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According to a Swiss study, taking into account the circadian rhythm improves the fight against cancer. According to the Swiss researchers, identifying the right time to treat would improve the effectiveness of treatment and reduce side effects.
A true internal body clock, the circadian rhythm not only regulates your sleep. It would have an impact on the development, diagnosis and treatment of cancer. According to a Swiss study, circadian rhythms influence the rhythm and spread of tumors, which could help us find the best times to make a diagnosis and administer anti-cancer therapies… and thus improve the prognosis.
Cancers grow and spread at specific rates
Our circadian rhythms help our bodies synchronize different tasks throughout the day, from gene expression to immune function to cellular repair. Chronically disrupted circadian rhythms – due to erratic sleep patterns, jet lag or shift work, for example – can increase cancer risk. On this subject, breast cancer has just been recognized for the first time as an occupational disease in a woman working night shifts for years. Other works have even pointed out that circadian rhythms are not only involved in the appearance of tumors, but also govern cancer progression and metastasis.
These metastases are the leading cause of death in cancer patients. Schematically, they are the result of cancer cells that break away from the primary tumor to reach and enter a new organ, via the bloodstream. A process that oscillates rhythmically throughout the day, with a rhythm that differs according to the types of cancer. For example, breast cancer is more likely to metastasize at night while we sleep, while prostate cancer and multiple myeloma peak at other times of the day.
Chronotherapy: determining the best time to treat
According to the authors, this information can help us determine the optimal time to administer chemotherapies and immunotherapies. This practice of administering drugs and immune therapies at specific times of the day is known as chronotherapy. “Chronotherapy promises to be a valuable complementary treatment option in the fight against cancer“say the authors.
Several studies have shown that chronotherapy can reduce the severity of side effects but also increase the effectiveness of treatment. The authors cite a recent study in which melanoma patients who received immunotherapeutic drugs before 4:30 p.m. were almost twice as likely to survive as patients who received the treatment later in the day.
The “rhythm of cancers” varies according to the types and the patients
One of the challenges is therefore to identify the optimal moment of care, which can vary according to the types of cancer and the treatments. The authors also note that the clinical benefits of chronotherapy could be affected by factors such as the patient’s gender and genetic history. Many questions therefore remain unanswered, but the stakes are high since it is a question of reducing the side effects and the effectiveness of anti-cancer treatments.