Older age, organ transplants increase risk of multiple cutaneous squamous cell carcinomas

Key takeaways:

• Patients aged older than 80 years and those with solid organ transplants have a higher risk of developing multiple cutaneous squamous cell carcinomas.
• Sex, race and smoking history are not host risk factors.

Solid organ transplantation, age and a history of cancer were significant host risk factors for multiple and subsequent cutaneous squamous cell carcinoma, according to a large chart review.

Many studies have highlighted the developmental factors of primary cutaneous squamous cell carcinoma (CSCC) which include sun exposure, age, Fitzpatrick phototype and immunosuppression. However, few studies have explored risk factors of subsequent CSCC, often combining it into the larger nonmelanoma skin cancer category.

“Given that the strongest predictor for CSCC development is a history of prior CSCC, it is important to develop a deeper understanding of the risk factors of subsequent CSCC,” Isabelle Moseley, BA, a student at The Warren Alpert Medical School of Brown University in Providence, Rhode Island, and colleagues wrote. “The objectives of this study were to characterize CSCC cases, investigate host risk factors associated with multiple CSCCs, and assess primary tumor characteristics that serve as risk factors for the development of subsequent primary CSCC in a single dermatology center.”

The retrospective chart review included 1,312 patients with CSCC diagnoses from a dermatology clinic in Rhode Island from 2016 to 2019. Of the total patient population, Moseley and colleagues identified 433 patients with multiple CSCC tumors.

Results showed that the largest risk factors for subsequent CSCC are age, history of solid organ transplant, skin cancer, family skin cancer, other cancers, actinic keratosis and sunscreen use.

According to the study, a history of solid organ transplantation was the highest risk factor for multiple CSCC tumors (adjusted OR = 2.41; 95% CI 1.2-4.8) followed by age older than 80 years (aOR = 2.18; 95% CI, 1.46-3.31) and a history of skin cancer (aOR = 1.96; 95% CI, 1.52-2.54).

A history of other cancers (aOR = 1.49; 95% CI 1.11-2) and actinic keratosis (aOR 1.52; 95% CI, 1.18-1.95) significantly factored into multiple CSCC tumors as well, as did family history of skin cancer (aOR = 1.36, 95% CI, 1.03-1.78) and sunscreen use (aOR = 1.32, 95% CI, 1.03-1.7).

On the other hand, results showed that sex, race/ethnicity and smoking history were not associated with multiple CSCCs.

After Moseley and colleagues adjusted for host risk factors, they also found that primary tumor characteristics including clinical tumor diameter, primary tumor location, histologic differentiation and treatment modality were not associated with multiple CSCC tumors.

The study population being predominantly white and coming from a single institution were considered limitations, according to the researchers.

“These findings may have implications for determining ideal follow-up intervals for patients diagnosed with one or multiple CSCCs,” Moseley and colleagues concluded.