Obstructive sleep apnea may increase risk of cancer

China: Obstructive sleep apnea (OSA) is linked to a 36% increased risk of cancer, according to a meta-analysis published in the International Journal of the Science and Practice of Sleep Medicine. The risk was much greater, greater than a twofold increase, in the subgroup of patients with moderate to severe OSA, however there was no upsurge with mild OSA.

Numerous cancer kinds rose, including kidney and central nervous system cancers but not lung cancer, the authors reported.

Although the exact mechanism by which OSA may cause cancer is uncertain, cellular research and animal models predict that intermittent hypoxia or sleep fragmentation, two characteristics of OSA, encourage carcinogenesis, development, invasion, and metastasis. The research came to the "biologically plausible" conclusion that there is a link between OSA and cancer risk as a result of the combination of animal and cellular evidence.

The goal of the study was to examine how obstructive sleep apnea (OSA) affects the chance of developing cancer.

For this objective, following a search of the Cochrane, Embase, and PubMed databases, a meta-analysis of 18 observational studies with more than 430,000 individuals was carried out. Results were shown as a combined relative risk (RR) of cancer in the exposed (i.e., those with OSA) compared to the risk in the unexposed (i.e., those without OSA). Analysis of subgroups was done according to gender, OSA severity, study design, and cancer type.

Key findings of the study:

• When confounding factors were taken into account, OSA (vs no OSA) was linked to a 36% rise in the total risk of cancer (RR, 1.36; 95% CI, 1.18-1.56).
• OSA was linked to a 49% higher chance of getting cancer when confounding factors weren't taken into account (RR, 1.49; 95% CI, 1.32-1.69).
• The category with moderate-to-severe OSA, defined as ≥ 15 events/hour, had the highest risk.
• The probability of cancer was more than two times greater in this category (RR, 2.62; 95% CI, 1.64-4.19), although the risk of mild OSA (5-14.9 events/hour) remained unaffected.
• The main findings are given credibility by the increasing risk associated with greater exposure.
• In the female subgroup with OSA (vs no OSA; RR, 1.27; 95% CI, 1.06-1.51), the risk of cancer ramped up by 27%, but not in the male subgroup.
• The following cancer type subgroups showed higher risk:

-breast cancer increased by 32% (95% CI: 1.03-1.70; RR: 1.32).

-cancer of the central nervous system increased by 71% (RR, 1.71; 95% CI, 1.06-2.75).

-kidney cancer increased by 81% (RR, 1.81; 95% CI, 1.20–2.74).

-liver cancer rose by 19% (RR, 1.19; 95% CI, 1.10-1.29).

-pancreatic cancer increased by 23% (95% CI: 1.14–1.33).

• The risk was not elevated for chest cancer, prostate cancer, Melanoma, intestinal cancer, breast cancer, cancer of the womb, syringe cancer, and thyroid tumors.

The researchers came to the conclusion that doctors should actively treat OSA in both primary care and specialist settings.

According to additional research, continuous positive airway pressure, the best OSA treatment, may lower the risk of cancer.

REFERENCE

Wu D, Zhao Z, Chen C, Lu G, Wang C, Gao S, Shen J, Liu J, He J, Liang W. Impact of obstructive sleep apnea on cancer risk: a systematic review and meta-analysis. Sleep Breath. 2022 Sep 21. doi: 10.1007/s11325-022-02695-y. Epub ahead of print. PMID: 36129602.