Skin Cancer Is Life-threatening in Junctional EB, Severe RDEB: Study
Dutch study examines squamous cell carcinoma statistics in varied EB types
Squamous cell carcinoma (SCC), a type of skin cancer well known in people with recessive dystrophic epidermolysis bullosa (RDEB), also affects patients with other EB types, according to data from the Dutch EB registry.
“The tumours might be discovered only when they are already large because of their indistinct clinical presentation,” the investigators wrote. “Therefore, regular skin screenings and biopsies of clinically suspect lesions are imperative for early detection and rapid intervention.”
The findings were published in a letter, titled “The aggressive behaviour of squamous cell carcinoma in epidermolysis bullosa: analysis of clinical outcomes and tumour characteristics in the Dutch EB Registry” and published in the British Journal of Dermatology.
People with EB, especially those with dystrophic disease, are at risk of developing SCC, and it’s the leading cause of death in people with RDEB. However, the underlying causes for this increased risk remain poorly understood.
Data collected via well-characterized EB registries could provide clues for the increased risk for SCC, which may help improve patients’ care and contribute to research into disease mechanisms.
In the Netherlands, the University Medical Center Groningen Center of Expertise for Blistering Diseases is the national expertise center for EB. Patients’ registers date back to 1988.
The study and its findings
Now, researchers at the center conducted a study in which they reviewed data from 578 patients with EB. The data were collected over 32 years (from January 1988 to October 2020).
Of the 578 EB patients in the registry, 22 patients developed 78 SCC cases. Regarding types of EB, the highest frequency was seen in patients with severe RDEB (26%), followed by those with Kindler syndrome (Kindler EB, 20%), intermediate junctional EB (JEB, 17%), and localized JEB (13%).
Patients with severe RDEB developed SCC at a much younger age (median age 27.7 years), compared with those with Kindler EB (59.2 years), intermediate JEB (median age 61.0 years), and localized JEB (median age 52.9 years).
In 11 of the 22 patients with SCC, the cancer had spread, forming metastases. The majority were severe RDEB patients (seven out of nine, 78%), followed by intermediate JEB (three of seven, 43%). Seventeen patients died, including all those with metastatic disease. Patients with severe RDEB died markedly earlier — at a median age of 37.5 years — compared with all other subtypes (above 57.3 years).
Patients with severe RDEB survived for a median of 41 months (around 3.4 years) after being first diagnosed with SCC, compared to a median of 228 months — 19 years — of those with intermediate JEB.
A total of 53 tumors (68%) were primary tumors, while 16 cases (21%) were recurrent tumors, meaning the cancer came back. Most primary tumors developed on the extremities (47 of 53, 89%). Overall, most tumors (74%) developed in areas of chronic wounds.
In 63% of tumors with invasive (spreading) features, no risk factors for metastasis or recurrence were seen, although they had a tumor size at or above two centimeters.
Overall, despite the relatively small sample size, these findings suggest SCC is a “life-threatening complication not only in RDEB-severe but also in JEB-intermediate, demonstrated by an increased risk of metastasis and disease-specific death in both subtypes.”
“In addition, identifying molecular pathways involved in [SCC] formation and its aggressiveness, and development of techniques for early in vivo tumour recognition, are of utmost importance to provide possibilities for earlier intervention and possibly prevention of this dreadful complication in EB,” they concluded.