November 27, 2025
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November 27, 2025

Spotting the Signs of Gastric Cancer Before They Become Serious

Cancer
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Cancer Awareness Months
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Reviewed By:
Dr Sophie Grice
,
Spotting the Signs of Gastric Cancer Before They Become Serious

Contents

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Gastric cancer, also known as stomach cancer, often develops quietly, without noticeable symptoms in its early stages. This makes it especially dangerous, as many people are diagnosed too late for effective treatment. By learning to recognise the subtle early signs, individuals can take action sooner, improving the chances of a better outcome. In this article, we explore what to look out for, who’s most at risk, and why early detection can make all the difference.

Gastric cancer, also called stomach cancer, happens when cells in the stomach lining start to grow in an abnormal, uncontrolled way, and form a tumour that can spread deeper into the stomach wall and to other parts of the body. Early detection is difficult because early-stage disease often causes no symptoms or only vague issues that are easy to dismiss as “normal” digestive problems1.

In this article, we explore the signs and symptoms of gastric cancer and find out what proactive steps can be taken to potentially catch the disease early.

What is Gastric Cancer?

As mentioned above, gastric cancer is a disease where cells in the lining of the stomach acquire genetic changes that cause them to grow and divide when they shouldn’t, eventually forming a malignant tumour.

In many cases, this process is driven over years by chronic irritation or inflammation of the stomach lining, for example, from Helicobacter pylori infection or long-standing gastritis, which leads to stepwise changes from normal mucosa to atrophy, intestinal metaplasia, dysplasia, and finally invasive cancer2.

In early gastric cancer, abnormal cells are confined to the innermost layers (mucosa/submucosa)3. The tumour is usually small, may cause non-specific symptoms, and is often curable with endoscopic resection (a minimally invasive procedure that uses an endoscope to remove abnormal growth from the digestive tract) or limited surgery4,4,5. 

Advanced gastric cancer means the tumour has penetrated deeper into the stomach wall, involved lymph nodes, or spread (metastasised) to distant organs, which is associated with more obvious symptoms and a much poorer prognosis.

Common Types of Gastric Cancer

There are several types of cancer that can arise from the stomach, including6:

  • Adenocarcinoma: The great majority of stomach cancers are adenocarcinomas, arising from the gland-forming cells in the stomach lining that normally produce acid, enzymes, and mucus.
  • Further classified into:
    • Intestinal
    • Diffuse
  • Lymphomas: Cancers that develop from the immune cells in the stomach wall.
  • Gastrointestinal stromal tumours (GISTs): Arise from specialised cells involved in gut motility.
  • Neuroendocrine tumours: Arise from hormone-producing cells in the gut.

Early Signs to Watch For

Common early symptoms Indigestion, bloating, nausea, or heartburn Early tumours can irritate the stomach lining and disrupt normal acid and motility, causing non-specific dyspepsia that doesn’t settle or slowly worsens [1].
Loss of appetite or feeling full quickly Thickening of the stomach wall or a growing mass reduces its capacity, so the stomach signals “full” sooner than normal [2].
When symptoms become serious Persistent abdominal pain As the tumour grows deeper, it can cause ongoing inflammation and nerve irritation, leading to more defined, persistent pain [3].
Vomiting (possibly with blood) Blood in vomit signals active bleeding in the upper digestive tract and is a medical emergency [4].
Unexplained weight loss Gastric cancer can reduce appetite, cause “full” feelings, and interfere with digestion and absorption [5].
Overlapping symptoms Ulcers Both conditions irritate and damage the stomach lining, sometimes leading to almost identical symptoms [6].
  Acid reflux/GERD Gastric cancer can coexist with, worsen, or mimic reflux-like symptoms that do not behave as expected or that steadily worsen [7].
  Irritable bowel syndrome (IBS) Because early gastric cancer symptoms are vague, they can be mislabelled as functional. However, cancer often brings progressive change and systemic features like weight loss or anaemia [8].
  Guidance on symptom duration The key clinical concern is persistence, progression, or a combination of symptoms [9].

