Obstructive sleep apnea and Fuhrman grade in patients with clear cell renal cell carcinoma treated surgically

A cross-sectional study of obstructive sleep apnea in patients with colorectal cancer

BACKGROUND

The association between colorectal cancer (CRC) and obstructive sleep apnoea (OSA) has been attracting increasing attention. several studies had confirmed that OSA increases the risk of CRC onset. However, the findings of studies on the morbidity of OSA in patients with CRC were unclear. Therefore, this study aimed to investigate the morbidity of OSA in patients with CRC as well as the association between the clinicopathological characteristics of OSA and CRC.

METHODS

A total of 414 patients with a pathological diagnosis of CRC from 1 January, 2020 to 30 December, 2020 were included in this study. Demographic characteristics, clinical information, and tumor characteristics of participants were collected; sleep was monitored using a wearable oximeter and via sleep quality questionnaire. The oxygen desaturation index (ODI) was used to classify OSA severity so that the diagnostic criteria for OSA were set based on the ODI as 0-5 (normal) and ≥5 (abnormal). After correcting for confounding factors, a logistic regression analysis was performed to calculate the odds ratio (OR) and 95% confidence interval (CI) for the factors affecting the tumor lymph node stage (N stage).

RESULTS

A total of 402 patients with CRC were included in this study, including 225 (55.97%) men and 177 (44.03%) women. The mean ODI value of participants was 3.40±8.17. The morbidity of OSA among the patients with CRC having ODI ≥5 was 16.17%. A comparison between the normal and abnormal ODI value groups revealed that the high proportion of abnormal ODI was related to higher N stage (P<0.05). Logistic regression analysis revealed a correlation of ODI values and age to the N stage. Specifically, CRC patients with an abnormal ODI had a higher risk of lymph node metastasis compared to those with normal ODI (OR =1.915, 95% CI: 1.025 to 3.579). Moreover, patients with CRC aged ≥65 years had a higher risk of lymph node metastasis compared to those aged <65 years (OR =2.190, 95% CI: 1.163 to 4.125).

CONCLUSIONS

CRC patients with abnormal ODI are susceptible to OSA. Additionally, abnormal ODI and age ≥65 years are relevant factors for the N2 stage.

Obstructive sleep apnea and incidence of malignant tumors: a meta-analysis

OBJECTIVES

This paper assessed the connection between obstructive sleep apnea (OSA) and the incidence of malignant tumors.

METHODS

PubMed, Cochrane, Scopus, Health Source Nursing Academic Edition, EMBASE, and Web of Sciences were searched until the date of July 25, 2020. The analysis included an assessment of the overall incidence of OSA malignancies, the incidence of OSA malignancies by age and gender, and the incidence of different types of malignancies in patients with OSA. The total rate and the corresponding 95% confidence interval (CI) of the incidence of malignant tumors in patients with OSA were calculated. Patients with OSA were classified according to age, gender, and different types of malignant tumors for meta-analysis.

RESULTS

A total of 12 studies involving 862,820 participants were included in this meta-analysis. Random effect model analysis showed that the total incidence of malignant tumors in patients with OSA was 0.046% (95% CI: 0.027-0.065, P < 0.001), higher than that of malignant tumors in the general population. According to the analytical results classified by gender, the incidence of malignant tumor in female patients with OSA was 4.0% (95% CI: 0.014-0.066), higher than that in male patients at 3.5% (95% CI: 0.012-0.058). The analytical results classified by age showed that the incidence of malignant tumors in patients with OSA aged below 60 years was 1.8% (95% CI: 0.000-0.036), lower than that in patients aged above 60 years at 4.3% (95% CI: 0.002-0.084). The analytical results classified by the types of malignant tumors showed that the incidences of breast cancer, lung cancer, colorectal cancer, prostate cancer, kidney cancer, pancreatic cancer, and melanoma in patients with OSA were 0.5% (95% CI: 0.001-0.008), 0.5% (95% CI: 0.002-0.009), 0.5% (95% CI: 0.003-0.008), 1.1% (95% CI: 0.002-0.021), 0.3% (95% CI: 0.001-0.005), 0.1% (95% CI: 0.001-0.002), and 0.4% (95% CI: 0.003-0.005), respectively. Among them, the incidence of prostate cancer was the highest, followed by breast cancer, lung cancer, colorectal cancer, melanoma, and kidney cancer, whereas the incidence of pancreatic cancer was the lowest. However, the incidence of specific malignant tumors in patients with OSA did not have a significant increase compared with that in the general population.

