INTRODUCTION
Nonmelanoma skin cancer (NMSC) includes basal
cell carcinoma (BCC) and squamous cell carcinoma
(SCC), with BCC accounting for approximately 80%
of NMSCs.1,2 The National Cancer Institute estimates that more
than 2 million new cases of NMSC occurred in the United States
in 2012.3 The incidence of BCC has been rapidly increasing in recent
decades in both the United States1,4 and worldwide,5,6 with
the greatest increase noted in women under 40 years of age.4
The lifetime risk of developing a BCC may be as high as 30%.7
A variety of surgical and nonsurgical treatment options are
available for managing BCC.8,9 Surgery is the most common
treatment, but there are times when it is not suitable or not
preferred by patients.10,11 Treatment decisions become more
complex when there is recurrent disease and/or the BCC is locally
advanced. The oral agent vismodegib—recently approved
for the treatment of adults with metastatic BCC (mBCC), or with
locally advanced BCC that has recurred following surgery or
who are not candidates for surgery, and who are not candidates
for radiation—provides an additional option for these patients.10
This second in a series of 3 CME articles examines the diagnosis
and treatment of BCC, with particular focus on (i) identifying
patients at risk for recurrent or advanced disease and (ii) using
patient and disease characteristics to select among available
treatment options. The first (published in the October 2013 issue)
examined new agents for BCC and their mechanisms of
action. The 3rd installment, scheduled to appear in the December
2013 issue, will review various nonsurgical options for BCC,
their benefits and drawbacks, and how best to select appropriate
patients for these therapies.
Diagnosis of BCC
Experienced dermatologists can usually clinically diagnose
typical cases of BCC based on morphology and anatomic location.
12-14 When the presentation is less clear-cut, dermoscopy can
aid in the differential diagnosis of BCC from other conditions that
may clinically mimic its various subtypes.12,14,15 Dermoscopy may
be particularly useful when dealing with pigmented BCCs.12
A biopsy is used to confirm initial clinical suspicion,15-18 as well
as to stratify tumors in terms of risk.14 However, mixed BCC
subtypes may be inaccurately diagnosed by shave or punch biopsies
(ie, BCCs with a nonaggressive superficial component in
the epidermis and more aggressive component in the deeper
dermis).19-22 In such cases, the shave or punch biopsy may fail to
correctly identify the deeper aggressive component that drives
the overall growth pattern of the tumor and treatment decisions.
A complete skin examination and clinical history may
provide additional diagnostic clues, and should be obtained in
all patients with a suspected BCC.23 Patients with an NMSC may
report a history of nonhealing, ulcerative, bleeding lesions.16
Clinical Presentation
BCC subtypes and the location of the BCC help identify whether
there is an increased risk for recurrence or aggressive growth.
Nodular, superficial, morpheaform (also known as sclerosing
or fibrosing), infiltrative, micronodular, and basosquamous are
the major histologic subtypes of BCC. Less common subtypes
include adenoid (cystic) and fibroepithelioma of Pinkus.24,25
Nodular and superficial BCCs are sometimes considered indolent-
growth or low-risk BCC subtypes. That is, while any BCC
