Basal Cell Carcinoma.

BCC is the most common type of skin cancer.

What is a BCC?

A BCC (Basal Cell Carcinoma) is the most common type of skin cancer. Hugh Jackman did us all a favour by tweeting that he’s had a couple removed. BCC is a very common finding at a skin cancer clinic. The cancerous cells originate from the most bottom layer of the epidermis.

BCC is slow growing and only very rarely spreads elsewhere. On the other hand, SCC and melanoma can be very serious. So why is it still good to get a diagnosis of BCC earlier than later? There are two main reasons.

Firstly, a superficial BCC may be treated with cream if it’s still superficial at the time of diagnosis.

Secondly, the length of the scar required to cut out a nodular BCC will be longer than you’d expect. To illustrate this point with precise figures, a 4mm BCC will be cut out with a scar length of 24mm, and a 6mm BCC will have a scar length of 30mm. In other words, for every 1 mm of growth of a BCC the scar will be 3mm longer. This is clearly a problem on the face but also in areas that don’t heal so well such as the lower legs. Bear in mind that these figures are conservative. Some types of BCC will need a wider excision.

BCC does very rarely spread to other areas of the body. There is a new immunological agent (Vismodegib)  that can be used for metastatic BCC.

All this means that a small BCC may need to be cut out with much wider margins that you think.

What puts people at risk of BCC?

BCC is very common in Australia of course with UV light the major risk factor for BCC (primarily UVB). It’s thought that intermittent intense exposure to sunlight is especially important although so is long term cumulative sun exposure (though the latter is not as important a risk factor as that for squamous cell carcinoma). Use of tanning machines increases risk around 1.5 fold.

Genes are also very important in the development of BCC and there is increasing work in this area (eg p53 tumor suppressor gene).

Other common risk factors are prior radiotherapy and immunosuppression (though less important than with SCC). Rare risk factors are arsenic exposure and some hereditary conditions such as nevoid basal cell carcinoma syndrome.

The clinical types of BCC

There are different types of BCC requiring different treatments. The broad category of BCC may be established clinically prior to excision. However, the pathology report is required to identify any concerning features and to confirm the BCC subtype.

Let’s describe the two main types of BCC:

  • Nodular BCC that is raised, shiny, may be pigmented & usually occurs on the face. Nodular BCC needs to be cut out.
  • Superficial BCC that is flat, pink, & usually occurs on the trunk or limbs. This may be treated with skin cancer cream.

Now let’s look at all the main types of BCC in more detail.

Superficial BCC accounts for around 30% of Basal Cell Carcinoma. The condition tends to occur in a younger age group than those affected by other BCC types. UV light is a little less important in the development of superficial BCC than nodular BCC.

Superficial BCC appears as a pink or red flat lesion with well defined borders. On stretching the skin, there may be a slightly raised edge though this is a subtle sign. When you know what to look for, the edge may be slightly pearly in appearance. The lesion itself may be slightly shiny and/or  scaly. These signs are not very specific, and a superficial BCC may look similar to an IEC (Bowens disease). A dermatoscope will certainly help distinguish the two.

Superficial BCC may be treated non-surgically. The most common non-surgical treatment is with Imiquimod (®Aldara) cream.

superficial BCC 2

superficial BCC – note how spreading the skin is the best way to see the colours and texture. (Image reproduced with permission from PCDS.org.uk)

superficial BCC - typical

This superficial BCC is really typical – the red colour has a bluish tinge to it and there are some small ulcers within the lesion.