CONCLUSIONS

The analytical results of this meta-analysis suggested that OSA may be associated with an overall increase in the incidence of malignancies based on the currently available data, but the connection with specific types of malignancies was not significant. Further studies are needed to explore this association in the future.

Sleep Apnoea Adverse Effects on Cancer: True, False, or Too Many Confounders?

Obstructive sleep apnoea (OSA) is a prevalent disorder associated with increased cardiovascular, metabolic and neurocognitive morbidity. Recently, an increasing number of basic, clinical and epidemiological reports have suggested that OSA may also increase the risk of cancer, and adversely impact cancer progression and outcomes. This hypothesis is convincingly supported by biological evidence linking certain solid tumours and hypoxia, as well as by experimental studies involving cell and animal models testing the effects of intermittent hypoxia and sleep fragmentation that characterize OSA. However, the clinical and epidemiological studies do not conclusively confirm that OSA adversely affects cancer, even if they hold true for specific cancers such as melanoma. It is likely that the inconclusive studies reflect that they were not specifically designed to test the hypothesis or because of the heterogeneity of the relationship of OSA with different cancer types or even sub-types. This review critically focusses on the extant basic, clinical, and epidemiological evidence while formulating proposed directions on how the field may move forward.

Obstructive sleep apnea and cancer: a complex relationship

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) has been recognized as a risk factor for cancer mainly through hypoxia, based on studies that did not distinguish among cancer types. The purpose of this review is to discuss the most recent data on epidemiology and pathophysiology of the OSA-cancer association.

RECENT FINDINGS

According to epidemiological studies, OSA may have different influences on each type of cancer, either increasing or decreasing its incidence and aggressiveness. Time spent with oxygen saturation below 90% appears the polysomnographic variable most strongly associated with unfavorable effects on cancer. Experimental studies support the role of hypoxia as an important risk factor for cancer growth and aggressiveness, especially when it shows an intermittent pattern. These effects are largely mediated by the hypoxia-inducible factor, which controls the synthesis of molecules with effects on inflammation, immune surveillance and cell proliferation. Sleep fragmentation participates in increasing cancer risk. Modulating effects of age remain controversial.

SUMMARY

Effects of OSA on cancer may largely vary among neoplastic diseases, both in their magnitude and direction. The worse risk associated with intermittent rather than persistent hypoxia, and the effects of OSA therapy on cancer natural history are still poorly known, and deserve new careful studies.

The Association of Sleep Apnea and Cancer in Veterans

Objective

To test the association between preexisting obstructive sleep apnea (OSA) and subsequent cancer in a large long-term cohort of veteran patients.

Study Design

Retrospective matched cohort study.

Setting

The Veterans Affairs Health Care System.

Subjects and Methods

All veteran patients diagnosed with OSA between 1993 and 2013 by International Classification of Diseases, Ninth Revision ( ICD-9) codes in any Veterans Affairs facility and veteran patients without an OSA diagnosis, matched to patients with OSA by age and index year. Cancer diagnoses were identified by ICD-9 codes for the time period at least 2 years after OSA diagnosis or index date. We tested the association between OSA and cancer using multivariate Cox regression with time since cohort entry as the time axis, adjusting for potential confounders.

Results

The cohort included 1,377,285 patients (726,008 with and 651,277 without an OSA diagnosis) with mean age of 55 years, predominantly male (94%), a minority obese (32%), and median follow-up of 7.4 years (range, 2.0-25.2). The proportion of patients diagnosed with cancer was higher in those with vs without an OSA diagnosis (8.3% vs 3.6%; mean difference 4.8%; 95% confidence interval [CI], 4.7%-4.8%; P < .001). After adjusting for age, sex, year of cohort entry, smoking status, alcohol use, obesity, and comorbidity, the hazard of incident cancer was nearly double in patients with vs without an OSA diagnosis (hazard ratio, 1.97; 95% CI, 1.94-2.00; P < .001).

Conclusion

Preexisting OSA was strongly associated with subsequent cancer in this veteran cohort, independent of several known cancer risk factors. These findings suggest that OSA may be a strong, independent risk factor for subsequent cancer development.

Obstructive sleep apnea and comorbidities: a dangerous liaison

Obstructive sleep apnea (OSA) is a highly prevalent disease, and is traditionally associated with increased cardiovascular risk. The role of comorbidities in OSA patients has emerged recently, and new conditions significantly associated with OSA are increasingly reported. A high comorbidity burden worsens prognosis, but some data suggest that CPAP might be protective especially in patients with comorbidities. Aim of this narrative review is to provide an update on recent studies, with special attention to cardiovascular and cerebrovascular comorbidities, the metabolic syndrome and type 2 diabetes, asthma, COPD and cancer. Better phenotypic characterization of OSA patients, including comorbidities, will help to provide better individualized care. The unsatisfactory adherence to CPAP in patients without daytime sleepiness should prompt clinicians to examine the overall risk profile of each patient in order to identify subjects at high risk for worse prognosis and provide the optimal treatment not only for OSA, but also for comorbidities.