Who is Most at Risk?

People are most at risk of gastric cancer when long-term lifestyle exposures, chronic gastric inflammation and inherited factors combine to damage the stomach lining over time. 

Lifestyle and Behavioural Risk Factors

  • Smoking and heavy alcohol use each increase gastric cancer risk, likely through direct mucosal damage, promotion of chronic inflammation, and interaction with other carcinogens11. 
  • Diets high in salted, smoked, or processed/red meats and low in fresh fruits and vegetables are strongly associated with a higher risk, while higher fruit and vegetable intake appears protective12.

H.pylori and Chronic Gastritis

  • Chronic infection with Helicobacter pylori is the single most important risk factor for non-cardia gastric cancer, accounting for the vast majority of distal cases worldwide13. 
  • Long-standing H. pylori-related gastritis can progress through atrophic gastritis and intestinal metaplasia to dysplasia and carcinoma, so identifying and eradicating H. pylori in high-risk individuals is a key prevention strategy.

Family History and Genetic Predisposition

  • A family history of gastric cancer, especially in a first-degree relative, roughly doubles risk, suggesting shared genetic and environmental influences14.
  • Several inherited cancer syndromes, including Lynch syndrome and hereditary diffuse gastric cancer (CDH1 mutations), markedly increase gastric cancer risk, making it crucial for people with strong family histories to seek genetic counselling and tailored surveillance.

The Role of Imaging in Early Detection

Imaging helps with gastric cancer, mainly by characterising known or suspected disease and surveying the body, rather than by truly “screening” the general population for very early tumours. Endoscopy with biopsy remains the gold standard for early detection.

CT Scans and Gastric Cancer

  • Computed tomography (CT) is primarily used for staging gastric cancer once it is suspected or diagnosed, helping to assess tumour size, depth of invasion, lymph-node involvement, and distant metastases, and to plan surgery or systemic therapy15,16.
  • On CT, gastric cancer may appear as focal or diffuse thickening of the stomach wall, an enhancing intraluminal mass, or evidence of local invasion; however, subtle early lesions and flat mucosal changes can be easily missed, so CT is not relied on as a first-line early detection test15,17.

Multi-Region MRI Screening

  • MRI is more often used for multi-region surveillance in higher-risk contexts (for example, hereditary cancer syndromes) because it can image many organs without ionising radiation, but it is not a standard screening tool for gastric cancer15,17.

Ezra offers multi-region scans that may flag suspicious areas or incidental findings for further targeted tests; they do not diagnose cancer, and any concerning stomach or abdominal finding should always be followed up with dedicated imaging and, crucially, endoscopy or biopsy to confirm or exclude gastric cancer.

Summary: Spotting the Signs of Gastric Cancer

Recognising early signs of gastric cancer really matters because symptoms such as persistent indigestion, early fullness, unexplained weight loss, or ongoing upper‑abdominal discomfort are often subtle and easy to dismiss, yet they can appear months or years before a diagnosis. If these symptoms last, keep coming back, or gradually worsen, especially in someone with risk factors like Helicobacter pylori, chronic gastritis, smoking, heavy alcohol use, or a family history of gastric cancer, they should be discussed with a healthcare professional rather than managed with over‑the‑counter remedies alone.

Proactive assessment and screening, when appropriate for your risk level and symptom pattern, can provide reassurance when tests are normal and, crucially, the chance to detect problems early while treatment options are broader and outcomes are better. Paying attention to your body, monitoring persistent changes, and seeking medical advice promptly offers peace of mind and the opportunity to act before it is too late.

If you want to be proactive about your health, why not book an Ezra MRI Scan with Spine? Our annual scan catches potential cancer earlier by leveraging AI through the screening process, making it more efficient, affordable, and faster.

Understand your risk for cancer with our 5 minute quiz.

