Atopic allergic conditions and colorectal cancer risk in the Multiethnic Cohort Study

Allergic Diseases and Risk of Malignancy of Gastrointestinal Cancers

The aim of this study was to investigate the effect of allergic diseases, including allergic rhinitis, asthma, and atopic dermatitis, on the development of gastrointestinal (GI) cancers. We analyzed 9,892,633 Korean adults who underwent a medical check-up in the year 2009, and they were followed up until the year 2017. Allergic diseases and cancers were defined using the International Classification of Disease Codes. A Cox proportional hazards model was adapted to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs). During a 7.3-year follow-up period, 48,045 patients were diagnosed with cancer. For all-combined allergic diseases, significant inverse associations were observed for cancers of the esophagus, stomach, colorectum, and liver (adjusted hazard ratios (aHRs [95% confidence interval, CI] 0.86 [0.82-0.91], 0.93 [0.91-0.94], 0.95 [0.93-0.96], and 0.90 [0.88-0.92], respectively). The sex-stratified analysis showed that the preventive effect of allergic diseases was persistent in gastric, colorectal, and liver cancers regardless of sex, while the inverse associations with esophageal and pancreatic cancers were observed only in men (aHR [95% CI] 0.84 [0.80-0.89] and 0.96 [0.93-0.99]). Allergic diseases, particularly allergic rhinitis, in adults were significantly associated with a decreased risk of most GI cancers, except for gallbladder and biliary tract cancers.

Atopic diseases and oncopathology. What do they have in common? A review

The increasing prevalence of cancer worldwide has influenced the interest of researchers to search for factors that may trigger oncogenesis in order to prevent and treat cancer. There is a burning question, can allergic diseases cause or prevent cancer? Numerous epidemiological studies have been conducted that have evaluated aspects of the relationship between allergic diseases and the occurrence of cancers of various localizations. The results of most of these studies are inconsistent, both in the nature of the course of the disease and in the variety of localizations of the occurrence of cancer. In this connection, two basic theories were suggested: the theory of immune surveillance and the theory of inflammation. This review analyzed current scientific work to estimate the incidence of neoplasms against the background of atopic diseases. The analysis of clinical studies shows inconsistent results of the association between allergic diseases and cancer. Several studies an inverse relationship between atopic diseases and cancer risk, which supports the theory of immune surveillance [brain tumor (glioma), pancreatic cancer, colorectal cancer, non-Hodgkin's lymphoma, and breast cancer, cancer of the mouth and throat, larynx]. At the same time, a number of studies note a positive association between atopic diseases and cancer, which confirms the theory of chronic inflammation (lung cancer and colorectal cancer combined with bronchial asthma). The lack of an unequivocal explanation testifies to the urgency of long-term prospective studies aimed at studying the risk factors of cancer in combination with atopic diseases with the subsequent development of risk scale for the purpose of patient stratification, screening, development of early detection programs and new approaches to the treatment of malignant neoplasms.

Down-regulation of the expression of cyclooxygenase-2 and prostaglandin E2 by interleukin-4 is mediated via a reduction in the expression of prostanoid EP4 receptors in HCA-7 human colon cancer cells

Chronic inflammatory bowel disease (IBD), which is characterized by prolonged inflammation of the gastrointestinal tract is associated with an increased risk of colorectal cancer. Recent studies revealed that the pathology of IBD is caused by hyperactivated immune responses mediated by differentiated CD4⁺ naïve helper T cells, such as Th1 and Th17 cells, but not Th2 cells. The human E-type prostanoid 4 (EP4) receptor and its pathways have also been implicated in and/or associated with the early developmental stages of colorectal cancer along with increases in the levels of prostaglandin E₂ (PGE₂) and cyclooxygenase-2 (COX-2), the hallmarks of colorectal carcinogenesis. In the present study, using an in silico analysis and pharmacological experiments, we demonstrated that interleukin (IL)-4, a signature cytokine of Th2 cells, down-regulated the expression of COX-2 and PGE₂ in the human colon cancer cell line, HCA-7. This result may be attributed to a reduction in the expression of prostanoid EP4 receptors through the induction of hypoxia inducible factor-1α via the interleukin-4 receptor-stimulated activation of signal transducer and activator of transcription 6. However, another major Th2 cytokine IL-13 had no effect on the expression of COX-2 or prostanoid EP4 receptors in HCA-7 cells. Therefore, instead of the hyperactivation of Th1/Th17 cells, the deactivation/down-regulation of Th2 cells followed by a decrease in the production of IL-4 in IBD may play a role in the cancerous transformation of cells, at least in prostanoid EP4 receptor-overactivated tumorigenesis.

