Esophageal and Gastric Cancer | Clinical Medicine

What's up Ninja Nerds? In this video today we're going to be talking about esophageal and gastric cancer.

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All right, so let's talk a little bit about esophageal and gastric cancer here.

And we talk about these, The unfortunate thing about these is that usually when they're diagnosed, they're oftentimes late stage.

It's because they don't usually present with symptoms most of the time. Because usually they're smaller tumors, and as they kind of grow and grow and grow, they become obstructive.

And then that obstructive kind of nature of them precipitates symptoms, sometimes dysphagia and esophageal cancer or dyspepsia.

Usually that's just the general abdominal epigastric discomfort.

You feel bloated, you feel full, and you just kind of have some discomfort there. Those don't usually come to the later stage.

So when you see that, unfortunately, they're already kind of like almost stage three, stage four, et cetera. So that's the unfortunate thing about these.

But the next thing that we have to talk about is that when it comes to these, they have different subtypes. So it's not just like esophageal cancer.

Well, there's actually esophageal cancer that can be two subtypes of esophageal cancer. So squamous cell and adenocarcinoma.

All I really need you to know about this is just location-wise. So we can break the esophagus up. So here's the upper esophageal sphincter.

And then here's just the entire esophagus tube. and then we get down here to the lower esophageal sphincter.

When we think about this, we can kind of break this up into two points here and two points here.

Squamous cell carcinoma oftentimes tends to involve the upper two-thirds of the esophagus.

So here we're going to have like a nasty-looking tumor, and it's involving the upper two-thirds. Which one do you think that's more likely going to be?

It's going to be the squamous cell carcinoma. So it's usually going to be the upper two-thirds of the esophagus.

So that's the first thing I want you guys to know right here is that squamous cell carcinoma, oftentimes upper two-thirds.

Adenocarcinoma, you probably already guessed it, it's the lower one-third of the esophagus.

So this is going to be near like the gastroesophageal sphincter.

So it gets into a point here when you start thinking about these things, what really causes these tissues to become abnormal?

What causes the squamous cells to undergo dysplasia? What causes the squamous cells to turn into columnar cells? Because here's the thing.

When we talk about esophageal tissue, you know what the inner, the mucosa is made up of?

It's stratified squamous, non-keratinized, stratified squamous epithelial tissue, because it's designed to have resistance to friction and abrasion, because we can swallow some pretty warm liquids.

We can eat some really rough potato chips that could scratch that thing up, right?

So we needed to have that resistance to abrasion and friction.

Well, unfortunately, some of these tissues can change when they're put in a different type of environment.

So what I want to do is, okay, I want to now say, okay, swamisal carcinoma, I can kind of have that off location.

Adenocarcinoma, I can have that also off of kind of like location of where you can get this tumor.

What I want to now talk about is the tissues, like the changes, the genetic changes for some part.

So let's say here, I take a piece here. I just want to take and I want to look in and I want to say, how does this thing really grow?

How does this happen? So what I'm going to do is I'm going to kind of zoom in here. So as I zoom in, I'm going to have a piece of the esophagus that I'm looking at.

When we look at the tissue, again, I already told you, like imagine there's no mass here.

When you look at the cell types, again, I told you, it's squamous cells. So it's going to be squamous cells, and it's going to be layered.

And all that means is that it's stratified, right? So when we look at this, it's stratified squamous epithelial tissue.

All of a sudden, the patient starts to experience some dysplasia.

And that dysplasia is a change. It becomes abnormal. It becomes atypical types of squamous cells.

And that atypical squamous cell, unfortunately, develops more and more mutations.

And that mutation then brings about an opportunity for this cancer to be self-surviving.

It can evade death apoptosis because it shut down the tumor suppressor genes or it can proliferate because it amped up the proto-oncogenes.

And now this thing becomes a cancer.

The question is, is what in the heck led to this dysplasia?

So squamous cell carcinoma, you got to think about it.

This thing is usually going to cause this change where it goes from a squamous cell and it's still squamous cells.