Did the CIA Hide Documents With a Potential Cure for Cancer? Declassified Files Spark Backlash

A decades-old CIA intelligence report is igniting fresh outrage online, but the full story is far more complicated than the headlines suggest.

A newly surfaced CIA document suggests US intelligence once reviewed research that hinted at a possible cancer treatment more than 60 years ago. The document was prepared by the Central Intelligence Agency in February 1951, and although it was officially declassified in 2014, it has only recently gained widespread attention after being shared on social media.

The gap between what the document actually says and how it is being characterised online is significant, and understanding that gap matters enormously for public health.

The Document: What the CIA Filed Away

The document, produced in February 1951, summarises a Soviet scientific paper that examined striking similarities between parasitic worms and cancerous tumours. The report describes how researchers believed both organisms thrived under nearly identical metabolic conditions and accumulated large reserves of glycogen, a form of stored energy. The original paper is accessible directly on the CIA's FOIA Electronic Reading Room.

The CIA routinely monitored foreign science during the Cold War; this was standard intelligence work. The document was quietly declassified in 2014 and has been publicly available on the CIA's own website ever since. It was not secretly 'unlocked' recently. The current viral wave is simply people discovering it for the first time.

That document carries a header that reads plainly: 'This Is Unevaluated Information.' That single line is critical. The agency did not endorse its contents, did not advance its findings, and did not classify it to suppress a cure. American intelligence analysts translated and circulated the paper because it was considered potentially relevant to biomedical and national defence research during the early years of the Cold War.

The Soviet paper was authored by Professor V.V. Alpatov and published in Priroda, Vol. XIX, No. 10, in October 1950, out of Leningrad. Alpatov argued that endoparasites, organisms that live inside a host's body, and malignant tumours shared a metabolic profile unusual enough to suggest a possible biological kinship. Both exhibit anaerobic metabolism and deposit glycogen in their tissues, indicating a similar amphibiotic type of metabolism.

The Compounds at the Centre of the Controversy

One drug cited in the CIA document was Myracyl D, a compound synthesised in 1938 by German chemist H. Mauss. The drug had already shown effectiveness against bilharzia, a parasitic disease caused by blood flukes. According to the Soviet research, it also demonstrated activity against malignant tumours.

Another substance discussed in the report was Guanozolo, a compound chemically similar to guanine, one of the building blocks of DNA and RNA. In laboratory tests, Guanozolo interfered with the production of nucleic acids, molecules essential for cells because they carry genetic information. The Soviet experiments showed that Guanozolo could suppress nucleic acid production in tumour cells grown in mice.

The research also examined how tumours and parasites reacted to a chemical known as atebrin, which exists in two mirror-image forms known as enantiomers. In most animals studied, the left-rotating version of the compound proved more toxic. But tumour tissues from mice, certain molluscs with left-spiralling shells, and parasitic worms inside frogs were more sensitive to the right-rotating form.

This kind of asymmetric chemical response interested Soviet researchers because it pointed to shared receptor characteristics between parasite tissue and tumour tissue, a novel observation for the early 1950s.

The scientists theorised that malignancy might arise from chemical changes within a cell's internal environment, particularly changes affecting enzymes and the proteins that carry them. The CIA document concluded by noting that ongoing Soviet research into tumour proteins and cancer cell chemistry was considered especially important at the time.

The Social Media Storm — and What the Science Supports

The document's reappearance this week sent parts of the internet into revolt. On X (formerly Twitter), surgeon and commentator Dr Jason Williams wrote: 'The Americans knew. They read it, classified it CONFIDENTIAL, and locked it in a vault for 60 years,' sharing the CIA documents in the post. Another user declared: 'The CIA knew from 1951 that cancer was parasites.' Neither claim holds up to scrutiny.

The CIA classified countless foreign scientific papers during the Cold War as part of routine intelligence gathering, including Soviet research on agriculture, physics, and medicine. There is no evidence the Alpatov paper was withheld to protect pharmaceutical profits or hide a cancer cure.

That said, the underlying science is not without merit. Cancer biologist Dr Thomas Seyfried of Boston College has argued that parasites and cancer cells share certain mitochondrial energy pathways, so drugs designed to kill parasites can sometimes hit those same pathways in tumours. That is a legitimate and active line of research, but laboratory findings in mice and cell cultures are a long distance from proven human treatments.

Ivermectin, best known as an antiparasitic drug that transformed global health, is now being investigated for a role in oncology. Laboratory and preclinical studies suggest it may interfere with cancer cell growth, promote tumour cell death, and enhance immune recognition of tumours. A Phase I/II clinical trial registered as NCT05318469, now managed by Cedars-Sinai Medical Centre, is evaluating ivermectin in combination with the checkpoint inhibitor balstilimab for patients with metastatic triple-negative breast cancer.

Of eight evaluable patients in that trial, one had stable disease, six had progressive disease, and one had a partial response. The combination was found to be safe and well tolerated, with investigators noting the clinical benefit rate warranted continued investigation. As of 2025, this remains the only ClinicalTrials.gov entry investigating ivermectin in humans as a cancer treatment. The scientific rationale exists. The clinical proof does not — yet.