Routine CA 19-9 surveillance detects recurrences early and enhances survival in resected ampullary cancer patients.

• Five-year overall survival stands at 56.4% in 572 patients, with 43.88% experiencing recurrences, predominantly distant.
• A serial rise in CA 19-9 is a strong predictor for recurrence, showing 71.05% sensitivity and 91.67% specificity.

Detecting recurrences early through CA 19-9 testing results in a median survival of 12.8 months versus 7.6 months without the elevated marker.

• Absolute CA 19-9 levels over 200 U/ml correlated with recurrence in nearly 93% of cases.