Gastric MALT lymphoma: epidemiology and high adenocarcinoma risk in a nation-wide study.

BACKGROUND

Gastric marginal zone non-Hodgkin lymphomas MALT type (gMALT) and gastric adenocarcinomas (GC) are long-term complications of chronic Helicobacter pylori gastritis, however, the incidence of gMALT and the GC risk in these patients is unclear.

OBJECTIVE

To evaluate epidemiological time trends of gMALT in the Netherlands and to estimate GC risk.

METHODS

Patients with a first diagnosis of gMALT between 1991 and 2006 were identified in the Dutch nation-wide histopathology registry (PALGA). Age-standardised incidence rates were calculated. The incidences of GC in patients with gMALT and in the Dutch population were compared. Relative risks were calculated by a Poisson Model.

RESULTS

In total, 1419 patients were newly diagnosed with gMALT, compatible with an incidence of 0.41/100,000/year. GC was diagnosed in 34 (2.4%) patients of the cohort. Patients with gMALT had a sixfold increased risk for GC in comparison with the general population (p<0.001). This risk was 16.6 times higher in gMALT patients aged between 45 and 59 years than in the Dutch population (p<0.001).

CONCLUSIONS

GC risk in patients with gMALT is six times higher than in the Dutch population and warrants accurate re-evaluation after diagnosis and treatment for gMALT.