About the article “Targeted therapies against cancer fall short of the hopes raised” by Professor Ian Tannock of the University of Toronto, Canada.
In this article, originally published in the prestigious New England Journal of Medicine, and then in Le Monde, Professor Tannock says aloud what is said in a low voice in the oncology community: targeted therapies are not and will not be the solution – And the personalized medicine that goes with does not bring much.
Let’s review all this in detail:
The Theoretical Support:
Everything is based on the hypothesis that the cause of the cancer is a series of genetic mutations and that by developing molecules that will target the cells carrying these mutations they will disappear. Everything happens, says I. Tannok, as if the seductive simplicity of this postulate dispensed with analyzing its results, the only criticism concerning the otherwise exorbitant costs of these treatments.
But then what are the hopes in 2017…?
Mutations, the only cause of cancer…?
Certainly not. Mutations accompany (they are correlated to …) carcinogenesis, tumor growth and metastasis.
But other causes can cause cancer of a tissue: a virus (think of the current outbreak of cancer of the amygdala, penis, anal canal, linked to HPV virus, change in morals obliges); a hormonal disorder; a change in cellular and tissue architecture, etc.
And let us not forget the experiments which showed the role of the environment of the tumor (the “ExtraCellular Matrix” surrounding the tumor tissue) in the appearance of a cancer and in the possible “reversion” (return to the Normal) of the tumor tissue.
What did the Targeted Therapies bring?
In terms of healing for “solid tumors” (as opposed to hematological malignant diseases) the only success was trastuzumab (Herceptin®) given to patients with breast cancer after surgery. That is 3% of breast cancers.
Targeted therapies have very modestly contributed to the “chronicisation” of some breast cancers, even of the colon/rectum.
For the other solid tumors there are some very transient successes, but, note I. Tannock, when measuring the service rendered only 5% of patients have a significant prolongation of their life when compared to hormone therapy and chemotherapy. And the toxicity of these “new cancer drugs” is far from negligible.
So what to do? What are the real hopes?
Obviously, there is no justification for the prices of these drugs.
Multiplying clinical trials and combinations of molecules is an obvious leak forward that does not call into question the theoretical support deficit and the toxicities that will quickly limit this artifice.
Immunotherapy is more promising: giving back to the body the means to eliminate cancer cells by the patient’s own immune system is in 2017 a reality. Immunotherapy has recently emerged from the treatment of only cancers of the kidney and skin melanoma, of which it is known for a long time that they have an intrinsic immunological “fragility”. We are now dealing with cancers of the lung, ENT, bladder and many others by these new molecules. But we can already see the limits of this new approach. Healing will be rare. Chronicisation is a more realistic option.
Let us go further than I. Tannok.
There is a new approach that is advancing in the research community: the use of mechanical rather than biological signals to influence the behavior of solid tumors.
This paradigm shift is one of the strongest avenues for rethinking the cure of cancer. And oncology as a whole.