Basal Cell Carcinoma (BCC): Is it on Your Radar?

Basal cell carcinoma (BCC) is the most common type of skin cancer but the least serious (SunSmart 2018).

If addressed early, BCC can be easily resolved in most cases (CC 2020a).

Non-melanoma skin cancer (NMSC), which comprises BCC and squamous cell carcinoma (cSCC) (along with very rare skin cancers such as Merkel cell carcinoma), is the most common type of cancer in Australia and accounts for about 98% of all skin cancer cases (CC 2020a).

BCC has several features distinguishing it from cSCC and melanoma. Awareness of these differences can assist with timely referral and treatment, thereby reducing morbidity associated with aggressive tumours and enhancing overall patient outcomes. All healthcare professionals should be able to identify lesions and refer appropriately.

What is BCC?

BCC is triggered by DNA mutation (caused by UV radiation, usually from the sun) to the block-like basal cells located in the lower layer of the epidermis, which causes the cells to grow and change abnormally. (Skin Cancer Foundation 2019; CCV 2018).

BCC has a comparatively slow growth rate to cSCC, usually developing over several months or years, and rarely spreads to other areas of the body. It is possible for BCCs to grow rapidly or metastasise, but this is a rare occurrence (CC 2020a; Oakley 2015).

NSMCs as a whole, have a low mortality rate of about 1.9 deaths per 100 000 patients (Khong, Gorayski & Roos 2020).

Despite this, neither patients nor healthcare staff should be complacent when addressing any kind of skin cancer as it is possible for untreated BCC to grow deeper into the skin and cause tissue damage, complicating treatment (Khong, Gorayski & Roos 2020; CCa 2020).

A past history of BCC increases the likelihood of developing another BCC, with approximately 50% of patients developing a new lesion within three years of treatment. An individual can also have more than one BCC simultaneously (Oakley 2015; CC 2020a).

BCCs can develop anywhere on the body but are most commonly found in areas that receive frequent sun exposure, including:

• Head;
• Face;
• Neck;
• Shoulders;
• Back;
• Lower arms; and
• Lower legs.

(CCV 2018)

Prevalence of BCC

BCC accounts for about 70% of the 980 000 NSMCs that are treated every year in Australia. It is most common in those over 40 years of age but can affect anyone (CC 2020a).

In 2018 the total number of mortalities from NMSCs (including BCCs, cSCCs and other rare cancers) was 665 (CC 2020b).

Warning Signs of BCC

The most common type of BCC is nodular BCC, which accounts for more than 60% of cases. It commonly presents as a shiny, firm, dome-shaped nodule ranging from a few millimetres to several centimetres in diameter. It is generally pearly, pink, skin-coloured or translucent in colour with a smooth surface. It may bleed or ulcerate spontaneously, then form a scab and appear to heal like a normal wound (Bader 2020; Oakley 2015; Wells 2019).

Some less common types of BCC include:

• Superficial BCC: Usually presents as a flat and slightly scaly red or pink patch. It is most commonly found on the upper trunk or shoulders, grows slowly and is not overly aggressive.
• Morpheaform BCC: Usually presents as a flat white, yellow or waxy lesion resembling a scar. Accounts for about 10% of lesions.
• Basosquamous carcinoma: A more aggressive cancer that displays characteristics of both a BCC and a cSCC. Accounts for somewhere around 2% of lesions.

(Wells 2019; Oakley 2015; Bader 2020; Anand, Collins & Chapman 2017)

Risk Factors for BCC

• Older age (older males are particularly at risk);
• Fair complexion (particularly if the individual has freckles, blonde or red hair or blue or green eyes);
• History of skin cancer (BCC or another type);
• Unprotected UV exposure (either from the sun or artificial sources);
• History of sunburns;
• Family history of skin cancer;
• Exposure to arsenic;
• Reduced immune function due to illness or immunosuppressive medications; and
• Certain genetic conditions.

