Today I started the third chemotherapy program. It’s very similar to the first two. The main ingredient is still 5-fluorouracil, which damages dividing cells by messing with DNA replication in a way that’s not fully understood. Fasting convinces healthy cells to go into a deep sleep. 5-FU should thus only harm cancer cells, which can’t keep from growing. So far, this hasn’t worked as well as I had hoped and, naively, expected.
The difference today is the antibody. Going by the trade name of Vectibix, it binds to the epidermal growth factor receptor and prevents it from receiving growth signals, such as EGF, and reacting to them by stimulating cellular growth. Without growth signals, cells don’t grow, or much less so. Tumor will be held in check. That, anyway, is the idea.
Some of the mutations in the signaling protein KRAS stimulate growth without requiring activation by EGFR. This is why these mutations are linked to cancers. My mutation is apparently different. I really have to make an effort to understand what’s going on at a biochemical and structural level. There’s a fair number of nice papers out there on this topic, waiting to be read.
The major side effect of the previous antibody was diarrhea. That’s what the doctor and the patient information sheet said. But might have been right, but my case was different. As I received the antibody after three days of fasting, with my gut cleaned out already, diarrhea wasn’t an issue for me. It became an issue a day later during the transition from fasting to eating. What I ate didn’t always find my digestive tract a hospitable place and frequently didn’t linger. I take a drug that helps with this like a charm.
At the beginning of each treatment session, I always get a pile of drugs to swallow. By now I don’t know what they’re all good for. One pill is against nausea, two are steroids of obscure purpose, the fourth I have no idea about. This morning, I got a fifth, against possible allergic reactions against the antibody. During the therapy, I get an injection that’s supposed to keep the excessive sweating that irinotecan might cause in check. By now, I get more drugs to be able to endure chemotherapy than make up the therapy.
The antibody I got today for the first time can trigger an acne-like reaction with severe pustules on the skin, my doctor said. Most patients suffer from this. I read that this can be seen as the antibody doing its job. A bit of acne will make me feel 30 year younger, I told the doctor. Nothing to worry about. I might have to show my ID the next time I buy a beer, but that’s ok with me.
As I wander down the ladder of therapy options, from first-line therapy to second-line and now third-line therapy, I wonder what places individual therapies in this ranking. Is it that the first therapy is the one that’s proven most successful in clinical trials and with patients and that the others will work less well? Or are they comparable in their efficacy but the first therapy given is the one patients tend to accept most happily because of the fewest side effects overall? This is hard to tell for me. I don’t get many side effects, but today was probably the worst day of all.
Maybe it was in my head. I’ve started almost every therapy session so far with a mind full of optimism. Nothing concrete, just a feeling that things are going well and that I’m on the right track. This morning was different. After too many scans that didn’t show any progress (to put it mildly), it’s hard to keep up a positive façade. The question of why I’m doing this kept popping up in my head. I didn’t help that I found fasting almost unbearable this time. There is no point, my mind wailed. This is not the answer I would give, but I felt too weak to give any answer.
Chemotherapy went as usual, without any problems. I started reading and writing a bit but dozed off pretty quickly. When I rode my bicycle home, I didn’t feel much better. I had a couple of hours on the sofa before picking up the boy from childcare. Back home, Flucha told me I looked like a ghost. I felt like a ghost too, or a least like someone not part of the living anymore. I went to bed before 7, utterly destroyed. At this rate, it will take more than the new antibody’s side effects to make me feel young again.
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