A team of researchers from different departments across The Catholic University of Korea, Seoul, have investigated cancer risks associated with the various phenotypes of Alopecia Areata
This autoimmune disorder can affect different hair-bearing areas of the head and body, depending on the severity of the form. For instance, the mildest form - also known as Alopecia Areata (AA) - causes patchy hair loss
of the scalp only, whilst Alopecia Totalis
(AT)leads to total baldness of the scalp, often accompanied by the loss of facial hair, eyelashes and eyebrows, whilst the most extreme variation, Alopecia Universalis
(AU) causes a person to become completely hairless from head to toe.
Other types of autoimmune alopecia
can affect the beard area or the entire circumference of the hairline, however it was only the three key phenotypes outlined above which were considered in this June 2018 study.
Areas affected by hair loss shown in blue
Increased risk of certain cancers
National statistical data was used to study the risk of cancers in people with Alopecia Areata, Totalis and Universalis, with the aim of establishing whether each individual phenotype of alopecia carried the same associations.
Researchers enrolled 668,604 patients who had been treated within the January 2007 to December 2014 period for one of these hair loss conditions
. The participants were then separated into two groups by condition - AA or AT/AU - then by age and sex, and paired with a matched control volunteer without any form of AA in order to draw comparison data.
Risks were measured using hazard ratios (HR) - in this instance, the measure of how likely people with the various forms of alopecia were to develop cancer over a specific period of time - and confidence intervals (CI) - the defined range of values within which the likely value lies or, essentially, how likely the HR is to be correct.
According to the report's findings, which were published in the Nature Research journal Science Reports
on 27th June 2018 and make for interesting reading, all Alopecia Areata (1.0221.065 HR), Totalis and Universalis (1.0131.129 HR) had a slightly higher general risk of developing cancer than control participants. The CIs were reported as being 95 per cent in each case, providing a high level of certainty in the HR data.
No increased risk of developing some cancers, including lung, kidney, breast, pancreas, or skin cancer, lymphoma and leukaemia, was uncovered in any AA, AT or AU patients. However both groups demonstrated an higher propensity towards thyroid cancer, whilst scalp-only AA patients also had increased risks of bladder and prostate cancer.
Other health issues to monitor for
The Korean team concluded that 'Careful monitoring is needed to explore if the actual risks of thyroid, bladder, and prostate cancers are increased in alopecia patients'.
This research follows other reports which have established links between additional health issues
that people with all forms of Alopecia Areata may be more prone to, including other autoimmune disorders, dry eye disease
, and mental health issues