Risk Factors Identified for Cutaneous Squamous Cell Carcinoma Recurrence Timing

Lymphovascular invasion (LVI) and large-caliber or deep perineural invasion (LCDPNI) are strongly associated with early locoregional metastasis of cutaneous squamous cell carcinoma (cSCC), while poor differentiation remains an important predictor of recurrence risk 2 years after diagnosis, according to results of a study published in the Journal of the American Academy of Dermatology.

Key Recurrence Risk Factors and Timelines

Early Relapse (≤ 4 months): Driven heavily by lymphovascular invasion (SHR = 3.01) and large-caliber/deep perineural invasion (SHR = 2.55). These features necessitate aggressive initial staging (such as sentinel lymph node biopsy). [1]
Intermediate Relapse (4 - 24 months): Tumors with high-risk features like diameters ≥20 mm (SHR, 1.89), invasion beyond subcutaneous fat, and desmoplastic growth independently increase the risk of local recurrence and metastasis. [1, 2]
Late Relapse (> 24 months): Poor tumor differentiation remains an important, sustained predictor of relapse risk even beyond two years post-diagnosis. [1]

Patient-Specific and Location Factors

Anatomical Site: Tumors located on high-exposure and delicate regions like the ears, lips, and scalpare at a significantly elevated baseline risk for both local recurrence and metastasis. [1, 2]
Immunosuppression: Patients with compromised immune systems have a vastly higher incidence and significantly more aggressive cSCC behavior, driving up the likelihood of early locoregional spread. [1, 2]
Prior Interventions: Tumors arising from chronic inflammatory wounds (e.g., burn scars, leg ulcers) and incomplete surgical margins carry a higher probability of early recurrence. [1, 2]

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Sirolimus reduce incidencia de NMSC, en transplantados de riñón...

Does sirolimus have a protective role against nonmelanoma skin cancer?

A Brief Report in JAAD demonstrated sirolimus’ long-term efficacy in reducing nonmelanoma skin cancer (NMSC) incidence in kidney transplant recipients. The retrospective case series included 214 predominantly Caucasian, male adult kidney transplant recipients on sirolimus. NMSCs that developed two years after initiating sirolimus were attributed to sirolimus, whereas those occurring earlier were attributed to tacrolimus. 

[The ever-changing world of nevus sebaceus. Read more.]

NMSC incidences per 12 treatment months were 0.41 for sirolimus compared to 4.27 for tacrolimus, more than a 90% reduction in overall tumor burden with sirolimus. Squamous cell carcinoma (SCC) rates per year decreased from an adjusted rate of 2.97 on tacrolimus to 0.31 on sirolimus, with basal cell carcinoma incidence declining as well. The authors concluded that sirolimus treatment in kidney transplant recipients provided a significant long-term reduction in NMSC incidence compared to tacrolimus, with especially pronounced decreases in SCC.

Alergeno del año...alcohol benzilico...

Chris Mowad, MD, FAAD

For all the contact dermatitis patch testing enthusiasts out there, this hot topic is about the Allergen of the Year 2026: benzyl alcohol (Dermatitis. 2026. 37(1): 4-12). This allergen is frequently found in personal care products, topical medicaments, and industrial products. It functions as a preservative, fragrance, or solvent. It can also be found in adhesives, cleaning agents, and construction and flooring materials. Benzyl alcohol is an emerging allergen. It is not on most standard trays, including the FDA-approved series, and therefore this allergen can be missed.

Allergic contact dermatitis to benzyl alcohol has been reported at rates ranging from 0.21-0.5% in several studies. Numerous case reports have documented the type IV reactions to benzyl alcohol in personal care products, paints, hearing aid molds, and medicated creams. Non-immunologic contact urticaria has also been seen with exposure to this allergen though this is less commonly reported. 

Sensitization rates of benzyl alcohol are low. However, usage is expected to continue to increase, so it is considered an emerging allergen that we should consider adding to our patch testing series. Relevance is also frequently high, ranging from 87.6-93.3% in the most recent NACDG cycle papers. Those allergic to benzyl alcohol may also have cross- and co-reactivity to other allergens such as Balsam of Peru, benzyl cinnamate, benzyl parabens, benzoic acid, fragrance, and sodium benzoate.

There is currently no consensus on the best concentration for patch testing and several concentrations and vehicles are being used. Given the expected continual rise in usage of this allergen, the observed sensitization, and the reported high relevance attributed to allergy to benzyl alcohol, this is an allergen to watch and to consider adding to your testing panels.