Cancer cells have the potential to spread from the skin to other parts of the body where they can grow into new tumours. This process is called metastasis. The tumours are also called metastasis (singular) or metastases (plural). Metastases are also called secondary tumours.
Understanding the usual progression of cancer helps the doctor to predict its probable course, plan treatment and anticipate further care.
BCC is usually slow growing. It is very rare for a BCC to spread to nearby lymph nodes or to distant parts of the body. However, if a BCC is left untreated, it can grow into nearby areas and spread to the bone or other tissues beneath the skin. The most common sites where untreated BCC spreads are:
SCC tends to be more aggressive than BCC. It is more likely to spread to fatty tissues under the skin, lymph nodes or distant parts of the body. The most common sites where SCC spreads are: