Basal cell carcinoma (BCC)
What is a BCC?
BCC is the commonest skin cancer and the overall most frequent cancer affecting humans. It is strongly related to sun exposure, especially intense and intermittent with sunburns, and fair freckled skin. BCCs may arise at any age, but are more frequent after the age of 40. The majority of them are located on the head and neck, with a predilection to the face, and although uncommon, areas not-exposed to the sun may be affected as well. The typical presentation is a small pale to pink bump, smooth and pearly, that may bleed and does not heal completely. Superficial BCC looks like a pink patch slightly scaly, located more frequently on the trunk. Usually the lesions are painless and slow-growing, but if left untreated they can erode the skin causing an ulcer and local destruction. Distant dissemination to other organs (metastasis), however, are extremely rare.
How are BCCs diagnosed?
Diagnosis is based on skin examination, preferentially with the aid of a dermoscope, and may need confirmation with a biopsy.
How are BCCs treated?
BCCs need to be treated because they can be locally aggressive even though they rarely metastasise. The standard treatment for BCC is surgery, which involves cutting the tumour out, including a safety margin of normal appearing skin surrounding it. When pathology report shows “clear margins” following surgery, the cure rates are higher than 90% for most BCCs.
Some types of BCC and some locations, however, have a higher risk of coming back after surgery (recurrence), even when apparently completely removed. These cases may benefit from real-time assessment of the excision margins under microscopy during the operation, before closure. This procedure is known as micrographic surgery or Mohs surgery. Some of the indications for this approach would be:
BCCs located in cosmetically sensitive areas, such as eyelids, nose, lips and ears;
More “aggressive” subtypes of BCCs, such as micronodular, morpheiform or sclerodermiform and infiltrative;
Tumours whose limits are not easily visible.
For BCCs considered to have a “low risk” of recurrence (small lesions, with well-defined borders, superficial or nodular subtypes), non-surgical alternative treatments may be a good option, including:
Curettage and cautery
Cryotherapy (liquid nitrogen freezing)
Photodynamic therapy (PDT)
Imiquimod cream (Aldara®, APO-Imiquimod®)
5-fluouracil cream (Efudix®)
Radiotherapy is rarely the treatment of choice for BCCs, but may be an option when surgical management may not be tolerated, considering age and other health conditions presented by the patient.
In the rare situations where BCC spreads to other organs (“metastatic” BCC) or when it’s locally advanced (too big on the skin) and not treatable by surgery or radiation, a drug named vismodegib (Erivedge®) may be considered. It works by slowing or stopping the cancer cells from growing. Vismodegib is taken orally and was added recently to PBS list of medications subsidised by Australian government.
How important is follow-up after having a BCC treated?
At least one in three BCC patients will develop another BCC. Long-term follow-up, including full skin examination every 6-12 months, is recommended to check for new lesions and recurrence of the treated ones. Regular self-examination is also very helpful for early detection of skin cancers.
How can non-melanoma skin cancers be prevented?
NMSC, including BCC, SCC and pre-cancerous sun spots (actinic or solar keratosis), are strongly related to ultraviolet (UV) radiation. The predisposition related to skin colour and ability to tan cannot be changed. However, our behaviour towards sun exposure can always be improved and, ideally, since early childhood. Some protective advices are:
Seek shade and avoid outdoor activities in peak sun-hours (10am to 4pm), but especially around midday;
Wear sun-protective clothes, covering as much skin as possible;
Wear a wide brim hat, that protects head, face and ears;
Wear sunglasses with adequate UV protection (lens categories 2, 3 and 4 – according to Australian/NZ standards);
Apply a thick layer of broad spectrum sunscreen (protection against both UVA and UVB rays, SPF30+ or higher, preferably 50+ in Australia) – 20 minutes before going out, reapplying regularly (every 2 hours and after swimming);
Always remember: there is no “safe tan”!
What is the role of nicotinamide in the prevention of non-melanoma skin cancers?
A clinical trial conducted from 2012-2014 in Australia (ONTRAC Study) showed that taking vitamin B3 (nicotinamide) in high doses (500mg orally twice a day) can prevent NMSC (BCC and SCC). Individuals taking the nicotinamide tablets had 23% less skin cancers comparing to the ones taking placebo. The benefits were higher in participants that had multiple previous skin cancers.
It is a low-cost, safe and effective intervention that has been incorporated into standard recommendations in recent years, especially for people with a past history of multiple NMSC, but not yet available to the general population.
When prescribed nicotinamide by your doctor, beware not to use nicotinic acid tablets, which is another form of vitamin B3. This can cause headache, facial redness and low blood pressure. It is essential, also, to maintain your regular skin checks and general sun protection measures.