Department of Non-communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark.
JAMA Dermatol. 2020 Oct 1;156(10):1086-1097. doi: 10.1001/jamadermatol.2020.1948.
Associations between atopic eczema and cancer are unclear, with competing theories that increased immune surveillance decreases cancer risk and that immune stimulation increases cancer risk. Establishing baseline cancer risk in people with atopic eczema is important before exploring the association between new biologic drugs for atopic eczema and cancer risk.
To investigate whether atopic eczema is associated with cancer.
DESIGN, SETTING, AND PARTICIPANTS: Matched cohort studies were conducted from January 2, 1998, to March 31, 2016, in England and from January 1, 1982, to June 30, 2016, in Denmark. We conducted our analyses between July 2018 and July 2019. The setting was English primary care and nationwide Danish data. Participants with atopic eczema (adults only in England and any age in Denmark) were matched on age, sex, and calendar period (as well as primary care practice in England only) to those without atopic eczema.
Atopic eczema.
Overall cancer risk and risk of specific cancers were compared in people with and without atopic eczema.
In England, matched cohorts included 471 970 individuals with atopic eczema (median [IQR] age, 41.1 [24.9-60.7] years; 276 510 [58.6%] female) and 2 239 775 individuals without atopic eczema (median [IQR] age, 39.8 [25.9-58.4] years; 1 301 074 [58.1%] female). In Denmark, matched cohorts included 44 945 individuals with atopic eczema (median [IQR] age, 13.7 [1.7-21.1] years; 22 826 [50.8%] female) and 445 673 individuals without atopic eczema (median [IQR] age, 13.5 [1.7-20.8] years; 226 323 [50.8%] female). Little evidence was found of associations between atopic eczema and overall cancer (adjusted hazard ratio [HR], 1.04; 99% CI, 1.02-1.06 in England and 1.05; 99% CI, 0.95-1.16 in Denmark) or for most specific cancers. However, noncutaneous lymphoma risk was increased in people with atopic eczema in England (adjusted HR, 1.19; 99% CI, 1.07-1.34 for non-Hodgkin lymphoma [NHL] and 1.48; 99% CI, 1.07-2.04 for Hodgkin lymphoma). Lymphoma risk was increased in people with greater eczema severity vs those without atopic eczema (NHL adjusted HR, 1.06; 99% CI, 0.90-1.25 for mild eczema; 1.24; 99% CI, 1.04-1.48 for moderate eczema; and 2.08; 99% CI, 1.42-3.04 for severe eczema). Danish point estimates also showed increased lymphoma risk in people with moderate to severe eczema compared with those without atopic eczema (minimally adjusted HR, 1.31; 99% CI, 0.76-2.26 for NHL and 1.35; 99% CI, 0.65-2.82 for Hodgkin lymphoma), but the 99% CIs were wide.
The findings from 2 large population-based studies performed in different settings do not support associations between atopic eczema and most cancers. However, an association was observed between atopic eczema and lymphoma, particularly NHL, that increased with eczema severity. This finding warrants further study as new immunomodulatory systemic therapeutics are brought to market that may alter cancer risk.
特应性皮炎与癌症之间的关联尚不清楚，存在两种相互竞争的理论，一种认为增强免疫监视会降低癌症风险，另一种认为免疫刺激会增加癌症风险。在探索新型特应性皮炎生物药物与癌症风险之间的关联之前，确定特应性皮炎患者的癌症风险基线非常重要。
研究特应性皮炎是否与癌症相关。
设计、地点和参与者：本研究于 1998 年 1 月 2 日至 2016 年 3 月 31 日在英格兰，以及 1982 年 1 月 1 日至 2016 年 6 月 30 日在丹麦进行了匹配队列研究。我们在 2018 年 7 月至 2019 年 7 月之间进行了分析。研究地点为英格兰的初级保健机构和丹麦的全国性数据。特应性皮炎患者（仅在英格兰为成人，在丹麦为任何年龄）与无特应性皮炎患者匹配，匹配因素包括年龄、性别和日历时期（仅在英格兰还包括初级保健实践）。
特应性皮炎。
比较了有和无特应性皮炎患者的总体癌症风险和特定癌症风险。
在英格兰，匹配队列包括 471970 名特应性皮炎患者（中位[IQR]年龄，41.1[24.9-60.7]岁；276510[58.6%]为女性）和 2239775 名无特应性皮炎患者（中位[IQR]年龄，39.8[25.9-58.4]岁；1301074[58.1%]为女性）。在丹麦，匹配队列包括 44945 名特应性皮炎患者（中位[IQR]年龄，13.7[1.7-21.1]岁；22826[50.8%]为女性）和 445673 名无特应性皮炎患者（中位[IQR]年龄，13.5[1.7-20.8]岁；226323[50.8%]为女性）。研究结果表明，特应性皮炎与总体癌症（调整后的危险比[HR]，1.04；99%CI，1.02-1.06 在英格兰和 1.05；99%CI，0.95-1.16 在丹麦）或大多数特定癌症之间几乎没有关联。然而，在英格兰，特应性皮炎患者的非皮肤淋巴瘤风险增加（调整后的 HR，1.19；99%CI，1.07-1.34 为非霍奇金淋巴瘤[NHL]和 1.48；99%CI，1.07-2.04 为霍奇金淋巴瘤）。与无特应性皮炎患者相比，特应性皮炎患者的淋巴瘤风险随着疾病严重程度的增加而增加（NHL 调整后的 HR，0.90-1.25 为轻度湿疹；1.04-1.48 为中度湿疹；1.42-3.04 为重度湿疹）。丹麦的点估计也显示，与无特应性皮炎患者相比，中重度特应性皮炎患者的淋巴瘤风险增加（最小调整后的 HR，0.76-2.26 为 NHL 和 0.65-2.82 为霍奇金淋巴瘤），但 99%CI 较宽。
这两项在不同环境中进行的大型基于人群的研究结果均不支持特应性皮炎与大多数癌症之间存在关联。然而，观察到特应性皮炎与淋巴瘤，特别是 NHL 之间存在关联，且随着湿疹严重程度的增加而增加。这一发现值得进一步研究，因为新的免疫调节全身治疗药物不断推向市场，可能会改变癌症风险。
