Some attempts at chemotherapy of cancer.

The development of anything like a systematic approach to the chemotherapy of cancer began with the discovery that some chemical substances were capable of so profoundly interfering with the processes of cell division that either mitosis was prevented or else the daughter cells from the mitotic division were so damaged that they died. It was apparently because of this property that these substances were capable of inhibiting the growth at least of experimental tumours, and in the most favourable cases, holding out some therapeutic advantage in the treatment of some or other of the lymphadenopathies. Thus colchicine, a drug derived from the autumr crocus-or a more recently discovered derivative, deacetylmethylcolchicine (Demecolcin) -can inhibit the formation of the spindle in metaphase and so arrest mitosis. Demecolcin, which is much less toxic than the parent substance, has been reported to give good results in the treatment of chronic myeloid leukaemia. Other plant materials which possess similar antimitotic activity, podophyllin for example, have been found to inhibit experimental tumours but to offer no clinical advantage. But it was the wartime studies of the physiological effects of the war gases, sulphur and nitrogen mustard, that greatly accelerated research into the possibility of chemically inhibiting abnormal growth. It had been observed that methyl di-2chloroethylamine (Fig. i)-the war gas known as