Chemotherapy and Autologous Marrow Transplantation in Palliation of Malignant Ocular Tumors

Abstract

This is a discussion of the new chemotherapeutic agents for symptomatic treatment of metastatic tumors of the orbit, with illus­ tration of usage in three consecutive cases. If curative therapy of malignancy is planned, surgery or irradiation are the pres­ ent methods of choice, but frequently are in­ sufficient. Some forms of chemotherapy have been used for a number of years, for exam­ ple, stilbestrol in prostatic carcinoma and sex hormones in metastatic carcinoma of the breast. The mechanism of action of these drugs is based on alteration of the environ­ ment of the tumor. ACTH or adrenal corticosteroids may also be of value in this re­ spect, and may protect the bone marrow from drug toxicity. Recently there has been an exploration of medical therapy of cancer with a group of drugs which all simulate radiation to some extent. For instance, radioactive isotopes ac­ tually deliver ionizing radiation directly to the cell. A great number of other cytotoxic agents simulate radiation effect so much they have been termed radiomimetic. These may vary in their mode of action. Alkylating agents (fig. 1) act by intro­ ducing a toxic bis, B-chloroethyl group into the nucleus of the normal and malignant cells. Since malignant cells contain enzymes which release the B-chloroethyl group in larger amounts than normal, there is a selec­ tive nuclear inhibition of neoplastic cells, as well as some toxicity to all cells. The pros­ thetic group (R) (fig. 1) functions by con­ verting the B-chloroethyl group to an inac­ tive transport form which is activated at the site of therapy. Among the available alkylat­ ing agents are nitrogen mustard, triethylene ALKYLATING