Cancer Treatment Timing Matters: Study Shows Morning Doses Boost Immunity & Survival
A randomized trial involving 210 patients with advanced lung cancer has provided the strongest evidence yet that the timing of immunotherapy can significantly impact patient outcomes, bolstering decades of speculation about the body’s internal clock and its influence on cancer treatment. The study, published February 2 in Nature Medicine, found that administering immunotherapy earlier in the day led to substantially improved progression-free survival and overall survival rates.
Patients receiving the first four cycles of treatment – a combination of an immune checkpoint inhibitor and chemotherapy – in the morning or early afternoon experienced a nearly doubled progression-free survival, averaging 11 months compared to 6 months for those treated later in the day. Average overall survival was approximately 28 months for the earlier-treatment group, versus 17 months for those receiving treatment later, according to the research led by Yongchang Zhang, a thoracic oncologist at Hunan Cancer Hospital in Changsha, China.
“Just adjusting the infusion time can lead to better survival outcomes,” Zhang stated.
The findings build upon earlier observations suggesting a link between circadian rhythms and cancer treatment efficacy. Previous studies, however, were often limited by retrospective data analysis, making it difficult to isolate the effect of timing from other potentially confounding factors. “The data are very clear that time of day makes a difference,” said Chi Van Dang, a cancer biologist at the Ludwig Institute for Cancer Research in New York City, who was not involved in the study. He noted that prior research had hinted at similar effects, but lacked the rigor of a randomized, controlled trial.
Researchers analyzed blood samples from participants and discovered that those treated earlier in the day exhibited a more robust immune response, characterized by higher levels of cancer-fighting T cells. Importantly, the study did not find an increase in immune-related side effects associated with the earlier dosing schedule, suggesting that optimizing timing can enhance the immune system’s anti-tumor activity without exacerbating autoimmune risks.
The study’s results suggest a potentially low-cost and easily implementable strategy for improving cancer care. However, logistical challenges related to hospital scheduling and patient availability may hinder widespread adoption. Michael Lowe, a surgical oncologist at Emory University’s Winship Cancer Institute in Atlanta, is currently conducting a separate trial examining the optimal timing – morning, midday, or afternoon – for administering immune-targeted drugs to patients with advanced skin tumors.
Lowe indicated that if further randomized trials confirm these benefits across different cancer types and immunotherapy regimens, healthcare systems will need to adapt to accommodate morning dosing as a standard practice.