Models of intermittent hypoxia and obstructive sleep apnea: molecular pathways and their contribution to cancer

Obstructive sleep apnea (OSA) is common and linked to a variety of poor health outcomes. A key modulator of this disease is nocturnal intermittent hypoxia. There is striking epidemiological evidence that patients with OSA have higher rates of cancer and cancer mortality. Small-animal models demonstrate an important role for systemic intermittent hypoxia in tumor growth and metastasis, yet the underlying mechanisms are poorly understood. Emerging data indicate that intermittent hypoxia activates the hypoxic response and inflammatory pathways in a manner distinct from chronic hypoxia. However, there is significant heterogeneity in published methods for modeling hypoxic conditions, which are often lacking in physiological relevance. This is particularly important for studying key transcriptional mediators of the hypoxic and inflammatory responses such as hypoxia-inducible factor (HIF) and NF-κB. The relationship between HIF, the molecular clock, and circadian rhythm may also contribute to cancer risk in OSA. Building accurate in vitro models of intermittent hypoxia reflective of OSA is challenging but necessary to better elucidate underlying molecular pathways.

Intermittent Hypoxia Is Associated With High Hypoxia Inducible Factor-1α but Not High Vascular Endothelial Growth Factor Cell Expression in Tumors of Cutaneous Melanoma Patients

Epidemiological associations linking between obstructive sleep apnea and poorer solid malignant tumor outcomes have recently emerged. Putative pathways proposed to explain that these associations have included enhanced hypoxia inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) cell expression in the tumor and altered immune functions via intermittent hypoxia (IH). Here, we examined relationships between HIF-1α and VEGF expression and nocturnal IH in cutaneous melanoma (CM) tumor samples. Prospectively recruited patients with CM tumor samples were included and underwent overnight polygraphy. General clinical features, apnea–hypopnea index (AHI), desaturation index (DI4%), and CM characteristics were recorded. Histochemical assessments of VEGF and HIF-1α were performed, and the percentage of positive cells (0, <25, 25–50, 51–75, >75%) was blindly tabulated for VEGF expression, and as 0, 0–5.9, 6.0–10.0, >10.0% for HIF-1α expression, respectively. Cases with HIF-1α expression >6% (high expression) were compared with those <6%, and VEGF expression >75% of cells was compared with those with <75%. 376 patients were included. High expression of VEGF and HIF-1α were seen in 88.8 and 4.2% of samples, respectively. High expression of VEGF was only associated with increasing age. However, high expression of HIF-1α was significantly associated with age, Breslow index, AHI, and DI4%. Logistic regression showed that DI4% [OR 1.03 (95% CI: 1.01–1.06)] and Breslow index [OR 1.28 (95% CI: 1.18–1.46)], but not AHI, remained independently associated with the presence of high HIF-1α expression. Thus, IH emerges as an independent risk factor for higher HIF-1α expression in CM tumors and is inferentially linked to worse clinical CM prognostic indicators.

Intermittent hypoxia increases kidney tumor vascularization in a murine model of sleep apnea

We investigate the effects of intermittent hypoxia (IH), a characteristic feature of obstructive sleep apnea (OSA), on renal cancer progression in an animal and cell model. An in vivo mouse model (Balb/c, n = 50) of kidney cancer was used to assess the effect of IH on tumor growth, metastatic capacity, angiogenesis and tumor immune response. An in vitro model tested the effect of IH on RENCA cells, macrophages and endothelial cells. Tumor growth, metastatic capacity, circulating vascular endothelial growth factor (VEGF) and content of endothelial cells, tumor associated macrophages and their phenotype were assessed in the tumor. In vitro, VEGF cell expression was quantified.Although IH did not boost tumor growth, it significantly increased endothelial cells (p = 0.001) and circulating VEGF (p<0.001) in the in vivo model. Macrophages exposed to IH in vitro increased VEGF expression, whereas RENCA cells and endothelial cells did not. These findings are in keeping with previous clinical data suggesting that OSA has no effect on kidney cancer size and that the association observed between OSA and higher Fuhrman grade of renal cell carcinoma may be mediated though a proangiogenic process, with a key role of macrophages.