Tumor markers are molecules occurring in blood or tissue that are associated with cancer, and whose measurement or identification is useful in patient diagnosis or clinical management. This book analyses potential signals of cancerous tumors, otherwise known as markers or indicators. This includes, direct and rapid determination of cancer antigen, potential tumor markers for cholangiocarcinoma, melanoma inhibitory activity, metastatic uveal melanoma, measurement of tumor oxygenation, bladder cancer markers, epithelial cell adhesion and progresion markers in prostate tumors.