The mortality from leukaemia and other cancers among patients with Down's syndrome (mongols) and among their parents

A theory of the action of cancer chemotherapeutic drugs

This paper presents an analysis of the results of cancer therapy, based on the histories of treated and untreated cancers taking into account the biology of immunity and drug action.

Cancer chemotherapeutic drugs in addition to a direct action on the malignant cells, act on the host's immune system. The importance of tumour–host interactions in determining the overall progress of the tumour is emphasized.

It is postulated that in the early stages of therapy, remission occurs because the drug is given at a time when the host has either some degree of immunity against the tumour, or has a reversible immune tolerance with respect to the tumour antigen. In contrast, in the later stages of treatment, immunity against the tumour is depressed and this is a major cause of therapeutic failure.

Susceptibility of human diploid fibroblast strains to transformation by SV40 virus

A quantitative system has been developed for the study of transformation of human diploid fibroblasts in culture by two oncogenic viruses, SV40 and the E46 strain of adeno 7-SV40 "hybrid" virus. Seven of the eleven cell strains derived from human skin biopsies when infected with SV40 (10(9) tissue culture infective doses per milliliter) gave rise to transformed colonies with approximately the same frequency (0.03 percent). Two strains derived from patients with Fanconi's anemia, an autosomal recessive disease associated with a high incidence of chromosome abnormalities and spontaneous neoplasms, gave values more than ten times higher. Two strains from persons heterozygous for this gene were also considerably more susceptible to viral transformation.