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Possible association between tattoos and lymphoma

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Re: Possible association between tattoos and lymphoma

#71

Post by usgroup »

skadamou wrote: post #63

"We found no evidence of increasing risk with a larger area of total tattooed body surface." Without a dose response, I'm inclined to believe that the increase in lymphoma seen in people with tattoos has more to do with confounding factors than with the ink or the act of getting a needle poked into your skin. I would think that controlling for all confounders in a study like this would be exceptionally difficult. Tha…

Yeah totally agree. That the size of the tattoo or the number of them not increasing risk makes no sense. Somewhat like claiming whether you smoke a cigarette or 20 a day, the risk is the same. If the latter was true it would more likely indicate that there is some other commonality in that group increasing the risk.

Also the slicing and dicing, “11 more than the index year” and so on, is multiple hypothesis testing on the face of it; I wonder if they adjust for that.

Re: Possible association between tattoos and lymphoma

#73

Post by throw_pm23 »

coldtea wrote: post #26
swayvil wrote: post #22

Earlier quoted context omitted.

Back when they were pushing public literacy, reading books was disparaged as a morbid activity. (Sitting unmoving for a long time, staring...) But now everybody does it.

> reading books was disparaged as a morbid activity. (Sitting unmoving for a long time, staring...) And for people that overdid it, it was. The modern sedentary lifestyle starting from that era's combo (office / clerical jobs + stationary entertainment with books and magazines, and later tv and radio). > But now everybody does it. Read books? Nah: If we count only fully-read books, the average American adult reads ju…

less-than-ideal? You want more than half of people to read no books?

Re: Possible association between tattoos and lymphoma

#74

Post by refulgentis »

office_drone wrote: post #69
skadamou wrote: post #63

"We found no evidence of increasing risk with a larger area of total tattooed body surface." Without a dose response, I'm inclined to believe that the increase in lymphoma seen in people with tattoos has more to do with confounding factors than with the ink or the act of getting a needle poked into your skin. I would think that controlling for all confounders in a study like this would be exceptionally difficult. Tha…

Indeed. It's not the ink content that led to Am J Clin Pathol. 2014;142(1):99-103. saying: "The mean age of death for tattooed persons was 39 years, compared with 53 years for non-tattooed persons (P = .0001). There was a significant contribution of negative messages in tattoos associated with non-natural death (P = .0088) but not with natural death."

I'm not sure "people with negative msgs in tattoos died 14 years earlier" sheds light for me on the TFA.

TFA has a more direct, physical, concern - it starts from a well-known, that tattoo ink ends up in lymph nodes, and it does a statistical analysis showing there's a significant statistical result in lymphoma occurence.

I think people with negative tattoos dying younger reduces the # of people with tattoos who get lymphoma, as they have less ink-in-lymph-nodes years.

Re: Possible association between tattoos and lymphoma

#75

Post by usgroup »

timr wrote: post #68
skadamou wrote: post #63

"We found no evidence of increasing risk with a larger area of total tattooed body surface." Without a dose response, I'm inclined to believe that the increase in lymphoma seen in people with tattoos has more to do with confounding factors than with the ink or the act of getting a needle poked into your skin. I would think that controlling for all confounders in a study like this would be exceptionally difficult. Tha…

Yes. Also, the survey response rate was the biggest difference between groups (54% vs 47%), which could easily explain the observed differences. The confidence intervals cross 1.0 for nearly all reported IRR values. For those who don't know how to interpret medical evidence, this study is very weak.

Those response rates are fairly awful with two groups that are markedly different. Seems very likely that they’d self-select on the face of it especially if they knew what the research question was.

Re: Possible association between tattoos and lymphoma

#76

Post by roughly »

> A hypothesis that Christel Nielsen's research group had before the study was that the size of the tattoo would affect the lymphoma risk. They thought that a full body tattoo might be associated with a greater risk of cancer compared to a small butterfly on the shoulder, for example. Unexpectedly, the area of tattooed body surface turned out not to matter.

As someone pointed out on the other thread about this[1], the lack of dose response makes it very difficult to see this as a direct correlation and not reflective of other confounding factors.

[1] https://news.ycombinator.com/item?id=40492364

Re: Possible association between tattoos and lymphoma

#77

Post by gwern »

skadamou wrote: post #63

"We found no evidence of increasing risk with a larger area of total tattooed body surface." Without a dose response, I'm inclined to believe that the increase in lymphoma seen in people with tattoos has more to do with confounding factors than with the ink or the act of getting a needle poked into your skin. I would think that controlling for all confounders in a study like this would be exceptionally difficult. Tha…

This is a Swedish study, so what might be possible is using the population registry to contact siblings of the cancer patients to ask about traits like tattooing and then their health data would already be in Swedish system and linkable. This would control for a lot of the relevant confounders.

Re: Possible association between tattoos and lymphoma

#78

Post by marcosdumay »

refulgentis wrote: post #74
office_drone wrote: post #69

Earlier quoted context omitted.

Indeed. It's not the ink content that led to Am J Clin Pathol. 2014;142(1):99-103. saying: "The mean age of death for tattooed persons was 39 years, compared with 53 years for non-tattooed persons (P = .0001). There was a significant contribution of negative messages in tattoos associated with non-natural death (P = .0088) but not with natural death."

I'm not sure "people with negative msgs in tattoos died 14 years earlier" sheds light for me on the TFA. TFA has a more direct, physical, concern - it starts from a well-known, that tattoo ink ends up in lymph nodes, and it does a statistical analysis showing there's a significant statistical result in lymphoma occurence. I think people with negative tattoos dying younger reduces the # of people with tattoos who get…

It shows the existence of some very strong confounding mechanisms.

Re: Possible association between tattoos and lymphoma

#79

Post by blinkingled »

GuB-42 wrote: post #47
blinkingled wrote: post #28

Hair dyes would have similar absorption mechanism right?

Hair is dead, skin is not. Your body doesn't care about what you do to your hair, you can cut it, dye it, anything as long as it doesn't touch the root. Tattoos are about injecting a foreign substance in live tissue, which triggers an immune response, and that's what the article is about. There is a reason tattoos hurt and haircuts don't.

Well sure, but the scalp underneath the hair that's gotta have some skin properties - sure it's thicker than the rest of the skin and has some protective properties against some forms of environmental damage but the dye does go in there and years of use should cause _some_ thing - not sure there's any research around what exactly.

Re: Possible association between tattoos and lymphoma

#80

Post by mewpmewp2 »

prepend wrote: post #29
invalidusernam3 wrote: post #21

Earlier quoted context omitted.

Who cares if others think it's a midlife crisis, do what makes you happy. I'm nearing 40 and still get a couple tattoos a year. I love the feeling of a new tattoo, it boosts my confidence and gives me a sense of accomplishment for sitting through the fairly painful process.

Exactly. Part of the fun of tattoos is everyone thinking you look stupid and being able to practice the stoicism of not caring what other people think and focusing on the intrinsic joy of doing what you want.

I can do that without getting a tattoo though.
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