Skin Squamous Cell Cancer: The Time Is Right for Greater Involvement of the Medical Oncologist

Abstract

Squamous cell cancer (SCC) of the skin is a paradox for the medical oncologist. It is one of the most common malignancies, yet medical oncologists are involved infrequently in the management of most skin SCCs. Most patients with the disease have an excellent prognosis and are treated by a dermatologist, surgeon, or radiation oncologist. There has been no established role for systemic therapy in the adjuvant setting, either alone or with radiation, with the recent exception of the potential use of oral retinoids with preventive intent in selected patients at increased risk for the development of new skin cancers. 1 Historically, the medical oncologist’s role has been relegated largely to the palliative treatment and symptom management of patients with recurrent locoregional or distant disease not amenable to further local treatment measures. Although chemotherapy has limited efficacy in this setting, relatively little attention has been paid to the prospective evaluation of promising new agents in patients with cutaneous SCC. Oncologists have regularly relied on low-quality evidence from the literature, preclinical data, expert opinion, experience with the treatment of SCC from other primary sites such as the aerodigestive tract or cervix, and clinical judgment to assist in chemotherapy drug selection. However, several factors point toward the need for more investigations into the pathogenesis, molecular biology, prevention, developmental therapeutics, and combined-modality therapy of SCC of the skin, as well as a growing awareness of the disease and its management among medical oncologists. Because the incidence of SCC of the skin increases after age 40, 2,3 an aging population of baby boomers will contribute to a further increase in the incidence of the disease. A number of risk factors have been identified that predispose one to developing cutaneous SCC— exposure to sunlight and related ultraviolet radiation is the most important and best characterized risk factor. 3 A prior diagnosis of SCC of the skin is associated with an increased likelihood of subsequent skin cancer, 4 as well as cancer at other sites. 5 Many such factors lend themselves to risk-reduction strategies, so there is a keen interest in preventive interventions, including chemoprevention. 6,7 Skin cancer preventive education warrants broad-based attention across all age groups, 1 and it