Positive pregnancy test diagnoses man's cancer

The science behind the story of how Reddit saved yet another life.

If you are a lady, and you think you might be pregnant, you can take an at-home test to find out. You simply pee on a stick. Whether the results are measured in pink lines, blue lines, plus and minus symbols, or a "pregnant"/"not pregnant" digital readout, all the home pregnancy tests on the market are really looking for the same thing — Human chorionic gonadotropin (HCG).

HCG is a pregnancy hormone. It's produced by the placenta, a temporary organ that only forms in female bodies when an embryo has attached to the uterine lining. And so it was kind of weird when a male friend of a Reddit user known as CappnPoopDeck peed on a home pregnancy test and it came back positive.

Turns out, HCG can show up in men, too. And when it does, bad things are happening. You might have seen this story on Gawker earlier this week, but the science behind it is so crazy that I wanted to discuss it in a little more depth.

First, let's talk about HGC in ladies. The specific cells that produce HCG are called trophoblasts. At the point where a human is quite literally nothing more than a ball of 70-100 cells, trophoblasts form the outer layer. The mochi to our ice cream center, if you will. These cells eventually grow into the placenta, but at the earliest stages of pregnancy, their primary function is to rip through flesh and secure the embryo to uterine wall. Seriously.

I'm going to quote from Jon Cohen's excellent book on miscarriage, Coming to Term, because it has heavily influenced the mental pictures I see when I think "trophoblast".

Successful implantation occurs only if the embryo properly "invades" the lining of the uterus, which requires that the placenta's trophoblast cells penetrate deeply, boring into maternal arteries to shunt blood to the growing baby. If the mother did not stop the trophoblasts' drilling, they might burrow so deeply into her uterus that she could hemorrhage and die. [He goes on to explain how the female body prevents this. Although he notes that, sometimes, it doesn't work.]

Fun!

The outermost cells in a layer of trophoblasts are called syncytiotrophoblasts. These are the cells that actually produce HCG, which plays a huge role in making sure that you actually miss that first missed period. The chain of command works like this: When you ovulate, you release an egg from a follicle on your ovary. But that follicle doesn't just instantly disappear afterwards. Instead, it hangs out, producing progesterone — a chemical that is instrumental in preventing you from shedding your uterine lining and having a period.

On a normal, non-pregnant cycle, progesterone levels will go up for a bit, but then the spent follicle — the corpus luteum — will wither away. Your progesterone levels will drop. And you'll ride the crimson wave.

But, if you're pregnant, the corpus luteum doesn't go away. It keeps on producing progesterone, and no period happens. What keeps the corpus luteum alive and kicking? Human chorionic gonadotropin, that's what.

So why on Earth would HCG end up in a man?

When that pregnancy test came back positive, CappnPoopDeck made a rage comic about it, and posted it to Reddit. The very first response, from a user named goxilo, was this: "If this is true, you should check yourself for testicular cancer. Seriously. Google it."

Yes, HCG in men can be a sign of a rare (and dangerous) form of testicular cancer — choriocarcinoma. This is a cancer made up of syncytiotroblastic cells, said Katherine McGlynn, a senior investigator with the National Cancer Institutes. The tumor secretes HCG because that's what syncytiotroblasts do. They secrete HCG. And they don't particularly care whether they're secreting it into a man or a woman.

But how do they get into a guy, to begin with? That's where things get really weird. The truth is that nobody is entirely certain, McGlynn told me. But there are a couple of theories. One possibility is that these syncytiotroblasts that turn cancerous were leftovers — remnants of the time when that guy was just a ball of 70-100 cells. One way or another, they persisted in his body and then started to grow out of control.

The other theory: Somehow, normal cells in the man's testes just start regressing, reverting to one of the earliest forms of cells in a human's life cycle. Either way, one thing is certain, "It's exactly the same cell as in the placenta," McGlynn said.

The bad news: Choriocarcinomas move really fast. They're more common in men under 30 and the prognosis is usually bad, because most of the time nobody catches them until they've already spread to other parts of the body, especially the lungs. In that, CappnPoopDeck's friend is incredibly lucky. Both that he decided to pee on a stick for LULZ and that his friend posted the news to Reddit. In a follow-up, CappnPoopDeck reported that doctors found a very small tumor in his friend's right testicle. But they found it early enough that it's going to make treatment much easier.

The good news: Men should know that their chances of developing a choriocarcinoma are extremely rare. A 2002 paper in the Canadian Journal of Emergency Medicine reported that only about 2 men in 100,000 will get any kind of testicular cancer. Pure choriocarcinomas — the dangerous kind that I'm talking about here — make up less than 1% of those diagnoses. It's not clear whether CappnPoopDeck's friend has a pure choriocarcinoma, or a much-less-deadly form of testicular cancer that happens to incorporate some syncytiotrophoblasts.