(CC 2020a; Oakley 2015)

Diagnosis of BCC

BCCs can be diagnosed through physical examination and biopsy if required. They rarely require staging (Wells 2019; CC 2020a).

Treatment of BCC

If detected early, BCCs can almost always be treated successfully. The treatment method will depend on the specific lesion, however, surgical excision is usually the most appropriate choice. Sometimes a biopsy will have already removed the entirety of the cancer. Other options include:

• Curettage and electrocautery;
• Cryotherapy;
• Photodynamic therapy;
• Imiquimod (immunotherapy) cream;
• Fluorouracil (chemotherapy) cream; and
• Radiotherapy.

(Wells 2019; Oakley 2015; CC 2020a)

Advanced, recurrent or metastatic BCCs may require a combination of surgery, radiotherapy, targeted therapies or other treatments (Oakley 2015).

Due to the likelihood of developing another BCC, melanoma or other skin cancer post-treatment, patients are encouraged to undergo annual skin checks (Oakley 2015).

Conclusion

Although BCCs are usually easy to treat and are not overly aggressive, they should be addressed early in order to reduce the likelihood of complications, and patients should be regularly assessed post-treatment to ensure any new skin cancers are quickly resolved.

Being able to identify and appropriately respond to BCCs is not only integral to treatment, but also ensures lesions can be differentiated from more aggressive and dangerous cancers that require urgent action.

Additional Resources

• Cancer Council, Understanding Skin Cancer
• DermNet NZ, Basal Cell Carcinoma (with pictures)
• Cutaneous Squamous Cell Carcinoma (cSCC): Dysplasia to Invasion
• Recognising Melanoma

References

• Anand, R L, Collins, D & Chapman, A 2017, ‘Basosquamous Carcinoma: Appearance and Reality’, Oxf Med Case Reports, viewed 20 August 2020, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209554/
• Bader, R S 2020, Basal Cell Carcinoma Q&A, Medscape, viewed 20 August 2020, https://emedicine.medscape.com/article/276624-questions-and-answers
• Cancer Council Australia 2020b, Skin Cancer Incidence and Mortality, CC, viewed 20 August 2020, https://wiki.cancer.org.au/skincancerstats/Skin_cancer_incidence_and_mortality#cite_note-Citation:Australian_Institute_of_Health_and_Welfare_2019-9
• Cancer Council Australia 2020a, Understanding Skin Cancer, CC, viewed 20 August 2020, https://www.cancercouncil.com.au/wp-content/uploads/2020/04/Understanding-Skin-Cancer-2019.pdf
• Cancer Council Victoria 2018, Skin Cancer, CCV, viewed 20 August 2020, https://www.cancervic.org.au/cancer-information/types-of-cancer/skin_cancers_non_melanoma/skin-cancer-overview.html
• Khong, J, Gorayski, P & Roos, D 2020, ‘Non-melanoma Skin Cancer in General Practice: Radiotherapy is an Effective Treatment Option’, Australian Journal of General Practice, vol. 49 no. 8, viewed 20 August 2020, https://www1.racgp.org.au/ajgp/2020/august/nonmelanoma-skin-cancer-in-general-practice
• Oakley, A 2015, Basal Cell Carcinoma, DermNet NZ, viewed 20 August 2020, https://dermnetnz.org/topics/basal-cell-carcinoma/
• Skin Cancer Foundation 2019, Basal Cell Carcinoma Overview, Skin Cancer Foundation, viewed 20 August 2020, https://www.skincancer.org/skin-cancer-information/basal-cell-carcinoma/
• SunSmart 2018, Skin Cancer Types, SunSmart, viewed 20 August 2020, https://www.sunsmart.com.au/skin-cancer/skin-cancer-types#:~:text=There%20are%20three%20main%20types,squamous%20cell%20carcinoma%20and%20melanoma.
• Wells, G L 2019, Basal Cell Carcinoma, MSD Manual, viewed 20 August 2020, https://www.msdmanuals.com/en-au/home/skin-disorders/skin-cancers/basal-cell-carcinoma