Cancers of the papilla of Vater: mutator phenotype is associated with good prognosis

Cancer of the papilla (ampulla) of Vater is an uncommon disease that kills 60% of affected patients. There is general agreement that local spread of the tumor (T stage) is the only significant and independent prognostic factor for this cancer, whereas the predictive value of tumor grade and lymph node metastases is controversial. The genetic anomalies involved in this process have the potential to serve as additional prognostic markers. We explored 25 ampullary cancers for the occurrence of instability at simple repeat DNA sequences (microsatellites) of the type seen in replication error phenotype (RER-positive) cancers. Ten microsatellites from five different chromosomes were amplified by PCR from both normal and cancer tissue DNA of the same patients. A tumor was defined as RER-positive when microsatellite instability was found in the majority (>/=6) of the loci analyzed. Five cancers (20%) showed a RER phenotype and were associated with long survival of patients (32-96 months), whereas RER-negative cancers had a significantly poorer prognosis (Mantel-Cox test; P = 0.0084), with a median actuarial survival of 17 months. We also report that three (12%) patients belonged to cancer-prone families and four (16%) were cancer-prone individuals