# Gastric Cancer and GIST

> Gastric cancer and GIST for NEET-PG Medicine: H. pylori, Lauren types, Virchow node, Sister Mary Joseph nodule, CD117 and KIT mutation, and imatinib therapy.

- Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/gastric-cancer-and-gist
- Exam / course: NEET-PG · Subject: Medicine
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-08
- Last updated: 2026-10-08
- Reference basis: Harrison's Principles of Internal Medicine; Bailey and Love's Short Practice of Surgery; Sleisenger and Fordtran's Gastrointestinal and Liver Disease
- How to cite: "Gastric Cancer and GIST", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/gastric-cancer-and-gist

## Direct answer

Gastric cancer is mostly an adenocarcinoma, with Helicobacter pylori as its major modifiable driver, while gastrointestinal stromal tumour is a separate mesenchymal tumour arising from the interstitial cells of Cajal, usually carrying a KIT or PDGFRA mutation. Adenocarcinoma presents with epigastric pain, weight loss and anaemia, and enlargement of the left supraclavicular node, the Virchow node, signals distant spread. GIST responds to imatinib, which targets the mutated receptor.

## What you must remember

- **Helicobacter pylori:** the strongest modifiable risk factor, classed as a group I carcinogen; eradication lowers risk, most in people without established atrophy.
- **Lauren classification:** the intestinal type arises on atrophic gastritis and intestinal metaplasia, while the diffuse type forms signet-ring cells and is linked to CDH1 mutations.
- **Virchow node:** left supraclavicular lymph node enlargement; Sister Mary Joseph nodule is a periumbilical metastasis and Krukenberg tumour bilateral ovarian metastasis.
- **Blumer shelf:** a palpable shelf on rectal examination in advanced gastric cancer, reflecting peritoneal seeding in the rectovesical pouch.
- **GIST origin:** the interstitial cells of Cajal; the stomach is the commonest site, and CD117 (c-KIT) positivity is the diagnostic marker, with DOG1 also useful.
- **c-KIT mutation:** most GISTs carry a KIT exon 11 mutation, which predicts a good response to imatinib, the first-line drug for advanced disease.
- **Adjuvant imatinib:** given for high-risk resected GIST for about three years, with risk judged by tumour size, mitotic count and site.

## A dyspepsia case and a stomach lump

Two patients with stomach problems need different pathways, and the table sets them side by side.

| Feature | 62-year-old man | 50-year-old patient |
|---|---|---|
| Presentation | Three months of epigastric discomfort, early satiety and 7 kg weight loss | Incidental submucosal gastric mass, smooth and non-ulcerated |
| Key finding | Ulcerated antral mass on endoscopy | Hypoechoic lesion from the muscularis propria on endoscopic ultrasound |
| Diagnosis | Adenocarcinoma on biopsy, with an H. pylori test sent from the same specimen | CD117 and DOG1 immunostaining confirm GIST rather than leiomyoma |
| Management | Contrast CT of chest, abdomen and pelvis; localised disease gets perioperative chemotherapy, then gastrectomy with lymphadenectomy; HER2 status is checked because trastuzumab adds benefit in HER2-positive disease | Small, low-risk lesions may simply be resected; unresectable or metastatic disease gets imatinib; high-risk resected tumours get adjuvant imatinib for about three years |

In the first patient, a palpable left supraclavicular node is generally treated as distant spread in gastric staging, so curative surgery is usually not offered. The two diagnoses share a site but not a treatment logic.

## Where the examiner tries to catch you

Examiners often test the names of the signs.

- **Trap:** mixing up the named signs of spread — **Correct:** Virchow node is the left supraclavicular node, Sister Mary Joseph nodule is a periumbilical deposit, and Blumer shelf is a rectal pouch deposit felt on rectal examination; all three are sites of spread rather than primary features.
- **Trap:** confusing GIST with leiomyoma or schwannoma — **Correct:** these are all submucosal, but GIST is CD117 positive while leiomyoma is desmin and smooth muscle actin positive, so immunohistochemistry separates them.
- **Trap:** expecting conventional chemotherapy for GIST — **Correct:** it is largely ineffective, and tyrosine kinase inhibitors are the mainstay.
- **Trap:** forgetting what follows imatinib failure — **Correct:** resistance usually reflects secondary KIT mutations, and sunitinib is the standard second-line drug, with regorafenib used next.

## Frequently asked questions

### What does a Virchow node signify in gastric cancer?

A Virchow node is an enlarged left supraclavicular lymph node, and in gastric cancer it signals spread of tumour through the thoracic duct to a distant site. It is generally regarded as distant metastasis in staging, which usually rules out curative surgery.

### What is the Sister Mary Joseph nodule?

The Sister Mary Joseph nodule is a palpable periumbilical metastasis, most often from a gastric or other intra-abdominal primary. Its presence indicates peritoneal disease and advanced stage, so it changes the management from surgery towards palliative chemotherapy in most patients.

### Which marker confirms a diagnosis of gastrointestinal stromal tumour?

CD117 (c-KIT) immunohistochemistry confirms gastrointestinal stromal tumour, as the large majority of GISTs are CD117 positive, and DOG1 staining is a useful adjunct when CD117 is negative. Leiomyoma and schwannoma are typically negative for CD117, which helps separate them on biopsy.

### What is the first-line drug for metastatic gastrointestinal stromal tumour?

Imatinib is the first-line drug for metastatic gastrointestinal stromal tumour, as it inhibits the mutated KIT or PDGFRA tyrosine kinase that drives the tumour. Sunitinib is the standard second-line option after imatinib resistance, and regorafenib is used when those fail.

### Does Helicobacter pylori eradication prevent gastric cancer?

Helicobacter pylori eradication reduces the risk of gastric adenocarcinoma, with the greatest benefit in people who have not yet developed extensive atrophy or intestinal metaplasia. It is therefore most useful as prevention in appropriate populations rather than as treatment once a cancer is established.