In diagnosing uterine cancers, cells and tissue samples can be directly obtained from the lesion. Cytologic and histologic investigation is the best method for screening and early detection of primary uterine cancers. Tumor markers may be useful for monitoring the clinical course of therapy and early detection of recurrence for which cytologic examination can not be done. Moreover, high levels of tumor markers may represent tumor invasiveness and metastasis to lymph nodes and/or other organs, and may indicate a poor prognosis for the patient. Strictly speaking, tumor markers are not tumor-specific but tumor-associated substances. They can be elevated in sera from healthy individuals under various conditions, and from patients with benign tumors. Squamous cell carcinoma-associated antigen (SCC) is relatively tumor-specific, and widely used for monitoring patients with squamous cell carcinoma not only of the uterine cervix. On the other hand, there is no specific tumor marker for uterine corpus carcinoma. Combination assay of several tumor markers including cancer antigen 125 (CA125) as a core marker may be of greater diagnostic value in cases of uterine corpus carcinoma.