All about Non-Melanoma Skin Cancers

Autor: OncoLink Team
Última Vez Revisión: 19 de febrero de 2019

What is the skin? 

Skin is a thin layer of tissue that is a barrier between the outside world and our internal organs. It is the largest organ in the body. It is made up of three layers:

  • The epidermis is the outermost layer of our skin provides a barrier from UV radiation, chemicals, bacteria and viruses.
  • The dermis is the layer underneath the epidermis it contains connective tissues, hair follicles and sweat glands.
  • The hypodermis is the layer below the dermis and is made up of fat and connective tissue.

Over the years, the skin is exposed to numerous potential carcinogens, or cancer-causing agents, most importantly the sun and its damaging ultraviolet rays.  

What is non-melanoma skin cancer? 

Non-melanoma skin cancer is any type of cancer affecting the skin that is not melanoma. Cancer cells are abnormal cells that grow and can affect other organs in the body. There are two primary types of non-melanoma skin cancers - basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) and these are the two discussed in this article. These cancers derive their name from the cells in which they originate. Both types of cells, basal and squamous, are located within the epidermis, or the outer layer of our skin. Pre-malignant lesions may occur before the development of non-melanoma skin cancers.  

Other types of non-melanoma skin cancers include angiosarcoma, cutaneous B and T cell lymphomas, dermatofibrosarcoma protuberans, Kaposi’s sarcoma, Merkel cell carcinoma, and sebaceous gland carcinoma. 

What causes non-melanoma skin cancer and am I at risk? 

Skin cancer is the most common type of all cancers diagnosed each year in the United States. It is estimated that nearly half of cancers diagnosed every year will be skin cancers. Over the past decade, the incidence of skin cancers has increased dramatically. About 5.4 million basal and squamous cell skin cancers are diagnosed each year, with 8 out of 10 being basal cell and 2 out of 10 being squamous cell. Although these cancers can be locally progressive, they rarely metastasize or spread to other parts of the body. Because of early detection and the decreased metastatic potential, non-melanoma skin cancer is often effectively treated and cured with only local treatment.  

The most common risk factor for development of skin cancer is exposure to ultraviolet radiation from the sun. Ultraviolet radiation from both sun exposure and tanning salons damage the epidermis and the DNA in the cells found throughout the skin. This damage continues to occur with repeated exposure, eventually leading to mutations that accumulate to cause the development of cancerous cells. It has been shown that severe sunburns are particularly damaging when they occur in children. Childhood sun exposure is the strongest correlate with the development of basal cell carcinomas, while sun damage in the decade preceding diagnosis is closely correlated with the development of squamous cell carcinomas. Over 90% of skin cancers occur in individuals with no risk factors other than excess sun exposure.  

There are many other factors that may increase your risk of developing non-melanoma skin cancer including:

  • Having a fair complexion.
  • Occupational exposures to radium and/or arsenic.
  • Personal history of atypical moles.
  • Personal and family history of skin cancers.
  • Smoking tobacco.
  • Immunosuppression from certain medications and HIV infection.
  • Chronic non-healing wounds or previous burns.
  • Genetic syndromes such as basal cell nevus syndrome and xeroderma pigmentosum.
  • HPV infection. 

How do I prevent non-melanoma skin cancer?

There are many things we can do to prevent skin cancer including:

  • Practice sun safety and avoidance when possible. Avoid exposure to ultraviolet rays from the sun and tanning salons. General recommendations from the American Cancer Society include avoiding prolonged, unprotected exposure to the sun between 10 A.M. and 4 P.M, as damaging UV exposure is greatest between these times. Further recommendations include wearing a long-sleeve shirt and hat when outside, wearing sunscreen and re-applying often, and limiting swimming activities to mornings and evenings when the sun is not at its hottest. Don’t forget to protect your eyes with sunglasses.
  • Regular use of sunscreen is crucial to prevent skin cancers. Sunscreen with a sun protection factor (SPF) of 15 or greater should be worn every day, even in the winter, on any uncovered surface, including your lips. Consistent use of sunscreen has even shown the ability to reduce further skin damage in people with a history of extensive sun exposure. 
  • Don’t use tanning beds or sun lamps.
  • Teach your children early and often to use sunscreen, avoid sunburns and protect their skin.
  • Don’t smoke. Assistance and support for quitting is available.

What screening tests are used for non-melanoma skin cancers?

