing cancer. there are several types that it transforms into, but the most common is Diffuse Large B-Cell Lymphoma. Based on the estimates I have seen, anywhere from 15% to 50% of FL patients will transform.

DLBCL is most often treated with CHOP, often in combination with Rituxan. R-CHOP is pretty effective, especially when the transformation is caught early. When it isn't, or the R-CHOP doesn't work, patients typically have a Stem Cell Transplant. In this procedure, the patient is given high dose, aggressive chemo, which essentially wipes out the immune system including the bone marrow. Stem Cells are them introduced into the body, and they remake the immune system much quicker than the body could remake it on its own.

There are two types of SCTs: Allogeneic and Autologous. With an "Allo," a donor is found whose cells match up well with the patient. After the heavy chemo, the donor's cells are introduced into the patient. It often has great results. But it often results in some bad side effects as well. With an "Auto" transplant, the patient has her own Stem Cells removed, gets the chemo, and then has the same cells reintroduced into her body. The plus side is that there's no worry about the body rejecting these unfamiliar cells. The downside is, there may be some cancerous cells among the ones that were reintroduced.

[That's a really over-simplified description of SCTs. If you want a better description, watch this.]

Now, typically, Allo Transplants (using someone else's cells) are thought to be higher risk, but more effective. Research seems to bear this out.

Except for now, for Transformed Follicular Lymphoma.

The JCO article linked above describes a study of 172 patients with Transformed FL. 22 had an Allo transplant, 97 had an auto, and 53 had R-CHOP or other chemo + Rituxan. After 5 years, the overall survival was  46% for patients treated with the Allo, 65% with the Auto, and 61% with R + chemo.


This was a surprise. Now, there are some issues with comparison -- these patients weren't all part of the same tightly-controlled study, but were looked at retroactively. So it's possible that there were some slight variations in care that caused the results to be what they were. But at the very least, the study calls into question whether or not Allo is the way to go.

The JCO has a nice feature on its web site where they ask experts in the field to do a brief podcast commenting in the articles they publish. For this article, the expert comment comes from Dr. James Armitage of the University of Nebraska Medical Center (something of a Lymphoma Rock Star). The big take-away for me: look deeper into the statistics for transformed FL, and there are a whole bunch of factors that affect which of the three options will work best. And as surprising as it is that Auto seems overall more effective than Allo, it's even more surprising that the chemo option is just as effective as the Auto.

This certainly doesn't answer the question of which treatment is best. As we all know, there are darn few easy answers when it comes to treating Follicular Lymphoma. But even raising more questions has its benefits.

My guess is that there will be a lot more conversation on this topic in the next few months.