Chronic Rhinosinusitis and the Risk of Nasopharyngeal Cancer in a Taiwanese Health Study

The association between chronic sinonasal inflammation and nasopharyngeal carcinoma - A systematic review and meta-analysis

PURPOSE

There has been mounting evidence that inflammation is a key risk factor towards the development of certain cancers. Past studies have shown associations between nasopharyngeal carcinoma (NPC) and sinonasal tract inflammation. We aim to conduct a review and meta-analysis on the association between NPC and chronic sinus inflammation.

MATERIALS AND METHODS

We conducted a meta-analysis, searching 4 international databases from 1 January 1973 to 28 March 2022 for studies reporting on sinonasal inflammation and NPC in adult patients (>18 years old). We included cohort, case-control or cross-sectional studies. These studies must examine the association between a prior history of sinonasal inflammation and the risk of developing NPC. The outcome is the incidence of NPC in patients who had prior sinonasal inflammation.

RESULTS

8 studies (8245 NPC; 1,036,087 non-NPC) were included. The overall odds ratio (OR) of patients having NPC after reporting sinonasal inflammation was 1.81 (95 % CI 1.73-1.89). Of note, chronic rhinosinusitis (CRS) (OR of 1.78 (95 %-CI: 1.68-1.90)) was more closely associated with an increased risk of NPC, as compared to allergic rhinitis (AR) (OR of 1.60 (95 %-CI: 1.52-1.68)).

CONCLUSION

Chronic sinonasal inflammation is significantly associated with NPC in this systemic review and meta-analysis. The true cause-effect relationship and the potential effects of targeted screening need to be explored thoroughly with large scale prospective studies.

Malignant Sinonasal Tumors: Update on Histological and Clinical Management

Tumors of nasal cavity and paranasal sinuses (TuNSs) are rare and heterogeneous malignancies, presenting different histological features and clinical behavior. We reviewed the literature about etiology, biology, and clinical features of TuNSs to define pathologic features and possible treatment strategies. From a diagnostic point of view, it is mandatory to have high expertise and perform an immunohistochemical assessment to distinguish between different histotypes. Due to the extreme rarity of these neoplasms, there are no standard and evidence-based therapeutic strategies, lacking prospective and large clinical trials. In fact, most studies are retrospective analyses. Surgery represents the mainstay of treatment of TuNSs for small and localized tumors allowing complete tumor removal. Locally advanced lesions require more demolitive surgery that should be always followed by adjuvant radio- or chemo-radiotherapy. Recurrent/metastatic disease requires palliative chemo- and/or radiotherapy. Many studies emphasize the role of specific genes mutations in the development of TuNSs like mutations in the exons 4-9 of the TP53 gene, in the exon 9 of the PIK3CA gene and in the promoter of the TERT gene. In the near future, this genetic assessment will have new therapeutic implications. Future improvements in the understanding of the etiology, biology, and clinical features of TuNSs are warranted to improve their management.

Autoimmunity as an Etiological Factor of Cancer: The Transformative Potential of Chronic Type 2 Inflammation

Recent epidemiological studies have found an alarming trend of increased cancer incidence in adults younger than 50 years of age and projected a substantial rise in cancer incidence over the next 10 years in this age group. This trend was exemplified in the incidence of non-cardia gastric cancer and its disproportionate impact on non-Hispanic white females under the age of 50. The trend is concurrent with the increasing incidence of autoimmune diseases in industrialized countries, suggesting a causal link between the two. While autoimmunity has been suspected to be a risk factor for some cancers, the exact mechanisms underlying the connection between autoimmunity and cancer remain unclear and are often controversial. The link has been attributed to several mediators such as immune suppression, infection, diet, environment, or, perhaps most plausibly, chronic inflammation because of its well-recognized role in tumorigenesis. In that regard, autoimmune conditions are common causes of chronic inflammation and may trigger repetitive cycles of antigen-specific cell damage, tissue regeneration, and wound healing. Illustrating the connection between autoimmune diseases and cancer are patients who have an increased risk of cancer development associated with genetically predisposed insufficiency of cytotoxic T lymphocyte-associated protein 4 (CTLA4), a prototypical immune checkpoint against autoimmunity and one of the main targets of cancer immune therapy. The tumorigenic process triggered by CTLA4 insufficiency has been shown in a mouse model to be dependent on the type 2 cytokines interleukin-4 (IL4) and interleukin-13 (IL13). In this type 2 inflammatory milieu, crosstalk with type 2 immune cells may initiate epigenetic reprogramming of epithelial cells, leading to a metaplastic differentiation and eventually malignant transformation even in the absence of classical oncogenic mutations. Those findings complement a large body of evidence for type 1, type 3, or other inflammatory mediators in inflammatory tumorigenesis. This review addresses the potential of autoimmunity as a causal factor for tumorigenesis, the underlying inflammatory mechanisms that may vary depending on host-environment variations, and implications to cancer prevention and immunotherapy.

