Mitomycin-C acts as a bifunctional or trifunctional alkylating agent. It inhibits DNA synthesis and cross-links DNA to an extent proportional to its content of guanine and cytosine. Its action is most prominent during the late G1 and early S phases of the cell cycle.
Mitomycin-C is a broad spectrum cytostatic. Used on its own Mitomycin-C may be effective in the treatment of a wide variety of malignant tumours such as breast cancer and gastro-intestinal cancer. It is, however, very often used in combination with other cytostatics particularly in the treatment of gastric and pancreatic cancers. Mitomycin-C has also been reported to have an effect in the treatment of bladder cancer, non-small cell lung cancer, head and neck squamous cell cancer, and colorectal cancer.