Serum cytokeratin 19 fragment 21-1 and carcinoembryonic antigen combination assay as a biomarker of tumour progression and treatment response in extramammary Paget disease.

The combination of CEA and CYFRA 21-1 is useful for predicting metastasis and treatment response in patients with EMPD, especially in those who only have elevation of a single marker. What's already known about this topic? Serum levels of carcinoembryonic antigen (CEA) and cytokine 19 fragment 21-1 (CYFRA 21-1) have been shown to be elevated in patients with extramammary Paget disease (EMPD). Elevation of serum CEA levels is associated with tumour progression of EMPD. A single small study reported that serum CYFRA 21-1 levels are elevated in patients with EMPD with lymph node metastasis. What does this study add? Serum CEA and CYFRA 21-1 were present in 79% and 63% of 19 cases of metastatic EMPD, respectively. Elevations of CEA and CYFRA 21-1 were statistically independent. CEA and CYFRA 21-1 combination assays were positive in 95% of cases of metastatic EMPD. What is the translational message? Combination assays with CEA and CYFRA 21-1 are useful for monitoring treatment response in patients with metastatic EMPD, particularly in those with elevation of either marker.