Our risk for non-melanoma skin cancer grows as we age and have had more cumulative sun exposure. It is crucial to examine your own skin regularly and to note of any changes early. Examine your skin routinely in a mirror, including your back, face, lips, hands, forearms, and scalp. Be aware of the location, size, shape and coloring of any freckles and moles you have. Skin cancer often develops from an existing lesion, causing its appearance to change. Be sure to point out any changes and concerns about your skin to your healthcare provider. Early diagnosis is crucial in achieving the most appropriate treatment. 

Because skin cancers are related to exposures, people who have previously developed skin cancers are at much higher risk for future skin cancers. This can happen either in the primary (original) site or somewhere else on the body. Because of this, a complete skin exam should be performed by a healthcare provider at regularly scheduled visits.  

What are the signs of non-melanoma skin cancer? 

BCC typically presents as a small pearly or crusty patch that doe not to heal. Because they are painless and typically develop slowly, they are often present for months to years before they are brought to the attention of the healthcare provider. Often, BCC can be identified by blood vessels that are prominent within the bump. As the lesions grow, crusting and bleeding ulcers that do not heal are frequently the reason individuals present to their provider. BCC lesions are most often identified on the face, with more than 70% of BCC diagnosed on the lips, cheeks, ears, nose, and scalp. Other regions of the body commonly diagnosed with BCC include the back of the neck, the shoulders, the forearms and hands, the back, and lower legs.  

Although the lesions are slow-growing and rarely develop the ability to spread to lymph system or other parts of the body, the lesions can progress locally. As the BCC grows, it may invade adjacent areas, including blood vessels, cartilage, and bone. This spread can be disfiguring. Lesions are frequently neglected because of their slow growth. Risk factors for recurrence after treatment of basal cell carcinomas include depth of invasion, pathologic sub-type, and perineural invasion.  

The appearance of squamous cell carcinoma is typically a small, painless, elevated and crusty lump. As the lesions grow, they can become an ulceration and may bleed. SCCs tend to develop more rapidly than BCCs. Unlike BCC, SCC can spread to the local lymph system. Risk factors for lymph node involvement include tumors > 3 cm, poorly differentiated pathology, recurrent tumors, and tumors with > 4 mm depth of invasion. They can also be rather aggressive locally, causing significant damage and disfiguration to local structures. 

Risk factors for recurrence after treatment of squamous cell carcinomas include perineural invasion, tumor thickness, and poorly differentiated histology. The most common location of SCC is the face. Other areas at high risk include the back, shoulders, forearms and hands, and lower legs. 

Actinic keratosis, which is a precancerous dry, scaly lesion, and carcinoma in situ (Bowen’s disease) are typically located in areas of significant sun damage. They often have the potential to become malignant basal cell or squamous cell carcinomas. These lesions initially develop into dysplasia, or atypical cells. Approximately 10% of actinic keratoses will develop into invasive cancer.  

How is non-melanoma cancer diagnosed? 

When non-melanoma skin cancer is suspected, a biopsy is frequently performed to establish the diagnosis. This biopsy removes either the entire lesion or part of it and the layers beneath it, allowing the depth of the lesion to be accurately determined. There are several different types of biopsies: 

  • Shave Biopsy: A blade is used to shave off the top layers of skin.  
  • Punch Biopsy: A tool that looks similar to a small, round cookie cutter is used to remove a deep sample of skin.  
  • Incisional Biopsy: A scalpel is used to remove part of the lesion. 
  • Excisional Biopsy: A scalpel is used to remove the entire lesion.  

The sample of lesion is sent to a lab to be looked at by a pathologist who determines if the lesion is cancerous and if cancerous what type of skin cancer it is. Along with the biopsy your provider will do a full physical exam and health history. Your provider may order further testing to see if the cancer has spread. A lymph node biopsy and/or imaging tests like MRI, CT and chest x-rays may be used to complete the diagnostic work-up.

How is non-melanoma skin cancer staged?

The stage of cancer, or extent of disease, is based on information gathered through the various tests done as the diagnosis and work-up of the cancer is being performed. The TNM staging system assesses the extent of the tumor, nodal involvement, and distant metastases. This is reported on your pathology report – you may want to ask for a copy of this report for your personal files. 

