{"id":1559,"date":"2026-09-12T18:51:19","date_gmt":"2026-09-12T18:51:19","guid":{"rendered":"https:\/\/zachou.wearedoubledot.com\/elikovaktiridio-tou-pylorou-poioi-prepei-na-elegchthoun-pos-ginetai-i-dokimasia-anapnois-kai-i-schesi-me-ton-karkino-tou-stomachou\/"},"modified":"2026-09-25T13:27:27","modified_gmt":"2026-09-25T13:27:27","slug":"elikovaktiridio-tou-pylorou-poioi-prepei-na-elegchthoun-pos-ginetai-i-dokimasia-anapnois-kai-i-schesi-me-ton-karkino-tou-stomachou","status":"publish","type":"post","link":"https:\/\/zachou.wearedoubledot.com\/en\/elikovaktiridio-tou-pylorou-poioi-prepei-na-elegchthoun-pos-ginetai-i-dokimasia-anapnois-kai-i-schesi-me-ton-karkino-tou-stomachou\/","title":{"rendered":"Helicobacter pylori: Who Should Be Tested, How the Breath Test Works, and the Link to Stomach Cancer"},"content":{"rendered":"

Helicobacter pylori is a bacterium that colonises the lining of the stomach, usually in childhood, and then stays for life unless it is treated. Most people who carry it have no symptoms. A minority develop ulcers, and a smaller minority develop gastric cancer.<\/span><\/p>\n

It is the only bacterium classified by the International Agency for Research on Cancer as a Group 1 carcinogen, meaning there is sufficient evidence that it causes cancer in humans. That classification was made in 1994, and the evidence has only strengthened since.<\/span><\/p>\n

How common it is<\/b><\/h2>\n

Global prevalence has fallen substantially, from around 58% in the 1980s to around 43% in the period from 2011 to 2022. In Western Europe it is around 34%, and Southern and Eastern Europe sit significantly higher.<\/span><\/p>\n

The decline reflects better sanitation and living conditions across generations. It also means that prevalence in older adults, who grew up under different conditions, remains higher than the population average.<\/span><\/p>\n

The link with gastric cancer<\/b><\/h2>\n

The connection is stronger than most patients expect.<\/span><\/p>\n

The International Agency for Research on Cancer estimates that 89% of non-cardia gastric cancers are attributable to H. pylori. Modelling published in 2025 estimated that of the gastric cancers expected across the lifetime of people born between 2008 and 2017, 76% are attributable to this infection, and up to three quarters could be prevented by screening and treating for it.<\/span><\/p>\n

Crucially, eradication changes the outcome. A meta-analysis of randomised trials found that eradicating H. pylori in infected but otherwise healthy people reduced gastric cancer incidence by around 36% and gastric cancer mortality by around 22%.<\/span><\/p>\n

This is unusual in oncology. A single course of antibiotics, in the right person, measurably reduces the risk of a cancer that is otherwise often diagnosed late.<\/span><\/p>\n

Who should be tested<\/b><\/h2>\n

Testing is indicated, rather than optional, in the following situations:<\/span><\/p>\n

    \n
  • Current or previous peptic ulcer disease<\/span><\/li>\n
  • Gastric MALT lymphoma, where eradication alone produces long-term remission in 70% to 80% of cases<\/span><\/li>\n
  • Dyspepsia in a patient without alarm features, below the age threshold for endoscopy<\/span><\/li>\n
  • Functional dyspepsia<\/span><\/li>\n
  • Gastric premalignant conditions such as atrophic gastritis or intestinal metaplasia, or previous gastric cancer<\/span><\/li>\n
  • A first-degree relative with gastric cancer<\/span><\/li>\n
  • Before starting long-term NSAID treatment, which reduces the risk of ulcer<\/span><\/li>\n
  • Unexplained iron deficiency anaemia<\/span><\/li>\n
  • Immune thrombocytopenic purpura, where platelet counts rise after eradication<\/span><\/li>\n
  • Long-term proton pump inhibitor use, since untreated infection under long-term PPI shifts gastritis towards the body of the stomach and increases atrophy<\/span><\/li>\n<\/ul>\n

    For low dose aspirin, testing is recommended only in patients already at high risk of ulcer, because the number needed to treat in the general aspirin-using population is very high.<\/span><\/p>\n

    The test and treat approach<\/b><\/h2>\n

    For a younger patient with dyspepsia and no alarm features, the approach is to test non-invasively and treat if positive, rather than proceed straight to endoscopy. European consensus places the age threshold at around 50, with a range of 45 to 55 depending on local cancer incidence. Below that threshold the prevalence of gastric cancer among patients with dyspepsia is around 0.4%.<\/span><\/p>\n

    Above that age, or in the presence of alarm features such as weight loss, vomiting, difficulty swallowing, bleeding or anaemia, endoscopy comes first.<\/span><\/p>\n

    Which test to use<\/b><\/h2>\n

    The urea breath test<\/b> is the most accurate non-invasive option. You swallow a solution containing urea labelled with carbon-13. If H. pylori is present, the enzyme it produces splits the urea and releases labelled carbon dioxide, which is then measured in your breath. No bacteria, no labelled CO2.<\/span><\/p>\n