Risk, Mechanisms and Implications of Asthma-Associated Infectious and Inflammatory Multimorbidities (AIMs) among Individuals With Asthma: a Systematic Review and a Case Study

Our prior work and the work of others have demonstrated that asthma increases the risk of a broad range of both respiratory (e.g., pneumonia and pertussis) and non-respiratory (e.g., zoster and appendicitis) infectious diseases as well as inflammatory diseases (e.g., celiac disease and myocardial infarction [MI]), suggesting the systemic disease nature of asthma and its impact beyond the airways. We call these conditions asthma-associated infectious and inflammatory multimorbidities (AIMs). At present, little is known about why some people with asthma are at high-risk of AIMs, and others are not, to the extent to which controlling asthma reduces the risk of AIMs and which specific therapies mitigate the risk of AIMs. These questions represent a significant knowledge gap in asthma research and unmet needs in asthma care, because there are no guidelines addressing the identification and management of AIMs. This is a systematic review on the association of asthma with the risk of AIMs and a case study to highlight that 1) AIMs are relatively under-recognized conditions, but pose major health threats to people with asthma; 2) AIMs provide insights into immunological and clinical features of asthma as a systemic inflammatory disease beyond a solely chronic airway disease; and 3) it is time to recognize AIMs as a distinctive asthma phenotype in order to advance asthma research and improve asthma care. An improved understanding of AIMs and their underlying mechanisms will bring valuable and new perspectives improving the practice, research, and public health related to asthma.

Current status and perspectives regarding the association between allergic disorders and cancer

While activation of immune system may lead to a lower risk of some diseases, it has been shown that a history of atopic allergic disorders such as asthma, hay fever, eczema, and food allergies could be related to several types of cancer. However, the evidence is not entirely conclusive. Two proposals suggest a possible mechanism for the association between allergic disorders and cancers: immune surveillance and the antigenic stimulation. The association of allergy and cancer may vary by cancer site and the type of exposure. The aim of current review was to summarize the current knowledge of the association between allergic diseases and the risk of cancers with particular emphasis on case-controls and cohort studies to estimate the cancer risk associated with allergy.

Association between atopic dermatitis and colorectal cancer risk: A nationwide cohort study

The role of atopic dermatitis (AD) in the development of colorectal cancer (CRC) has been a matter of scientific debate with mixed results. We conducted a nationwide cohort study to assess the association between AD and risk of CRC. Drawing on Taiwan's National Health Insurance Research Database, 46,703 patients with AD (the AD cohort) and 186,812 sex, age, and index year-matched patients without AD (the non-AD cohort) were identified in the period between 2000 and 2008. Follow-up time was calculated from the date of entry in the cohort until the occurrence of a first CRC diagnosis, death, or the end of the observation period (December 31, 2013), whichever occurred first. Hazards ratios (HRs) and accompanying 95% confidence intervals (CIs) derived from the Fine-Gray competing risk model were used to estimate the association between AD and CRC risk. After multivariable adjustment, AD was associated with an increased risk of CRC (adjusted HR, 1.26; 95% CI, 1.14-1.40). Of note, a significant positive association between AD and CRC risk was evident in both men and women and in all age groups. In summary, this population-based cohort study revealed that AD was associated with an increased risk of CRC in an Asian population. It will be of interest for cohort studies with prediagnostic specimens to evaluate the potential relationship between AD and CRC using biomarkers for allergy status.