Non-melanoma skin cancer, specifically SCC of the head and neck, is most commonly staged using the “TNM system.” The TNM system is used to describe many types of cancers. It has three components: T-describing the extent of the "primary" tumor (the tumor in the anus itself); N-describing if there is cancer in the lymph nodes; M-describing the spread to other organs (metastases). The entire staging system is outlined at the end of this article. Though complicated, the staging system helps healthcare providers determine the extent of the cancer, and in turn, make treatment decisions for a patient's cancer. 

How is non-melanoma skin cancer treated?

The treatment of SCC and BCC is dependent on location of the tumor, the age of the individual at diagnosis, the extent of disease, and whether the area has been treated before. Non-melanoma skin cancers are generally treated locally with different methods including surgery, cryotherapy, and radiation.

 For lesions that are small and not locally progressive, the treatment options are numerous and include Moh’s surgery, excisional surgery, cryotherapy, curettage and electrodessication, photodynamic therapy, topical chemotherapy, and radiation therapy. In some instances, more than one treatment modality will be used to treat the cancer.

Cryotherapy

This type of treatment involves freezing off the lesions with liquid nitrogen. Cryotherapy is best for very small, well-defined superficial BCC and well-demarcated SCC. It is frequently used in patients that are not ideal surgical candidates due to other medical conditions.

Excisional Surgery

This traditional, simple surgical resection involves numbing the area with local anesthesia and removing the entire area of concern with a border or margin of healthy tissue, generally 3-10 mm. The skin is then closed with sutures (stitches). The tissue is then sent to a laboratory for a pathologist to confirm all the cancer has been removed. 

Curettage and Electrodessication

This treatment involves local anesthesia followed by removal of the tumor by curettage (scraping). The abnormality is scooped out with a curette until normal skin is appreciated. The entire area is then treated with an electrical current to stop any bleeding. The difficulty with curettage is found in evaluating the margins (edges) and depth of the tumor. Similar to cryotherapy, this technique is best for very small, well-defined superficial BCC and well-demarcated SCC. 

Moh's Surgery

Moh’s surgery is a procedure often performed by a dermatologist or a trained specialist in the office under local anesthesia. With Moh’s surgery, very precise surgery is performed with attempts to remove the least amount of tissue while the margins, or edges, of the resection are examined under a microscope immediately to ensure all of the cancer is removed. While other types of resection can have recurrence rates as high as 50%, Moh’s cure rates have been documented higher than 90%. This type of surgery is also very useful in traditionally difficult areas, including the face. Indications for Moh’s surgery include large lesions where cosmesis can be difficult and maximum skin preservation is crucial.

Radiation Therapy

Radiation therapy, which involves the use of non-invasive, painless, highly focused beams of ionizing energy, is often used when lesions are in locations that are not easily addressed with surgery, such as eyelids, lips, the nose, or ears. Radiation therapy involves daily treatments for several weeks. Radiation is more frequently used for skin cancers in the head and neck region as it offers improved cosmetic outcomes. The effectiveness of radiation as a primary treatment is related to tumor size, with smaller tumors generally responding better. As late skin effects from radiation are a concern, radiation is generally reserved for older patients. Radiation therapy can also be used in conjunction with surgery when tumors are considered high risk or have positive margins as well as with recurrent tumors.

Topical Chemotherapy Medications 

Topical medications are occasionally used to treat BCC. Fluorouracil (5-FU) is a type of chemotherapy often used intravenously for other types of cancer; however, it is also approved for topical use for basal cell carcinomas. The 5-FU cream is applied to the area twice daily for several weeks. Imiquimod is also an approved topical medication for BCC. This cream, which is thought to work by stimulating the immune system, is applied to the tumor five times a week for 6 weeks. This type of therapy is reserved for pre-malignant and very superficial lesions.

Photodynamic Therapy  

Photodynamic therapy (PDT) is a treatment in which a topical photosensitizing agent is put on the lesion and then the lesion is exposed to a to a wavelength of light. When the light is activated the photosensitizer reacts with the oxygen causing destruction of the cancer cells. This treatment is most often used in pre-malignant or superficial low-risk lesions.