    In pooled analysis of 39 studies, the carbon-13 breath test showed a sensitivity of 96.6% and a specificity of 96.9%. The carbon-14 version performs similarly for sensitivity but is less specific and involves a small dose of radiation, which is why the carbon-13 version is preferred.<\/span><\/p>\n

    Stool antigen testing<\/b> is the other reliable non-invasive option, with comparable accuracy in validated laboratory formats.<\/span><\/p>\n

    Blood antibody testing should not be used<\/b> to diagnose active infection, and must never be used to confirm eradication. Antibodies persist for years after the bacterium has gone, so a positive result cannot distinguish current infection from one treated a decade ago.<\/span><\/p>\n

    Biopsy-based testing<\/b> during gastroscopy includes the rapid urease test, histology and culture. Where a gastroscopy is being performed anyway, biopsies allow both diagnosis and assessment of the stomach lining. European guidance now also supports molecular testing for clarithromycin resistance mutations.<\/span><\/p>\n

    Preparing for the breath test<\/b><\/h2>\n

    These rules are not optional. Ignoring them produces a false negative, and a false negative means an infection stays untreated.<\/span><\/p>\n

      \n
    • Stop proton pump inhibitors at least two weeks before the test.<\/b> These are the medicines most people are taking for the symptoms that prompted the test in the first place, which is exactly why this is missed so often.<\/span><\/li>\n
    • Stop antibiotics and bismuth preparations at least four weeks before.<\/b><\/li>\n
    • H2 receptor antagonists do not interfere<\/b> with the test, so they are an option for symptom relief during the washout period. Discuss this with your doctor rather than simply stopping everything.<\/span><\/li>\n
    • Fasting is required<\/b> before the test. Follow the specific instruction given by the clinic performing it, as protocols vary.<\/span><\/li>\n<\/ul>\n

      Treatment in Greece, and why antibiotic resistance matters<\/b><\/h2>\n

      Treatment is not a single standard course everywhere in the world, because resistance patterns differ by region.<\/span><\/p>\n

      Across Europe, resistance in the most recent period has been reported at approximately 24% for clarithromycin, 33% for metronidazole and 21% for levofloxacin, with markedly higher rates in Southern European countries. Greek studies describe Greece as a high clarithromycin resistance area, above 20%.<\/span><\/p>\n

      That figure matters because the guideline threshold is 15%. Above it, the standard clarithromycin-based triple therapy that many patients remember from years ago is no longer reliable first-line treatment.<\/span><\/p>\n

      Current European guidance for high resistance areas recommends bismuth quadruple therapy as first line, or non-bismuth concomitant quadruple therapy where bismuth is not available. In a Greek trial, quadruple regimens achieved eradication in around 88% to 92% of patients.<\/span><\/p>\n

      Vonoprazan-based regimens, used in the United States and parts of Asia, are not available in the European Union at the time of writing.<\/span><\/p>\n

      The practical consequence for patients: do not assume the treatment a relative received ten years ago is the right treatment now, and complete the full course exactly as prescribed. Incomplete treatment is one of the main drivers of resistance.<\/span><\/p>\n

      Confirming the infection is gone<\/b><\/h2>\n

      This step is skipped far too often, and it should not be.<\/span><\/p>\n

        \n
      • Retest at least four weeks after finishing treatment, allowing a drug-free interval so that suppressed bacteria are not mistaken for eradicated ones<\/span><\/li>\n
      • Use a urea breath test or stool antigen test, never serology<\/span><\/li>\n
      • Stop PPIs for at least two weeks before the test of cure, as for the initial test<\/span><\/li>\n<\/ul>\n

        Reinfection after successful eradication is uncommon, at roughly 1% per year.<\/span><\/p>\n

        When to see a doctor<\/b><\/h2>\n

        Arrange an assessment if you have:<\/span><\/p>\n

          \n
        • Persistent upper abdominal pain or burning, particularly if it wakes you at night or improves with food<\/span><\/li>\n
        • Dyspepsia that keeps returning after you stop antacids<\/span><\/li>\n
        • Nausea, early satiety or unexplained loss of appetite<\/span><\/li>\n
        • A first-degree relative with gastric cancer<\/span><\/li>\n
        • Iron deficiency anaemia with no obvious cause<\/span><\/li>\n
        • A history of peptic ulcer that was never confirmed as eradicated<\/span><\/li>\n<\/ul>\n

          And seek assessment promptly, with endoscopy rather than a breath test, if you have difficulty swallowing, vomiting, weight loss, or evidence of bleeding such as black stools or vomiting blood.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

          Helicobacter pylori is a bacterium that colonises the lining of the stomach, usually in childhood, and then stays for life unless it is treated. Most people who carry it have no symptoms. A minority develop ulcers, and a smaller minority develop gastric cancer. It is the only bacterium classified by the International Agency for Research […]<\/p>\n","protected":false},"author":1,"featured_media":1373,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1559","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mi-katigoriopoiimeno"],"acf":[],"_links":{"self":[{"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/posts\/1559","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/comments?post=1559"}],"version-history":[{"count":2,"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/posts\/1559\/revisions"}],"predecessor-version":[{"id":1572,"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/posts\/1559\/revisions\/1572"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/media\/1373"}],"wp:attachment":[{"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/media?parent=1559"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/categories?post=1559"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zachou.wearedoubledot.com\/en\/wp-json\/wp\/v2\/tags?post=1559"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}