How Useful Are GELF Criteria?

The journal Haematologica just published a very interesting study about GELF criteria in Follicular Lymphoma. In some ways, it's a very Cancer Nerd kind of thing, but it also has serious implications for all of us as patients.

The article is called "Impact and Utility of Follicular Lymphoma GELF Criteria in Routine Care: An Australasian Lymphoma Alliance Study." It looks at 300 FL patients in a database and examines their GELF criteria, treatment decisions, and outcomes.

At this point, you are probably wondering what GELF criteria are and why they matter. GELF stands for Groupe d'Etudes des Lymphomes Folliculaires (Follicular Lymphoma Study Group), a French organization that developed a set of criteria to help determine when a Follicular Lymphoma patient needs to be treated. Because FL is slow-growing, and many of us don't need treatment immediately, the GELF criteria help to make that decision. 

The GELF criteria are:

• Any tumor mass greater than 7 cm (about 2.75 inches)
• Involvement of 3 or more nodal sites, each at least 3 cm
• B symptoms (night sweats, weight loss, etc)
• Enlargement of the spleen
• Compression syndrome (swelling that decreases blood flow)
• Pleural or Peritoneal effusion (fluid build up in lining of chest or abdomen)
• Leukemic phase (cancer cells in the blood) or cytopenias (low blood cell levels).

Having any of these issues, according to GELF criteria, means the patient has "high tumor burden" and should begin treatment immediately. To be clear, I'm not giving full information here. Go to this site and you can see more, like the exact blood cell levels that count as cytopenias.

And my giving less-than-full information is kind of part of the problem. More on that later. 

According to the article, one of the problems with GELF are how they are used. If you look at clinical trial criteria, many of them restrict enrollment to patients with high tumor burden -- meeting at least one of the GELF criteria. This is done to ensure that there is at least some kind of consistency among the patients in the trial.

The problem, though, comes when GELF is applied to real-world situations. Or not applied. 

In their analysis, they found, for example, that about 54% of patients in the study (163 of 300) were "high tumor burden," meeting one or more of the criteria. However, about 10% of those high tumor burden patients (16 of the 163) did not have treatment immediately, as the criteria would suggest, and instead watched and waited. And of the 215 patients in the study who did have treatment right away, 34% (74 of the 215) met no GELF criteria, meaning they did not have high tumor burden and may not have needed treatment right away. 

Clearly, GELF criteria are not necessarily being used by all oncologists to decide when a patient needs to start treatment. 

What's more, the study looked at outcomes, and found that, for both patients who watched and waited and for those who started treatment right away, the GELF criteria did not predict Progression Free Survival. In other words, meeting one or more criteria did not predict whether or not treatment would keep the disease in check.

The authors call for more research to try to figure out this disconnect. It's important for all of us. If clinical trials are being restricted to certain patients, there is an assumption that those patients will benefit from a treatment that gets approved. But if, in the real world, that same restriction isn't being applied to patients who receive the treatment, then that might ultimately be a waste. If patients with high tumor burden are determined to not need treatment right away, then those receiving treatment based on GELF criteria might be being treated unnecessarily.

There's another issue worth mentioning that's important to patients. I think we often see something like GELF criteria (or something like FLIPI) when we are researching our disease, and we misunderstand it. I think this happens early on, especially, soon after we are diagnosed. There are some good sites that describe GELF, like the one I link above and again here.  But there are lots of other that don't give very good descriptions. And frankly, the article I'm discussing is one of them, which gives an abbreviated list of GELF criteria without all of the important detail ("Patients required one or more of the following characteristics to be considered ‘high’ tumor burden according to GELF: any tumor mass >7 cm diameter; ≥3 nodal sites (each >3 cm diameter); B symptoms; splenomegaly; compression syndrome; serous effusion; leukemic phase or any peripheral blood cytopenias"). 

It's easy for a patient to read something like that and panic, thinking they need treatment immediately. The research in the article suggests otherwise, and that's why I tried to highlight that my own list above is not as detailed as it could be. These kinds of official lists, which try to quantify something that is hard to put a number on, make everything seem really definite. Numbers are tricky things, and they don't always represent the certainty that they seem to. A GELF number doesn't always signal a need for treatment, like a Overall Survival figure doesn't say anything about our own individual situations. Follicular Lymphoma is too heterogeneous a disease to have numbers provide any kind of certainty. It's just to different for each individual patient.

So if you're a Cancer Nerd and you enjoy diving into the analysis of statistics and outcomes, I hope you enjoy the article. But even if you're just a non-nerdy FL patient, this is all a good reminder to be careful with what you read and don't jump to conclusions about how the statistics for a large number of patients might affect you as an individual. If you read something and panic, do your best to take a step back, take a deep breath, and make a note to talk to your oncologist about it. We're all different.

Have a great day, and thanks for reading.