Advanced Lesions 

Locally advanced lesions that involve invasion into adjacent areas, the treatments are typically more aggressive. Frequently, the surgery will involve reconstruction if a large amount of tissue will be removed. When reconstruction must occur, a skin graft or muscle is often used to aid healing and reach an acceptable cosmetic outcome. Radiation therapy will be used in addition to surgery to improve local control for lesions that are large and / or total resections are not possible. When tumors recur at the primary (original) site, treatment becomes more complex and is often referred to specialists. The majority of recurrences occur within the first few years following diagnosis. When possible, surgery to achieve negative margins is the best option. However, as lesions often occur on the face near important structures such as the nose, lips, ears, and eyes, radiation is often used when surgery would result in disfigurement.  

Two new medications, vismodegib and sonidegib were recently approved for the treatment of recurrent BCC when surgical and radiation options have been exhausted. These are both oral medications called hedgehog pathway inhibitors.

With SCC, treatment of disease that has spread to lymph nodes may be treated with lymph node dissection and possible radiation therapy. Systemic chemotherapy may also be used. These medications include cisplatin, carboplatin, and fluorouracil. Some tumors are also susceptible to treatment with targeted EGFR inhibitors including cetuximab, gefitinib, erlotinib, panitumumab and lapatinib. These treatments may also be used if the disease has spread to distant organs.

Clinical Trials 

There are clinical research trials for most types of cancer, and every stage of the disease. Clinical trials are designed to determine the value of specific treatments. Trials are often designed to treat a certain stage of cancer, either as the first form of treatment offered, or as an option for treatment after other treatments have failed to work. They can be used to evaluate medications or treatments to prevent cancer, detect it earlier, or help manage side effects. Clinical trials are extremely important in furthering our knowledge of disease. It is through clinical trials that we know what we do today, and many exciting new therapies are currently being tested. Talk to your provider about participating in clinical trials in your area. You can also explore currently open clinical trials using the OncoLink Clinical Trials Matching Service.

Follow-up Care and Survivorship 

Patients with a history of non-melanoma skin cancer have been documented to be at greater risk of developing a secondary skin cancer. Therefore, all patients require close follow-up. Patients with BCC should be evaluated with a complete skin exam every 6 to 12 months for life. Patients with localized SCC should be evaluated with a complete skin exam every 3 to 12 months for the first 2 years after diagnosis, then every 6 to 12 months for 3 years, and then annually.  

It is important for patients to continue to examine his or her own skin for any changes or new lesions. As soon as you notice any changes you should contact your provider. It is also very important to practice sun safety.  

Fear of recurrence, financial impact of cancer treatment, employment issues and coping strategies are common emotional and practical issues experienced by non-melanoma skin cancer survivors. Your healthcare team can identify resources for support and management of these practical and emotional challenges faced during and after cancer. 

Cancer survivorship is a relatively new focus of oncology care. With some 15 million cancer survivors in the US alone, there is a need to help patients transition from active treatment to survivorship. What happens next, how do you get back to normal, what should you know and do to live healthy going forward? A survivorship care plan can be a first step in educating yourself about navigating life after cancer and helping you communicate knowledgeably with your healthcare providers. Create a survivorship care plan today on OncoLink.  

Resources for More Information

Skin Cancer Foundation 

Strive to education the public and medical professionals about the dangers of skin cancer, prevention methods and sun protection. Provides information on skin cancer and treatment. 

http://www.skincancer.org/skin-cancer-information 

National Institute of Health Medline Plus 

The United States medical research agency. Provides information on treatment and research, much of it in Spanish. http://www.nlm.nih.gov/medlineplus/skincancer.html

Appendix AJCC Complete Staging SCC of the Head and Neck, 8thed. 2017

T(Primary Tumor)

Description

TX

Primary tumor cannot be assessed

Tis

Carcinoma in situ

T1

Tumor smaller than 2cm in greatest dimension

T2

Tumor 2cm or larger, but smaller than 4cm in greatest dimension

T3

Tumor 4cm or larger in maximum dimension or minor bond erosion or perineural invasion or deep invasion

T4

Tumor with gross cortical bone/marrow, skull base invasion and/or skull base foramen invasion

  • T4a

Tumor with gross cortical bone/marrow invasion

  • T4b

Tumor with skull base invasion and/or skull base foramen involvement

 

Regional Lymph Nodes-Clinical (cN)

Description

NX

Regional lymph nodes cannot be assessed

N0

No regional lymph node metastasis

N1 

Metastasis in a single ipsilateral lymph node, 3cm or smaller in greatest dimension and ENE(-) (extranodal extension)

N2

Metastasis in a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(−);

or metastases in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(−); 

