However, no study has thoroughly evaluated the prognostic factors associated with metastasis until now.
In the Journal of Otolaryngology – Head & Neck Surgery, researchers wrote that immunocompromised individuals, such as solid organ transplant patients, make up 73.3% of all patients with cutaneous SCC who are at risk of metastasis and decreased overall survival.
Led by Alex M. Mlynarek, MD, a specialist in head and neck oncology and microvascular reconstruction at McGill University, Montreal, the finding is based on a systematic literature review of 40 studies involving 8,535 patients.
“The prognostic factors for head and neck cutaneous squamous cell carcinoma that were most consistently reported as significant in the literature are a state of immunosuppression, tumor depth, margins involved, number of lymph nodes affected by carcinoma, parotideal disease, and age,” Dr. Mlynarek and colleagues wrote.
Cutaneous SCC is the second most common nonmelanoma skin cancer with an increase of 263% between 2000 and 2010, shows research from the Mayo Clinic Rochester Epidemiology Project.
Patients in this study with tumors that are 6 mm or greater, or whose tumor invaded fat tissue, were found to have a poor prognosis followed by patients with perineural and lymphovascular invasion and in particular, patients with a poorer grade of cellular differentiation. The number of lymph nodes was significant at 70%, with more than two nodes involved linked to a worse the prognosis, followed by 66.7% for margins involved with carcinoma and 50% for tumor depth.
“The majority of patients with cutaneous SCC undergoes electrodesiccation and curettage, cryosurgery, or Mohs surgery, and have an excellent prognosis,” the authors wrote. “However, there is a subset of patients in which these therapies are unsuccessful and where cutaneous SCC appears to be far more aggressive, often resulting in metastasis and recurrence.”
Age was shown to be a significant factor in 53.3% of the studies, but the extent of its effect on prognosis was questionable.
Sentinel lymph node biopsy is commonly used to stage melanoma and has been used in oral SCC.
“A patient post biopsy with either two major criteria or one major and two minor criteria should be considered as a candidate for sentinel lymph node biopsy,” the authors wrote, adding that the findings were consistent with those for cutaneous SCC generally, not specified to the head and neck.
Limitations of the systematic review include potential selection bias as the majority of the studies were based in Australia and most studies were not specified to cutaneous SCC of the head and neck region.
“Given the low rate of metastasis from head and neck cutaneous SCC lesions, it can be challenging to identify the patients who are at high risk of having metastatic disease,” the authors wrote. “We believe this review could help identify patients that would require a closer follow-up and those that could possibly profit from a sentinel lymph node biopsy.”
No disclosures were disclosed for the authors.