Name: Understanding cancer: how cells become cancerous and why metastatic cancer is so deadly
Uploaded: 2024-11-28T06:00:18.000Z
Duration: 7 min 4 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Now, before we go further, I think it's worth making sure people understand some of the semantics.

Adverbs of manner

Because obviously, you and I can take so much of this for granted.

But let's start with some basics about cancer.

What separates a cancer cell from a non-cancer cell?

Well, if you look at the broadest properties, there are two properties that separate cancer from other cells in the body.

Virtually all of the tissues we have, be it fingernails or eyebrows or you name it, they'll grow to a given amount.

Well, cancers don't have that signal to stop.

And the second is it's the only cell that can arise in one part of the body and spread and live and divide and grow in another part of the body.

And that's not true of virtually any other kind of cell.

So cells with uncontrolled growth that can spread and grow elsewhere are the biologic properties.

Now, we can dig down layer by layer by layer and get to the point of, well, why does a normal cell ultimately become a cancer cell?

And we now understand that that's due to the accumulation of mutations in DNA of these cells divide, which explains why it's the common organs of the body, all of which have ducts.

The lining of those ducts are constantly turning over.

And as that DNA is turning over, mistakes are made called mutations.

And it's that accumulation of mutations that results in the cancer itself.

So we can take it all the way from the biology of uncontrolled growth, but down to the very molecules that are involved.

It doesn't mean we really understand it all, but we can describe it.

And let's also explain to people the difference between the epithelial tumors, the hematologic tumors, and even let's frame it as it was in 1974 in terms of what was a person's odds of surviving.

So maybe tell folks what the common epithelial tumors are and explain a little bit about the, we're not going to go into staging in great detail, but what's the difference between local tumor versus metastatic tumor?

And what's the impact that has on a person's survival at the time you arrived at NCI?

So the hematologic cancers, of course, are the blood cancers, and they start from progenitors in the hematopoietic system.

Because after all, the hematopoietic system starts from an individual stem cell that then divides into multiple different characteristics, much as we all grow from a single fertilized egg from one cell that makes us what we are.

So even back then, and a little more so now, if you developed a cancer of the bloodstream, which were about 10% of all cancer deaths are due to those, 90% of cancer deaths are due to the epithelial cancers.

So these start in the solid organs of the body, and that's all the way from the rectum up through the GI tract, through the stomach, through the esophagus, the pancreas, the GU organs, the testis, the ovary, the prostate.

And as I've mentioned, it's the epithelial lining of the ducts that are turning over that become the cancer.

In blood cancers, it's the more primordial cells that develop into neutrophils and lymphocytes and other types of cells.

So let's talk about the solid tumors, which are 90% of all cancer deaths.

Last year in the United States, there were about 600,000 deaths due to cancer. 550,000 were due to the solid epithelial cancers.

If you operate on a patient who develops a cancer, to remove that cancer, then well over half the time, that patient will be cured.

That is, go on and live their normal lifespan.

But the half, the little less than half of patients that cannot be cured result in this enormous tragedy of 600,000 innocent people dying of cancer every year.

Once the cancer spreads, however, and this in my view is the dirty little secret of oncology.

And that is that if a cancer spreads from its local site and cannot be surgically removed, then the death rate in that patient is 100%.

That is, we have virtually no treatments that can cure, systemic treatments that can cure a patient with a metastatic solid cancer, that is one that is spread to a different site that can't be surgically resected.

Now there are a couple of exceptions to that.

There are two solid tumor exceptions that have existed for several decades.

These are cancers that start in the placenta of pregnant women that then spread and you can have 90% of the lung replaced by that tumor, receive methotrexate, a chemotherapy drug, and it will all disappear.

Germ cell tumors in the male, tumors of the testis like Lance Armstrong who had brain mets and lung mets, no matter how much they've spread, if you give patients platinum-derived chemotherapy regimens, you can cause complete durable regression of that metastatic disease.

Up until 1985, those were the only cancers that could be cured.

We can now add to that list solid cancers.

We can now add to that list melanoma and renal cancer because interleukin-2 administered to patients back in the mid-80s caused complete regressions of widely metastatic cancer in patients that are still alive today.

Choriocarcinoma, germ cell tumors, melanoma, renal cancer.

Other than those four, everyone who develops a spread cancer will die of it despite all the best treatments that we have.

We read in the paper that this celebrity has cancer and they're gonna fight it and they're gonna beat it, but nobody beats it.

 We're in such desperate need of better treatments for patients with metastatic cancers because we just, we can beat them back a little bit, we can improve survival by months, and for some cancers, maybe a few years, like breast cancer and colon cancer, but everybody ultimately will succumb to the disease.