Risk of nasopharyngeal carcinoma in patients with chronic rhinosinusitis: A nationwide propensity score matched study in Taiwan

AIMS

Chronic inflammation is linked to cancer. This study aims to evaluate the association between chronic rhinosinusitis (CRS) and nasopharyngeal carcinoma (NPC) through a Taiwanese nationwide database.

METHODS

We used the National Health Insurance Research Database between January 1, 2003, and December 31, 2012. The starting date is either the date of the first clinical visit or the diagnosis of CRS. Patients were followed up until the first occurrence of target disease or the last date of medical record. Propensity score 1 to 2 matching was used to match pairs of patients with/without CRS.

RESULTS

A total of 951 380 eligible patients were included in our study, with 36 210 patients diagnosed with CRS. After 1 to 2 propensity score matching, non-CRS cohort consisted of 69 258 patients and CRS cohort consisted of 34 629 patients. CRS was associated with the risk of developing NPC (adjusted OR = 2.23; 95% CI, 1.61-3.09). However, no significant association among CRS and NPC was observed in patients followed up for more than 1 year (adjusted OR = 1.16; 95% CI, 0.76-1.78).

CONCLUSIONS

Patients with CRS diagnosis have relationship with developing NPC within 1 year of follow-up, but not for longer intervals. The short-term association may be due to reversed causation or biased diagnosis. Accordingly, the study suggests CRS a weak role for NPC.

Association of Gastroesophageal Reflux With Malignancy of the Upper Aerodigestive Tract in Elderly Patients

Importance

Chronic inflammatory states have been linked to the development of malignancy. Gastroesophageal reflux disease (GERD) is a known risk factor for esophageal adenocarcinoma as the end result of chronic inflammatory changes.

Objective

To investigate the association of GERD with the risk of malignancy in the upper aerodigestive tract (UADT).

Design, Setting, and Participants

We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to conduct a case-control study of individuals in the United States who had been added from January 2003 through December 2011 and were 66 years or older. The study included patients diagnosed with malignancy of the larynx, hypopharynx, oropharynx, tonsil, nasopharynx, and paranasal sinuses. GERD was examined as an exposure. Controls were matched from a 5% random sample of Medicare beneficiaries without cancer. Multivariable unconditional logistic regression was performed.

Main Outcomes and Measures

Incidence of invasive malignancies of the UADT.

Results

A total of 13 805 patients (median [range] age, 74 [66-99] years; 3418 women [24.76%] and 10 387 men [75.24%]) with malignancy of the UADT were compared with 13 805 patients without disease and were matched for sex, age group, and year of diagnosis. GERD was associated with a greater odds of developing malignancy of the larynx (adjusted odds ratio [aOR], 2.86; 95% CI, 2.65-3.09), hypopharynx (aOR, 2.54; 95% CI 1.97-3.29), oropharynx (aOR, 2.47; 95% CI, 1.90-3.23), tonsil (aOR, 2.14; 95% CI, 1.82-2.53), nasopharynx (aOR, 2.04; 95% CI, 1.56-2.66), and paranasal sinuses (aOR, 1.40; 95% CI, 1.15-1.70).

Conclusions and Relevance

GERD is associated with the presence of malignancy of the UADT in the US elderly population. This epidemiological association requires further examination to determine causality and diagnostic utility.

