Tumour 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 tumours, otherwise known as markers or indicators. This includes, direct and rapid determination of cancer antigen, potential tumour markers for cholangiocarcinoma, melanoma inhibitory activity, metastatic uveal melanoma, measurement of tumour oxygenation, bladder cancer markers, epithelial cell adhesion and progression markers in prostate tumours.