Sleep Apnea May Trigger Cancer Spread

Obstructive sleep apnea has been associated with increased cancer cases and deaths. Recent studies show that the hypoxic (low-oxygen) environment and irregular airflow in sleep apnea trigger tumor-cell growth.

In November 2016, the respected lung disease journal Chest published research examining sleep apnea’s effects on cancer cells in laboratory animals. Mice were divided into two groups: one received regular airflow, the other intermittent hypoxia to induce sleep apnea.

According to the Research Results:

• Lung cancer cells became more malignant in mice developing sleep apnea. The cause was identified as exosomes released into circulation because of sleep apnea.

Exosomes are microscopic carriers transporting proteins, lipids and miRNAs. They primarily contribute to cell communication. They resemble letters sent between cells, but cancer cells use them to increase growth. Excessive exosome numbers produce greater tumor growth and easier metastasis . Recent studies investigate detecting exosomes through blood tests for early diagnosis and selecting appropriate treatment.

• Low tissue oxygen was found to increase release of “cancer-cell-friendly” exosomes.
• An intriguing result was that exosomes isolated from mice and humans with sleep apnea produced the same effects in cell culture models.

What Does This Study Mean Clinically?

• Sleep apnea was identified as an independent factor in poor cancer course. It should therefore be taken seriously and treated in cancer patients.
• Researchers also examined RNA particles released from exosomes. Advanced genetic analysis may help identify molecules and pathways making cancer more aggressive.