Secondary Cancers in Follicular Lymphoma

On my last post, a reader asked if I could write about other malignancies in Follicular Lymphoma treatments. My guess is that the request came because, in discussing the updated results of a trial in my last post, I mentioned the rates of secondary malignancies in the patients in the study -- that is, how many patients developed new cancers besides FL.

I'm not surprised at the request. As I was writing that, I kind of made a mental note to look into that statistic a little more, but the original full article didn't get into a whole lot of detail. But I also know that writing a statistic like that without any context is a nice way to get some people worried. My apologies for that -- I know how worrisome statistics can be, and as I've said in the past, the times that my disease has worried me most have been because I've read some statistic and it got stuck in my head.

So I want to add some more context to that statement, and give a little more information from the past couple of years about secondary malignancies in FL.

But first, I'll remind everyone of something important -- I am not a medical doctor, or a cancer researcher, or a biologist. I'm just a cancer patient who reads a lot. If you have concerns about your disease, the best person to talk to is your doctor.

Now on to the recent research.

I actually wrote about this topic a few months ago, describing research done this year on secondary cancers in Non Hodgkin's Lymphomas, including FL. The research describes a study of patients with NHL in Sweden, looking at a large database of 30,000 patients that tracked how many of them developed a second cancer after treatment. The study compared the 30,000 NHL patients with another database of 30,000 who did not have NHL, and compared how many of them developed cancer over time. Doing this allowed the researchers to see how much more likely a lymphoma patient was to develop cancer than the general population. If a study just said "FL patients have a 12% chance of developing a secondary cancer," that might seem bad. But if the same study says everyone in the world has a 10% chance of developing cancer, then to me, that 12% doesn't seem quite so bad. 

You can read the original article in the link above, and read my (non-expert) commentary, but the conclusion comes down to a few things.

First, Lymphoma patients do have a higher risk of developing secondary cancers than the general population, according to this study. However, that risk also stayed steady over the years in the study (1993 to 2014), and actually decreased for some cancers or Follicular Lymphoma patients. The decrease seemed to come from more patients receiving treatments other than traditional chemotherapy (like CHOP or Bendamustine), which generally cause fewer secondary cancers. Let me explain that again: in the early years of this study, before Rituxan and other non-chemo treatments, FL patients were more likely to develop secondary cancers because they were more likely to receive chemo. As more non-chemo treatments become available (Ritixan and other monoclonal antibodies, R-Squared, Inhibitors, CAR-T and other immunotherapies), the chances of developing a secondary cancer become smaller.

Let's look at another study, this one from 2021 that looked at over 13,000 FL patients from the Netherlands. It's called "Risk of second primary malignancies in patients with follicular lymphoma: a population-based study in the Netherlands, 1989-2018." It's very similar to the study of FL patients in Sweden, and comes up with some very similar results.

The Swedish study found that 11% of FL patients eventually developed a secondary cancer, while the study from the Netherlands found that about 12% developed one. Patients were more likely to develop a secondary cancer the farther out from their diagnosis that they went. This makes sense -- in the general population, older people are more likely to develop cancer than younger people. 

The cancer most likely to be found? Squamous Cell Carcinoma of the skin. (Interestingly, William also commented on the last post, pointing out that his wife, an FL patient, has had several basal and squamous skin lesions removed. Thank you, William -- you're always on top of things, even before I ask.)

Other secondary cancers include myeloproliferative neoplasms (MPNs), and myelodysplastic syndromes (MDS), which can lead to leukemias (although the article from Sweden had good news about this for FL patients), and solid tumor cancers of the mouth, stomach, colon and rectum, and  kidney.

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So what to make of all of this?

I think it's fair to say that secondary cancers are just unavoidable for a segment of the FL population -- a little over 10% of us. As the study from the Netherlands points out, our higher risk of secondary cancer comes from treatments like chemotherapy that can damage DNA and cause irregular cells to develop. But the fact that we have a cancer that affects our immune system is also an issue, according to those same researchers. Our bodies don't have as strong a response to factors that might cause cancer as others might have.

So what can we do about it?

Well, for me, I've always tried to be vigilant about how I feel. I see a dermatologist every year, who checks me for possible skin cancers. If skin cancers are the most common secondary cancer for FL patients, that seems like an easy one. I also get whatever regular screenings I'm supposed to get (just had a colonoscopy a few months ago, and I have an annual physical every year). I like to think that I am in tune with my body, and I know when something doesn't seem right. I don't take chances with my health, and if something is bothering me and a doctor dismisses it, I don't take No for an answer when I want it followed up. Self-awareness and self-advocacy won't stop cancers from happening, but they may help them get caught early, when they're more treatable.

As far as self-advocacy goes, I think it's very important to talk to your doctor about treatment options when the time comes for treatment. Bring up concerns about short-term side effects, but ask questions about long-term side effects too. If you have heart issues or a family history of hearty issues, that's worth mentioning. And if you have concerns about developing a secondary cancer, that should be discussed as well. Hopefully, your oncologist can give you information to ease your fears, or suggest another treatment that might be as effective. If not, try to get a second opinion from someone who does that for you. But also understand that sometimes the best treatment might be one that increases the chances of a secondary cancer. 

I also like this advice about secondary cancers from MD Anderson Cancer Center. To me, it puts things in perspective. Secondary cancers can develop for reasons that have nothing to do with cancer treatments -- some cancers are hereditary, for example. I try my best to not obsess about the decisions I have made.

I'd like to be able to end on a positive note, which is hard, but I'll go back to what I said about self-awareness and self-advocacy. Secondary cancers are not inevitable, but they do happen. Before treatment, ask questions about possible long-term side effects. Use that knowledge to be aware of your own body and possible changes to it, and be sure that any concerns you have are not dismissed. When a patient has a recurrence of FL, research shows that most of the time, the recurrence is found by the patient. Not by the doctor, or by a scan, or by a blood test. But because something didn't feel right to the patient.

So trust yourself and your ability to know your body.

And in the meantime, enjoy your life as best you can.