Evidence base of prevention in upper gastrointestinal cancer


Year:

Session type:

Krish Ragunath

Wolfson Digestive Diseases Center, Nottingham University Hospitals NHS Trust, UK

Abstract

Oesophageal and gastric cancer accounts for nearly 13,000 deaths annually in the UK. Whilst oesophageal adenocarcinoma is on the rise, mortality rates for gastric cancer have fallen by around 70% over the last 30 years. This is probably related to decrease in H. Pylori prevalence and effective treatment. Chronic heartburns and Barretts oesophagus is the only identifiable pre-malignant condition that could account for the rapidly increasing oesophageal cancers. Advances in surgical techniques, chemo radiotherapy and more recently endoscopic therapy have not changed the prognosis for oesophageal cancers in the last 20 years. Although surveillance endoscopy detected Barretts cancer patients have better prognosis, only ~5% of oesophageal cancer patients have a pre-existing diagnosis of Barretts oesophagus. Moreover, about 40% of patients with Barretts do not have reflux symptoms. Thus current endoscopic surveillance even if extended to screening patients with chronic reflux symptoms will not have an effect in overall oesophageal cancer prevention.

Hence, for cancer prevention we need a robust strategy for identifying at risk individuals with simple non-invasive screening tests (e.g. biomarker blood test) and effective chemo-prevention agents to treat at risk individuals. Aspirin and proton pump inhibitors have emerged as promising chemo-preventive agents that are now tested in the largest randomized clinical trial in Barretts oesophagus (AsPECT). Furthermore, to detect at risk individuals a genome wide scan for genetic predisposition (ChoPIN) study has been linked to AsPECT participants. Thus, this trial clinical network provides a solid platform with translational studies embedded in it for cancer prevention

Throughout the world mortality from stomach cancer has been falling but at different times and rates for different countries. The global decrease has occurred without any significant improvements in diagnosis or treatment:

  • Helicobacter pylori, a bacterial infection of the lining of the stomach, is the major cause of stomach cancer. Most cases of stomach cancer are associated with the presence of H. pylori in the stomach.
  • Better living conditions with less overcrowding have led to a decrease in the prevalence of H pylori infection.
  • It has been estimated that about 1 in 5 stomach cancers in Europe are caused by smoking, with a higher proportion in men (22%) than women (14%).
  • Fruit and vegetables have a protective effect against stomach cancer.
  • People consuming high amounts of salt have an increased risk of stomach cancer.
  • Having a parent or sibling diagnosed with a stomach cancer increases risk of stomach cancer.
  • Oesophageal cancer is the sixth most common cause of cancer death and accounts for around 5% of all cancer deaths in the UK.
  • Every year in the UK over 7,300 people die from cancer of the oesophagus.
  • Oesophageal cancer mortality rates in men have increased by more than half since the early 1970s.