  • or in metastasis in bilateral or contralateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(−) 

 

  • N2a

Metastasis in a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(−) 

 

  • N2b

Metastasis in multiple ipsilateral nodes, none larger than 6 cm in greatest dimension and ENE(−) 

 

  • N2c

Metastasis in bilateral or contralateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(−) 

 

N3

Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(−); 

or metastasis in any node(s) and clinically overt ENE [ENE(+)] 

 

  • N3a

Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(−) 

 

  • N3b

Metastasis in any node(s) and ENE (+) 

 

 

Regional Lymph Nodes-Pathological(pN)

Description

NX

Regional lymph nodes cannot be assessed

N0

No regional lymph node metastasis

N1

Metastasis in a single ipsilateral lymph node, 3 cm or smaller in greatest dimension and ENE(−) 

N2

Metastasis in a single ipsilateral lymph node, 3 cm or smaller in greatest dimension and ENE(+); 

or larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(−); or metastases in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(−);

or in bilateral or contralateral lymph node(s), none larger than 6 cm in greatest dimension, ENE(−) 

  • N2a

Metastasis in single ipsilateral node 3 cm or smaller in greatest dimension and ENE(+); 

or a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(−) 

  • N2b

Metastasis in multiple ipsilateral nodes, none larger than 6 cm in greatest dimension and ENE(−) 

 

  • N2C

Metastasis in bilateral or contralateral lymph node(s), none larger than 6 cm in greatest dimension and ENE(−) 

 

N3

Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(−); or in a single ipsilateral node larger than 3 cm in greatest dimension and ENE(+); or multiple ipsilateral, contralateral, or bilateral nodes, any with ENE(+); or a single contralateral node of any size and ENE(+)

  • N3a

Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(−)

  • N3b

Metastasis in a single ipsilateral node larger than 3 cm in greatest dimension and ENE(+); 

or multiple ipsilateral, contralateral, or bilateral nodes, any with ENE(+); or a single contralateral node of any size and ENE(+) 

 

Distant Metastasis(M)

Description

M0

No distant metastasis

M1

Distant metastasis

 

Stage Grouping

T

N

M

Stage 0

T1s

N0

M0

Stage I

T1

N0

M0

Stage II

T2

N0

M0

Stage III

T3

T1

T2

T3

N0

N1

N1

N1

M0

M0

M0

M0

Stage IV

T1

T2

T3

Any T

T4

Any T

 

N2

N2

N2

N3

Any N

Any N

M0

M0

M0

M0

M0

M1

Referencias

American Cancer Society. (2018) Basal and squamous cell skin cancer. Retrieved from: https://www.cancer.org/cancer/basal-and-squamous-cell-skin-cancer.html, 18 Feb 2019.

Della Vittoria Scarpati, G., Perri, F., Pisconti, S., Costa, G., Ricciardiello, F., Del Prete, S., ... & Addeo, R. (2016). Concomitant cetuximab and radiation therapy: a possible promising strategy for locally advanced inoperable non-melanoma skin carcinomas. Molecular and clinical oncology4(4), 467-471.

Griffin, L. L., Ali, F. R., & Lear, J. T. (2016). Non-melanoma skin cancer. Clinical medicine16(1), 62-65.

Lucena SR et al. Combined treatments with photodynamic therapy for non-melanoma skin cancer. Journal of Molecular Science. 2015; 16(10):25912-25933. 

McLaughlin-Drubin, M. E. (2015, April). Human papillomaviruses and non-melanoma skin cancer. In Seminars in oncology (Vol. 42, No. 2, pp. 284-290). WB Saunders.

National Cancer Institute. (2018) Skin cancer treatment. Retrieved from: https://www.cancer.gov/types/skin/hp/skin-treatment-pdq#link/_369, 18 Feb 2019.

National Comprehensive Cancer Network (2018). Basal cell skin cancer. Retrieved from: https://www.nccn.org/professionals/physician_gls/pdf/nmsc.pdf, 18 Feb 2019.

National Comprehensive Cancer Network (2018). Squamous cell skin cancer. Retrieved from: https://www.nccn.org/professionals/physician_gls/pdf/squamous.pdf, 18 Feb 2019.

Torri, V. (2016). Chemotherapy and Molecular Therapy in Non-Melanoma Skin Cancer. Current Cancer Therapy Reviews12(3), 166-171.

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