Welcome to Study of the Week from Patient Worthy. In this segment, we select a study we posted about from the previous week that we think is of particular interest or importance and go more in-depth. In this story we will talk about the details of the study and explain why it’s important, who will be impacted, and more.
If you read our short form research stories and find yourself wanting to learn more, you’ve come to the right place.
This week’s study is…
Malignancy risk among children and adults with atopic dermatitis in a population-based cohort
We previously published about this research in a story titled “Severe Atopic Dermatitis Heightens Cancer Risk” which can be found here. The study was originally presented as a poster during the 2022 meeting of the American Academy of Dermatology. You can view the abstract of this study here. You can also check out the poster here.
What Happened?
Atopic dermatitis, a relatively common disease of the skin, has been associated in the past with some degree of immune system dysfunction. Abnormal immune system function can sometimes influence a person’s risk of cancer. In this study, the scientists sought to understand if atopic dermatitis could increase cancer risk. Some prior studies have suggested a link between severe atopic dermatitis and non-Hodgkin lymphoma; however, the researchers noted inconsistent results in prior studies that evaluated cancer risk the severity of disease, and there was very little data on child patients.
Using a medical records database from the UK, the researchers looked at records from 625,083 adult patients and 409,431 child patients. These patients were matched by index date, practice, and age with a control group of adults and children that did not have atopic dermatitis. The team evaluated patients as having mild, moderate, or severe atopic dermatitis based on the treatments that received. This could be considered a potential weakness of the study.
The team found that in children with the disease, the risk of cancer in general did not increase regardless of how severe their atopic dermatitis was. However, in children with moderate or severe disease, the risk of non-Hodgkin lymphoma specifically was greater than in children without atopic dermatitis. In adult patients, cancer risk did not differ by severity of disease. However, in comparison to adults without the disease, severe atopic dermatitis was linked to a 15 percent greater risk of cancer. Adults with moderate to severe disease also had a greater risk of non-Hodgkin lymphoma.
Interestingly, adults with moderate atopic dermatitis had a lower risk of solid tumor cancers of the internal organs, such as prostate, bladder, breast, lung, and colon cancer. Overall, the findings suggest that severe atopic dermatitis could increase the risk of non-Hodgkin lymphoma, yet may lower the risk of some solid tumor cancers. However, in an overall sense, a significant association between atopic dermatitis and cancer as a whole (considering all types together) was not found.
About Severe Atopic Dermatitis
Severe atopic dermatitis is a condition in which the patient’s skin becomes heavily inflamed. Skin often becomes red, itchy and cracked. An unpleasant clear fluid may ooze from affected areas. The back of the knees and inner fold of the elbows are the areas most commonly affected in children, but people with severe disease may experience symptoms all over the skin. Complications include asthma and hay fever. The hands and feet are commonly affected in adults. There is a heightened risk for skin infections. The exact cause of severe atopic dermatitis is not clear, though there is some evidence for genetic and environmental factors. Allergens and exposure to ‘hard water’ (determined by the concentration of calcium carbonate) could make the risk greater, especially in kids. Click here to learn more about severe atopic dermatitis.
About Non-Hodgkin Lymphoma
Non-Hodgkin lymphoma is a group of blood cancers that, in some cases, can grow rapidly. This cancer affects a type of white blood cell called a lymphocyte. As non-Hodgkin lymphoma can include any type of lymphoma that is not Hodgkin’s lymphoma, they probably have diverse array of causes. Risk factors for the development of these cancers include infections by certain viruses and bacteria, exposure to chemicals such as herbicides, prior autoimmune diseases, prior radiation or chemotherapy, and some genetic conditions. Symptoms may include itching, swollen lymph nodes, fatigue, fever, weight loss, and night sweats. Treatment often includes chemotherapy, stem cell transplant, and, less commonly, immunotherapy. The five year survival rate for these cancers is around 71 percent in the US. To learn more about non-Hodgkin lymphoma, click here.
Why Does it Matter?
Overall, the findings from this study suggest a relationship between atopic dermatitis and cancer that still isn’t very well understood. While the data does suggest that child and adult patients with moderate to severe atopic dermatitis may be at greater risk of non-Hodgkin lymphoma, in other cancer types, there is no association or even a reduction in risk. These findings might encourage physicians to potentially monitor atopic dermatitis patients for signs of lymphoma.
With that being said, the differences in risk between different cancer forms suggest that this is an area of research that requires substantial further investigation:
“As immunomodulatory therapies continue to emerge for AD, this heterogeneous relationship between AD and malignancy requires continued investigation.”