The Global Landscape of EBV-Associated Tumors

Epstein-Barr virus (EBV), a gamma-1 herpesvirus, is carried as a life-long asymptomatic infection by the great majority of individuals in all human populations. Yet this seemingly innocent virus is aetiologically linked to two pre-malignant lymphoproliferative diseases (LPDs) and up to nine distinct human tumors; collectively these have a huge global impact, being responsible for some 200,000 new cases of cancer arising worldwide each year. EBV replicates in oral epithelium but persists as a latent infection within the B cell system and several of its diseases are indeed of B cell origin; these include B-LPD of the immunocompromised, Hodgkin Lymphoma (HL), Burkitt Lymphoma (BL), Diffuse Large B cell Lymphoma (DLBCL) and two rarer tumors associated with profound immune impairment, plasmablastic lymphoma (PBL) and primary effusion lymphoma (PEL). Surprisingly, the virus is also linked to tumors arising in other cellular niches which, rather than being essential reservoirs of virus persistence in vivo, appear to represent rare cul-de-sacs of latent infection. These non-B cell tumors include LPDs and malignant lymphomas of T or NK cells, nasopharyngeal carcinoma (NPC) and gastric carcinoma of epithelial origin, and leiomyosarcoma, a rare smooth muscle cell tumor of the immunocompromised. Here we describe the main characteristics of these tumors, their distinct epidemiologies, histological features and degrees of EBV association, then consider how their different patterns of EBV latency may reflect the alternative latency programmes through which the virus first colonizes and then persists in immunocompetent host. For each tumor, we discuss current understanding of EBV's role in the oncogenic process, the identity (where known) of host genetic and environmental factors predisposing tumor development, and the recent evidence from cancer genomics identifying somatic changes that either complement or in some cases replace the contribution of the virus. Thereafter we look for possible connections between the pathogenesis of these apparently different malignancies and point to new research areas where insights may be gained.

Nasal polyps and future risk of head and neck cancer: A nationwide population-based cohort study

BACKGROUND

Nasal polyps are a common condition with a significant effect on quality of life. The association between nasal polyps and future risk of head and neck cancer is unknown.

OBJECTIVE

We sought to investigate the relative risk of nasal cavity and paranasal sinus (NCPS) and nasopharyngeal cancers in a nationwide, population-based, longitudinal retrospective cohort of patients with nasal polyps and matched comparators.

METHODS

The 2005-2017 National Health Insurance claims and National Health Screening program databases were used to construct a cohort of patients with nasal polyps and matched comparators in Korea. The relative risk of NCPS and nasopharyngeal cancer in patients with nasal polyps was examined.

RESULTS

The study consisted of 453,892 patients with nasal polyps and 4,583,938 matched comparators. The mean duration of follow-up was 6.2 years (range, 2-13 years). The incidence rate ratios of patients with nasal polyps compared with the comparators was 7.00 (95% CI, 5.28-9.25) for NCPS cancer and 1.78 (95% CI, 1.28-2.42) for nasopharyngeal cancer. Increased risks of these cancers were only evident in older subjects (age ≥50 years). There were trends toward weaker associations of nasal polyps with these cancers in younger subjects with comorbid asthma or allergic rhinitis (<50 years).

CONCLUSION

Although the absolute cancer incidence is very low, the relative risk of NCPS or nasopharyngeal cancers was significantly greater in older patients with nasal polyps. Given the regional and pathologic heterogeneity of nasal polyps, further studies are needed to explore the underlying mechanisms and validate the relationships.

Post-radiation sinusitis is associated with recurrence in nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy

BACKGROUND

This study investigated the impact of post-radiation sinusitis on the prognosis of nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiation therapy (IMRT).

METHODS

Two hundred and thirty patients with non-metastatic NPC were analyzed in terms of freedom from local failure (FFLF), freedom from distant failure (FFDF), overall survival (OS), and disease-free survival (DFS). For each patient, the status of the sinus mucosa was flexibly assessed by documenting mucosal changes as indicated by differences between images obtained before radiotherapy and more than 6 months post-radiation.

