The oesophagus is the muscular tube through which food passes from the pharynx to the stomach. The oesophagus is lined over most of its length by squamous epithelial cells, where squamous cell carcinomas arise. The portion just above the gastric junction (where the oesophagus meets the stomach) is lined by columnar epithelial cells, from which adenocarcinomas arise.
Incidence and survival rates
Oesophageal cancer is the eighth most common cancer worldwide, with an estimated 456,000 new cases in 2012, accounting for about 3.2 per cent of all cancers. It is the sixth most common cause of death from cancer, with an estimated 400,000 deaths (4.9 per cent of the total). These figures include both adenocarcinoma and squamous cell carcinoma. About 80 per cent of the cases worldwide occur in less developed regions, where the age-standardised rate is almost double that of more developed regions. Oesophageal cancer incidence rates worldwide in men are twice as high as those in women.
The two major histologic types of oesophageal cancer, squamous cell carcinoma and adenocarcinoma, differ substantially in their underlying patterns of incidence and key aetiologic factors. Both have a high mortality rate. Globally, squamous cell carcinomas account for 88 per cent of oesophageal cancer cases, although the incidence of oesophageal adenocarcinoma has increased sharply, and that of squamous carcinoma has declined over the past few decades. In the US, there has been a 30 per cent drop in the incidence of squamous cell carcinoma between 1973 and 2002 but a four-fold increase in the incidence of adenocarcinoma over the same period. Adenocarcinoma of the oesophagus shows similarities in its histological and morphological characteristics with adenocarcinoma of the gastric cardia.
Survival rates are poor mainly because cancer of the oesophagus is usually diagnosed at a late stage. Oesophageal cancer mortality closely follows the geographical patterns for incidence, with the highest mortality rates occurring in Eastern Asia and Southern Africa in men and in Eastern and Southern Africa in women. In the US, the five-year survival rate is 20 per cent compared with 10 per cent in Europe.
The cancer statistics quoted in the Third Expert Report are from the GLOBOCAN 2012 database. The International Agency for Research on Cancer (IARC) updated these statistics in September 2018, after the publication of the Third Expert Report. For the most recent statistics, please click here.
Lifestyle factors and oesophageal cancer risk
In this report from our Continuous Update Project (CUP) – the world’s largest source of scientific research on cancer prevention and survivorship through diet, nutrition and physical activity – we analyse global research on how certain lifestyle factors affect the risk of developing oesophageal cancer. This webpage forms part of the World Cancer Research Fund/American Institute for Cancer Research Third Expert Report Diet, Nutrition, Physical Activity and Cancer: a Global Perspective.
Findings on oesophageal cancer
There is strong evidence that:
- being overweight or obese INCREASES the risk of adenocarcinoma of the oesophagus. Being overweight or obese was assessed by body mass index (BMI), waist circumference and waist-hip ratio
- consuming alcoholic drinks INCREASES the risk of oesophageal squamous cell carcinoma
- regularly consuming mate, as drunk in the traditional style in South America, INCREASES the risk of oesophageal squamous cell carcinoma
There is some evidence that:
- consuming vegetables might decrease the risk of oesophageal cancer
- consuming fruit might decrease the risk of oesophageal squamous cell carcinoma
- being physically active might decrease the risk of oesophageal cancer
- consuming processed meat might increase the risk of oesophageal squamous cell carcinoma
Other causes of oesophageal cancer
In addition to the findings on diet, nutrition and physical activity outlined above, other established causes of oesophageal cancer include:
Smoking is a cause of both types of oesophageal cancer. Squamous cell carcinoma is more strongly associated with smoking than adenocarcinoma.
Between 12 and 39 per cent of oesophageal squamous cell carcinomas worldwide are associated with human papilloma virus (HPV) infection.
- other diseases
Risk of adenocarcinoma of the oesophagus is increased by gastro-oesophageal reflux disease, a common condition in which stomach acid damages the lining of the lower part of the oesophagus. This type of oesophageal cancer is also increased by a rare condition, oesophageal achalasia (where the valve at the end of the oesophagus fails to open and food gets stuck).
There are two main forms of cancer of the oesophagus. Adenocarcinomas arise from the columnar glandular cells that line the lower end of the oesophagus, and squamous cell carcinomas arise from the squamous epithelial lining. The epithelial cells lining the oesophagus are exposed directly to carcinogens in food. Repeated exposure, to burns from very high-temperature drinks or irritation from the direct action of alcohol, for instance, may cause inflammation. The role of irritation and inflammation in the development of oesophageal cancer is supported by the finding that gastro-oesophageal reflux (where stomach acid flows upwards to the oesophagus) increases the risk of adenocarcinomas as much as five-fold.
Barrett’s oesophagus, a probable intermediate stage between gastro-oesophageal reflux disease and oesophageal adenocarcinoma, is an acquired condition in which squamous cells are replaced by columnar epithelial cells; autopsy studies suggest that it usually remains undiagnosed. The increasing use of endoscopy to investigate abdominal symptoms has resulted in the earlier detection of a small proportion of adenocarcinomas in people with Barrett’s oesophagus.
In a condition called oesophageal achalasia, the lower oesophageal sphincter fails to relax and swallowed food is retained in the oesophagus. It is associated with a 16–28 per cent increase in the risk of squamous cell carcinomas, which may be due to chronic irritation of the lining of the oesophagus or increased contact with food-borne carcinogens. In addition, Tylosis A, a late-onset, inherited familial disease characterised by thickening of the skin of the palms and soles (hyperkeratosis), is associated with a 25 per cent lifetime incidence of squamous cell cancer of the oesophagus. Plummer Vinson syndrome is a rare condition associated with iron deficiency in which growths of tissue block part of the oesophagus, making swallowing difficult. Plummer Vinson syndrome is associated with an increased risk of oesophageal squamous cell carcinoma. Helicobacter pylori infection, an established risk factor for non-cardia stomach cancer, is associated with a 41–43 per cent decreased risk of oesophageal adenocarcinoma.
Full references and a summary of the mechanisms underpinning all the findings can be found in the oesophageal cancer report.
How the research was conducted
The global scientific research on diet, nutrition, physical activity and the risk of oesophageal cancer was systematically gathered and analysed, and then independently assessed by a panel of leading international scientists in order to draw conclusions about which of these factors increase or decrease the risk of developing oesophageal cancer.
Published findings in peer-reviewed journals
Selected findings from this report have been published in peer-reviewed journals. Details of the papers and links to the abstract in PubMed are below:
An update of the WCRF/AICR systematic literature review and meta-analysis on dietary and anthropometric factors and esophageal cancer risk. S Vingeliene, DSM Chan, AR Vieira, E Polemiti, C Stevens, L Abar, D Navarro Rosenblatt, DC Greenwood, T Norat. Ann Oncol. 2017 Oct 1;28(10):2409-2419. Abstract
This webpage is a summary.
For much more, download the full chapter.