A 1951 CIA Summary of Soviet Research on the Biochemical Similarities Between Parasites and Tumors
In February 1951, the Central Intelligence Agency prepared a two-page report summarizing a Soviet scientific paper published the previous year. The report carried the classification CONFIDENTIAL and was later released through the Freedom of Information Act in 2011. It was marked “unevaluated information.”
The underlying paper, written by Professor V.V. Alpatov and published in the Soviet journal Priroda, was titled “Biochemical Resemblance Between Endoparasites and Malignant Tumors.” Alpatov examined shared metabolic traits between certain endoparasites—particularly intestinal worms—and malignant tumors.
What the Soviet Research Observed
Both parasites and tumors were described as relying on anaerobic or partially anaerobic metabolism, generating energy with limited dependence on oxygen. Both were noted for accumulating large reserves of glycogen. The tissues were characterized as belonging to an “aerofermentor” (or amphibiotic) metabolic type, capable of functioning in both oxygen-rich and oxygen-poor conditions. These similarities, the paper suggested, helped explain why tumors could continue to grow even when blood supply was restricted.
The report also referenced experimental compounds that showed activity against both parasitic infections and malignant tumors in laboratory settings.
The Compounds Mentioned
One compound cited was Myracyl D, synthesized in 1938. It was already known to be effective against bilharzia parasites and was reported to demonstrate activity against malignant tumors as well.
Another was Guanazolo (also referred to as Guanozolo in some accounts), a guanine analog. It interfered with nucleic-acid synthesis—the process cancer cells use for rapid DNA replication and division. In laboratory tests on mice, it suppressed tumor growth.
These were early experimental observations, not clinical claims of a finished treatment.
Declassification and Later Research
The CIA summary remained classified for roughly six decades before its release. In the early Cold War period, the agency routinely collected and restricted foreign scientific literature that might have biomedical relevance.
Decades later, independent laboratory studies have continued to examine metabolic parallels between parasites and cancer cells and have tested certain antiparasitic agents for antitumor effects. A 2017 study from Osaka University, published in the Proceedings of the National Academy of Sciences, reported that ivermectin suppressed tumor development in epithelial ovarian cancer models. Other preclinical work has shown that benzimidazole anthelmintics such as albendazole and mebendazole can exhibit antitumor activity against various cancer cell types, including colorectal, gastric, and leukemia models.
These findings remain at the laboratory and preclinical stage. They do not constitute approved clinical therapies, but they illustrate ongoing scientific interest in the same general area of metabolic overlap first noted in the mid-20th century literature.
The 1951 CIA document is a concise intelligence abstract of open Soviet research. It records observed biochemical similarities and early experimental results with certain compounds. It does not present a completed cure, nor does it claim that cancer is simply a parasitic infection. The later laboratory work on antiparasitic agents shows that the underlying metabolic questions have continued to attract research attention.