RESULTS

With a median follow-up of 39.7 months (8 to 81 months), 19 (8.26%) patients relapsed locally, 13 (5.65%) patients failed in the neck, and 26 (11.3%) patients developed distant metastases. The presence of sinusitis noted in images post-radiation was a significant predictor for DFS (p = 0.001), FFLF (p = 0.004), and FFDF (p = 0.015), in addition to having high negative predictive value for local relapse (97.5%).

CONCLUSIONS

This is the first study to investigate the prognostic value of post-radiation sinusitis in NPC patients treated with IMRT. Post-radiation sinusitis was found to be a significant predictor for DFS, FFLF, and FFDF, and was also found to have high negative predictive value for local recurrence (97.5%). It may thus be used as an additional tool for clinicians to determine the possibility of recurrence.

Early Versus Late Computed Tomography and Nasal Endoscopy in the Diagnosis of Nasopharyngeal and Paranasal Sinus Malignancy

Background

Chronic rhinosinusitis (CRS) and allergic rhinitis (AR) may be associated with an increased risk of subsequent diagnosis of nasopharyngeal carcinoma (NPC) or paranasal sinus cancer (PSC) in elderly Americans. The clinical utility of this association remains uncertain.

Objective

To compare early computed tomography (CT) or nasal endoscopy (NE) with late diagnostic studies for the diagnosis of NPC or PSC in elderly Americans with CRS or AR.

Methods

The Surveillance, Epidemiology, and End Results (SEER)-Medicare database was queried from 2003 to 2011 and included 150 088 Medicare beneficiaries. Patients with a diagnosis of CRS or AR were examined for either NE or CT performed within 6 months of the exposure diagnosis. The risk of a cancer diagnosis was determined between the early and the late diagnostic groups.

Results

The relative risk of early cancer diagnosis with NE was 1.98 (95% confidence interval [CI], 1.60–2.43). The number needed to detect (NND) a case of cancer with NE was 503 (95% CI, 387–718). The relative risk of an early cancer diagnosis using CT was 3.40 (95% CI, 2.85–4.06) and NND was 221 (95% CI, 194–255). The stage of NPC or PSC for the late diagnostic group was not different from those with early NE ( P = .458) or CT ( P = .497). Overall survival was not different between diagnostic groups for NE ( P = .789) or CT ( P = .425).

Conclusions

Early NE or CT is associated with a higher likelihood of cancer diagnosis in elderly individuals with a diagnosis of CRS or AR. The clinical utility of this association is limited due to the low prevalence of these malignancies and lack of difference in disease stage and overall survival between diagnostic groups.

Matrix association region/scaffold attachment region: the crucial player in defining the positions of chromosome breaks mediated by bile acid-induced apoptosis in nasopharyngeal epithelial cells

Background

It has been found that chronic rhinosinusitis (CRS) increases the risk of developing nasopharyngeal carcinoma (NPC). CRS can be caused by gastro-oesophageal reflux (GOR) that may reach nasopharynx. The major component of refluxate, bile acid (BA) has been found to be carcinogenic and genotoxic. BA-induced apoptosis has been associated with various cancers. We have previously demonstrated that BA induced apoptosis and gene cleavages in nasopharyngeal epithelial cells. Chromosomal cleavage occurs at the early stage of both apoptosis and chromosome rearrangement. It was suggested that chromosome breaks tend to cluster in the region containing matrix association region/scaffold attachment region (MAR/SAR). This study hypothesised that BA may cause chromosome breaks at MAR/SAR leading to chromosome aberrations in NPC. This study targeted the AF9 gene located at 9p22 because 9p22 is a deletion hotspot in NPC.

Methods

Potential MAR/SAR sites were predicted in the AF9 gene by using MAR/SAR prediction tools. Normal nasopharyngeal epithelial cells (NP69) and NPC cells (TWO4) were treated with BA at neutral and acidic pH. Inverse-PCR (IPCR) was used to identify chromosome breaks in SAR region (contains MAR/SAR) and non-SAR region (does not contain MAR/SAR). To map the chromosomal breakpoints within the AF9 SAR and non-SAR regions, DNA sequencing was performed.

Results

In the AF9 SAR region, the gene cleavage frequencies of BA-treated NP69 and TWO4 cells were significantly higher than those of untreated control. As for the AF9 non-SAR region, no significant difference in cleavage frequency was detected between untreated and BA-treated cells. A few breakpoints detected in the SAR region were mapped within the AF9 region that was previously reported to translocate with the mixed lineage leukaemia (MLL) gene in an acute lymphoblastic leukaemia (ALL) patient.

