What is Basal Cell Carcinoma?
- Basal cell carcinoma is a cancer that can be locally aggressive, but rarely metastasizes (rarely spreads to other parts of the body) (Schwartz, 2018).
- BCC develops in stem cells that are pluripotent, meaning they can give rise to multiple cell types that are present in the skin (Schwartz, 2018).
- BCC is often grouped with squamous cell carcinomas under the umbrella term non-melanoma skin cancer, which represents the most common cancer type in the world (Lomas, Leonardi-Bee, & Bath-Hextall, 2012; Miller & Weinstock, 1994).
- The cause of BCC is repetitive and frequent exposure to UV radiation through sun exposure, tanning beds, and tanning lamps (Schwartz, 2018).
- Development of BCC is also thought to occur in individuals with a genetic susceptibility (Verkourteren, Ramdas, Wakkee, & Nijsten, 2017), which explains why only certain individuals who are exposed to UV radiation develop the cancer. For more information on the genetic link, click here.
Incidence:
It is estimated that 5.4 million new cases of squamous cell cancers are diagnosed each year in the United States, with approximately 80% of these cases representing cases of BCC (American Cancer Society, 2019).
What About Canada?
While Canada does not have a national survey for BCC, research suggests that individuals living in British Columbia have the highest risk for developing BCC, which may be related to greater participation in outdoor activities and subsequent exposure to UV radiation (Abbas & Kalia, 2016). Since 1960, rates of BCC have been increasing by 10% each year, worldwide (Abbas & Kalia, 2016). This increasing trend has been attributed to a greater awareness of the cancer, increased medical visits, the aging population (since risk for BCC increases with age), and changes to ultraviolet radiation exposure (Abbas & Kalia, 2016).
BCC Targets More Men:
BCC affects more men than women. However, rates in women are increasing! This is likely due to the greater awareness of skin health in women, which leads to a higher frequency of medical visits, where BCC is diagnosed, as well as higher tanning bed use compared to men (Pellegrini, Maturo, Di Nardo, Ciciarelli, García-Rodrigo, & Fargnoli, 2017).
Developmental Considerations:
The majority of BCC cases occur after age 50 and appear on sun-exposed skin areas (Pellegrini et al., 2017). However, younger cases do exist, mainly affecting the chest, shoulders, and limbs, as well as on the hands and feet of children (Pellegrini et al., 2017). BCC is more likely to affect younger individuals with a genetic predisposition to the disease, known as basal cell nevus syndrome (Pellegrini et al., 2017).
Mortality Rate:
The mortality rate is extremely low, affecting less than one per cent of those diagnosed.
Why? Because the cancer stays local, rarely metastasizes, and is therefore, easily managed and treated with current pharmacological and surgical therapies (Verkourteren et al., 2017)
Morbidity:
- People who are diagnosed with BCC are 17 times more likely to develop a second BCC than the general population, three times more likely to develop squamous cell carcinoma, and are twice as likely to develop melanoma (Verkourteren et al., 2017).
- The location in which metastases are found affects the risk of malignancy, indicated treatments, and quality and length of life:
- Low-risk lesions affect the chest, back and limbs (Puig & Berrocal, 2014).
- Intermediate-risk lesions affect the scalp, forehead, cheek, chin, and neck (Puig & Berrocal, 2014).
- High-risk lesions affect the nose and periorificial zones (around the eyes, nose, mouth, and ears) (Puig & Berrocal, 2014).
- The type BCC also impacts its risk of malignancy:
- Low-risk lesions are superficial and nodular types (Puig & Berrocal, 2014).
- High-risk lesions are morpheaform, sclerosing, infiltrating, micronodular, and metatypical types (Puig & Berrocal, 2014).
A summary sheet of relevant information is available to download here.