View source for Squamous cell carcinoma causes of squamous cell carcinoma

{{Squamous cell carcinoma}}
{{CMG}}; '''Associate Editor(s)-in-Chief:''' [[User:Aditya Govindavarjhulla|Aditya Govindavarjhulla, M.B.B.S.]][mailto:agovi@perfuse.org], [[User:Raviteja Reddy Guddeti|Raviteja Guddeti, M.B.B.S.]] [mailto:rgudetti@perfuse.org]

== Overview ==
[[Squamous cell carcinoma]] (SCC) may occur in normal skin or in already damaged skin (injured or inflamed). Most skin cancers occur on skin that is repeatedly exposed to sunlight or other form of ultraviolet radiation. The effect is cumulative, the more time spent in sun the greater the damage done to the skin. Although sun exposure is the major reason for most cases of Squamous cell carcinoma there are other causes, exposure to which can also lead to this invasive form of skin cancer. 


== Causes of Squamous cell carcinoma ==
The following are the most probable causes of squamous cell carcinoma.

* Sun light and UV light exposure.

* Therapeutic radiation : Psoralen plus ultraviolet A ([[PUVA]]) used in the treatment of [[Psoriasis]] and x-rays of head and neck increase the risk of squamous cell carcinoma. The likelihood that therapeutic radiation can lead to skin cancer also depends on other factors like pigmentation of the skin, the total cumulative dose of radiation received. PUVA is particularly phototoxic and mutations in both ''TP53'' and oncogene Ha-''Ras'' are found in PUVA associated Squamous cell carcinoma.In addition to being mutagenic UVA in association with UVB is a potent suppressor of the cutaneous immune system.

* People with fair complexion, albinism, blue or gray eyes, and those with light colored hair are particularly prone to  develop skin cancers as they lack the photo protective melanin pigment. Individuals with skin types 1 and 2 account for most of the patients who develop this cancer. 

* Patients with [[Xeroderma Pigmentosa]] have a deficiency of an enzyme that is essential for DNA repair and thus prone for innumerable Squamous cell carcinomas. Similarly there is increased risk of oral cancers in people with polydysplastic epidermolysis bullosa and Bloom syndrome. 

* Arsenic, a harmful toxin found in sea foods, mushrooms etc., is a well known cause of squamous cell carcinoma.

* The use of [[immunosuppressive drugs]] to prevent graft rejection in organ transplant recipients is associated with a 65 to 250 fold increased risk of developing [[SCC]] compared to the general population. Pretransplantation end-organ disease may also impact the development of post-transplantation SCC. For example among renal transplant patients the highest incidence of skin cancer is found in those with [[Poly cystic kidney disease]] while the lowest incidence is observed in [[Diabetic Nephropathy]]. Similarly [[Cholestatic Liver disease]] is found to be more associated with skin cancers than other causes of liver failure, post-transplantation.  

* 15% of patients with SCC have a viral etiology.Human Papilloma Virus ([[HPV]]) is a well known potential cause of squamous cell carcinoma. This virus is sexually transmitted and there are more than 100 strains reported so far. Some cause genital warts and some others are known to cause vaginal, cervix and penis cancers.      

* Tobacco use is a well known association of squamous cell carcinoma. Both smoked and smokeless form of tobacco contain putative carcinogens.

* SCC of the head and neck is commonly associated with alcohol use. The risk of oral cancer is additive and is up to 40 times more than people who neither drink nor smoke. Use of tobacco and alcohol increases the risk even further up to 100 fold. Mutations in ''TP53'' gene correlate with smoking and drinking habits.<ref>http://emedicine.medscape.com/article/1965430-overview#aw2aab6b2b4aa</ref>

==References==

{{reflist|2}}

 
[[Category:Dermatology]]
[[Category:Types of cancer]]
[[Category:Oncology]]
[[Category:Otolaryngology]]
[[Category:Mature chapter]]
[[Category:Grammar]]


[[de:Plattenepithelkarzinom]]
[[he:קרצינומת תאי קשקש]]
[[nl:Plaveiselcelcarcinoom]]
[[pl:Rak kolczystokomórkowy skóry]]
[[tr:Skuamöz hücreli karsinoma]]

 
{{WikiDoc Help Menu}}
{{WikiDoc Sources}}