Either way, McGlynn wanted to make it clear that you all shouldn't feel like you need to run out and stock up on home pregnancy tests. In fact, at least twice during our interview, she marveled at how amazing it was that this story even happened. "The actual odds of the man having this particular cancer, and then using a pregnancy test, are sky high. It's kind of amazing that this happened," she said.

Read More:
Read the Gawker story about this case
Read the original Reddit thread
Read a history of home pregnancy tests, which includes a lot of information about HCG
Read a full research paper about a different case of testicular choriocarcinoma

Photo: Shutterstock

Published 2:17 pm Thu, Nov 8, 2012

About the Author

Maggie Koerth-Baker is the science editor at BoingBoing.net. From August 2014-May 2015, she will be a Nieman-Berkman Fellow at Harvard University. You can follow Maggie's adventures in the Ivory Tower by subscribing to The Fellowship of Three Things newsletter.

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52 Responses to “Positive pregnancy test diagnoses man's cancer”

  1. “The actual odds of the man having this particular cancer, and then using a pregnancy test, are sky high.”
    Rather, the odds of that *not* happening…

    • Nylund says:

      Unless HCG gives men an overwhelming desire to pee on pregnancy tests…

      • alkali says:

         I think it’s correct to say that the odds of that happening are high — a low chance is expressed as a high number for purposes of “odds”, e.g., a million to one.

        That said, for those who are wondering, “What kind of demented person would urinate on something completely inappropriate just to see what happened?”, let me introduce you to the male gender.

        • mtdna says:

          You’re wrong. By your logic, when you say, “The odds of rain happening today are high” what you mean is that it’s unlikely to rain. Or, “The odds of getting hit by a meteorite are very low,” means that you’re likely to be hit.

        • ocker3 says:

           Not just that, but humans love to brag about the whacky stuff we do (just about Everyone I know is now aware that I’ve joined a viking re-enactment group for example), and the internet is a perfect venue for that. Plus, it hasn’t been done before!!!

          • dnebdal says:

            It’s weird what you get used to – I’ve been sitting around dressed as a viking every second summer for many years now, and it seems entirely normal to me. x)

          • ocker3 says:

             Just sitting, no fighting?? That’s not normal…

          • dnebdal says:

             Hah, well – we have a fighting group, I just happen to hang with the handiwork people instead. :)

          • ocker3 says:

             My group leader said yesterday we should all be able to make our own gear, just in case, except for boots, boots we should buy. I’m happy to add some leather to some gloves for padding, but making shirts is probably outside my skill area. Any intelligent warrior culture respects their smiths and crafters, you don’t want your pants falling down while in combat!

          • dnebdal says:

             Well, we started as a informational group – the largest camp at our first market (in … 1994, I think) was the “children in the viking ages” one. It’s drifted into more of a merchant’s market since then, though our blacksmith group still smelts their own iron (and makes some rather excellent knives from it).

            Personally, I only dropped in for the market – this year I just made a few knife-handles (as an excuse to be there) with a friend of mine, and we shared a tent with my mother and one of her friends, who were selling some (quite decent) plant-colored yarn.

            (This place: http://www.borrevikinglag.com/?page_id=961 )

        • It has more to do with them being teenagers than male. You know, the age when you do all kinds of things for the lulz.

          • cdh1971 says:

            I guess you’re right in principle, but if the girlz had the equipment, some of them might also might piss on random stuff. Wait…teen girls piss on random stuff too, but cultural mores and anatomy cause them to exercise more discretion.
             http://www.youtube.com/watch?v=QRmvNMUEFZg

        • datashaman says:

          Odds are usually expressed as the odds AGAINST something happening. A million to one  against is unlikely, two to one against will happen 1/3 of the time.

        • Zadaz says:

          “for those who are wondering, “What kind of demented person would urinate on something completely inappropriate just to see what happened?”, let me introduce you to the male gender.”

          You mean peeing on something that’s built specifically to be peed on?

    • cellocgw says:

      ok, X  vs. 1/X  .   Move on :-)

    • Its a product of the reddit New Queue where people do weird things for attention every minute, and lot of eyes are watching.

  2. beforewepost says:

    So 2 in 100,000 male redditors will get testicular cancer. Assuming 2/3 of redditors are male, that’s about 450 men http://blog.reddit.com/2012/01/2-billion-beyond.html If 1% of them get choriocarcinoma, that’s 4 to 5 redditors who might be saved by pissing on a stick.

  3. Grey Eyed Man of Destiny says:

    Best damn pop sci writing I’ve seen in a while. Cheers Maggie

  4. abstract_reg says:

    Law of big numbers for the win!

  5. Ashley Yakeley says:

    I wonder what other diseases could be found with pee-on sticks?

  6. SteveKiwi says:

     That’s a great idea! All us guys who are afraid of going to the doctor (in case they actually find something), but we’d have no problem peeing on a stick. All we need do is put it about a foot to the side of the toilet…

  7. hymenopterid says:

    Distributed intelligence FTW.

