What are the other Names for this Condition? (Also known as/Synonyms)

• Burn Scar Carcinoma
• Post-Burn Scar Squamous Cell Carcinoma
• SCC in Burn Scar

What is Squamous Cell Carcinoma in Burn Scar? (Definition/Background Information)

• Squamous Cell Carcinoma (SCC) in Burn Scar is an uncommon malignant tumor of skin that typically arises from a previous burn injury (mostly 3^rd and 4^th degree burns)
• The burns lead to the formation of severe scars on the skin. Other factors that may influence its development include sun’s ultraviolet rays, skin tanning, and exposure to coal tar and arsenic
• Squamous Cell Carcinoma in Burn Scar may appear as slow-growing skin lesions; the formation of the lesion may take several years. It is more aggressive than conventional squamous cell carcinoma affecting other body regions
• The treatment of choice for Squamous Cell Carcinoma in Burn Scar is a surgical excision with clear margins followed by radiation therapy or chemotherapy, as decided by the healthcare provider. In majority of the cases, the prognosis is good with appropriate early treatment
• Nevertheless, the prognosis of Squamous Cell Carcinoma in Burn Scar depends upon many factors including the stage of the tumor and health status of the affected individual. There is a possibility of local or regional metastasis, which can involve the lymph nodes. This may dictate the course of the condition

Who gets Squamous Cell Carcinoma in Burn Scar? (Age and Sex Distribution)

• Squamous Cell Carcinoma in Burn Scar can potentially affect any individual of any age. However, it is commonly seen in adults
• It can occur in both males and females
• The condition is prevalent worldwide, though dark-skinned individuals (Asians and Africans) are affected less than lighter-skinned individuals (Europeans and Americans)

What are the Risk Factors for Squamous Cell Carcinoma in Burn Scar? (Predisposing Factors)

A prior burn injury that results in severe scarring of the skin can lead to the formation of squamous cell carcinoma at the affected (burn) site. Nevertheless, other factors may contribute towards the development of Squamous Cell Carcinoma in Burn Scar. These include:

• Exposure to intense sun for long periods during the course of work or due to regular participation in outdoor sports activities
• Frequent use of tanning beds, tanning parlors
• People living in geographical regions where hot-dry, desert-like climatic conditions prevail
• Arsenic exposure
• Coal tar exposure
• Smoking, tobacco chewing
• Individuals with weak immune system, which could be due to cancer treatment, AIDS, or those on immunosuppressant drugs after receiving an organ transplant
• Those with sensitive skin, who get easily sunburned
• Caucasians are more vulnerable compared to other darker-toned individuals

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Squamous Cell Carcinoma in Burn Scar? (Etiology)

• Squamous Cell Carcinoma in Burn Scar occurs when skin cells (the keratinocytes that form the epidermis) are damaged from a prior burn injury. This causes DNA damage that results in a malignant transformation of the affected skin
• In order for Post-Burn Squamous Cell Carcinoma to arise, the burn should result in severe scars; such as those arising from 3^rd or 4^th degree burns. Minor or mild burn cases, such as from 1^st or 2^nd degree burns, does not frequently lead to carcinoma development
• The effect of ultraviolet sources, such as the sun and tanning lamps, on the affected radiation site may cumulatively contribute towards skin damage
• Sometimes, individuals working in certain industries may be exposed to chemicals or x-rays for a long duration. This may also contribute to the formation of this skin cancer type
• Scientific research has indicated that the human papillomavirus along with other risk factors, such as sun-exposure, skin color, and an advancing age, seem to greatly multiply the chance of an individual being affected by SCC arising in Radiation Scar. Nevertheless, the reason behind how the virus is responsible for influencing the condition’s development is not well-established

What are the Signs and Symptoms of Squamous Cell Carcinoma in Burn Scar?

The signs and symptoms of Squamous Cell Carcinoma in Burn Scar include:

• In majority of the cases, the SCC is asymptomatic and does not present any signs or symptoms (during the initial period)
• Generally, it is a slow-growing tumor that develops over a prolonged period (may be even many years)
• The skin lesion develops at the previous burn site
• The skin lesions may appear as crusted ulcer, plaques, and nodules
• It may ulcerate and bleed. Occasionally, after the ulcer heals, it may become ulcerated again
• The size of the lesions range from 1-10 cm; average size is usually less than 3 cm
• In some cases, the squamous cell carcinoma may appear more pigmented than surrounding skin
• Individuals with immunocompromised states have more aggressive tumors

How is Squamous Cell Carcinoma in Burn Scar Diagnosed?

