Risk of oesophageal cancer among patients previously hospitalised with eating disorder

It has been suggested that the risk of oesophageal adenocarcinoma might be increased in patients with a history of eating disorders due to acidic damage to oesophageal mucosa caused by self-induced vomiting practiced as a method of weight control. Eating disorders have also been associated with risk factors for squamous cell carcinoma of the oesophagus, including alcohol use disorders, as well as smoking and nutritional deficiencies, which have been associated with both main sub-types of oesophageal cancer. There have been several case reports of oesophageal cancer (both main sub-types) arising in patients with a history of eating disorders.

We used linked records of hospitalisation, cancer registration and mortality in Scotland spanning 1981-2012 to investigate the risk of oesophageal cancer among patients with a prior history of hospitalisation with eating disorder. The cohort was restricted to patients aged ≥10 years and <60 years at the date of first admission with eating disorder. Disregarding the first year of follow-up, we calculated indirectly standardised incidence ratios using the general population as the reference group to generate expected numbers of cases (based on age-, sex-, socio-economic deprivation category-, and calendar period-specific rates of disease).

After exclusions, the cohort consisted of 3617 individuals contributing 52,455 person-years at risk. The median duration of follow-up was 13.9 years. Seven oesophageal cancers were identified, as compared with 1.14 expected, yielding a standardised incidence ratio of 6.1 (95% confidence interval: 2.5-12.6). All were squamous cell carcinomas arising in females with a prior history of anorexia nervosa.

Patients hospitalised previously with eating disorders are at increased risk of developing oesophageal cancer. Confounding by established risk factors (alcohol, smoking, and nutritional deficiency) seems a more likely explanation than acidic damage through self-induced vomiting because none of the incident cases of oesophageal cancer were adenocarcinomas, and because the study cohort had higher than background rates of hospitalisation with alcohol-related conditions and chronic obstructive pulmonary disease.