Conclusions

Our findings suggest that MAR/SAR may be involved in defining the positions of chromosomal breakages induced by BA. Our report here, for the first time, unravelled the relation of these BA-induced chromosomal breakages to the AF9 chromatin structure.

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0465-4) contains supplementary material, which is available to authorized users.

Matrix association region/scaffold attachment region (MAR/SAR) sequence: its vital role in mediating chromosome breakages in nasopharyngeal epithelial cells via oxidative stress-induced apoptosis

Background

Oxidative stress is known to be involved in most of the aetiological factors of nasopharyngeal carcinoma (NPC). Cells that are under oxidative stress may undergo apoptosis. We have previously demonstrated that oxidative stress-induced apoptosis could be a potential mechanism mediating chromosome breakages in nasopharyngeal epithelial cells. Additionally, caspase-activated DNase (CAD) may be the vital player in mediating the chromosomal breakages during oxidative stress-induced apoptosis. Chromosomal breakage occurs during apoptosis and chromosome rearrangement. Chromosomal breakages tend to cluster in certain regions, such as matrix association region/scaffold attachment region (MAR/SAR). We hypothesised that oxidative stress-induced apoptosis may result in chromosome breaks preferentially at the MAR/SAR sites. The AF9 gene at 9p22 was targeted in this study because 9p22 is a deletion site commonly found in NPC.

Results

By using MAR/SAR recognition signature (MRS), potential MAR/SAR sites were predicted in the AF9 gene. The predicted MAR/SAR sites precisely match to the experimentally determined MAR/SARs. Hydrogen peroxide (H₂O₂) was used to induce apoptosis in normal nasopharyngeal epithelial cells (NP69) and NPC cells (HK1). Nested inverse polymerase chain reaction was employed to identify the AF9 gene cleavages. In the SAR region, the gene cleavage frequency of H₂O₂-treated cells was significantly higher than that of the non-treated cells. A few chromosomal breakages were detected within the AF9 region which was previously found to be involved in the mixed lineage leukaemia (MLL)-AF9 translocation in an acute lymphoblastic leukaemia patient. As for the non-SAR region, no significant difference in the gene cleavage frequency was found between the untreated control and H₂O₂-treated cells. Furthermore, H₂O₂-induced cleavages within the SAR region were reduced by caspase-3 inhibitor, which indirectly inhibits CAD.

Conclusions

These results reaffirm our previous findings that oxidative stress-induced apoptosis could be one of the potential mechanisms underlying chromosome breakages in nasopharyngeal epithelial cells. MAR/SAR may play a vital role in defining the location of chromosomal breakages mediated by oxidative stress-induced apoptosis, where CAD is the major nuclease.

Electronic supplementary material

The online version of this article (10.1186/s12867-018-0116-5) contains supplementary material, which is available to authorized users.

Oxidative stress-induced chromosome breaks within the ABL gene: a model for chromosome rearrangement in nasopharyngeal carcinoma

Background

The mechanism underlying chromosome rearrangement in nasopharyngeal carcinoma (NPC) remains elusive. It is known that most of the aetiological factors of NPC trigger oxidative stress. Oxidative stress is a potent apoptotic inducer. During apoptosis, chromatin cleavage and DNA fragmentation occur. However, cells may undergo DNA repair and survive apoptosis. Non-homologous end joining (NHEJ) pathway has been known as the primary DNA repair system in human cells. The NHEJ process may repair DNA ends without any homology, although region of microhomology (a few nucleotides) is usually utilised by this DNA repair system. Cells that evade apoptosis via erroneous DNA repair may carry chromosomal aberration. Apoptotic nuclease was found to be associated with nuclear matrix during apoptosis. Matrix association region/scaffold attachment region (MAR/SAR) is the binding site of the chromosomal DNA loop structure to the nuclear matrix. When apoptotic nuclease is associated with nuclear matrix during apoptosis, it potentially cleaves at MAR/SAR. Cells that survive apoptosis via compromised DNA repair may carry chromosome rearrangement contributing to NPC tumourigenesis. The Abelson murine leukaemia (ABL) gene at 9q34 was targeted in this study as 9q34 is a common region of loss in NPC. This study aimed to identify the chromosome breakages and/or rearrangements in the ABL gene in cells undergoing oxidative stress-induced apoptosis.

