Mitomycin 40 mg injection is aimed to treat certain cancer of the pancreas, lung, breast, and stomach. It can be prescribed alone or along with some drugs as part of combination chemotherapy. The mitomycin 40 mg works by interfering with the growth of cancerous cells, which are eventually killed. Mitomycin 40 mg is administered as an injection into the vein under the supervision of a health specialist and must not be self-administered. Your specialist will decide what dosage is apt and how often you should take it. It is advised to take this drug as exactly as your health specialist has advised.