Squamous cell carcinoma is the second most common skin cancer with over 700,000 new cases reported annually. It is most often found on the head (including scalp), neck, backs of hands, legs or tends to occur on any area that has had chronic sun exposure over many years. Squamous cell carcinomas are often hard, rough, scaly and thickening. They can bleed. Those whose occupations or leisure activities are spent in the sun (or artificial UV) are at much greater risk. Because of this, present or past tanning bed users are much more likely to get SCCs (2.5 times as likely) and to get them at a young age. Other risk factors for developing squamous cell carcinoma include chronic skin infection, skin inflammation, and diseases that compromise the immune system. In a minority of cases, the Human Papillomavirus Virus (HPV) has been linked to the development of SCC. Skin areas commonly affected by HPV-associated SCC include the mouth, nails and genitals. SCCs usually only metastasize to other areas of the body if allowed to grow untreated, so early detection and treatment is paramount.