What is this very atypical brain tumor?

June 1, 2009 11:43 AM

My mother's brain tumor was revealed at biopsy to be glioblastoma - yet its physical characteristics are completely different from the definition of glioblastoma. Has anyone else ever heard of this? What did it mean?

Glioblastoma is, by definition, as far as I can tell, defined in part by being made up of the most aggressive type of cancer cells. Another part of its definition, however, appears to be that it is infiltrative and undifferentiated. My mother's tumor, in the petri dish, is shown to be made up of those aggressive little a-holes. But it is also highly differentiated and well encapsulated. I can find nothing anywhere on the web - not even in proprietary medical databases - that even refers to such a possibility. It seems that glioblastoma=undifferentiated. But not in this case.

Obviously I would like to believe that this improves her prognosis from the incredibly grim one usually attached to glioblastoma. But since I can find no information about it I don't know what to think (other than "f**k off tumor") and it is driving me insane.

Has anyone else out there ever seen or heard of a situation like this? If so, what did it mean in that situation? I know I cannot extrapolate from your experiences to my mother's prognosis - but I am desperate for any sort of light to be shed, and so far the doctors are noncommittal.

Thank you...

posted by Betsy Vane to health & fitness (4 comments total)

Sorry to hear this. It's a tough thing to handle for the patient and the family.

This won't answer all your specifics, and I'm definitely not a medical expert, but I'll share what happened in my family, and maybe it will be helpful.

My brother in law was diagnosed with a stage 4 glioblastoma. It was encapsulated by a baseball-sized mass that grew around it. This was "good news" in this situation, since it prevented the cancer from spreading into the brain more than it otherwise would have. But even so, he was not given long to live. We were told it could be six months, and at the longest, with continual treatment, 5 years. He was only 29 at the time, so this was obviously devastating to hear.

It was a tough recovery, requring a couple more surgeries. His initial diagnosis was almost 6 years ago now. He is back to probably 90% of the activity level he was pre-diagnosis.

Obviously, none of us can predict the future, and every situation is different. But I just want to encourage you that there is still hope after such a devastating diagnosis. Good luck, and remember to take care of yourself as well.
posted by The Deej at 12:10 PM on June 1, 2009

I suggest you take this question to your mother's oncologist, who could probably tell you whether this is an atypical tumor.

A little detour into terminology might be in order, though...

Normal glioblast cells are undifferentiated in the sense that they are stem cells that can mature into the various glial cells (astrocytes, etc.). Most often, when you look at stem cells under the microscope, they are blobby things that don't really resemble their final form. Unfortunately, what's in mom's Petrie dish is not normal, so those cells may not look like ordinary, placid little glioblasts.

The term 'differentiated' could mean the cells seem to be in their mature form, or it could be a physical description of the cells having a shape like they're differentiated. Also, "highly differentiated" does not necessarily mean "fully differentiated." Perhaps they are in some between-state.
posted by zennie at 12:43 PM on June 1, 2009

I'm one of the many people working on The Cancer Genome Atlas Project, which is sequencing and characterizing lots of glioblastoma tumors, in an effort to better understand what makes them tick. I'm a bioinformatician, though, not a clinical oncologist, which is really who you should be talking to. If your mother's doctor is unavailable, try checking out some of the many cancer support forums on the internet. Some of these people are astoundingly up-to-date on the research, and you may find more detailed and relevant info there.

That all said, what the TCGA is discovering is that even within the generic 'glioblastoma' label, there are lots of differences, at both a histological/morphological level, and even more profoundly at a genomic level. All this underscores that cancer is really thousands of different diseases, each somewhat unique to the person carrying it.

The fact that your mother's cancer is still highly differentiated may mean that it's an earlier-stage cancer, in which case prognosis tends to be better. There are several caveats, though. Glioblastoma is a very difficult tumor to treat, and even with the best treatment, the outlook is not good. It's also worth noting that tumors themselves are heterogenous, and it may just mean that they sampled from a relatively benign region. These sorts of histological measurements are frustratingly inexact, and that's why we're working on finding better prognostic markers based on molecular assays, so that appropriate treatments can be used for different subtypes of cancer.

I'd suggest that you go to PubMed and start doing some searches through the literature, using relevant terms (some suggestions to start with: glioblastoma differentiation survival prognosis). The terminology can be a little dense, but you should be able to pick out the relevant parts from the abstracts or discussions. If you run into any paywalls, email me and I'll see if I can help you get access to the articles you need.

Best wishes to you, your mother, and the rest of your family in this difficult time.
posted by chrisamiller at 2:00 PM on June 1, 2009 [2 favorites]

Thanks so much to all of you for these answers. I've been looking through the medical literature, and really appreciate the offer of help accessing articles and the additional search terms. I also appreciate the help understanding the terms and the story of your brother-in-law's survival, which is very heartening. I'll be able to use this info to ask more targeted questions of the oncologists, who up until now have simply said that it's atypical and we should be glad, because for a glioblastoma, typical really sucks. Which is true, but very opaque, and nowhere near the level of information I need to maintain my illusion of control.

Thanks again to all.
posted by Betsy Vane at 9:47 AM on June 2, 2009