WEDNESDAY, Oct. 18, 2023 -- Extensive perineural invasion (ePNI) seems to be the best prognostic measure for cutaneous squamous cell carcinoma (CSCC), according to a study published online Oct. 18 in JAMA Dermatology.

Paul R. Massey, M.D., M.P.H., from the Cheyenne Skin Clinic in Wyoming, and colleagues compared four assessments of PNI (nerve caliber, number of involved nerves per section, PNI maximal depth, and PNI location) with respect to tumor in patients with primary, localized, invasive CSCC in a retrospective cohort study performed at a single tertiary care institution. Data were included for 140 patients with CSCC.

The researchers found that only involvement of multiple nerves was associated with poor outcomes. Independent associations were seen for PNI of five or more distinct nerves (ePNI) with local recurrence, disease-specific death, and any poor outcome (subhazard ratios, 13.83, 6.20, 10.21, respectively). Compared with current Brigham and Women's Hospital (BWH) staging criteria that use nerve caliber as the measure of PNI, a revised BWH staging system with substitution of ePNI for large-caliber PNI resulted in improved area under the curve and test characteristics.

"Although these findings require further validation in other cohorts, inclusion of ePNI as a high-risk factor in CSCC staging may optimize recurrence risk assessment and patient selection for surgical treatment modality and postoperative adjuvant interventions," the authors write.

One author disclosed ties to the pharmaceutical industry.