Allergies and Asthma in Relation to Cancer Risk

BACKGROUND

Allergies and asthma, conditions commonly characterized by immunoglobulin E-mediated atopic reactions, may decrease cancer risk via increases in immunosurveillance, but may increase risk due to persistent immune stimulation. Associations between allergies and asthma and cancer risk remain unclear, and it is unknown whether associations vary by race/ethnicity.

METHODS

We evaluated these associations in the Southern Community Cohort Study. At baseline (2002-2009), 64,170 participants were queried on history of allergies and asthma; participants were followed through 2011, during which time 3,628 incident, invasive cancers were identified, including 667 lung cancers, 539 breast cancers, and 529 prostate cancers. Cox proportional hazards regression was used to estimate multivariable-adjusted HRs and 95% confidence intervals (CI).

RESULTS

Neither allergies nor asthma was associated with risk of developing invasive cancer overall. Asthma was associated with increased lung cancer risk (HR, 1.25; 95% CI, 1.00-1.57), with no variation by race/ethnicity (P _interaction = 0.84). Conversely, history of allergies was associated with decreased lung cancer risk (HR, 0.80; 95% CI, 0.65-1.00), with an inverse association observed among non-Hispanic whites (HR, 0.65; 95% CI, 0.45-0.94) but not non-Hispanic blacks (HR, 0.95; 95% CI, 0.73-1.25; P _interaction = 0.10). No statistically significant associations were observed for risk of breast or prostate cancers, overall or by race/ethnicity.

CONCLUSIONS

No associations were observed for risk of overall cancer, breast cancer, or prostate cancer. While asthma was associated with increased lung cancer risk, history of allergies was associated with decreased risk, an association driven by an inverse association among non-Hispanic whites.

IMPACT

Associations pertaining to lung cancer merit follow up in a large, diverse study.

Allergies and the Subsequent Risk of Cancer among Elderly Adults in the United States

BACKGROUND

Allergic conditions may prevent some cancers by promoting immune surveillance. We examined associations of allergic rhinitis, asthma, and eczema with cancer risk among elderly Americans.

METHODS

We used Surveillance Epidemiology and End Results (SEER)-Medicare linked data to perform a case-control study. Cases were individuals with first cancer diagnosed in SEER registries (1992-2013, ages 66-99; N = 1,744,575). Cancer-free controls (N = 100,000) were randomly selected from Medicare and matched on sex, age, and selection year. Allergic conditions were identified using Medicare claims, and logistic regression was used to estimate adjusted ORs (aOR) with significance gauged with a Bonferroni P cutoff (P < 0.00034).

RESULTS

Allergic rhinitis, asthma, and eczema were present in 8.40%, 3.45%, and 0.78% of controls, respectively. For allergic rhinitis, strong inverse associations (aORs, 0.66-0.79) were observed for cancers of the hypopharynx, esophagus (squamous cell), cervix, tonsil/oropharynx, and vagina/vulva. More modest but significant inverse associations were noted for cancers of the esophagus (adenocarcinoma), stomach, colon, rectosigmoid/rectum, liver, gallbladder, lung, uterus, bladder, and miscellaneous sites. Associations were stronger in analyses requiring a dispensed medication to confirm the presence of allergic rhinitis. Asthma was associated with reduced risk of liver cancer [aOR 0.82; 95% confidence interval (CI), 0.75-0.91], whereas eczema was associated with elevated risk of T-cell lymphoma (aOR, 4.12; 95% CI, 3.43-4.95).

CONCLUSIONS

Inverse associations with allergic rhinitis are present for multiple cancers and require etiologic investigation.

IMPACT

Understanding of mechanisms by which allergic conditions reduce cancer risk may advance cancer prevention and treatment.