  8. Eric Strong says:

    Seriously, the science editor should be better with the reporting of science.   “…only about 2 men in 100,000 will get any kind of testicular cancer.”  This is from fourth hand data, the original source for which is 25+ years out of date.  The actual annual incidence of testicular cancer (at least in the US) in 2008 (the most recent data I could find in 2 minutes of searching) is 5.5 per 100,000 per year.  If the average life expectancy for a man is in the neighborhood of 76 years, than a back-of-the-envelope calculation would estimate that 418 men in 100,000 will get testicular cancer.  Only off by a factor of 200…

  9. Ben Hunt says:

    What’s crazy is not that a man + the internets used incredibly cheap and useful diagnostics technology to diagnose a life threatening disease. ($1 at the Sav-A-Lot nearby).

    What’s crazy is that diagnostics technology isn’t available for us to do this all the time for all kinds of proteins produced by tumors and other maladies.

    It’s not like your doctor is going to do it.

  10. If the chances of something happening to an individual are larger than (approx.) 7 billion to one, it’s happening somewhere. Sure, the odds of this happening to this particular man are enormous, but the odds of it happening in general are not.

    Or: the chance that someone will win the lottery are 100%

  11. de34 says:

    What an excellent marketing strategy, to sprinkle a little fear with a “story” and suddenly sales increase in a market that never before even considered using the product. Fantastic idea! Or I’m incredibly paranoid:)

  12. “a friend of a Reddit user”.

    It’s weird how on Reddit no one ever has their own experiences – and yet their ‘friends’ encounter crazy shit every single day.

  13. autark says:

    “Successful implantation occurs only if the embryo properly “invades” the lining of the uterus, which requires that the placenta’s trophoblast cells penetrate deeply, boring into maternal arteries to shunt blood to the growing baby.”

    I want to have this quote memorized the next time somebody talks about life beginning at conception, trying to emotionally manipulate people into a romantic view of pregnancy and reproduction.  God doesn’t come down and touch your uterus and bless you with a fully formed baby… a group of rogue cells uses chemicals to penetrate your body and implant a parasite into your flesh, and siphoning off your natural resources for its own use!! The real miracle is that anybody would allow such an invader to stay and develop to fruition.

    • Robert says:

      Also you should mention the X and Y chromosomes, which have fun trying to kill each other off. It’s theorized that the Y is very small to make itself a smaller target for the teratogens given off by the X. Also that when sperm and egg meet, X and Y do their damnedest to make sure that they remain in charge — hence, when one is particularly puissant against the other, we get families of all girls or all boys. (*)

      Do I get +1 for using puissant?

      (*) Sykes, Adam’s Curse: A Future without Men

  14. As a testicular cancer survivor, I can tell you it is interesting to go get blood work done and see the lab people look at you weird because the tumor markers being tested for are bHCG and alpha-fetoprotein — both are normally pregnancy hormones.

  15. This happened to me!  And it’s not just choriocarcinoma.  Just finished up 3 months of chemo, and an RPLND surgery for stage 2a teratoma.  Peeing on the stick helped to confirm the need to get checked out.

  16. John Maple says:

    If other tests for cancer were as easy to administer as this HPT is, more people could benefit from them.

  17. dayhat says:

      a discussion about sensitivity versus specificity.  yes a urinary beta-hCG test is very sensitive but what does a positive tell us? 
    As rule 10 would tell us, don’t take a temperature if you don’t want to find a fever.
    Although I am happy to confess I don’t know the numbers I am confident in assuming there is no net  benefit in mailing out pregnancy tests for males to pee on.

  18. criolle says:

    Forbes doesn’t seem to think it’s worth the cost.
    The test stick costs SIX DOLLARS.
    MY life (and MY testicles) are worth more to me than six dollars.
    You can make your own decisions about your own balls. Then again, if my balls were worth six dollars, they’d be covered by Obama-care, wouldn’t they?
    http://www.forbes.com/sites/daviddisalvo/2012/11/10/how-a-pregnancy-test-told-a-man-that-he-has-testicular-cancer/

  19. Robert says:

    “…their primary function is to rip through flesh and secure the embryo to uterine wall.”

    “If the mother did not stop the trophoblasts’ drilling, they might burrow so deeply into her uterus that she could hemorrhage and die.”

    “And you’ll ride the crimson wave.”

    */me hides in the corner and cries*

  20. Guy Chapman says:

    HCG is also sold as a miracle diet scam. This despite the fact that solid science shows it to be bogus – but of course no miracle diet scammer or any other altie has ever responded to science by accepting they are wrong!

  21. Wild Autumn says:

    This didn’t surprise me one bit (the man-taking-the-test part, not the cancer DX part). When I was pregnant I saw this so many times on forums and it was usually the woman asking the man to take the test. The usual reason: to see whether a certain test could just be giving out false positives.

    Anyone outside the TTC world would go, “Whaaat?” LOL. Those of us who have been there will shrug and go, “I wonder if we should try that?”

    Sue

  22. John Kahen says:

    Interesting story! 

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