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0:00Your body is incredibly good at repairing itself.
0:03A skinned knee quickly fades to just a memory.
0:06And if you give that runny
nose a few days of rest,
0:09you’ll be able to breathe
through it again in no time.
0:11But one big problem that your
body often can’t fix is cancer.
0:15Without treatment, cancer will keep growing
0:17nd spreading until it kills you.
0:20Thankfully, we have many treatments --
0:23chemotherapy and other treatments
that have saved millions of lives.
0:27These therapies are pretty much your
only option for surviving deadly cancers.
0:31However, there are a few cases where
something truly remarkable happens.
0:36Doctors have reported some rare
instances of tumors shrinking
0:40or even disappearing without treatment.
0:43Getting to the root of this medical marvel
0:45could help more cancer patients in the future.
0:48That is, if we ever figure
out what the heck is going on.
0:51So here’s what we know
about spontaneous remission.
0:58The idea that cancer might heal all by itself
1:00has been around for a long time.
1:02The first mention of cancer
pulling a vanishing act
1:04shows up in the Ebers papyrus around 1550 BCE.
1:08And perhaps the most famous historical
example dates back to the 13th century.
1:12As the story goes, an Italian
priest called Peregrine Laziosi
1:16had a tumor in his leg that required amputation.
1:19But his tumor miraculously
disappeared before his surgery.
1:23This miracle earned him the title
of patron saint of cancer patients.
1:27Then, in 1813, the French
physician Arsène-Hippolyte Vautier
1:31claimed that tumors in cancer
patients who were sick with gangrene
1:34sometimes mysteriously shrunk.
1:36Around the same time,
1:37other physicians also wrote reports about patients
1:40with incurable cancers who miraculously recover
1:43after becoming ill with some other disease.
1:46This is not a whole lot to go off of.
1:48But medical reports from the last 200 years
1:51do seem to confirm that cancers
sometimes shrink or go away
1:56To be crystal clear, I’m not
saying that this happens often.
2:00Cancer patients should not
bank on spontaneous remission
2:04as a solution to their life-threatening diagnosis.
2:07These cases are exceedingly rare.
2:09A generous estimate puts
spontaneous remission happening
2:12in only one in 60,000 cancer patients.
2:16And since it’s cancer, even
cases of spontaneous remission
2:19have been known to be just a temporary respite,
2:22with cancer coming back
after a few months or years.
2:25So if your doctor recommends a cancer therapy,
2:28that’s still your best bet.
2:30Listen to your doctor.
2:31They’ll probably tell you
it’s still not really clear
2:34why some cancers go away like this.
2:36That said, scientists have
picked up on a few trends.
2:40For one thing, some types
of cancers are more likely
2:43to exhibit spontaneous remission than others.
2:47a nerve cancer that mostly impacts
kids under the age of five.
2:51One study from Denmark found that
2:53up to 2% of Danish neuroblastoma patients
experienced spontaneous remission.
2:58Other cancers that occasionally
go away by themselves
3:00include kidney cancer, metastatic
skin cancer, and leukemia.
3:04But when I say “occasionally,”
3:07As of 2013, there were only
76 well-documented cases
3:12of spontaneous remission in
late-stage skin cancer. …
3:16And that included all reports dating back to 1866.
3:19In all of that time, scientists have
only started to build an understanding
3:23of what’s behind spontaneous remission.
3:26Insufficient data really slows research down.
3:30But one thing they’ve noticed is that
people who experience spontaneous remission
3:33have sometimes been exposed to tiny intruders.
3:36Nasty viral and bacterial stuff.
3:39In 2023, doctors reported 14
cases of spontaneous remission
3:43in cancer patients who had caught COVID-19.
3:46Although! If you have cancer,
3:49don’t try to get COVID in the hopes
that your cancer will go away.
3:52Cancer almost always increases
your odds of dying from COVID.
3:56There are safer ways to test this connection.
3:59Like in 1978, a 78-year-old man with leukemia
4:02who received the smallpox vaccine
4:04went into total remission.
4:06In another more recent case,
4:08a patient recovered from skin cancer
after getting the Tdap vaccine.