Allergies and risk of colorectal cancer: a systematic review and meta-analysis of observational studies

A history of allergy or allergic condition has been reported to be associated with reduced risk of some types of malignancies. However, the understanding of this association for colorectal cancer (CRC) is controversial. We conducted a meta-analysis of CRC risk in individuals who had history of allergy compared to those without the history of allergic condition. Pumbed and Embase databases were searched for relevant studies. The adjusted relative risk (RR) and 95% confidence interval (CI) were pooled using the random-effects model. Nine studies, including 775, 178 individuals, were eligible for inclusion. The pooled estimate showed no significant association between history of allergy and CRC risk (adjusted RR 1.01, 95 % CI 0.88–1.17). Subgroup analyses confirmed the neutral association stratified by tumor location (colon: n = 6 studies; adjusted RR 1.01, 95 % CI 0.81–1.25; rectum: n = 6 studies; adjusted RR 0.94, 95% CI 0.77–1.15; colorectum: n = 3 studies; adjusted RR 0.92, 95 % CI 0.70 to 1.21), sex (male: n = 4 studies; adjusted RR 0.93, 95 % CI 0.81–1.07; female: n = 6 studies; adjusted RR 0.94, 95 % CI 0.80–1.09) or by allery type (asthma: n = 5 studies; adjusted RR 1.16, 95 % CI 0.96–1.42; hay fever: n = 4 studies; adjusted RR 0.93, 95 % CI 0.86–1.03). Meta-analysis of existing evidence provides a neutral association between allergies and CRC risk. Future well-designed prospective cohort studies should be conducted to better understand this association.

Association between allergic conditions and colorectal cancer risk/mortality: a meta-analysis of prospective studies

We aimed to assess the association between allergic conditions and risk/mortality of colorectal cancer (CRC). A systematic literature search was conducted using Pubmed and Embase to identify relevant studies. Prospective studies assessing the association between allergic conditions and risk/mortality of CRC were included. Risk ratios (RRs) were pooled with either a fixed- or a random-effects model according to heterogeneity. A total of 515379 participants and 10345 CRC cases from 12 studies were included in the analysis of CRC risk, while four studies with 1484741 individuals and 30040 CRC deaths were included in the analysis of CRC mortality. The pooled RR for the association between allergic conditions and CRC risk was 0.88 (95% CI 0.83–0.92). The inverse association was observed both in colon cancer (pooled RR = 0.83, 95% CI 0.72–0.97) and rectal cancer (pooled RR = 0.83, 95% CI 0.74–0.93). Moreover, no gender difference was observed in the analysis of CRC risk (for males, pooled RR = 0.88, 95% CI 0.81–0.96; for females, pooled RR = 0.88, 95% CI 0.82–0.95). And allergic conditions were also found to be inversely associated with CRC mortality (pooled RR = 0.88, 95% CI 0.83–0.92). In conclusion, the current meta-analysis provides further evidence that allergic conditions were inversely associated with CRC risk and mortality.

Atopy and Specific Cancer Sites: a Review of Epidemiological Studies

Mounting evidence appears to link asthma and atopy to cancer susceptibility. This review presents and discusses published epidemiological studies on the association between site-specific cancers and atopy. PubMed was searched electronically for publications between 1995 and 2015, and cited references were researched manually. Quantitative studies relating to atopy, allergy, or asthma and cancer were identified and tabulated. Despite many exposure-related limitations, patterns in the studies were observed. Asthma, specifically, has been observed to be a risk factor for lung cancer. A protective effect of atopic diseases against pancreatic cancer has been shown consistently in case-control studies but not in cohort studies. Allergy of any type appears to be protective against glioma and adult acute lymphoblastic leukemia. Most studies on atopic diseases and non-Hodgkin lymphoma or colorectal cancer reported an inverse association. The other sites identified had varying and non-significant outcomes. Further research should be dedicated to carefully defined exposure assessments of "atopy" as well as the biological plausibility in the association between atopic diseases and cancer.