A method for treatment of skin cancer in tissue within the skin of a mammal uses the ingestion, injection, infusion or application of an ingredient having a pharmaceutically active phenyl boric acid or salts of a phenyl boric acid to treat the affected tissue. The treatment may be with an amount of ingredient that inhibits the growth of at least one cancer cell line selected from basal cell carcinoma skin lines, and squamous cell carcinoma skin lines and melanoma skin cell lines.