4:12So the link between infections
and spontaneous cancer remission
4:15has been seen multiple times over the years.
4:17And researchers are trying to figure out why.
4:20But before we explore their various
hypotheses, it’s time for a quick ad.
4:24All research needs funding after all!
4:27Thanks to our Presidents of Science
for supporting this SciShow video!
4:30Harry Plumley, Charlie Stanley, and TJ Steyn
4:33help bring you knowledge through
their support on patreon.
4:36And all of the patrons over
there make a big difference
4:38in the quality of science story we can tell.
4:40With the help of our awesome patrons,
4:42we’re able to have full time staff
who create animations that clarify
4:46complicated molecular interactions,
chemical cascades, genetic manipulations,
4:50and all the other technical
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4:53Patrons also help employ the staff
4:54who answer the animators’ science questions
4:56to make sure what they’ve created is accurate.
4:58Really, our Presidents of
Science help us pay everybody
5:01on the SciShow team for their work.
5:02And you can join them at patreon.com/SciShow.
5:08Scientists have suggested that infections
5:10might help the immune system
identify cancer as a problem.
5:14Sometimes, anti-tumor
treatments trigger the release
5:17of a bunch of tumor-related
markers called antigens.
5:20When your immune cells
recognize these tumor antigens,
5:23they might be able to find
and attack the cancer cells.
5:26That’s a possibility.
5:28But it doesn’t explain all
cases of spontaneous remission.
5:31Sometimes, spontaneous remission
happens without any sign of infection.
5:35Like when doctors witnessed
spontaneous remission occur
5:38after biopsies or other routine medical screening.
5:41It could be that surgery or biopsies make
it harder for cancer cells to get blood.
5:46And, like vampires, cancer cells
need a lot of blood to get by.
5:50So these interruptions might just
starve cancer cells to death.
5:54There might even be a genetic reason
5:56for the mysterious disappearance of cancer.
5:58While the case is definitely not closed,
6:00the search for answers has led
us down really helpful paths.
6:04Like life-saving cancer therapies
dating back to ancient Egypt.
6:07An Egyptian physician named Imhotepno,
6:09not that guy, different guy,
6:11suggested treating cancer patients
6:13by making a precise incision near the tumor,
6:16where an infection could brew.
6:18Later, an American doctor
worked off the same concept,
6:21using bacteria to treat cancer directly.
6:24In 1890, William Coley,
6:25started injecting inactivated
bacteria into patients
6:29with inoperable skin and bone cancers.
6:31Their prognoses were …not good.
6:34But after his unconventional treatment,
6:36around 52% of his patients went
into remission for five years,
6:40and another 20% were still alive
20 years after their injections.
6:44The ‘Coley Toxin,’ as it was called,
6:46was used to treat this type of cancer until 1963.
6:50But concerns about injecting
people full of bacteria
6:52made some doctors skeptical about the treatment.
6:55Then there was the issue that to this day
6:57no one fully knows why Coley’s Toxin works.
7:00So, when chemotherapy and
radiotherapy came around,
7:04many doctors opted to use that instead.
7:06But even today, researchers are
still working on viral mechanisms
7:10to make your cancer go away.
7:12The FDA has approved a therapy called T-Vec
7:15that uses a modified virus to
essentially blow up cancer cells.
7:20Though, if you go on the drug’s website,
7:22there’s a little asterix on this description
7:24where the drug company admits they don’t
actually know how the virus does that.
7:28Still, this kind of medication could give
hope to people with tough-to-treat cancers,
7:32thanks to ancient cancer medicine.
7:35Cancer remains one of the leading
causes of death worldwide.
7:38Even at the height of the
COVID-19 pandemic in 2020,
7:41it was still responsible for
around one in every six deaths.
7:45I think, obviously, The extremely rare instances
of spontaneous remission
7:50don’t mean you can shut your
eyes and reject treatment.
7:53Odds are, your cancer won’t be one
of those cases that just disappears.
7:58But with some research and a little luck,
8:00this phenomenon might lead to more treatments
8:03that help more cancer patients in the long run.
8:06And remember, I know I talk very confidentally
8:08but I am definitely not your doctor.
8:11for any actual conversations
about actual treatment plans
