Studies on the treatment of malignant tumors with fibroblast-inhibiting agent III. Effects of chloroquine on human cancers

A fibroblast-inhibiting agent, chloroquine, used in the treatment of animal tumors led to a reasonably good result, and this approach was extended to the treatment of human cancers. Of histologically proven 54 cases, the drug was effective in 38, ineffective in 15, and unknown in one. It proved to be effective in all the patients who were treated for over 2 months with exception of terminal patients. Of the various malignant tumors treated, excellent therapeutic effects were obtained in patients with carcinoma of the lung and bladder. In the cases where the drug was effective there were a decrease of the size of tumors, fall of serum lactic dehydrogenase, increase of necrosis, inhibition of the stroma, as well as improvement of the symptoms and general condition. As to the mechanisms of the drug action, it would be necessary to consider of its anti-inflammatory and humoral effects upon the host in addition to its inhibitory action on the stromal connective tissue of cancers. The present chloroquine treatment appears to have its indication in inoperable cases, and pre- and post-operative cases, and for the prevention of reccurrence of tumors. Studies are currently in progress in our laboratory to discover more potent fibroblastinhibiting agents and on the combined chemotherapy of chloroquine and other anti-turnor agents. We are indebted to the Department of Urology of our University for the generosity to allow us to use the clinical data on patients with cancer of the urinary bladder.