Squamous cell skin cancer
Squamous-cell skin cancer, also known as cutaneous squamous-cell carcinoma (cSCC), is one of the main types of skin cancer along with basal cell cancer, and melanoma.[10] It usually presents as a hard lump with a scaly top but can also form an ulcer.[1] Onset is often over months.[4] Squamous-cell skin cancer is more likely to spread to distant areas than basal cell cancer.[11]
The greatest risk factor is high total exposure to ultraviolet radiation from the Sun.[2] Other risks include prior scars, chronic wounds, actinic keratosis, lighter skin, Bowen’s disease, arsenic exposure, radiation therapy, poor immune system function, previous basal cell carcinoma, and HPV infection.[2][12] Risk from UV radiation is related to total exposure, rather than early exposure.[13] Tanning beds are becoming another common source of ultraviolet radiation.[13] It begins from squamous cells found within the skin.[14] Diagnosis is often based on skin examination and confirmed by tissue biopsy.[2][3]
Decreasing exposure to ultraviolet radiation and the use of sunscreen appear to be effective methods of preventing squamous-cell skin cancer.[5][6] Treatment is typically by surgical removal.[2] This can be by simple excision if the cancer is small otherwise Mohs surgery is generally recommended.[2] Other options may include application of cold and radiation therapy.[7] In the cases in which distant spread has occurred chemotherapy or biologic therapy may be used.[7]
As of 2015, about 2.2 million people have cSCC at any given time.[8] It makes up about 20% of all skin cancer cases.[15] About 12% of males and 7% of females in the United States developed cSCC at some point in time.[2] While prognosis is usually good, if distant spread occurs five-year survival is ~34%.[4][5] In 2015 it resulted in about 51,900 deaths globally.[9] The usual age at diagnosis is around 66.[4] Following the successful treatment of one case of cSCC people are at high risk of developing further cases.[2]
USA
The United States of America (USA), commonly referred to as the United States (U.S.), America, and sometimes the States, is a federal republic[17][18] consisting of 50 statesand a federal district. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is located in the northwestern part of North America and the state of Hawaii is an archipelago in the mid-Pacific. The country also has five populated and nine unpopulated territories in the Pacific and the Caribbean. At 3.80 million square miles (9.85 million km2)[4] and with around 318 million people, the United States is the world’s fourth-largest country by total area and third-largest by population. It is one of the world’s most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries.[19]The geography and climate of the United States is also extremely diverse, and it is home to a wide variety of wildlife.[20]
The United States is a developed country and has the world’s largest national economy.[6] The economy is fueled by an abundance of natural resources and high worker productivity.[29] While the U.S. economy is considered post-industrial, it continues to be one of the world’s largest manufacturers.[30] The country accounts for 37% of global military spending,[31] being the world’s foremost economic and military power, a prominent political and cultural force, and a leader in scientific research and technological innovations.[32]