There is no risk to others. Some metastases can be removed surgically. This depends on the type of cancer and its location. This is usually the case when there are very few metastases or the metastasis is isolated. Medical treatment is the usual approach.
Some cancers respond well and are curable, even if there are multiple metastases.
Radiation can be useful for local tumor recurrence. Otherwise, systemic therapy is needed. This includes chemotherapy and immune-based therapy. These treatments are administered intravenously or orally. The drugs circulate in the body.