Basal Cell Carcinoma of the Skin

Background

• Basal cell carcinoma (BCC) is a malignant keratinocyte carcinoma. It is a nonmelanoma, epidermal skin cancer of the basal cells of the epidermis that is characteristically slow growing and locally invasive.
• Clinical subtypes include nodular (most common), superficial (second most common), morpheaform, infiltrative, micronodular, and basosquamous, which vary in their aggressiveness and likelihood for recurrence.
• It is the most common type of nonmelanoma skin cancer, particularly among White persons, with increasing incidence among many subgroups, such as younger women. It typically occurs on sun-exposed skin, most commonly appearing on the head and neck, and less commonly appearing on the trunk.
• Risk factors for BCC include exposure to sun and ultraviolet light, increased age, fair complexion, family and personal history of skin cancers, immunosuppression, and prior radiation treatment.

Evaluation

• Consider basal cell carcinoma in patients with a history of a slowly expanding, painless growth, or as a bleeding or scabbing sore that heals and recurs.
• Examine all suspicious lesions and perform a full-body skin exam. The nodular type (which is most common) appears as a well-defined papule or nodule that is firm and painless, with a flesh-colored, translucent, pearly appearance with overlying telangiectasias and a rolled border. Other clinical subtypes may vary in their appearance.
• Consider dermoscopy (also called dermatoscopy) for a more detailed exam of suspicious lesions. Clinical diagnosis can be made by dermatologists in most cases.
• Biopsy for histologic confirmation and to assess for subtype. Pathology is also useful to assess for high-risk histologic features..
• TNM staging of basal cell carcinoma is based primarily on size (smaller or larger than 2 cm) and depth (less or deeper than 6 mm) and if present, local or distant metastasis.

Management

• Base decisions regarding treatment on whether the tumor is at high-risk or low-risk of recurrence in conjunction with patient preferences.
• Method of lesion removal depends on size, location, and histologic features, and need for histopathologic analysis (Strong recommendation).
• Mohs micrographic surgery (complete circumferential peripheral and deep margin assessment) is the primary treatment for high-risk primary lesions, most lesions on the face, incompletely excised lesions, or recurrent BCC (Strong recommendation).
• Wide local excision is recommended for most low-risk BCC that is not on cosmetically sensitive or functionally sensitive areas (Strong recommendation).
• For treatment of low-risk superficial basal cell carcinoma in patients who are not surgical candidates, options also include:
  • curettage and electrodessication (Weak recommendation) if lesion is not on hair bearing areas or if curettage and electrodessication reaches adipose layer
  • imiquimod for primary small superficial basal cell carcinoma (Weak recommendation)
  • photodynamic therapy (Weak recommendation)
  • radiation therapy (Weak recommendation)
  • topical 5-fluorouracil (5-FU) (Weak recommendation)
• Consider radiation therapy for high-risk BCC if surgery is not an option (Weak recommendation).
• For patients with advanced basal cell carcinoma, such as high-risk primary BCC with positive margins not surgically or radiation amenable, or BCC with nodal or distant metastases, options include vismodegib (Erivedge) or sonidegib (Odomzo) (Strong recommendation).
• Follow up every 6-12 months with history and complete skin exam.

Prevention and screening

• For prevention of skin cancer, consider counselling patients and parents of young children about minimizing exposure to UV radiation for persons aged 6 months to 24 years who have fair skin about minimizing exposure to ultraviolet (UV) radiation to reduce risk of skin cancer (Weak recommendation).
• Remain vigilant for suspicious skin lesions while performing physical exams for other reasons.