The Immune System after Chemo

Back in my post about finishing chemo, I mentioned the possibility of needing to have childhood immunizations redone. As I have mentioned on numerous occasions, chemo gives the immune system a beating. The worst of the cycles wiped it out to trace levels during the second week, which led to hospital trips upon getting sick. I only escaped this fate in the first two cycles, where I bounced back by Thursday of week 2, but the subsequent "bag" cycles (3, 6, 9, 12, 15) all ended up including hospital stays, and I didn't bounce back until the beginning of week 3.

But there are long term effects as well. One thing is that chemo carries with it an elevated risk of developing acute myeloid leukemia. Acute leukemia involves the bone marrow rapidly producing cancerous white blood cells. While this can happen to anyone, chemo ups the risk. The period of elevated risk lasts for about 10 years. Regular complete blood counts are done to catch this early if it does happen.

A lot more common is that acquired immunity to some diseases is lost. This is not just a concern during treatment itself. The cells killed by chemo include ones that produce antibodies that help fight diseases. So if enough of these cells die, the immunity given by these antibodies is lost even after treatment. But as the immune system needs time to recover for a vaccine to stimulate a proper immune response, so reimmunization cannot happen right away. In my case, the process took almost a year.

At the 6 month scan (September 2014), I was given a few blood tests to check my immune function and see what immunities I still had. The results of these tests determined whether I could stop taking the bactrim antibiotic for pneumonia prevention that I'd started back when I started chemo, what vaccines I would need again, and when I could get them. The September results had me almost at the point where I could stop taking bactrim, but not yet. More importantly, the majority of my immunizations were still in effect. The only ones missing were measles and rubella. However, I was instructed to wait before getting reimmunized. The MMR (measles, mumps, rubella) vaccine uses live but weakened viruses. A weak enough immune system, however, would not mount a sufficient response, which would lead to actual illness. I had repeat tests in December, and this time, the results were good enough for me to stop taking bactrim and get my MMR shot, which I did in January after the holidays. And just in the nick of time, as it was shortly thereafter that the California measles outbreak was all over the headlines.

I was generally able to keep any worry about catching an illness like measles in the back of my mind, but that didn't mean it wasn't there, especially when I had to travel to highly populated areas. And with a weakened immune system, the results would not have been pretty. Before my cancer experience, I didn't think all that much about the rise in parents who do not vaccinate their children beyond expressions of puzzlement every now and then, but now, the thought of future cancer patients being at heightened risks of hitting roadblocks or even losing their fights due to preventable illnesses I find very worrisome. Same goes for taking chances with having your children catch these diseases. What enabled the spread of the recent measles outbreak was a critical mass of unvaccinated individuals. Modern day residents of developed countries are privileged to be able to grow up without worrying about illnesses that used to claim many, many people in their youth. Most young parents today haven't had these illnesses, and quite possibly their parents haven't either. So with these diseases seen more and more as parts of history rather than ailments with tangible effects that caused loved ones to suffer, it becomes easier to question preventative measures such as vaccines. I'm going to say it here, as someone who's gone through a nasty illness young: if there were a vaccine for what I had, I sure would have liked to have had it.

Treatment is not the end of things

It's been almost a year since I updated this blog. I certainly did not intend it to be this way. There have been medical developments since I finished treatment, thankfully nothing that indicates a return of my cancer. But as I was so used to writing about treatment, once it stopped, my usual routine stopped with it and I found it much harder to think of topics to discuss.

A lot has happened since then. I have had scans four times (March, June, September, and December 2014). All of them have turned out clear so far; here's hoping for the rest to be the same as well. My next round of scans is at the end of March of this year. These will mark the "official" one year mark, after which my scans will decrease in frequency and I'll start being followed by Sloan-Kettering's long term team. They are internists who specialize in the effects of treatment on all the noncancerous parts of cancer patients' bodies. There are a number of long term effects that chemo and radiation can have, that varies by the drugs, treatment site, and dosage. I won't get into them here, but needless to say, I will be talking about them in future posts.

I successfully finished what remained of my Ph.D. work, defended my dissertation in early June, and deposited it a month later. Then Ashley and I at long last got married! We had a small ceremony in Champaign with a reception afterwards at a restaurant in neighboring Urbana. I was pleasantly surprised that I was able to stay out on the dance floor on just one natural leg, though I was sore for an entire week afterwards!

I also fulfilled a dream, moving back to California at the end of July to work my first "no more school" job. I'm in the Bay again, which I had featured in this much earlier post as a place I was hoping I could see again. This time I'm hoping for a longer tenure here than the four years (2003-07) that made up my prior one. The very first time I'd come back here after I left (Summer 2010) was quite the experience. I could feel memories all around me as I walked around where I used to live and then found myself missing my former times there and hoping things could have worked out differently and enabled me to stay there versus having had to come back to Illinois to finish my education. This feeling went away in subsequent summer visits (2011, 2012) as I built new memories through my internships, where I was making progress towards my Ph.D. And then in October 2012, my symptoms hit.

Nowadays, I'm reminded of my pre-cancer life on an almost everyday basis. That I simply have to put on a prosthetic leg each morning is one of them, versus the past where I could just roll in and out of bed at my own leisure without having to take any extra steps. I can't lift heavy weights anymore because of the heart toxicity associated with doxorubicin, when in the past weightlifting was one of my favorite forms of exercise. I can't help but worry that my current healthy state is going to be short-lived when in the past I had no health worries at all. This all has an effect on me. I'd like to think this will all end up working out in the end. Leaving California the first time turned out to do just that, as I wouldn't have met Ashley had I not done so. But while the feelings associated with my first return began to fade at the end of that summer, it's been just over a year since I finished treatment and the pre-cancer vs. post-cancer comparisons are still going on strong. I'm certainly hoping that the same process will happen there as it did with all the 2003-07 memories showing up in 2010, but clearly this is going to be a much longer journey.

So just as I shared the journey of treatment with you, I'm going to share this journey as well. It's easy to think that you get treated and go back to life and everything is back to normal, but as I've seen over the past year, it is unfortunately not so simple.