Recently, a few studies have reported a link between sleep apnea and the presence of cancer. These studies were very impressive and used large databases with thousands of individual health records. However, these studies have been limited by lumping together individuals with different types of cancer. This is not ideal, because it limits our ability to draw lines of causation between types of cancer and apnea. A recent study, however, has focused specifically on melanoma, or skin cancer. Using melanoma, a research team set out to see whether worse sleep apnea is linked with cancer severity.
Fifty-six individuals were used in this investigation, and these individuals had already been diagnosed with melanoma. Each subject was given a full overnight study for the assessment of sleep apnea presence and severity. Apnea-hypopnea index (AHI) and the amount of oxygen deprivation caused by these apneas were used as measures of sleep apnea severity. In this study, melanoma severity was determined by how quickly the melanoma was spreading and by the depth of the growth, which was determined based on Breslow’s index. Results showed that of all subjects tested, 60.7% had mild sleep apnea (AHI>5) and 14.3% had severe sleep apnea (AHI>30).
Results also showed that AHI and oxygen desaturation levels were both independently related to the rate of melanoma growth. In other words, higher AHI and worse oxygen deprivation were related to faster the melanoma growth. They were also associated with Brelow’s index, meaning worse sleep apnea was related to greater depth of the melanoma.
This study was one of the first to take a specific type of cancer and link it with sleep apnea. Unfortunately, this same pattern likely persists for other types of cancer. It may be that oxygen deprivation caused by apneas and bodily stress caused by a lack of sleep hinders recovery and healing that may otherwise be present. Luckily, we have a known effective treatment for sleep apnea in the form of PAP treatments. The message, as always, is clear. Pick your treatment and stick to it!
Sources: Martínez-García, M. Á., Martorell-Calatayud, A., Nagore, E., Valero, I., Selma, M. J., Chiner, E., ... & Farré, R. (2014). Association between sleep disordered breathing and aggressiveness markers of malignant cutaneous melanoma. European Respiratory Journal, 43(6), 1661-1668.