The incidence of cancer, and the success rates in therapy, oblige us to examine every avenue of approach. Accordingly, itis suggested that certain turn-of-the century publications be re-examined. The distinguished embryologist John Beard, following up his elucidation of the trophoblastic origin of the mammalian placenta, made certain observations about the common origin, behaviour and chemistry of both the pregnancy trophoblast and the cancer cell, and of the mechanisms which control both in a healthy subject. These conclusions were published as The Trophoblast Theory of Cancer1-. Some aspects of this hypothesis, supported by recent research and observation, may now offer enough evidence for its re-introduction into contemporary orthodox thinking. Current pilot work holds out the prospect of inexpensive and methodologically simple cancer therapy with few and manageable side effects.

Trophoblast theory Beard argued that cancer cells, irrespective of appearance, were characteristically trophoblast in behaviour, having their origin either in pregnancy complications or the stimulation ofpluripotent repair cells. Thus, the invasion of the uterine lining by the cytotrophoblast during the first 56 days of pregnancy models the tumour; placental and malignant cells sharing common immune suppressive mechanisms. Similarly, the control oftrophoblastic infiltration by the maternal pancreas enzymes, and the check and decay of the cytotrophoblast to the syncitial formwith the appearance of the foetal pancreas proteases, models the containment of malignancy in the healthy subject. Accordingly, Beard proposed the therapeutic administration of a protease/amylase mixture to destroy that'irresponsibletrophoblast', the-cancer cell. The resulting early efforts may be summarized as follows: