Gastrin High

[runnergirl24]

I have had High gastrin lecels that concern my GI dr n Hemotologist so much they have me scheduled for a CT scan (w IV) and a endoscopy/colonoscopy. I know there is a chance I have a neoendocrine tumor. How likely is this cancerous? I do not see much posts on High gastrin levrls on here but do know it’s an indicator of PA which I know I have.

[fbirder]

There are two types of Neuroendocrine Tumour (NET) associated with high gastrin.

Type two gastric NETs are the more serious type. They cause high gastrin and are, themselves, the result of a mutation in a gene called MEN1.

But the type associated with Pernicious Anaemia is Type one. These are much less nasty.

In normal people eating food stimulates the production of the hormone gastrin. This hormone makes Gastric Parietal Cells (GPCs) to produce hydrochloric acid. This acid lowers the pH of the stomach and this increase in acidity switches off gastrin secretion.

But if you have PA then you don’t have GPCs as your immune system attacks them. That means you don’t produce any stomach acid and your stomach pH doesn’t get lowered. As a result gastrin production doesn’t get switched off properly and you end up with high levels of gastrin.

At this stage you have hypergastrinaemia but no NETs. And most people seem to stay like this.

The high levels of gastrin promote the production of new stomach cells - metaplasia. A gastroscopy will show signs of atrophy in the top parts (body and fundus) of the stomach. Biopsy samples will show signs of metaplasia. The diagnosis should be Autoimmune Metaplastic Gastric Atrophy (AMGA). And just about everybody with PA has AMGA.

In a very few people with AMGA the growth of new cells goes slightly wrong and they turn into NETs. That’s what happened to me.

But they’re really not a lot to worry about. Mine were found three and a half years ago. Originally we decided that annual surveillance gastroscopies, just to keep an eye on them, would be a good idea. After the last one we decided to make it every two years - because there had been no change.

Indeed, when I was first diagnosed, I discovered that the 5-year survival rate for people my age with gastric NETs was actually better than for those without. I guess I have more health checks that normal people.

They very rarely become dangerous. If you do find you have them then various scans specific for NETs can look for metastasis. I had Indium-112 gamma ray scans and a Gallium-68 PET/MRI scan. All clear. To tell the truth, I think my gastroenterologist just wanted them as he’d never had the opportunity before.

So. It’s almost certain you have AMGA and the gastroscopy will show that. It’s quite unlikely that you have gastric NETs, but a biopsy will show that. If you do, it’s very unlikely that they will become cancerous and just keeping an eye on them will be enough.

Your gastroscopy might well find a polyp. Don’t panic if it does. They are quite common and are nearly always benign.

Here’s a scientific paper this describes gastric NETs. It’s a bit complex, but worth having a look at....

onlinelibrary.wiley.com/doi...

[JanD236 in reply to fbirder]

Very informative, thanks fbirder.

[runnergirl24 in reply to fbirder]

How do you get your gastrin level to normal then if you leave the tumor alone? Wont High gastrin cause problems with your stomach lining?

[fbirder in reply to runnergirl24]

The tumour doesn’t affect gastrin levels, it’s the other way round.

One research group is investigating a drug that lowers gastrin to see if it reduces the incidence of NETs in people with PA. But it’s not easy because they are so rare.

Because it’s the lack of stomach acid (achlorhydria) that causes the hypergastrinaemia I’m hoping that replacing the acid will fix the hypergastrinaemia. So I take about 40 ml of lime juice with each large meal. That certainly helps with the other symptoms of achlorhydria- the diarrhoea being the most obvious.

[tnkarthik28 in reply to fbirder]

again, very good info from fbrider. thnx. one query. what is considered high level gastrin in the blood? > 500 or > 1000? If I am correct, the it should be <100 right?

[fbirder in reply to tnkarthik28]

It depends on the units.

Fasting gastrin of less than 100 ng/L or 40 pmol/L is considered normal.