Deep tumor invasion, perineural invasion associated with poor prognosis in CSCC

Tumor invasion beyond the subcutaneous fat, along with perineural invasion, were associated with poor outcomes in primary cutaneous squamous cell carcinoma, according to a study.

“Primary cutaneous squamous cell carcinoma is usually curable; however, a subset of patients develops poor outcomes, including local recurrence, nodal metastasis, distant metastasis, and disease-specific death,” George A. Zakhem, MD, MBA, of The Ronald O. Perelman Department of Dermatology, NYU Langone Health, New York, and colleagues wrote.

In the review of PubMed, Embase and SCOPUS databases, Zakhem and colleagues assessed all evidence-based reports of patient risk factors and tumor characteristics associated with poor outcomes in this disease. They further identified the treatment modalities that could minimize those outcomes.

Data from database inception through Feb. 8, 2022 were included. The initial search revealed 310 studies with a sample size of at least 10 patients.

Risk ratios and incidence proportions served as the primary endpoints for risk factors. For studies analyzing treatment modalities, incidence proportion was the primary outcome measure.

The final analysis included 137,449 patients with primary cutaneous squamous cell carcinoma and 126,553 tumors from 129 studies.

The researchers observed a number of patient risk factors and tumor characteristics that predicted local recurrence, nodal metastasis, distant metastasis, disease-specific mortality and all-cause mortality.

For example, tumor invasion beyond subcutaneous fat was associated with the highest risk for both local recurrence (RR = 9.1; 95% CI, 2.8-29.2) and disease-specific mortality (RR = 10.4; 95% CI, 3.0-36.3), according to findings from more than one data set.

Moreover, perineural invasion was associated with the highest risk for any metastasis (RR = 5; 95% CI, 2.3-11.1), according to findings from more than one study.

Conversely, Mohs micrographic surgery yielded the lowest incidence of most poor outcomes of interest, according to the findings. That said, the confidence intervals for those patients also “overlapped” with other treatment modalities, indicating Mohs micrographic surgery can still be considered a first-line therapy for high-risk squamous cell carcinoma.

“This meta-analysis identified the prognostic value of several risk factors and the effectiveness of the available treatment modalities,” Zakhem and colleagues concluded. “These findings carry important implications for the prognostication, workup, treatment, and follow-up of patients with primary cutaneous squamous cell carcinoma.”