According to the National Cancer Institute, common signs of lip cancers include a sore on the lip that will not heal, a lump in the lip and unusual bleeding or pain. Lip cancer may also not have any obvious signs and instead may be found during a dental exam.
According to the Skin Cancer Foundation, the most common types of cancers of the lip are the skin cancers basal cell carcinoma and squamous cell carcinoma. These cancers are typically very curable when detected early. Seeing a doctor is recommended if any sores or lumps that do not go away appear on the lips.