What if the key to improving certain cancer treatments was not only found in the discovery of a new molecule? What if it was also a question of timing? A large study, the most robust ever conducted on the subject, announces that receiving immunotherapy before 3 p.m. could almost double the survival time of certain patients with lung cancer.
Our cells do not continually function uniformly. They follow twenty-four hour cycles, the famous circadian rhythms, which regulate sleep, metabolism… but also the activity of the immune system. For several years, studies have suggested that patients treated earlier in the day responded better to certain immunotherapies. No solid experimental evidence yet existed.
This is where Francis Lévi comes in. This French researcher from Paris-Saclay University and his team recruited 210 patients with lung cancer. All received a combination of chemotherapy and immunotherapy, including immune checkpoint inhibitors, drugs that help immune cells attack tumors. During the first four treatment cycles, spaced three weeks apart, half of the participants were treated before 3 p.m., the other half after.
The researchers followed the patients for almost 29 months. Result: those treated at the start of the day lived on average 28 months, compared to 17 months for the others. A gap that Francis Lévi describes as“absolutely huge”.
Towards an even finer adaptation?
The probable explanation lies with T lymphocytes, key cells in the immune response. In the morning, they concentrate more around the tumors before gradually dispersing into the blood circulation throughout the day. Administering immunotherapy at this strategic moment would therefore amount to striking the enemy when the troops are already there. Whereas doing it afterwards would mean waiting for their trip and losing efficiency, summarizes New Scientist.
This approach, called chronotherapy, is attractive for its simplicity: no additional cost, no new medication, just a different organization of care. This is obviously not a miracle solution and the model remains to be refined, but in this area, all gains are welcome. The researchers now want to determine whether treatment administered even earlier in the day could enhance the effect observed, and whether these benefits extend to other cancers treated with immunotherapy.
Another crucial question remains: does each patient have their own optimal schedule? “Early riser” and “night owl” profiles present distinct immune variations, which may require fine-grained personalization of treatments. Each cycle would be personal, according to our own biological clock.
If these results are confirmed, they could profoundly transform hospital practice. In the fight against cancer, timing could become a therapeutic tool in its own right.