A diagnosis of Squamous Cell Carcinoma arising in Burn Scar is made by the following exams and tests:

• Complete physical examination with detailed medical history evaluation (including history of previous burns)
• Examination by a dermatologist using a dermoscopy, a special device to examine the skin
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation

Although the above modalities can be used to make an initial diagnosis, a tissue biopsy of the tumor is necessary to make a definitive diagnosis to begin treatment.

Tissue biopsy:

• A tissue biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
• Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies to assist in the diagnosis

In case of metastatic SCC, the following diagnostic procedures can be used to procure the tissue sample: 

• Fine needle aspiration (FNA) biopsy of the tumor: A FNA biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a FNA biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred
• Core biopsy or open biopsy of the tumor: Generally, these methods are not suited or preferred

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Squamous Cell Carcinoma in Burn Scar?

The possible complications due to Squamous Cell Carcinoma in Burn Scar could include:

• Discomfort, irritability of the affected skin
• Large lesions may ulcerate and bleed resulting in superimposed bacterial or fungal infections
• Permanent scarring might occur with SCC and cosmetic surgery may be required to restore the skin condition
• They can metastasize to the lymph nodes
• Tumors that invade into nerves (perineurial invasion) have higher chances of recurrence and metastasis
• Tumors that are over 2 cm in size have a higher incidence of recurrence and metastasis, than tumors that are less than 2 cm in size

How is Squamous Cell Carcinoma in Burn Scar Treated?

Early diagnosis and treatment of Squamous Cell Carcinoma (SCC) arising in Burn Scar is important to avoid complications such as metastasis to other regions. The treatment measures may include:

• In most cases, a wide surgical excision and removal of the entire tumor is the preferred treatment option
• Mohs micrographic surgery is frequently performed to ensure complete removal of the cancer at one session
• After surgical removal, local radiation therapy may be considered for certain cases
• If the tumor has metastasized (in rare cases), then a combination of chemotherapy, radiation therapy, and invasive procedures may be used to treat the tumor
• Targeted therapy medications are generally used for locally infiltrated or metastatic SCCs. This therapy destroys the tumor cells by acting against the proteins that are responsible for tumor growth
• Cryotherapy: Controlled use of liquid nitrogen, to cause local tissue necrosis
• Large tumors after complete skin excision may need skin grafting or a flap procedure
• Post-operative care is important until the surgical wound heals
• Follow-up care with regular screening and check-ups are important and encouraged

How can Squamous Cell Carcinoma in Burn Scar be Prevented?

It may not be possible to prevent Squamous Cell Carcinoma in Burn Scar. However, the following contributing factors may be avoided and these include:

• Prolonged and chronic exposure to the sun: If this is unavoidable (such as due to an occupational requirement), then it is important to take safety steps to reduce exposure to the UV rays by using sunscreens with high sun-protection factor, by using wide-brimmed hats and protective clothing
• Be aware of the hazards of prolonged sun exposure and take steps to protect yourself. Plan and modify your work tasks to stay out of the sun during the period, when it is the most intense
• Avoid excessive sunbathing (particularly if you are fair-skinned), use of tanning beds, sun lamps, and chemical agents that accelerate sun tanning
• Individuals, who are regularly exposed to the sun or work under the sun, should get their skin periodically examined by a physician. This is crucial if they suspect or notice any skin changes

Regular medical screening at periodic intervals with blood tests, scans, and physical examinations are mandatory, due to its high metastasizing potential and possibility of recurrence. Often several years of active vigilance is necessary.

What is the Prognosis of Squamous Cell Carcinoma in Burn Scar? (Outcomes/Resolutions)

• In general, Squamous Cell Carcinoma in Burn Scar is an aggressive form of skin cancer. If metastasis (such as to the local lymph nodes) is observed, then the prognosis is guarded or unpredictable
• Tumors in their early stage with complete excisional treatment typically have good prognosis
• In cases of metastasis, its prognosis depends upon a set of several factors that include:
  • Stage of tumor: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
  • The surgical resectability of the tumor (meaning, if the tumor can be removed completely)
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared to those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • Whether the tumor is occurring for the first time or is a recurrent tumor. Recurrent tumors have a poorer prognosis compared to tumors that do not recur
  • Response to treatment: Tumors that respond to treatment have better prognosis compared to tumors that do not respond so well to treatment

Additional and Relevant Useful Information for Squamous Cell Carcinoma in Burn Scar:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/diseases-conditions/cancer/