Results

In the present study, in silico prediction of MAR/SAR was performed in the ABL gene. More than 80% of the predicted MAR/SAR sites are closely associated with previously reported patient breakpoint cluster regions (BCR). By using inverse polymerase chain reaction (IPCR), we demonstrated that hydrogen peroxide (H₂O₂)-induced apoptosis in normal nasopharyngeal epithelial and NPC cells led to chromosomal breakages within the ABL BCR that contains a MAR/SAR. Intriguingly, we detected two translocations in H₂O₂-treated cells. Region of microhomology was found at the translocation junctions. This observation is consistent with the operation of microhomology-mediated NHEJ.

Conclusions

Our findings suggested that oxidative stress-induced apoptosis may participate in chromosome rearrangements of NPC. A revised model for oxidative stress-induced apoptosis mediating chromosome rearrangement in NPC is proposed.

Electronic supplementary material

The online version of this article (10.1186/s40246-018-0160-8) contains supplementary material, which is available to authorized users.

Bile acids at neutral and acidic pH induce apoptosis and gene cleavages in nasopharyngeal epithelial cells: implications in chromosome rearrangement

BACKGROUND

Chronic rhinosinusitis (CRS) increases the risk of developing nasopharyngeal carcinoma (NPC) while nasopharyngeal reflux is known to be one of the major aetiological factors of CRS. Bile acid (BA), the component of gastric duodenal contents, has been recognised as a carcinogen. BA-induced apoptosis was suggested to be involved in human malignancies. Cells have the potential and tendency to survive apoptosis. However, cells that evade apoptosis upon erroneous DNA repair may carry chromosome rearrangements. Apoptotic nuclease, caspase-activated deoxyribonuclease (CAD) has been implicated in mediating translocation in leukaemia. We hypothesised that BA-induced apoptosis may cause chromosome breaks mediated by CAD leading to chromosome rearrangement in NPC. This study targeted the AF9 gene located at 9p22 because 9p22 is one of the most common deletion sites in NPC.

METHODS

We tested the ability of BA at neutral and acidic pH in inducing phosphatidylserine (PS) externalisation, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP) disruption, and caspase 3/7 activity in normal nasopharyngeal epithelial (NP69) and NPC (TWO4) cells. Inverse-PCR (IPCR) was employed to detect AF9 gene cleavages. To investigate the role of CAD in mediating these cleavages, caspase inhibition was performed. IPCR bands representing AF9 cleaved fragments were sequenced.

RESULTS

BA-treated cells showed higher levels of PS externalisation, ROS production, MMP loss and caspase 3/7 activity than untreated control cells. The effect of BA in the induction of these intracellular events was enhanced by acid. BA at neutral and acidic pH also induced significant cleavage of the AF9 gene. These BA-induced gene cleavages were inhibited by Z-DEVD-FMK, a caspase-3 inhibitor. Intriguingly, a few chromosome breaks were identified within the AF9 region that was previously reported to participate in reciprocal translocation between the mixed lineage leukaemia (MLL) and AF9 genes in an acute lymphoblastic leukaemia (ALL) patient.

CONCLUSIONS

These findings suggest a role for BA-induced apoptosis in mediating chromosome rearrangements in NPC. In addition, CAD may be a key player in chromosome cleavages mediated by BA-induced apoptosis. Persistent exposure of sinonasal tract to gastric duodenal refluxate may increase genomic instability in surviving cells.

Chronic sinonasal tract inflammation as a precursor to nasopharyngeal carcinoma and sinonasal malignancy in the United States

BACKGROUND

Chronic inflammatory states have been linked to the development of malignancy. Chronic rhinosinusitis (CRS) and allergic rhinitis (AR) have been associated with nasopharyngeal carcinoma (NPC) in population-based studies in Asia. A similar association with NPC and paranasal sinus malignancy (PSM) has not been defined in a North American population. Our purpose was to investigate the impact of CRS and AR on the risk of NPC and PSM.

