Although the five-year survival rate for pediatric cancers now approaches 85%, some of them, including infiltrative brainstem glioma, remain with a poor prognosis. Inoperable, these cancers are usually treated with radiotherapy, which sometimes helps slow the disease but whose effects are short-lived. No drug has yet demonstrated its effectiveness. Progression is very rapid indeed and the outcome is usually fatal within 9 to 12 months after the tumor is discovered.
A Belgian child, Lucas, who is now 13 years old, however, has defied all predictions: diagnosed at the age of 6 with a disease considered incurable, he is now considered cured, his brain no longer showing signs of a tumor. “Lucas has exploded all the counters of life,” said his doctor, Jacques Grill, pilot of the brain tumor program in the pediatric oncology department of the Gustave-Roussy anti-cancer center south of Paris.
The pediatrician remembers with emotion announcing to Lucas’ parents seven years ago that their son was going to die. At the time, his family came to France for treatment, where the little boy was one of the first patients to join a clinical trial to test the new drug, a targeted therapy. From the beginning, Lucas responded very well to the treatment. “During the MRIs, I saw that the tumor had completely disappeared,” Dr. says Grill, who, despite these miraculous results, does not dare to decide to stop the drug. Until he found out that a year and a half ago, the child himself had stopped taking it.
“I don’t know of a case like this in the world,” confides the doctor, whose team started researching this cancer about fifteen years ago. What remains to be understood is why Lucas recovered and how his medical case could bring hope to hundreds of young people in the future.
A dozen other children included in the same clinical trial found their life expectancy exceeded and were still alive many years after diagnosis – but their cancer had not completely disappeared. “The biological characteristics of their tumor” undoubtedly led to increased life expectancy, which explains their better response to treatment compared to other patients undergoing the same therapy, Dr Grill underlined.
“Long Term Work”
“Lucas’ tumor had a very rare mutation and we believe it was this mutation that made his tumor cells more sensitive to the drug,” adds the pediatrician, also a researcher at Insurm. In an ongoing trial (Biomed), which compares the drug discovered by Lucas with a promising new treatment, the Gustave-Rousseau researchers are not only studying the genetic abnormalities of all patients’ tumors but also creating tumor organoids (3D copies of the patient). Tumors are studied in the laboratory to understand their biology and their sensitivity to drugs.
“Lucas’ case opens up real hope: we will try to reproduce in vitro the changes we have identified in his cells,” says Marie-Anne Debilly, teacher-researcher, overseeing this work. Specifically, medical teams want to find out whether the DNA changes Lucas introduced, once “reproduced” in other patients, also result in their tumors shrinking.