Sunday, July 7, 2013

Follicular Lymphoma: Cells of Uncertain Origin

Just about to be published in Haematalogica:  an article with maybe the most awkward title ever, but with some interesting information about cells that may become Follicular Lymphoma cells.

First, here's the title: "Follicular Lymphoma-like B-Cells of Uncertain Significance (In Situ Follicular Lymphoma) May Infrequently Progress, But Precedes Follicular Lymphoma, Is Associated with Other Overt Lymphomas and Mimics Follicular Lymphoma in Flow Cytometric Studies."

I absolutely love that the cells are called "Follicular Lymphoma-like B-Cells of Uncertain Significance." It just sounds too much like the Rodents of Unusual Size from The Princess Bride. [Important not to my mom: -- Do NOT click that link! It's a video of a giant rat!]

Now I have visions of my nurse in the treatment room holding a sword to a cancer cell and saying, "Hello. My name is Sue. You have sickened my patient. Prepare to die." [Important note to my mom: That one's OK.]

So here's the deal: "Follicular Lymphoma-Like B-Cells of Uncertain/Undermined Significance" used to be called (and are sometimes still called) In Situ Follicular Lymphoma cells. "In situ" is a Latin phrase meaning "in position." Oncologists use "in situ" to describe cancer cells which are still in the place where they originated; that is, they haven't broken off and metastasized. Follicular Lymphoma, being a blood cancer, is kind of constantly metastasizing, in a sense -- it is a "systemic" cancer, meaning the FL cells are in the blood and can travel pretty much anywhere the blood travels (which is pretty much anywhere).

In Situ Follicular Lymphoma, then, involves cells that are sorta like FL, but not quite, and which kind of sit in the lymph nodes and don't take off quite yet. The idea of In Situ Follicular Lymphoma has been around for a while (maybe 10 years?), but no opne has been quite able to figure out what the cells are. Maybe pre-FL cells? Maybe the start of some other blood cancer? Maybe just weird cells that are what they are and nothig more?

The study above with the awkward title involved looking at In Situ Follicular Lymphoma cells and trying to figure out just what they were. The authors acknowledge that we don't really have answers to those questions because the information that we do have seems to all conflict.

They looked at 31 biopsy samples, and ran them through a flow cytometer, a very cool machine that lets researchers look at individual cells and their characteristics, like their size and various features. Quite the instrument.

What they found was that 52% of biopsies with In Situ Follicular Lymphoma were related to a previous or currently diagnosed lymphoma (which would suggest that FL grows out of those cells). However, after following those patients for over 2 years, they found that only 6% of them actually developed into lymphoma.

Their conclusion is, basically, those cells might turn into FL, but they might not.

The big lesson from this seems to be directed toward other researchers:  don't just assume that In Sutu Follicular Lymphoma (or Follicular Lymphoma-Like B-Cells of Uncertain/Undermined Significance) will lead to Follicular Lymphoma.

I think this is ultimately one of those studies that is valuable not because it tells us something new, but because it slows us down.

Personally, I'd like to see more than 26 month follow-up on the In Situ cells. Wouldn't an indolent lymphoma potentially take more than 2 years to develop? Just a thought.

Interestingly, another article on this topic came out a couple of months ago, and had a very similar conclusion.  It will be interesting to see if more research on the topic continues, and if they ultimately find some connection between the FL-like cells and actual Follicular Lymphoma.

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