Can bulimia nervosa (eating disorder) increase the risk of throat cancer in patients with a history of chronic self-induced vomiting?

Can Bulimia Cause Throat Cancer?

While there is a documented association between eating disorders and increased risk of esophageal cancer, the evidence suggests this risk is primarily driven by confounding factors (alcohol use, smoking, nutritional deficiencies) rather than direct causation from self-induced vomiting, as all documented cases in the highest quality study were squamous cell carcinomas—not the adenocarcinomas that would be expected from chronic acid exposure. 1

The Evidence on Cancer Risk

Direct Research Findings

The most rigorous study examining this question followed 3,617 patients previously hospitalized with eating disorders over a median of 13.9 years and found:

• Seven cases of esophageal cancer occurred versus 1.14 expected, yielding a standardized incidence ratio of 6.1 (95% CI: 2.5-12.6) 1
• Critically, all seven cases were squamous cell carcinomas in females with anorexia nervosa—not a single case was adenocarcinoma 1
• This pattern strongly suggests the increased risk stems from alcohol use disorders, smoking, and nutritional deficiencies rather than acid damage from vomiting 1

Supporting Evidence from High-Risk Populations

One study from the Transkei region (which has one of the world's highest rates of esophageal cancer) found:

• Self-induced vomiting was independently associated with chronic esophageal inflammation (OR 1.83,95% CI: 1.13-2.96) 2
• However, this was a cross-sectional study in a population with multiple confounding risk factors and cannot establish causation 2

Understanding the Mechanism Question

If chronic acid exposure from vomiting were the primary mechanism, we would expect to see adenocarcinomas (the cancer type associated with gastroesophageal reflux and Barrett's esophagus), not squamous cell carcinomas 1, 3

The fact that only squamous cell carcinomas were observed indicates:

• The cancer risk is more likely mediated through behavioral comorbidities (alcohol abuse, smoking, malnutrition) that are common in eating disorder patients 1
• These patients had higher-than-expected rates of hospitalization for alcohol-related conditions and chronic obstructive pulmonary disease 1

Clinical Implications for Bulimia Nervosa Specifically

Bulimia nervosa is characterized by recurrent binge eating followed by compensatory behaviors including self-induced vomiting, occurring at least once weekly for 3 months 4, 3

The medical complications from self-induced vomiting in bulimia are well-documented and serious, but direct causation of throat cancer is not established: 5

• Dental erosion from gastric acid exposure
• Electrolyte abnormalities (particularly hypokalemia)
• Esophageal complications including inflammation
• Cardiac complications from electrolyte disturbances 5

Critical Clinical Recommendations

For patients with bulimia nervosa and chronic self-induced vomiting, focus screening and prevention efforts on:

1. Addressing alcohol use disorders and smoking cessation—these are the established risk factors for esophageal squamous cell carcinoma 1, 3

2. Correcting nutritional deficiencies, which contribute to squamous cell carcinoma risk 1, 3

3. Providing immediate medical and psychological treatment, as mortality rates for eating disorders are among the highest for any psychiatric disorder 3, 4

4. Monitoring for established complications of purging behaviors (electrolyte abnormalities, cardiac complications, dental erosion) rather than focusing disproportionately on cancer risk 5

Common Pitfall to Avoid

Do not counsel patients that vomiting directly causes throat cancer based on the available evidence. The association appears confounded by behavioral comorbidities. However, do emphasize the serious and immediate medical complications of purging behaviors, and aggressively address modifiable cancer risk factors like alcohol use and smoking 1, 5