In 1911 Peyton Rous published one of the earliest proofs of virally-induced cancer in A Sarcoma of the Fowl Transmissible by an Agent Separable from the Tumour Cel. Significantly it took until 1966 for him to be awarded a Nobel Prize for this discovery.
Dr J Nuzum, in 1925, cultured a minute gram-positive micrococcus unidentified (but possibly a member of the streptococcus group) from a breast tumour. Inoculation with this bacteria into mice and dogs caused the growth of some pre-cancerous lesions and, in some cases, mammary carcinomas. Control mice inoculated with cultures of other strains of streptococcus and staphylococcus did not develop such lesions.
Also in 1925 The Lancet published a section entitled New Research into the Origin of Cancer including papers from Gye and Barnard. Dr Gye had come to the conclusion that cancer was a disease caused by a virus or group of viruses. Although he found that the virus alone was insufficient to induce cancer, in the presence of an irritation such as coal-tar or paraffin oils the virus would multiply in the cell provoking the host cell to multiply.
Dr Barnard’s paper was on microscopy techniques for the examination of small filterable spheroids. Consistency in microscopy techniques was needed to allow other researchers to view these small organisms.
In 1930 Dr TJ Glover, working at the Hygienic Laboratory in Washington, found an organism that was shown in subculture to be highly pleomorphic: thus its life cycle included coccoids, rods, mycelial stages and filter passing forms. These organisms were able to be stained in cancerous tissue appearing as intracellular forms.
He obtained such an organism from an adenocarcinoma of the human breast. He inoculated the organism into the breast tissue of full grown female guinea pigs and female albino rats. Tissue from the resulting lesions was cultured and the organisms obtained were subcultured several times before being passed through four successive groups of rats. After the fourth passage the rats developed peritoneal carcinomas with metastases to the upper abdomen and peritoneal endotheliomas with focal infiltration.
Glover found this organism in 85% of 3000 cases.
Further studies on pleomorphic forms
Glover’s work was reproduced by Dr JL Engle in Philadelphia and subsequently in a larger study by Dr George A Clark (1953). Clark found that he could consistently isolate a highly pleomorphic organism from blood or tissue biopsies from his cancer patients.
In this study the organisms were cultured from patient tissue and the filtrate injected into two guinea pigs. One was given 1 cc of the filtrate and the other 5 cc. The guinea pig receiving the larger dose died 45 hours later. A drop of blood was aspirated from the heart and the liver of this guinea pig. The blood was cultured and by the next morning the same motile bacillus could again be shown to be present.