Tattoos and cancer: no clear answers yet

Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient" with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. Does tattoo ink increase a person's risk for developing certain cancers? Dr. Scott Albert is my guest today, and he'll go over research on this potential association. Dr. Albert is an assistant professor of surgery at Upstate and a member of the Society of Surgical Oncologists. Welcome back to "The Informed Patient," Dr. Albert.

Scott Albert, MD: Hi. Thanks for having me.

Host Amber Smith: In a recent study published in BMC Public Health, researchers from Denmark concluded that there is an increased risk of lymphomas and skin cancers among people with tattoos. What can you tell us about this study?

Scott Albert, MD: First of all, I think this is an interesting topic. I would say overall, these studies, the way they're designed, actually ask more questions and they really answer questions. And that's because of the study to design. And these are sort of population based studies. Europe is pretty good at keeping track of their patients, meaning most European countries have large national databases, so they're able to sort of harvest data from their populations pretty easily. And most of their populations actually find it helpful to participate in studies.

Host Amber Smith: So they drew from an existing database of patients, then?

Correct. So this looked at, it was a twin study where they looked at a database of their population, and they pulled out twins and they looked at twins who had tattoos and then the twins who did not. And they looked at various cancers, specifically looking at lymphomas and skin cancers. And they were trying to look for a signal, meaning is there any association between tattoos and malignancy?

Do you know how many people were in the study?

Scott Albert, MD: It looked like they were doing a survey study. So they reach out by a questionnaire. It looks like perhaps this was done during COVID, and then they look for responses. And it looks like there was two subsets, meaning they looked for twins that already had a diagnosis, and then they looked at just a large population of twins and it looked like they reached out to a couple thousand twins.

Host Amber Smith: Is that a good number to give them a conclusion?

Scott Albert, MD: It's a pretty small sample size because if you think about it, these cancers are rare, and so you really need to look at probably tens of thousands of patients to really get a stronger signal. But I think this is maybe a start.

And I do think when you do survey studies, you try to get participation, and their participation rate was about 50%. So it's pretty good. Overall, when you start honing down to the actual population they looked at was really pretty small. The number of patients that actually had a malignancy in one arm of the study was close to 10.

Host Amber Smith: Have there been previous studies that looked at this and reached similar conclusions?

Scott Albert, MD: There's a few studies out there. They're similar in design, meaning they're just database studies, looking at cohorts of populations and trying to make an association between tattoos and malignancies. And these are all very weak studies, and the association has been, I would say, weak as well. I think the jury's still out if there's a strong link, but it does raise some questions.

Host Amber Smith: So what is in the ink that might be causing cancer?

Scott Albert, MD: In the studies, you can't say. They propose that these inks may have some carcinogens in them.

Again, this is not really what the study was looking at, but the theory is that there's materials in the inks that cause inflammation in the skin and, more specifically, in the lymph nodes.

You know, I do a lot of lymph node surgery, and it is interesting. You do find tattoo ink routinely in lymph nodes. In fact, sometimes it actually helps me when I'm operating because we're removing selective lymph nodes, and these selective lymph nodes in, for example a sentinel node procedure, are typically the ones that also take up the tattooed ink. So it's easy to visualize the lymph node.

And even kind of more specifically to melanoma is malignant lymph nodes with melanoma look black, and these tattooed lymph nodes also look black. So you have to be aware of that. And I hear it every couple yearsin the area that patients who thought they had malignant melanoma in a lymph node was actually just a tattooed lymph node.

So it's clear that tattooed ink does go to lymph nodes, but whether or not it's causing the inflammation that this study is suggesting leading to other malignancies is I think it's still premature to say that there's a strong, strong link there.

Host Amber Smith: Is there anything on the market that's, safe, an ink that doesn't spread or an ink that stays in place where the tattoo is?

Scott Albert, MD: I'm not entirely sure. I'm sure there's inks that aren't maybe as permanent. It probably depends on the makeup of the ink that that probably adds risk, but I can't say for sure.

Host Amber Smith: Now what about, a lot of the tattoos are plain black ink...

Scott Albert, MD: Correct.

Host Amber Smith: ...but some of them use colors. Do you think one is better or worse than the other, for traveling through the lymph system?

Scott Albert, MD: Yeah, that was mentioned in the article, about different colors.

