“Raindrops on roses and whiskers on kittens … These are a few of my favourite things.” Oddly enough, none of the items that Maria sang about makes my personal list of favourite things. I only like “brown paper packages tied up in string” if they have Amazon printed on the side.
On my list are the things I could not eat in the past two months because of mouth ulcers. Now, at last, the sores have faded and I can enjoy my personal list of favourite things: dill pickles, Mexican food, curries, chocolate, potato chips, salted nuts, seafood with lemon. Yum!
Greetings again, Doug fans. Here’s the latest update.
Our meeting with our oncologist, Nick, on November 22 delivered more good news. I had thought that there was one lonely tumor in my liver. In fact, six lesions were identified by the previous CT scan at the end of July. Based on my most recent scan (November 20), three of them have shrunk or disappeared, the other three are stable. Nick was very happy with that result. He believes that the immunotherapy alone will keep these guys under control or kill them. No further chemo will be needed, and no targeted radiotherapy. Instead, I’m on one 30-minute drip of immunotherapy alone every three weeks, each treatment followed by two weeks of recovery.
This was VERY good news for us as well, worthy of a few glasses of Pinot Gris with that evening’s dinner!
I had my latest immunotherapy treatment on December 13 along with a quick consult with Nick. He’s still happy with my progress and is talking about switching my treatment frequency from 3 weeks to 6 weeks. That will definitely give us more flexibility in the new year! I’ll have another CT scan in six weeks to check on how it’s going.
The Skinny on Immunotherapy
Some of you have asked how immunotherapy works. For the non-nerds among you, feel free to skip this section. For the rest, here’s my limited grasp of the basics.
Chemotherapy drugs are poisons that target and kill fast-growing cells, mainly cancerous ones. Immunotherapy drugs are completely different: they are not poisons. They take the brakes off the body’s natural immune system so that it kills the cancer calls. There are five distinct types of immunotherapy. The most common type, the one I’m taking, is a group of drugs called immune checkpoint blockers. Let’s dive into how they operate.
T-cells, a type of white
blood cell, are part of the body’s immune system. They kill infection-causing viruses,
bacteria, parasites, and other harmful cells. Like cancer cells. On their
surfaces, T-cells carry immune checkpoints, special proteins that act as
natural brakes to stop them from destroying healthy cells. One of these checkpoints
is called PD-1. (Programmed Cell Death-1; cute, eh?) When a PD-1
attaches to a PD-L1 (Programmed Cell Death Ligand-1), a protein carried
on the surface of some normal cells, it tells the T-cell to leave the normal
cell alone.
But…
Some clever cancer cells also carry PD-L1, so they look to T-cells like healthy cells. “Normal cell here. Not cancer. All normal. Nothing to see. Nothing to see. Move along now ...” And the T-cell does. It is fooled and doesn’t attack the cancer cell.
Checkpoint blockers that target either PD-1 or PD-L1 proteins can prevent this attachment and allow the T-cells to target and destroy cancer cells. The only problem with this is, they also block checkpoints on some healthy cells, which then become targets for T-cells. And that leads to side effects, though typically milder than the ones from chemo.
Pembrolizumab -- my carers call it Pembro –the immunotherapy drug I’m taking, targets the PD-1 protein. It’s marketed by its creator, Merck & Co., under the brand name Keytruda. Its molecule is pictured on the left next to a molecule of H2O. I told you it’s complicated!
The first checkpoint blocker drug was approved for use in 2011. Pembro was first approved in 2014. It’s sobering to realise that the drug that is possibly saving my life may not have been available as recently as 10 years ago.
So far my side effects have been pretty minor compared to chemo: my energy level is bit lower than usual. And that’s about it. It’s hard to predict these things but I’m hopeful of leading an even more normal life into the new year.
Thanks again to you all for your support. And for your patience in tolerating my little science lessons.
My next update will probably be in six weeks, after my next CT scan results are in. See you all then. Meanwhile, have a terrific end-of-year holiday, however you celebrate it. And all my best wishes to you all for a happy and healthy 2024!
Comments, questions words of inspiration are all welcome. As always, I'd love to hear from you.