Compared with early-stage cutaneous squamous cell carcinoma (CSCC), advanced CSCC poses a less clear path to positive treatment outcomes. Results of a study of use of adjuvant radiation therapy to treat advanced CSCC were published in JAMA Otolaryngology-Head & Neck Surgery.
Outcomes with or without adjuvant radiation therapy were assessed in this retrospective analysis of 349 patients with head and neck CSCC that was treated surgically, 54.7% of whom had received adjuvant radiation therapy. The researchers also examined whether certain patient or tumor features affected survival.
The 5-year overall survival (OS) rate was 47.4%, and the 5-year disease-free survival (DFS) rate was 59.4%. In a multivariate analysis, postoperative adjuvant radiation therapy was associated with higher OS (HR 0.59; 95% CI 0.38-0.90).
In multivariate analyses, factors associated with worse OS among all patients were presence of N2 or greater nodal disease (HR 2.43; 95% CI 1.42-4.17) and immunosuppression (HR 2.17; 95% CI 1.12-4.17). DFS was worse with periorbital tumors (HR 2.48; 95% CI 1.00-6.16), N2 or greater nodal disease (HR 2.16; 95% CI: 1.13-4.16), and perineural invasion (HR 1.90; 95% CI 1.12-3.19).
In patients with regional disease, adjuvant radiation therapy was associated with higher OS (HR 0.30; 95% CI 0.15-0.61) and DFS (HR 0.36; 95% CI 0.15-0.84). In the presence of perineural invasion, adjuvant radiation therapy was associated with higher OS (HR 0.44; 95% CI 0.24-0.86) and DFS (HR 0.47; 95% CI 0.23-0.93).
The authors concluded that among these patients with advanced head and neck CSCC, those with regional disease or perineural invasion showed better survival outcomes associated with adjuvant radiation therapy.
Harris BN, Pipkorn P, Nguyen KNB, et al. Association of adjuvant radiation therapy with survival in patients with advanced cutaneous squamous cell carcinoma of the head and neck [published online December 20, 2018]. JAMA Otolaryngol Head Neck Surg. doi: 10.1001/jamaoto.2018.3650