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References

1. Ikenoyama Y, Hirasawa T, Ishioka M, et al. Detecting early gastric cancer: Comparison between the diagnostic ability of convolutional neural networks and endoscopists. Dig Endosc. 2021;33(1):141-150. doi:10.1111/den.13688 

2. Causes of stomach cancer. Accessed November 27, 2025. https://www.macmillan.org.uk/cancer-information-and-support/stomach-cancer/causes-and-risk-factors-of-stomach-cancer 

3. Arakawa N, Irisawa A, Ishida K, et al. Clinical Differences in c-Myc Expression in Early-Stage Gastric Neoplasia: A Retrospective Study Based on the WHO Classification. J Clin Med. 2022;11(3):544. doi:10.3390/jcm11030544 

4. Ryu DG, Choi CW, Kim SJ, et al. Possible indication of endoscopic resection in undifferentiated early gastric cancer. Sci Rep. 2019;9:16869. doi:10.1038/s41598-019-53374-0 

5. Espejo Romero H, Navarrete Siancas J. [Gastric Cancer in Early Stage: study of 371 lesions in 340 patients in the E. Rebagliati National, Lima-Peru]. Rev Gastroenterol Peru. 2005;25(1):48-75. 

6. Types and grades of stomach cancer. Accessed November 27, 2025. https://www.cancerresearchuk.org/about-cancer/stomach-cancer/types-and-grades 

7. Maconi G, Manes G, Porro GB. Role of symptoms in diagnosis and outcome of gastric cancer. World J Gastroenterol. 2008;14(8):1149-1155. doi:10.3748/wjg.14.1149 

8. cancer CCS/ S canadienne du. Nutrition and stomach cancer. Canadian Cancer Society. November 2019. Accessed November 27, 2025. https://cancer.ca/en/cancer-information/cancer-types/stomach/supportive-care/nutrition-and-stomach-cancer 

9. Vomiting blood. nhs.uk. October 18, 2017. Accessed November 27, 2025. https://nhsuk-cms-fde-prod-uks-dybwftgwcqgsdmfh.a03.azurefd.net/symptoms/vomiting-blood/ 

10. Hansson LE. Risk of stomach cancer in patients with peptic ulcer disease. World J Surg. 2000;24(3):315-320. doi:10.1007/s002689910050 

11. Rawla P, Barsouk A. Epidemiology of gastric cancer: global trends, risk factors and prevention. Prz Gastroenterol. 2019;14(1):26-38. doi:10.5114/pg.2018.80001 

12. Wu B, Yang D, Yang S, Zhang G. Dietary Salt Intake and Gastric Cancer Risk: A Systematic Review and Meta-Analysis. Front Nutr. 2021;8:801228. doi:10.3389/fnut.2021.801228 

13. Duan Y, Xu Y, Dou Y, Xu D. Helicobacter pylori and gastric cancer: mechanisms and new perspectives. J Hematol Oncol. 2025;18(1):10. doi:10.1186/s13045-024-01654-2 

14. What Are the Risk Factors for Stomach Cancer? Accessed November 27, 2025. https://www.cancer.org/cancer/types/stomach-cancer/causes-risks-prevention/risk-factors.html 

15. Shi H, Li T, Liu Z, Zhao J, Qi F. Early detection of gastric cancer via high-resolution terahertz imaging system. Front Bioeng Biotechnol. 2022;10. doi:10.3389/fbioe.2022.1052069 

16. Tests for Stomach Cancer | Diagnosis of Stomach Cancer. Accessed March 13, 2025. https://www.cancer.org/cancer/types/stomach-cancer/detection-diagnosis-staging/how-diagnosed.html 

17. Huang Y, Shao Y, Yu X, Chen C, Guo J, Ye G. Global progress and future prospects of early gastric cancer screening. Journal of Cancer. 2024;15(10):3045-3064. doi:10.7150/jca.95311