The upper and lower mucosal lips (or pink lips) are a subsite of the oral cavity. The skin above and below the pink lips is still considered part of the lips, but not the mucosal lip, and is grouped in with skin cancers.
More than 90 percent of lip cancers are located on the lower lip. This is probably because the lower lip is more exposed to ultraviolet radiation from the sun, particularly in people who spend a great deal of time outside in sunny weather. Therefore, while lip cancer is still associated with tobacco and alcohol like other oral cancers, sun exposure plays a major role as well.
Most lip cancers are diagnosed at an early stage. In fact, according to a national database, 83 percent of lip cancers are diagnosed in Stage I. Because lip cancers are usually caught early, there is a good chance they can be cured.