++
SUMMARY
Chemoprevention uses pharmacologic intervention to prevent the development or recurrence of skin cancers in high-risk patients.
Most current chemoprevention methods target ultraviolet (UV) radiation–induced photocarcinogenesis, though other tumorigenesis pathways may be involved as well. There are multiple promising chemoprevention agents available, and some have greater clinical evidence of efficacy for specific populations or skin cancer types.
Chemoprevention agents have demonstrated significant protection against the new onset and recurrence of nonmelanoma skin cancers (NMSCs) in high-risk patient populations.
++
DON’T FORGET
The decision to start patients on a chemoprevention plan should be made after patient-physician discussion.
Many chemoprevention agents are effective against cutaneous squamous cell and basal cell cancers, but more clinical studies are needed to evaluate their prophylactic effects against melanoma.
++
CLINICAL PEARLS
++
PATIENT EDUCATION POINTS
For the general population, the best method for skin cancer prevention remains protection from UV radiation through appropriate sunscreen application and reduced sun exposure. However, additional pharmacologic prevention can be implemented for patients with a history of extensive premalignant or malignant lesions, immunosuppression, or dermatologic conditions that increase susceptibility to UV damage and carcinogenesis.
++
Cancers of the skin represent the most common type of cancer, particularly in the Caucasian population, with incidence rates of melanoma and nonmelanoma skin cancer (NMSC) continuing to increase worldwide.1 The keratinocyte carcinomas basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) account for 99% of NMSC. Within the United States, the incidence of NMSC is estimated to be greater than 1,000,000 per year, consisting of about 20% to 30% SCC and 70% to 80% BCC.1 Although large strides have been made in diagnosis and treatment options, contributing to a stabilizing mortality rate, increasing incidence rates highlight the value of cancer prevention to help address the growing public health burden.
++
The term chemoprevention was first introduced by Sporn et al in 1976 to refer to a pharmacologic approach to cancer prevention.2 The concept outlines having a reasonable, cost-effective approach to prevent carcinogenesis by inhibiting tumor initiation, promotion, and progression to invasive, metastatic stages. The approach to cancer prevention can be categorized into three groups: primary, secondary, and tertiary prevention (Figure 52-1). Primary prevention targets the processes of tumor initiation, preventing de novo malignancy in healthy populations. One major method of primary prevention for skin cancer is sun protection, as damage by UV radiation significantly contributes to most cases. Secondary prevention intervenes during tumor progression and is aimed at preventing the progression of existing premalignant lesions to malignant transformation. Tertiary prevention addresses individuals with prior history of cancer, using strategies that reduce the development of new, independent malignancies. Trials for cancer prevention methods are traditionally timely and costly to conduct. However, evaluating chemoprevention options is ...