Cutaneous squamous cell carcinoma (SCC) is a common cancer arising from malignant proliferation of the keratinocytes of the epidermis. Treatment of cutaneous SCC is indicated since progression of the tumor may lead to local tissue destruction or metastasis resulting in significant morbidity or death. Early treatment provides the best opportunity to cure cutaneous SCC.
In contrast to basal cell carcinoma (BCC), which rarely metastasizes, around 2 to 5 percent of cutaneous SCCs metastasize to regional lymph nodes or more distant sites [1-3]. The approach to treatment is dependent upon the presence or absence of tumor features and patient characteristics that portend an increased risk for aggressive tumor behavior. Cutaneous SCCs that do not have high-risk features have low frequencies of recurrence and metastasis.
The treatment of cutaneous SCCs without features associated with aggressive behavior (low-risk cutaneous SCC) and the prognosis of cutaneous SCC will be reviewed here. The management of high-risk and metastatic cutaneous SCCs, the treatment of keratoacanthomas, and the risk factors, clinical features, and diagnosis of cutaneous SCC are reviewed separately. (See "Recognition and management of high-risk (aggressive) cutaneous squamous cell carcinoma" and "Systemic treatment of advanced cutaneous squamous and basal cell carcinomas" and "Keratoacanthoma: Management and prognosis" and "Epidemiology and risk factors for cutaneous squamous cell carcinoma" and "Clinical features and diagnosis of cutaneous squamous cell carcinoma (SCC)" and "Evaluation for locoregional and distant metastases in cutaneous squamous cell and basal cell carcinoma".)
APPROACH TO TREATMENT
The risk of locoregional recurrence and regional or distant metastasis is the most important factor for determining the approach to the treatment for cutaneous squamous cell carcinoma (SCC). Examples of characteristics that impact the risk for recurrence and metastasis include the site, size, and histologic features of a tumor, as well as patient comorbidities (table 1). "High-risk" SCCs are tumors that exhibit characteristics that are associated with an elevated risk for aggressive tumor behavior.
A consensus on the specific characteristics that define high-risk SCC has not been established and major entities such as the National Comprehensive Cancer Network (NCCN) and the American Joint Committee on Cancer (AJCC) have described dissimilar "high-risk" criteria [4,5]. We follow the NCCN criteria when categorizing tumors as high-risk or low-risk for determining the approach to treatment (table 1). The features of high-risk cutaneous SCC are reviewed in greater detail separately. (See "Recognition and management of high-risk (aggressive) cutaneous squamous cell carcinoma".)