Prognostic Value of Tumor Staging: Predicting Nodal Metastases in Cutaneous Squamous Cell Carcinoma

Abstract

Objectives Determine the ability of three staging systems to stratify the risk of nodal metastases in cases of cutaneous squamous cell carcinoma (cSCC). Examine differential staging of tumors across the three systems and the resulting implications for clinical decision making. Study Design Retrospective chart review. Methods This study included 118 patients who underwent excision of primary cSCC of the head and neck as well as elective neck dissection for the same tumor between 2006 and 2017. Tumors were staged using the 2010 7th edition American Joint Committee on Cancer (AJCC 7) staging system, the 2016 8th edition AJCC staging system (AJCC 8), and the Brigham and Women's Hospital (BWH) alternative tumor staging system published in 2013. Results There were 28 patients (23.7%) with positive nodal metastases at the time of tumor excision. Almost all tumors staged as tumor (T)2 using AJCC 7 were upstaged to T3 or T4 using the new AJCC 8, and these two groups accounted for the majority of the nodal metastases. Similarly, the BWH‐staged T3 group contained the highest number of tumors with nodal metastases. None of the three staging systems significantly stratified tumors in a manner that predicted the presence of nodal metastases. Conclusion Individuals with cSCC tumors staged T3 or higher in the AJCC 8 and BWH staging systems should undergo neck dissection, whereas those with lower staging should be discussed with the patient on a case‐by‐case basis. Level of Evidence: 4

Current Methods and Caveats to Risk Factor Assessment in Cutaneous Squamous Cell Carcinoma (cSCC): A Narrative Review

“…Perineural invasion (PNI) is most commonly defined as tumor cells surrounding, invading, or passing through peripheral nerves [17]. In cSCC specifically, the incidence of PNI has been reported to range from 2% to 14%, [18], and its presence is often associated with poor prognosis, such as increased LR, NM, and/or DSD [2,[19][20][21][22][23][24][25][26][27]. Several studies support the prognostic value of PNI of large-caliber nerves (deep, named, large nerves, or those C 0.1 mm in diameter) compared to PNI of small-caliber nerves (superficial, unnamed, dermal nerves, \ 0.1 mm in diameter), or the absence of PNI.…”

“…-LR [2,20,21,30] -NM [2,19,[22][23][24][25] -DSD [2,19,21,26,31] Large caliber is significant risk factor for:…”

“…-LR [2,19,21,42,43] -NM [2,19,21,22,24,25,[39][40][41]45] -DSD [19,21,35,44] Moderate differentiation significant predictor for:…”

“…Histopathologic grading of cSCC was first described in 1921 by Broders [38] and today is still the standard guideline grading system of cell differentiation. Poorly differentiated histology has been identified as an independent predictor of LR, metastasis, and/or DSD [24,25,35,36,[39][40][41][42][43] for cSCC. In a study at BWH [19], multivariate models using 256 tumors from 237 patients identified poorly differentiated histology as the only risk factor able to predict all poor outcomes of interest (LR, NM, DSD, and all-cause mortality).…”

“…Another clinical factor assessed when determining metastatic risk is the horizontal size of a cSCC lesion. Many studies have shown that a tumor size [ 2 cm is indicative of a greater risk of tumor metastasis [2,24,25] and DSD [2,14,19]. Bourlidou [50] and Roozeboom et al [37] both found that with each additional 1-cm increment in tumor diameter there was a significantly higher risk of LR.…”