Warburg and cancer: when the past illuminates the future of oncology

Otto Warburg's legacy: an inconvenient truth?

Otto Warburg discovered a fact that remains absolute and undisputed to this day: cancer cells take up sugar avidly and ferment it, even when oxygen is available.

For decades, this observation was regarded as a secondary "oddity". The dogma that took hold from the 1970s onwards ran as follows: "Cancer is a disease of the genes (DNA mutations). The strange metabolism is merely a consequence of those mutations, one symptom among many."

As a result, research focused 99% on DNA sequencing and the search for defective genes, leaving metabolism and the mitochondria to pure biochemists, far removed from the oncology wards.

Schwartz's rehabilitation: what if Warburg was right about the cause?

Laurent Schwartz's intellectual approach was to reopen the Warburg file with a simple, provocative question: what if this metabolism was not a symptom, but the driver?

Schwartz does not claim that Warburg was right about everything (the science of the 1930s knew nothing of DNA), but he suggests that Warburg's central insight was thrown out with the bathwater. Re-reading Warburg in the light of modern biology, Schwartz proposes a synthesis:

1. The energy failure: Warburg said "the mitochondria are broken".
2. The modern answer: we now know that the mitochondria are not always physically "broken", but they are often functionally inhibited or hyperpolarised (blocked).
3. Schwartz's conclusion: whether the mitochondrion is broken or blocked, the outcome for the cell is the same: it suffocates. It is forced to ferment. And this fermentation (the Warburg effect) is the engine that drives the cell to divide and to resist death.

Why does this reappraisal matter today?

This shift in perspective is crucial for the patient.

• If Warburg metabolism is merely a "symptom", it can be ignored and the hunt for genes can continue.
• If Warburg metabolism is a "driver" that the tumour requires (as Schwartz believes), then blocking this metabolism or restoring mitochondrial respiration becomes a major therapeutic target.

Therein lies the hope: whereas the genome of a tumour is an unstable chaos that is forever changing (making targeted therapies difficult to sustain over time), the Warburg metabolic profile is remarkably stable and universal across most aggressive cancers.

Targeting the Warburg effect (cutting off the sugar supply, preventing fermentation, or reviving the mitochondrion) could be the Achilles heel common to many cancers.

A healthy but lopsided scientific debate

It should be noted, in fairness, that the scientific community is not "against" this idea on principle. In fact, over the past ten years, metabolic oncology (the field studying cancer metabolism) has been booming. Thousands of papers are being published. It is being rediscovered that Warburg was right about the importance of the phenomenon.

The move from "interesting theory" to "available therapy" is, however, stalling. Why?

• Complexity: metabolism is an intricate network, difficult to manipulate without affecting healthy cells.
• The economic wall: the molecules capable of acting on the Warburg effect and the mitochondria are often old, "ordinary" molecules that are off-patent (such as dichloroacetate, methylene blue, or metformin).

The reality of pharmaceutical research

This is a point that must be addressed without anger but with clear-sightedness. Developing a new anticancer drug costs hundreds of millions of euros (clinical trials, regulation). That cost is only bearable for a private company if a patent guarantees a sales monopoly for 20 years to recoup the investment.

A molecule such as methylene blue, or those targeting the Warburg effect, can no longer be patented. By definition, no one will put 100 million euros on the table to prove their efficacy, because once it were proven, any generic manufacturer could sell the molecule cheaply the very next day.

It is not that science has "proved that it does not work". It is often that the economic system makes it impossible to build the proof that it does work. Schwartz's theory about Warburg therefore remains in a grey area: biologically plausible, supported by small studies and clinical cases, but orphaned from the major "gold standard" clinical trials for want of a viable economic model.

Conclusion

Schwartz's reappraisal of Warburg is a major intellectual contribution that puts biological common sense back at the centre of the debate. It reminds us that cancer is also a disease of energy and matter, not solely of genetic information. Even if all the answers are not yet in, this metabolic avenue offers rational, physiological grounds for hope that deserve, more than ever, the attention of public and philanthropic research.