METHODS

The Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database was queried as a case-control study of adults ≥65 years of age. The study cohort included 2009 patients diagnosed with NPC and/or PSM diagnosed between 2003 and 2011, and 2009 propensity-score-matched controls selected from a 5% random sample of Medicare beneficiaries without cancer. CRS and AR were examined as exposures. Multivariable unconditional logistic regression was employed.

RESULTS

Overall, NPC and PSM patients were more likely to have previous CRS diagnosis than the controls (9.2% vs 3.0% and 11.1% vs 2.7%, respectively). CRS was associated with greater odds of developing NPC (odds ratio [OR], 3.51; 95% confidence interval [CI], 2.12-5.79) and PSM (OR, 5.30; 95% CI, 3.55-7.92). AR was associated with greater odds of developing NPC (OR, 4.23; 95% CI, 2.96 to 6.06) and PSM (OR, 3.35; 95% CI, 2.49-4.49). The number needed to harm in the exposed population was 311.

CONCLUSIONS

CRS and AR are associated with the presence of NPC and PSM in the elderly population of United States. This epidemiologic association will need to be examined for causative pathophysiologic mechanisms and utility in clinical diagnosis.

Risk of depression in patients with chronic rhinosinusitis: A nationwide population-based retrospective cohort study

BACKGROUND

Depression is prevalent in patients with chronic rhinosinusitis (CRS). However, no population-based study has ever investigated this relationship. We used nationwide population insurance data to conduct a retrospective cohort study to evaluate the subsequent risk of depression among patients with CRS.

METHODS

We used the National Health Insurance Research Database (NHIRD) of Taiwan identified 15,371 CRS patients diagnosed during 2000-2010. The non-CRS group consisted of 61,484 individuals without CRS frequency matched by sex, age, and the year of diagnosis. The occurrence of depression was monitored until the end of 2011. The hazard ratios (HRs) of depression were estimated using the Cox proportional hazards model after adjusting for demographic characteristics and comorbidities.

RESULTS

The overall incidence of depression was 77% higher in the CRS group than in the non-CRS group (8.25 vs. 4.66/1000 person-years, p<0.001), with an adjusted HR of 1.56 (95% confidence interval=1.43-1.70). Further data analyses revealed that the adjusted HRs of depression in the CRS group compared with the non-CRS group by sex, age, urbanization level, monthly income, occupation category, and comorbidity were all significant. However, there was no difference in incidences of depression between CRS patients with and without surgical treatment (8.31 vs. 8.24/1000 person-years).

CONCLUSION

The present study suggests that patients with CRS are at an increased risk of depression, compared with those without CRS. Therefore, we should pay attention to the psychiatric status of these patients and provide adequate support for them.

Sinonasal Tract Inflammation as a Precursor to Nasopharyngeal Carcinoma: A Systematic Review and Meta-Analysis

OBJECTIVE

Chronic inflammation has been described as a precursor to the development of malignancy in several disease states. However, the relationship of sinonasal tract inflammation to nasopharyngeal carcinoma (NPC) remains poorly defined.

DATA SOURCES

Systematic review of primary studies identified through PubMed, EMBASE, MEDLINE, and Cochrane.

METHODS REVIEW

Systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. MEDLINE, EMBASE, and Cochrane databases were queried for English-language studies published between 1980 and 2015. Studies were excluded that did not provide quantitative data on sinonasal tract inflammation such as chronic rhinosinusitis (CRS), allergic rhinitis (AR), or human papillomavirus (HPV) status and NPC. An itemized assessment of the risk of bias was conducted for each included study.

RESULTS

Of the 325 studies identified during systematic review, 5 met the criteria for analysis. The level of evidence of those studies was generally low. There was an increased risk of NPC in patients with a previous diagnosis of CRS or AR. Meta-analysis demonstrated an odds ratio (95% confidence interval [CI]) of 2.35 (2.00-2.76) for all studies. Subgroup analysis of patients with sinonasal inflammation had an odds ratio of 2.39 (95% CI, 2.20-2.60). Patients with AR had an odds ratio of 2.29 (95% CI, 2.06-2.54), while those with CRS had an odds ratio of 2.70 (95% CI, 1.98-3.70).

