Are cancer treatments more effective in the morning?: Study reveals shocking findings

Typically, when your doctor's office asks for scheduling an appointment for treatment, you would choose any time when they could schedule you in. However, according to reports from a recent study, when it comes to treatment for common cancers, the timing of your appointment can matter a lot.Researchers from China, at the June meeting of the American Society of Clinical Oncology (ASCO) presented preliminary findings of an unpublished study in a peer-reviewed journal where 210 patients receiving treatments for advanced lung cancer were randomised to receive two important treatments- standard chemotherapy and immunotherapy treatment, before or after 3 pm.After following the patients for about 18 months, researchers found that those who had their infusion earlier in the day had improved survival, going months without progression of their cancer, when compared to the patients who had it later in the day.They also saw evidence of increased immune-system response in patients with earlier treatment timings. One of the factors for this is the body's circadian rhythms. The immune system's function varies throughout the day, and thus, the treatment could generate different effects, as the study suggests.The researchers also analysed other studies to build on the findings on this type of immunotherapy on different kinds of cancer and found improved outcomes in patients treated earlier in the day.A 2025 study analysing data from 713 patients in France and China with advanced lung cancer revealed that patients who received immunotherapy earlier in the day lived longer with cancer. The results were quite shocking as patients who received the treatments before 11:30 am lived an average of 33 months, whereas those who received them after that time lived an average of 20 months.However, this is only one of the plausible factors. It could also be that the people who received the infusions in the morning were different, and they may have been more likely to survive longer from cancer regardless of the treatment timings. They could be medically healthier, wealthier and have better access to care. The study, as mentioned, is peer reviewed, but it does reveal that the previous works on the topic were onto something.