Alternative staging system improves SCC distinction

A proposed alternative staging system for cutaneous squamous cell carcinoma (CSCC) improves the prognostic discrimination of tumors, results of a recent study suggest.

Researchers with the University of Pennsylvania, Philadelphia, sought to identify a tumor staging system that would more precisely define a small subset of tumors that carry a high risk of metastasis and death, according to the study abstract. The investigators identified study participants through a pathology and dermatopathology database search for those diagnosed with high-risk CSCC. Researchers examined the 2010 American Joint Committee on Cancer (AJCC) tumor staging system to assess its ability to stratify occurrence of poor outcomes in CSCC.

Stage T2 cases were found to have the poorest outcomes, with 83 percent of nodal metastases and 92 percent of death from CSCC. For this group, the investigators identified four risk factors that were “statistically independent prognostic factors for at least two outcomes of interest in multivariate modeling.” Factors included perineural invasion, poor differentiation, tumor diameter of 2 cm or more and invasion beyond subcutaneous fat.

T1 was indicated when there were no factors present; one factor indicated T2a; two or three factors indicated T2b; four factors or bone invasion, T3. Researchers noted all four factors were significantly different between stages T2a and T2b.

In the cohort, 19 percent had stage T2b tumors, but these accounted for 72 percent of nodal metastases and 83 percent of CSCC-related death.

“The proposed alternative staging system offers improved prognostic discrimination via startifcation of stage T2 tumors,” study authors wrote. “Validation in other cohorts is needed. Meanwhile, stage T2b tumors are responsible for most poor outcomes and may be a focus of high-risk CSCC study.”

The findings were published online Jan. 16 in JAMA Dermatology.