Increased mortality in patients with porphyria cutanea tarda-A nationwide cohort study.

BACKGROUND

Porphyria cutanea tarda (PCT) is a rare hepatocutaneous disease for which the prognosis is largely unknown.

OBJECTIVE

To compare all-cause and cause-specific mortality between a nationwide cohort of patients with PCT and a matched population sample.

METHODS

We included all Danish patients who received a diagnosis of PCT from 1989 through 2012. Each patient was matched by age and sex to 10 random population control individuals. We compared survival and cause-specific mortality between patients and control individuals and adjusted for confounding from alcohol-related diseases, hepatitis, hemochromatosis, HIV, diabetes, acute myocardial infarction, stroke, cancer, chronic obstructive pulmonary disease, and cirrhosis.

RESULTS

The 20-year survival was 42.9% (95% confidence interval [CI], 36.9-48.7) for patients with PCT compared with 60.5% (95% CI, 58.6-62.4) for matched control individuals. All-cause mortality hazard ratio (HR) was 1.80 (95% CI, 1.56-2.07) before adjustment and 1.22 (95% CI, 1.04-1.44) after adjustment. The cause-specific mortality was markedly increased for nonmalignant gastrointestinal diseases (HR, 5.32; 95% CI, 2.71-10.43) and cancers of the gut (HR, 2.05; 95% CI, 1.24-3.39), liver/gallbladder (HR, 11.24; 95% CI, 4.46-28.29), and lungs (HR, 2.17; 95% CI, 1.41-3.33).

LIMITATIONS

We had no data on lifestyle factors.

CONCLUSIONS

Patients with PCT have increased mortality, primarily explained by an increased mortality from gastrointestinal diseases and from cancers of the gut, liver/gallbladder, and lungs.