Update in the Management of Basal Cell Carcinoma

Abstract

Basal cell carcinoma is the most frequent cancer in fairskinned adults. The molecular background to these tumours includes activation of a cellular pathway called the "sonic hedgehog pathway". Basal cell carcinomas are induced by ultraviolet light and occur more frequently on areas of skin that are exposed to the sun. Basal cell carcinomas rarely spread to other sites in the body, al though there is a risk that they will recur. There are different subtypes of these tumours with different potential to relapse. This paper gives an update of what is known about basal cell carcinomas and their treatment. The standard treatment is surgery. The prognosis for advanced basal cell carcinomas that cannot be operated on has improved with the development of systemic drugs targeting the hedgehog pathway. Basal cell carcinomas are the most frequent skin cancers in the fair-skinned adult population over 50 years of age. Their incidence is increasing throughout the world. Ultraviolet (UV) exposure is the major carcinogenic factor. Some genodermatosis can predispose to formation of basal cell carcinomas at an earlier age. Basal cell carcinomas are heterogeneous, from superficial or nodular lesions of good prognosis to very extensive difficult-to-treat lesions that must be discussed in multidisciplinary committees. Recent guidelines have updated the management of basal cell carcinoma. The prognosis is linked to the risk of recurrence of basal cell carcinoma or its local destructive capacity. Characteristic molecular events in these tumours are: (i) activation of the hedgehog pathway, which has allowed the development of hedgehog inhibitors for difficult-to-treat lesions that are not accessible to surgery or radiotherapy; (ii) high mutational burden, which suggests that hedgehog inhibitor refractory tumours could be offered immunotherapy; some trials are ongoing. The standard treatment for most basal cell carcinomas is surgery, as it allows excision margin control and shows a low risk of recurrence. Superficial lesions can be treated by non-surgical methods with significant efficacy.

A Clinicopathological Analysis of Melanocytic Nevi: A Retrospective Series

“…NMSC is the most common human cancer, and sun exposure is an important risk factor for this disease (22). In addition, it has been reported that the incidence of NMSC is higher in men than in women, and 80% of cases occur in people aged 60 years and older (23). Basal cell carcinomas are usually small and have a translucent or pearly appearance (24,25).…”

“…In addition, it has been reported that the incidence of NMSC is higher in men than in women, and 80% of cases occur in people aged 60 years and older ( 23 ). Basal cell carcinomas are usually small and have a translucent or pearly appearance ( 24 , 25 ). Approximately 80% of all basal cell carcinomas occur on the head and neck.…”

Photodynamic Therapy for Basal Cell Carcinoma: The Clinical Context for Future Research Priorities

“…Nanoformulation with the potential for the topical treatment of BCC has moved forward with the development of ultra-deformable liposomes made of sodium cholate and soy phosphatidylcholine suited to penetration of the stratum corneum [62]. It has been shown that this nanovesicle can be loaded with the hedgehog inhibitor Vismodegib, which is approved for systemic use with certain very high-risk BCC, the reason for the restriction being the adverse effects arising from systemic administration; this nanoformulation may allow topical BCC treatment with reduced adverse effects [62,63].…”

“…It would be of interest for research to be carried out to assess any increased risk of treatment failure arising from such delays. It is accepted that sBCC is the least concerning subtype [63], and it is found that sBCC show higher complete response rates to topical PDT than any other subtype of BCC; this is usually attributed to their relative thinness, allowing the easier penetration of both the light and prodrug [95,96]. However, although the incidence of BCC is increasing worldwide, the rate of increase appears to be greater for the sBCC subtype, with an increasing proportion being found at younger ages.…”

“…Rarely, this is not the case-for example, in locally advanced BCC, which commonly occur either through patient neglect or tumor recurrence following prior insufficient treatments. Trials in Gorlin syndrome patients showed that, although hedgehog inhibitor treatment reduced the tumor burden in these patients, when the treatment was interrupted, BCC recurred [63,128]. Although the resistance to BCC treatment is being intensively studied in respect to hedgehog inhibitor treatment, it is relatively neglected in PDT treatment for BCC.…”