Rectal cancer patients with contra-indicatory risks may not be able to undergo surgery. In these cases the preferred treatment is chemotherapy. The present dosage formulation, consisting of an anti-cancer drug bound to activated carbon particles, was designed to deliver the anti-cancer drug at high concentration selectively to the injection site as well as to the regional lymph nodes and to improve survival of mice bearing cancer with nodal metastases, as compared to the same dose of aqueous anti-cancer drug in animal experiments. The present clinical trial includes two patients with histologically confirmed adenocarcinoma of the rectum and who had risks contra-indicating surgery. Carbon particles adsorbing anti-cancer drugs totaling 400 mg of methotrexate and 32 mg of mitomycin C in one patient and 100 mg of methotrexate and 8 mg of mitomycin C in another patient were injected into the cancer tissue under guidance of a colono-fiberscope. The rectal cancers were successfully reduced in size and controlled over 2 years or 6 months until the patients died from other causes. Side effect was mild. Local injection of this dosage formulation will be useful for the control of rectal cancer in patients who cannot undergo surgery.