CONCLUSIONS

This systematic review and meta-analysis suggests an association between previous sinonasal inflammatory disease and subsequent NPC. Prospective studies are needed to further examine this relationship.

Carcinogenesis of nasopharyngeal carcinoma: an alternate hypothetical mechanism

Current proposed mechanisms implicate both early and latent Epstein-Barr virus (EBV) infection in the carcinogenic cascade, whereas epidemiological studies have always associated nasopharyngeal carcinoma (NPC) with early childhood EBV infection and with chronic ear, nose, and sinus conditions. Moreover, most patients with NPC present with IgA antibody titers to EBV capsid antigen (VCA-IgA), which can precede actual tumor presentation by several years. If early childhood EBV infection indeed constitutes a key event in NPC carcinogenesis, one would have to explain the inability to detect the virus in normal nasopharyngeal epithelium of patients at a high risk for EBV infection. It is perhaps possible that EBV resides within the salivary glands, instead of the epithelium, during latency. This claim is indirectly supported by observations that the East Asian phenotype shares the characteristics of an increased susceptibility to NPC and immature salivary gland morphogenesis, the latter of which is influenced by the association of salivary gland morphogenesis with an evolutionary variant of the human ectodysplasin receptor gene (EDAR), EDARV370A. Whether the immature salivary gland represents a more favorable nidus for EBV is uncertain, but in patients with infectious mononucleosis, EBV has been isolated in this anatomical organ. The presence of EBV-induced lymphoepitheliomas in the salivary glands and lungs further addresses the possibility of submucosal spread of the virus. Adding to the fact that the fossa of Rosen Müller contains a transformative zone active only in the first decade of life, one might be tempted to speculate the possibility of an alternative carcinogenic cascade for NPC that is perhaps not dissimilar to the model of human papillomavirus and cervical cancer.

Epidemiology of chronic rhinosinusitis, selected risk factors, comorbidities, and economic burden

Chronic rhinosinusitis (CRS) is a relevant and prevalent medical condition in Germany, Europe and the world. If analysed in detail, the prevalence of CRS shows regional and temporary variety. In this review, currently available data regarding the prevalence of CRS is therefore sorted by country and/or region, time point of data collection and the CRS-definition employed. Risk factors like smoking and gastroesophageal reflux are discussed regarding their influence on CRS prevalence. Moreover, comorbidities of CRS, like asthma, conditions of the cardiovascular system and depression are listed and their influence on CRS is discussed. Furthermore, data on CRS prevalence in special cohorts, like immunocompromised patients, are presented. To estimate the economic burden of CRS, current data e.g. from Germany and the USA are included in this review.

Case Definitions for Chronic Rhinosinusitis in Administrative Data: A Systematic Review

Background

The use of administrative data for pharmacoepidemiology research on chronic rhinosinusitis (CRS) has become increasingly popular. Although large sample sizes and ease of accessibility have made electronic health data an attractive data option, the risk of inaccurate cohort identification can lead to biased outcomes.

Objectives

The objectives of this systematic review were to (1) report current case definitions for CRS used in administrative data base research, and (2) define the various administrative data bases used for CRS research.

Methods

Medical literature data bases were searched from the date of their inception to February 1, 2015. Included studies were publications that obtained CRS-specific data from a health records data base. Studies were excluded if they evaluated a non-CRS cohort, failed to use or report an international classification of disease (ICD) code in the case definition, or published in a non-peer-reviewed journal.

Results

Of the 27 studies that met inclusion criteria, 8 different CRS case definitions were identified and 13 administrative data bases were evaluated. Of the 8 different CRS case definitions identified, only one was validated. The most commonly used CRS case definition was the ICD-9 473.x code alone.

Conclusion

To optimize the accuracy of pharmacoepidemiologic research for CRS that used administrative data, it is important to apply appropriate case definitions for CRS. Various nonvalidated CRS case definitions are currently being used in administrative data base research. There is a need to develop a generalizable and validated ICD-based CRS case definition to increase the accuracy of future pharmacoepidemiologic research.