Circadian Rhythm, Internal Body Clock May Affect How Effective Some Cancer Treatments Are, Study Reveals

A new study suggests that the circadian rhythm of the body could affect the effectiveness of some cancer treatments.

While the circadian rhythm is known to affect various things of health, from metabolism to sleepiness, this study shows that it may also affect yet another health aspect.

Cancer Treatments

Checkpoint inhibitors are types of immunotherapy drugs that block certain proteins from being binded to cancerous tumors. This means that the T cells of the immune system would be able to recognize and kill cancer more easily.

In theory, these drugs are good, especially since the drugs have lesser toxicity compared to chemotherapy. However, scientists are still looking for ways to boost the effect of such an approach in practice.

Across the US, various checkpoint inhibitor treatments have been approved for human application. However, though such drugs can treat various cancers, they have only been observed to be effective among some patients.

Now, according to a new study, it appears that the circadian rhythm could play a role in the effectiveness of such treatments.

ALSO READ: What is Circadian Rhythm? The Science of Biological Clock Mechanism and Its Effects on Sleep Cycles

Circadian Rhythm Could Affect Cancer Treatment Effectiveness

As part of the study, researchers from the University of California, Irvine discovered that in mouse colorectal cancer models, the 24-hour body clock impacted the defense stretch that the tumors put up. It also affected the capacity of checkpoint inhibitors to combat such tumors.

Moreover, when the mice had disrupted circadian rhythms, it was found to reduce the ability of their immune system to tackle cancer. Coupled with rich earlier research, this suggests that treatment times and lifestyle changes could help fight cancer.

Sema Masri, a biological chemist from the university, explains that understanding how circadian disruption could promote the progression of the disease could result in behavior modification for cancer risk reduction.

For colorectal cancer, tumors typically produce immunosuppressive cells in order to try disabling the protections of the body's immune system. The first finding of the study was that the abundance of such cells altered as time passed with the mice's circadian rhythms.

The study also found that disrupting the body clock further increased these cells, boosting the progression of cancer. The last finding was that checkpoint inhibitor therapies appeared to work best when the levels of immunosuppressive cells were peaking.

These were all noted in the "Circadian control of tumor immunosuppression affects the efficacy of immune checkpoint blockade" study.

This shows how circadian rhythms could be maximized in order to give a better chance to treatments. However, further research is necessary to uncover other factors that play a role.

Masri noted that proper circadian rhythm regulation is crucial for inflammation suppression and peak immune function support.

Scientists keep on looking into the connection between bodyclock and functions of the immune system. Optimizing or managing the circadian rhythm has also recently been associated with Alzheimer's disease and biological aging.