Little diagnosed and without treatment for centuries, cancer has undergone a therapeutic revolution in a few decades. Innovations are multiplying, without replacing traditional therapies.
Cancer was diagnosed in ancient Egypt, before the Greek doctor Hippocrates gave it a name: “karkinos”, crab in Greek. The first treatments, at the end of the 19th century, involved surgery, which consists of removing the tumor. Today, surgery remains “an important therapeutic weapon”, underlines Professor Steven Le Gouill, onco-hematologist at the head of the Institut Curie hospital complex in Paris: “Breast cancer, colon cancer, sarcoma. .. Many tumors are treated by surgeons”.
But surgery is also “a gateway to many cancers: it is thanks to surgery that we have tumor tissue which allows diagnosis”, he notes.
Radiotherapy emerged thanks to the advances of German physicist Wilhelm Röntgen, who discovered X-rays in 1895. Even today, it continues to play a major role, since more than 70% of cancer treatments include radiotherapy sessions. . This consists of delivering rays (electrons, photons, protons) which destroy cancer cells. The downside: the rays will damage all the tissues passed through.
Many innovations attempt to remedy this, including high-precision, high-dose irradiation. It is a question of “being as precise as possible and delivering the strongest possible dose of radiation to the tumor, but sparing healthy tissue”, explains Steven le Gouill.
These are cytotoxic drugs – several molecules often used in combination – which will also destroy cancer cells. If it is often associated with significant side effects (hair loss for example), this therapy continues to be very effective, as for acute leukaemias for example.
There are two vaccines to prevent the occurrence of cancer, when it is linked to a virus: the vaccine against human papillomaviruses and that against hepatitis B (causing liver cancer). A lot of research has been going on for years on “therapeutic vaccines”. In this case, it involves producing tumor antigens – via messenger RNA or viruses – which will enable the immune system to activate by producing the appropriate response in cancer patients.
Over the past twenty years, targeted therapy has changed the lives of many patients. These are molecules derived from chemistry, designed specifically to block or interrupt a molecular mechanism essential to the progression, proliferation or survival of tumor cells.
This is the great revolution of recent years. It involves boosting the patient’s immune system to help it track down and kill cancer cells. Immunotherapy is based on synthetic antibodies, produced in the laboratory. Several modes of action are possible. These antibodies will, for example, target a protein on the surface of cancerous cells: by binding to the target cell, the antibody causes an antitumor action, either directly or by stimulating the immune system.
This is cell therapy. The principle: teach our immune system to recognize and attack cancer cells. The cells of the patient’s immune system (most often T lymphocytes) are taken, genetically modified in the laboratory and then reinjected into the patient: they will then target the cancer cells.
Biotechs have also launched into so-called allogenic CAR-Ts. This time, the scientists will genetically modify cells that do not come from the patient himself but from a healthy carrier. CAR-Ts have shown their effectiveness in blood cancers such as lymphomas, certain forms of acute leukemia and multiple myeloma. But this therapy is very expensive.
“The interest is to combine all these approaches and new therapies to have a personalized plan for the patient”, observes Professor Le Gouill, who says he is optimistic: “We have passed a milestone in our understanding of the tumor cell. Cancer remains a test, but progress has been made, exponentially”.