Published in:
Open Access
01-03-2020 | Prostate Cancer | Original Paper
Allergy, asthma, and the risk of breast and prostate cancer: a Mendelian randomization study
Authors:
Xia Jiang, Niki L. Dimou, Zhaozhong Zhu, Carolina Bonilla, Sarah J. Lewis, Sara Lindström, Peter Kraft, Konstantinos K. Tsilidis, Richard M. Martin, the PRACTICAL, CRUK, BPC3, CAPS and PEGASUS consortia
Published in:
Cancer Causes & Control
|
Issue 3/2020
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Abstract
Purpose
The relationship of allergic diseases, such as asthma, hay fever, and eczema, with cancer is under debate. Observational studies have reported conflicting findings, but such studies are susceptible to confounding and reverse causation. Understanding the potential role of allergy in carcinogenesis may shed new light on the biological mechanisms underpinning intrinsic immunity and cancer.
Methods
We conducted a Mendelian randomization study, using germline genetic variants as instrumental variables, to determine the causal relevance of allergic disease and on two most common malignancies: breast cancer and prostate cancer. We used the summary statistics from the largest ever genome-wide association studies conducted on allergic disease (ncase = 180,129), asthma (ncase = 14,085), breast (ncase = 122,977), and prostate cancer (ncase = 79,148) and calculated odds ratios (ORs) and 95% confidence intervals (CIs) of cancer for allergic disease.
Results
We did not observe any evidence to support a causal association between allergic disease and risk of breast cancer overall [OR 1.00 (95% CI 0.96–1.04), p = 0.95] or by subtype (estrogen receptor (ER)+ [0.99 (0.95–1.04), p = 0.71], ER− [1.05 (0.99–1.10), p = 0.11]). We also did not find any evidence for an association with prostate cancer [1.00 (0.94–1.05), p = 0.93] or advanced subtype [0.97 (0.90–1.05), p = 0.46]. Sensitivity analyses did not reveal directional pleiotropy.
Conclusion
Our study does not support a causal effect of allergic disease on the risk of breast or prostate cancer. Future studies may be conducted to focus on understanding the causal role of allergic disease in cancer prognosis or drug responses (e.g., immunotherapy).