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SEER Training Modules

Tumor Markers

Key Information

Monitoring levels of tumor and indicating a recurrence

CEA (Carcinoembryonic Antigen) (Stomach)

Persistent elevated levels indicate residual or recurrent metastatic carcinoma; nonspecific to stomach cancer

CA 19-9 (Cancer Antigen 19-9) (Stomach)

Monitors post-therapeutic gastrointestinal cancer for recurrence; nonspecific to stomach cancer

CA 195 (Cancer Antigen 195) (Stomach)

Detects gastrointestinal cancers; changing level indicates progression or regression of tumor load; nonspecific to stomach cancer

SCC (Squamous Cell Carcinoma Antigen) (Esophagus)

Monitors tumor burden after treatment for squamous cell carcinoma; used in advanced cases; squamous cell specific

5-HIAA (5-Hydroxy-Indol Acetic Acid) (Small intestine)

Quantitative analysis of urine levels; levels above 15 mg/24 hours indicate malignant carcinoid tumors (argentaffinomas), which may also appear in stomach, appendix, or lower intestine

Go to the Tumor Markers page of the Diagnostic Tests module for more information.