Can Covid-19 Cure Follicular Lymphoma?

If I was trying for a click bait title to get you to read, I don't think I could do much better that "Can Covid-19 Cure Follicular Lymphoma?"

 But it seems like it might actually be true. A Follicular Lymphoma patient in Italy had his FL disappear after he was diagnosed with Covid-19, and the only explanation that his doctors can come up with is that the Coronavirus did the job. They write about it the European Journal of Nuclear Medicine and Mollecular Imaging in an article called "Complete remission of follicular lymphoma after SARS-CoV-2 infection: from the “flare phenomenon” to the “abscopal effect”."

The article was published in February, but it was discussed in a piece in the online magazine Slate about a week ago. The Slate piece does a good job of explaining things, but there are some interesting issues I think are worth highlighting.

Before getting into any of that, a couple of reminders:

The risks that come with getting Covid far outweigh the remote possibility of the virus helping anyone.

That possibility is extremely remote -- the medical journal article looks at a single person's experience, and we all know that one person's experience with FL says nothing about our own experience.

But it's a fascinating situation.

The FL patient being discussed is a 61 year old man in Italy. He was diagnosed with FL in August 2019, and began Bendamustine and Rituxan, finishing treatment in February 2020. In June, a scan revealed that the cancer appeared to be growing. But a biopsy came back negative. In September, another scan and biopsy also came up negative -- no cancer, and no additional treatment since the B-R.  But he had been diagnosed with pneumonia in both lungs, brought on by Covid.

They considered some possible explanations for this, including possible spontaneous remission, which is rare, but does happen with some FL patients. The explanation they decided on was the Covid killed the cancer cells.

The Slate article gives some history on how researchers have (for centuries) tried to use bacteria and viruses as ways to kill cancer cells. Viruses might have an easier time killing cancer cells than killing normal cells. Normal cells, if attacked by a virus, will send a signal to the immune system, and immune cells will attack the virus. But cancer cells don't signal the immune system, since the immune cells might attack the cancer cells. So without the immune system to come to the rescue, cancer cells just might be more vulnerable to the virus. 

An immune response to a virus can also trigger massive inflammation -- the "Cytokine Storm" from Cytokine Release Syndrome that is a potentially dangerous side effect of CAR-T. But that inflammation caused by the immune system's huge response (a danger for Covid patients as well) might result in immune cells killing both the attacking virus and the cancer cells.  

The patient's doctors considered spontaneous remission as well as the possibility that the B-R was continuing to do its job. But they ruled those out because the cancer seemed to get worse before it got better. Those explanations wouldn't have resulted in that -- the cancer would have just kept getting better without first getting worse. That getting worse is called a "flare phenomenon" and its common to immunotherapy, but not traditional chemotherapy (or immuno-chemo like B-R).

As the Slate article points out, this single case doesn't mean much for all Follicular Lymphoma patients. Plenty of blood cancer patients have gotten Covid, and for many, the outcome was death or serious illness. Covid isn't going to cure FL.

But it does say something about the possibility of using viruses to treat cancer. The trick, of course, is to find a way to control the virus so it only affects cancer cells and doesn't grow on its own and attack normal cells. Like any cancer treatment, it's all about the balance between effectiveness and safety. That's a tough thing to pull off with a virus.

The other lesson I'm getting from this doesn't have anything to do with the virus as a cure. It has ore to do with the explanations that were rejected. Follicular Lymphoma seems especially open to spontaneous remission (it goes away all on its own) and spontaneous regression (it gets better on its own, with nodes shrinking, even if the lymphoma doesn't go away completely). I wrote about this in 2013, and that post is still on the most read on the blog.

I think it's important for us all to remember that FL often behaves differently than other cancers. It does sometimes become more aggressive, but it sometimes lies dormant for months or years, or gets worse and then gets better on its own. It's easy to say that the FL is behaving a certain way because of something we did or didn't do (exercise a certain amount or a certain way, or eat a certain food, or avid a certain food). Those actions might affect our immune system in some way, and that might affect our FL (like what happened with the Covid patient). But there isn't a lot of evidence that those changes will cure FL. If anything, they might contribute to a temporary change, but it's also possible that eating a lot of broccoli just happened to coincide with a spontaneous regression that would have happened no matter what someone was eating.

(I like to remind people in support groups, who ask me what I eat that has kept me from needing treatment for so long, that about once every week or so, I eat a hot dog and french fries from my favorite local joint. I go there so often I actually have a Christmas tree ornament from them. My steady injection of nitrates and trans fats probably isn't keeping cancer away, and I don't think a steady diet of kale and turmeric will do it, either. Cancer and food is much ore complicated than that.)

I'm sure none of you were planning to get Covid deliberately in an effort to jump start your immune systems. And I hope you'll trust science enough to do what you can to stay safe -- keep away from others, wear a mask, and with your doctor's advice, get a Covid vaccine when you are able to.

Stay safe, everyone.