Clinical oncology is a subtly nuanced art. It has to be due its complexity and the fact that there's so much we don't know. I'll try to do my best to explain my dad's plight in understandable terms.
- His cancer arises from a type of white blood cell (lymphocyte) called a B Cell. A B Cell's job normally is to fight infection, mostly by the production of antibodies (those are what you generate in response to immunizations and infections which allows your immune system to 'remember' the invader).
- B Cells are produced from stem cells in your bone marrow and exist as clones of each other. They don't live very long. Consequently, they are constantly being produced and turned over. At some point, one of his B Cells mutated and formed a cancerous cell that becomes immortal. It just keeps dividing and dividing, but not owning up to any of its responsibilities as a member of the immune system. Because it just replicates endlessly, it crowds out other stem cells that are responsible for making my dad's red blood cells, platelets, and neutrophils (another white blood cell that is a first responder to infections, especially bacterial). Reduced numbers of these cells make him anemic, at risk for a bleed, and at risk of infections, respectively. We've already experienced 2 out of those 3 life threatening risks.
- There are LOTS of different reasons for the immortalization process - viruses, mutagens, random mutations, etc. We don't know what causes it in CLL. Current dogma suggests that multiple hits occur such as genetic susceptibility, exposure to a mutagen/virus, and an impaired mechanism to fix/destroy the mutation. A royal flush of deadly proportions, so to speak.
- CLL is broadly categorized into low, medium and high risk based on a multitude of factors - clinical presentation, blood counts, chromosomal abnormalities, genetic mutations, etc. We do know that my dad has several genetic/molecular abnormalities that put him in the high risk category. One study I read suggested that median survival time was 3 years from diagnosis for those in the high risk category. That means that half of the patients have died by 3 years. The nuance comes into play here. MDACC's data is suggesting that how one responds to their chemo regimen is also a big determinant of prognosis. We do not definitively know my dad's response yet, nor will we until the 6 rounds of chemotherapy are complete.
- Time to progression is a measure of how long a patient can go after receiving initial treatment before their cancer begins to act up again. Median time to progression is a measurement in which half of the population lasts that long. Based on my dad's molecular markers, that's 6 months. That means if you were to take a population of people with a disease similar to, but not identical because each patient is unique, then by 6 months half of the people would have had their disease flaring up again by 6 months. I don't kow what percent make it to 24 or 36 months, though some patients do. We don't know why some do and some don't. That's where the response to chemo may come into play.
- My dad could go 6 to 36 months after chemotherapy is finished without any major complications. Longer? I don't know. It is reasonable to then begin to expect progression of the disease in the form of infections, critical anemia, bleeds and ultimately death. There are second line chemotherapy agents but they just don't work very well.
- Add all of these up and it is very prudent to begin to prepare for a stem cell transplant. Some may ask, why not go directly to a stem cell transplant? It takes time, especially to find a donor. Out of his 3 siblings tested so far, none are a match. We're still looking. The chemo buys time for that. It's also greatly improved my dad's condition. Even though he probably doesn't feel like it has improved his quality of life, when this all started, he couldn't walk more than 20 feet due to exhaustion. He's able to do much more than that now thanks to the chemo.
- I would encourage everyone to register for Be The Match. If not my dad's, you may save someone else's life. The risk to the donor is almost non-existent. Boredom is about the biggest risk as all sorts of medical tests are run on you. The benefit to the patient means life. Seems a fair trade to me.
- This was all a huge bomb to my parents. Perhaps I was wrong for not correcting their false expectations but what's done is done. I'm ok with my choices. Regardless, it is going to be a very rough road ahead for my dad and my mom.