The Letter: Cornelius Rhoads, Puerto Rico, and the Cancer Researcher Who Appeared on the Cover of Time

In November 1931, a young cancer researcher from the Rockefeller Institute named Cornelius Packard Rhoads was working in Puerto Rico, studying anaemia in a population that had very few other medical resources available to them. He had been there for several months and was, by some accounts, unhappy with his situation. He wrote a letter to a colleague. The letter was never mailed, but it was found by a laboratory assistant and given to a Puerto Rican nationalist leader named Pedro Albizu Campos, who made it public.

The letter, which Rhoads later described as a joke written in a moment of frustration, contained the following sentences: “The Porto Ricans are the dirtiest, laziest, most degenerate and thievish race of men ever to inhabit this sphere. I have done my best to further the process of extermination by killing off 8 and transplanting cancer into several more. The latter has not resulted in any fatalities so far.” It then stated that all physicians took delight in the abuse and torture of their subjects, and that the island needed a “tidal wave or something to totally exterminate the population.”

The fallout was immediate in Puerto Rico. In the United States, it was managed.

The Investigations

Albizu Campos sent the letter to the League of Nations, to the Vatican, and to the American press. The governor of Puerto Rico ordered an investigation. The Rockefeller Institute conducted its own internal review. Both investigations concluded that there was no evidence that Rhoads had actually killed patients or transplanted cancer cells. The governor’s investigation found no deaths that could be attributed to deliberate harm, and no clinical records supporting the specific claims in the letter.

Rhoads returned to New York in December 1931 and was treated by his colleagues with uninterrupted professional warmth. He continued his research career at the Rockefeller Institute, moved in 1939 to become director of Memorial Hospital for Cancer Research in New York, served during the Second World War as a colonel in the Chemical Warfare Service, won the Legion of Merit in 1945 for work that contributed to the development of nitrogen mustard as a chemotherapy agent, became the first director of the Sloan-Kettering Institute in 1945, and appeared on the cover of Time magazine in 1949 under the headline “Cancer Fighter.”

In 1979, twenty years after his death from a heart attack in 1959, the American Association for Cancer Research established the Cornelius P. Rhoads Memorial Award for promising young cancer researchers. It was renamed in 2003 after a Puerto Rican biology professor contacted the association and raised the history of the letter. A commissioned investigation by bioethicist Jay Katz concluded that while there was no evidence that Rhoads had killed patients or transplanted cancer, the letter itself was reprehensible enough to warrant removing his name.

What the Letter Was and Was Not

The question of whether the letter was a “savage and reckless joke,” as Rhoads described it, or a confession, has been debated for nearly a century. The investigations conducted at the time found no clinical evidence of deliberate patient harm. No death certificates, no ward records, no contemporaneous documentation supported the specific claims of killing eight patients or transplanting cancer into several more.

What the investigations could not assess, and what the documentary record cannot resolve, is what Rhoads actually did or thought during his months in Puerto Rico, or what it meant that a physician working with a vulnerable population wrote, even in a supposedly private letter, about exterminating that population as a matter of personal satisfaction. The letter describes attitudes toward the people in his care that are incompatible with the obligations of a physician, regardless of whether the specific acts it describes occurred.

The 2003 investigation noted that the letter itself was reprehensible, and that was sufficient justification for removing Rhoads’s name from a professional award. It was a more modest conclusion than the letter’s language might seem to demand, but it was the conclusion that the available evidence supported.

What This Case Illustrates

The Rhoads case sits uncomfortably between the confirmed cases of physician-perpetrated harm in this series and the category of documented professional misconduct short of the acts alleged. What is certain is that a prominent American researcher, working with a colonised population in a context of profound inequality, wrote a private document expressing a dehumanising contempt for his patients that was functionally indistinguishable in its terms from an admission of deliberate harm. What happened to him as a consequence was nothing, and then a distinguished career, and then a posthumous award in his name that stood for twenty-four years before someone thought to ask about the letter.

The case is also a study in how institutional protection operates in research medicine. The Rockefeller Institute investigated and cleared him. The professional community welcomed him back. Memorial Sloan Kettering built his career. Time magazine put him on its cover. None of those institutions, at the moment each of those decisions was made, were primarily concerned with the letter. They were concerned with the research, and the research was good. That the letter existed was known. That it had described the people he worked with as a race fit for extermination, by his own hand, was a fact that the professional architecture of mid-century American medicine absorbed without apparent difficulty.

TL;DR: Key Facts and Why This Case Matters

Who was Cornelius Rhoads?

Cornelius Packard Rhoads (1898–1959) was an American cancer researcher and administrator who trained at Harvard and worked at the Rockefeller Institute before becoming the first director of the Sloan-Kettering Institute and scientific director of Memorial Sloan-Kettering Cancer Center. He is credited with contributions to the development of cancer chemotherapy. In 1931, while working in Puerto Rico, he wrote a private letter describing his contempt for Puerto Ricans and claiming to have killed eight patients and transplanted cancer into several more, a letter he later described as a frustrated joke.

What did the investigations find?

Both the Puerto Rican governor’s investigation and the Rockefeller Institute’s internal review found no clinical evidence that Rhoads had killed patients or transplanted cancer. No supporting documentation, death records, or ward records corroborated the specific claims in the letter. The investigations cleared him of the specific acts alleged while not addressing the attitudes expressed in the letter itself.

What happened to his career?

Rhoads’ career was unaffected by the letter. He returned to New York in 1931, continued at the Rockefeller Institute, and rose to lead Memorial Hospital and then the Sloan-Kettering Institute. He received the Legion of Merit for wartime service, appeared on the cover of Time magazine in 1949, and had a major professional award named for him in 1979. The award was renamed in 2003 following renewed attention to the letter.

Why does this case matter?

The Rhoads case illustrates how professional standing and research productivity can insulate a researcher from consequences for documented expressions of contempt for the populations they work with. It also raises a question that the available evidence cannot definitively answer but that the history of research ethics makes relevant: when a physician working with a vulnerable, colonised, relatively powerless population writes, even privately, about the satisfaction of harming them, what weight should that expression carry in assessing the integrity of the clinical relationship? The question was not seriously asked in 1931. It was partially addressed in 2003. It has not been fully answered.