I don't think you can make any judgements about the different types of colors. By far, more commonly is black ink, and sometimes I see black or blue ink in lymph nodes. They do mention red ink. But I don't think there's really enough information to make a conclusion about the different colors and risk.

They do also comment on size of tattoos and whether or not larger tattoos add risk, that there was a bit of a signal there, large tattoos and elevated risk of a malignancy. But again, I think it's probably premature to conclude that tattoos are directly related to risk for cancer.

Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host Amber Smith. I'm talking with Dr. Scott Albert about whether tattoos impact a person's cancer risk.

Now, this study talked about lymphomas and skin cancers. Can I have you explain what a lymphoma is?

Scott Albert, MD: Yeah. So lymphomas are cancers that involve immune cells, and so I would say lymphomas are really, in some ways, a generic term for for this type of cancer because there's many subtypes. There can be lymphomas that are involving B cells and T cells. There can be lymphomas that are slow growing and indolent. And there can be lymphomas that are very aggressive.

So to say the word "lymphomas" is sort of like saying the word "breast cancer," in the sense that there's many different types, and the treatments can vary based on how aggressive that subtype is.

Host Amber Smith: Are there symptoms for people to be aware of? I mean, how would they know that they need to be checked to see whether they have lymphoma?

Scott Albert, MD: Sometimes lymphomas can occasionally cause what we call B-type symptoms, fevers, night sweats. You can develop a swelling in lymph nodes that's significant. So swelling and lymph nodes that's easily palpable, that you can feel, and does not go away in a few months, generally is something that would require further workup.

Lymph nodes are the source of many of our immune cells, so that's where they live. That's where they hang out. They're sort of the houses. And they can get enlarged for other reasons beside lymphoma, since inflammation causes swelling of these lymph nodes as well.

Host Amber Smith: And since there's so many different varieties, I'm assuming they're treated differently and their prognosis is different. Is that right?

Scott Albert, MD: Absolutely. In fact, now many lymphomas can be evaluated for specific mutations, and they can be treated with targeted drugs as well as chemotherapies if needed.

Host Amber Smith: Well, let me ask you about the skin cancers that were a concern in this study. Do they develop at the site of the tattoo?

Scott Albert, MD: That's a great question. They did not really specify. I think the word skin cancer, too, is a little bit difficult, in terms of what they were looking at.

I would be most interested in tattoos and melanoma, because melanoma is really the ones that would spread to lymph nodes.But they were mostly looking at basal cell carcinomas, which is... Those are very, very common. We see these frequently, and they don't have the ability to metastasize generally speaking. But I was curious because they didn't really specify whether these basal cells were related to the tattooed site, or are they just popping up somewhere in the body?

Host Amber Smith: And if basal cell carcinoma is so common, someone could definitely have that and also have a tattoo, and them not be related?

Scott Albert, MD: Absolutely. I think that is probably most likely the scenario, is these are just two coincidental findings in the population.

Host Amber Smith: Well, at this point -- and I know this is one study, or a handful of studies -- but would you advise people to reconsider tattoos?

Scott Albert, MD: No. I think based on this study, you cannot make that conclusion.

I do think that having tattoos, like anything, you just need to be aware of your body and, have someone keeping track of your skin. And if you develop anything unusual on the skin or within a tattoo area, you have it evaluated.

Host Amber Smith: Do you think that removing a tattoo would reduce a person's -- if there is a risk -- would that help reduce it?

Scott Albert, MD: That's a good question. I think they did allude to removal of tattoos in the study, and perhaps that that, if anything, adds inflammation because the way tattoos are removed, from my understanding, is that the inks are basically broken up into smaller sort of droplets in some ways and kind of spread through the body. So I'm not sure removal of a tattoo would necessarily reduce risk based on the discussion in this article. But again, I think it's really premature to know.

Host Amber Smith: Well, Dr. Albert, thank you so much for giving us your time and insight on this study. I appreciate it.

Scott Albert, MD: You're welcome. Thanks for having me.

Host Amber Smith: My guest has been surgical oncologist, Dr. Scott Albert from Upstate. "The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe, with sound engineering by Bill Broeckel and graphic design by Dan Cameron. Find our archive of previous episodes at upstate.edu/informed. If you enjoyed this episode, please invite a friend to listen. You can also rate and review "The Informed Patient" podcast on Spotify, Apple Podcasts, YouTube, or wherever you tune in. This is your host, Amber Smith, thanking you for listening.