Treatment. As stated previously there are many factors that infl uence the treatment of BCC, these

include: tumour characteristics; patient characteristics; experience of the clinician; and local

facilities. In the case of BCC the factors that infl uence prognosis are shown in Table 52.1 and should

be considered when choosing treatment options.

The aim of any therapy selected for BCC is to ensure complete removal or destruction of the primary

tumour to prevent local recurrence and the need for further therapeutic intervention whilst

exposing the patient to the least risk of complications and producing an acceptable cosmetic result.

The wide range in natural history and biology of the different subtypes of BCC and the large number

of treatment modalities available for the removal and destruction of skin tumours means it is diffi

cult to draw up rigid guidelines for the management of this common cancer. Successful management

of BCC requires a clear understanding of the clinicopathological factors that affect prognosis and a

good theoretical and practical knowledge of the strengths and limitations of the many different

treatments available. From published series on outcomes it is clear that successful treatment can be

achieved by any one of the large range of therapies, subject to appropriate matching of the

treatment to the tumour characteristics [46,47]. In most cases, treatment selection is usually based

on a clinical assessment which considers a number of factors that are known to infl uence tumour

prognosis. These factors include tumour size, location, clinical subtype and defi ned margin. In

addition to the tumour characteristics, other factors such as the patient’s age, adequacy and success

of previous treatments and coexisting medical conditions that infl uence tumour biology or

treatment tolerability need to be considered. For reasons that are still unclear, BCCs recurring

following radiotherapy are particularly diffi cult to eradicate by conventional surgical excision and

this needs to betaken into account when selecting the most appropriate therapy[48].

Destructive therapies used appropriately, mainly for low-risk tumours, can offer an effective

alternative to surgical excision for small primary tumours at non-critical sites. A number of studies

have shown that curettage and cautery of low-risk BCCs can give cure rates of up to 97% [49]. Similar

high cure rates have also been reported for cryotherapy for low-risk BCCs [50,51]. Tumour size has

an important effect on prognosis for BCCs and there is good evidence that the recurrence rate

following curettage and cautery or cryotherapy increases signifi cantly with increasing size [52,53]. In

addition to risk of recurrence, it is also important to bear in mind that the morbidity associated with

cryotherapy also increases with increasing size.

Conventional surgical excision with predetermined margins based on the clinical characteristics of

the tumour is regarded by many as the most appropriate therapy for most nodular BCCs and

provides a specimen for histological examination and assessment of the lateral and deep margins

yielding <2% recurrence rate at 5 years post surgery [54,55]. Studies of Mohs surgical specimens

have provided useful information about the probability of achieving complete excision in tumours

with predetermined margins in different sized BCCs. For BCCs less than 2 cm in diameter with well-

defined clinical margins, a 3-mm margin will clear the tumour in 85% of cases and a 4–5-mm margin

in 95% of cases [56–58].

Although it has been estimated that careful inspection of the common nodular and plaque forms of

the tumour with a loupe allows the margin to be determined to within 0.5 mm of the histologically

proven border, inaccuracies in the clinical assessment of tumour margins are an important cause of

incomplete excision of nodular BCCs. Small ulcerated nodular BCCs, which present as non-healing

erosions, not infrequently extend several millimetres beyond the clinically defi ned margin. For these

tumours and others where the margin is less clearly defi ned, curettage prior toexcision is a useful

technique for more accurately defi ning the true borders of the BCC [59,60]. Even in experienced

hands there is a risk that nodular BCCs with apparently well-defi ned clinical margins may have infi

ltrated more extensively, leading to incomplete excision with residual tumour. In some cases,

strands of cells extend along nerves for a considerable distance beyond the obvious clinical edge of

the tumour [61,62]. The outlook is poor when cartilage, bone or the orbit have been invaded.

Studies of incompletely excised BCCs have demonstrated that not all incompletely excised tumours

will recur but that between 21 and 41% will do so over a 2 to 5 year period [63–67]. Based on

information generated over the years on residual tumour in reexcision specimens and recurrence

rates of incompletely excised tumours, it may be reasonable in cases where there is incomplete

excision of the lateral margin only, not to re-excise if the BCC is a primary tumour on a non-critical

site with a non-aggressive histology.

For all other cases and in those where the surgical defect has been repaired using a skin graft or local

fl aps, immediate reexcision with frozen section control or using Mohs micrographic surgery is the

treatment of choice [47]. The management of morphoeic BCC, large BCCs (more than 2 cm in

diameter), some smaller nodular BCCs with poorly defined clinical margins and recurrent BCCs needs

to take into account the increased likelihood of subclinical extension. In the absence of either frozen

section control or Mohs surgery, these tumours will require large predetermined margins; even a 5-

mm margin will only give complete excision of 82% of morphoeic BCCs [56]. Management of

recurrent BCCs is a diffi cult problem as cure rates areconsistently poorer than those achieved for

primary tumour. Mohs surgery is an important treatment option for the treatment of high-risk BCCs

as it offers consistent high cure rates for even the most diffi cult BCCs. For primary BCCs and

recurrent BCCs, treated with Mohs surgery, 5-year cure rates of 98.6% and 96% respectively have

been reported [68]. The proportion of BCCs treated using Mohs surgery varies considerably between

different countries as it is a relatively specialized technique and is more resource-intensive than

simple surgical excision. Tumour characteristics that warrant consideration of Mohs surgery include

BCCs at high-risk sites (nasolabial fold, periocular and nose), BCCs greater than 2 cm in diameter,

morphoeic, infi ltrative or micronodular BCCs and recurrent BCCs [46,47].