So let's look at metastasis, this is a
feature that's unique to cancer cells.
I'm gonna look at number 1, you see that
picture, that's a benign tumor in your epithelium
because that's a really common
place for cancer to start, is in your skin.
so you've got a benign tumor
in your epithelium in picture 1.
Now look at the next picture, the tumor
breaks through the basal lamina layer.
Okay, so now it's starting to invade
other spaces, definitely big dumb bullies.
Now look at it invades the cappillary, uh-oh.
Now that that has gone through the basal lamina,
in that third picture you see get into the capillary
now it's gonna stick to the
wall of the vessel in the liver.
That's in picture number 4.
Now you've got more extravasation,
and finally it proliferates.
That means it makes multiple, multiple,
multiple, multiple cells to form the metastasis.
So that's what happens in the process.
So you've got something, it may start
benign, it can turn into a cancerous tumor.
Metastasis means that you got a
lot of it spreading into other areas.
That's a factor unique to cancer, that's how
we know when the cells are really bad guys.
So let's go a little more into detail about metastasis.
Now they've got a great picture
there, see the green normal cells
then you got the big bullies that are weirdly
irregularly-shaped and they've outgrown.
Look how it's got its own blood supply up in
there, and it'll break through to the capillaries,
So cancer cells break away from where they first
formed, we always consider that the primary site.
So in metastasis, the cancer cells, remember they go rogue,
they break away and travel from where they first formed.
They'll travel through the blood
vessels or the lymph system.
That's why often you'll see, with a physician or
a surgeon when they're following up on a patient,
removing a tumor, they always check the lymph
nodes to see where it possibly may have spread.
Now when it travels through the blood and
the lymph system, it will form new tumors.
Those are considered metastatic
tumors, now it forms in other body parts.
Certain primary sites have favourite sites they like to
go to and that's one of the ways we help identify them.
But the metastatic tumor is usually the
same type of cancer as the primary tumor.
Now I'll tell you what..
So you've got microscopic view of the the
metastatic cells are similar to the primary cancer cells.
So here's the deal, if I named the metastatic
cancer, it's named by the primary site.
So if I have breast cancer and its pressed to the lungs,
we call that metastatic breast cancer, not lung cancer.
So it's important for physicians in planning a
plan of care, the most effective chemotherapy
to recognize what was the primary site of cancer and
then is this metastatic cancer, or is it a brand new cancer?
because it is possible for patients to have
two different types of cancer at the same time.
So they want to know, is this just metastatic
cancer, is this breast cancer that spread to the lung
or is it a different or new type of cancer for your patient.
So our primary goal treatment with metastasis
is just to slow down the growth of the cancer
and treat the symptoms that are caused by metastasis.
Okay, so hopefully that's starting to make sense.
We're talking about metastasis as the ability for
the cancer to spread throughout the rest of the body.
If you have cancer on one side, like your breasts
and it travels to the lung, that's metastatic breast cancer
we wouldn't call that lung cancer,
it's metastatic breast cancer.
Now let's talk about other tissue changes.
Now you see our normal tissue on the left, now
hyperplasia, compare those two tissues, what's different?
Well you can tell there's more
going on in that hyperplasia, right?
Hyper- means "excess" so get some extra growth.
Now in the third picture, we've got mild dysplasia.
In the fourth well we have carcinoma in situ but
all the way at the end, we've got straight up cancer.
So not every tissue change is cancer.
Maybe an indication that there's some problems
upcoming but sometimes cell tissue can look a little weird
but it's not exactly cancer.