Basal-cell carcinoma

Individuals with basal-cell carcinoma typically present with a shiny, pearly skin nodule. However, superficial basal-cell cancer can present as a red patch similar to eczema. Infiltrative or morpheaform basal-cell cancers can present as a skin thickening or scar tissue – making diagnosis difficult without using tactile sensation and a skin biopsy. It is often difficult to visually distinguish basal-cell cancer from acne scar, actinic elastosis, and recent cryodestruction inflammation.{{Cite web |title=Basal Cell Carcinoma Warning Signs and Images |url=https://www.skincancer.org/skin-cancer-information/basal-cell-carcinoma/bcc-warning-signs-images/ |access-date=2023-03-02 |website=The Skin Cancer Foundation |language=en-US}}

image:Basal cell carcinoma.jpg|Basal cell carcinoma on patient's back

Basal-cell Carcinoma.jpg|Basal-cell carcinoma

File:Basal Cell Carcinoma Left Upper Back nodular and micronodular.jpg|Basal cell carcinoma on the left upper back, nodular and micronodular, marked for biopsy

image:Dermoscopy_nodular_basal_cell_carcinoma.jpg|Dermoscopy showing telangiectatic vessels

{{See also|List of cutaneous conditions associated with increased risk of nonmelanoma skin cancer}}

The majority of basal-cell carcinomas occur on sun-exposed areas of the body.{{Cite web|url=https://www.cancer.gov/types/skin/hp/skin-genetics-pdq|title=Genetics of Skin Cancer|date=2009-07-29|website=National Cancer Institute|language=en|access-date=2019-05-06}}

Image:Basal cell carcinoma - 2 - intermed mag.jpg of a basal-cell carcinoma, showing the characteristic histomorphologic features (peripheral palisading, myxoid stroma, artefactual clefting). H&E stain]]

Basal-cell carcinoma is named after the basal cells that populate the lowest layer of the epidermis due to the histological appearance of the cancer cells under the microscope. Nevertheless, not all basal-cell carcinomas actually originate within the basal layer.{{cite web |title=Basal Cell Carcinoma - Skin Disorders |url=https://www.msdmanuals.com/en-gb/home/skin-disorders/skin-cancers/basal-cell-carcinoma |website=MSD Manual Consumer Version}} Basal-cell carcinomas are thought to develop from the folliculo–sebaceous–apocrine germinative cells known as trichoblasts. Trichoblastic carcinoma is a term used to describe a rare and potentially aggressive malignancy that is also thought to arise from trichoblasts and may resemble a benign trichoblastoma (differential diagnosis can be challenging).{{cite journal |vauthors=Boettler MA, Shahwan KT, Abidi NY, Carr DR |title=Trichoblastic carcinoma: a comprehensive review of the literature |journal=Arch Dermatol Res |volume=314 |issue=5 |pages=399–403 |date=2022 |pmid=33993349 |doi= 10.1007/s00403-021-02241-y|s2cid=234598207 |url=}}{{cite journal |vauthors = Laffay L, Depaepe L, d'Hombres A, Balme B, Thomas L, De Bari B |title = Histological features and treatment approach of trichoblastic carcinomas: from a case report to a review of the literature |journal = Tumori |volume = 98 |issue = 2 |pages = 46e–49e |year = 2012 |pmid = 22678003 |doi = 10.1700/1088.11948 |doi-broken-date = 1 November 2024 }}{{cite journal |vauthors=Cribier B |title=From basal cell carcinoma to trichoblastic tumors: a diagnostic challenge |language=French |journal=Ann Dermatol Venereol |volume=145 |issue= Suppl 5|pages=VS3–VS11 |date=2018 |pmid=30477681 |doi=10.1016/S0151-9638(18)31254-7 |s2cid=81618758 |url=}} It has been suggested that lesions diagnosed as 'trichoblastic carcinoma' may actually themselves be basal-cell carcinoma.{{cite book |last1=Ackerman |first1=A. Bernard |last2=Kerl |first2=Helmut |last3=Sánchez |first3=Jorge |last4=Guo |first4=Ying |title=A clinical atlas of 101 common skin diseases: with histopathologic correlation |date=2000 |publisher=Ardor Scribendi |location=New York |isbn=978-1-893357-10-5 |chapter = Basal-cell carcinoma: integration unifying concept}}{{Update inline|date=June 2022}}

Overexposure to the sun leads to the formation of thymine dimers, a form of DNA damage. While DNA repair removes most UV-induced damage, not all crosslinks are excised. There is, therefore, cumulative DNA damage leading to mutations. Apart from the mutagenesis, overexposure to sunlight depresses the local immune system, possibly decreasing immune surveillance for new tumor cells. Studies of the role of DNA repair in susceptibility to sunlight-induced basal cell carcinoma indicated that reduced DNA repair capacity is one of the underlying molecular mechanisms for sunlight-induced skin carcinogenesis in the general population.{{cite journal |vauthors=Wei Q, Matanoski GM, Farmer ER, Hedayati MA, Grossman L |title=DNA repair and susceptibility to basal cell carcinoma: a case-control study |journal=Am J Epidemiol |volume=140 |issue=7 |pages=598–607 |date=October 1994 |pmid=7942760 |doi=10.1093/oxfordjournals.aje.a117297 |url=}}{{cite journal |vauthors=Wei Q, Matanoski GM, Farmer ER, Hedayati MA, Grossman L |title=DNA repair capacity for ultraviolet light-induced damage is reduced in peripheral lymphocytes from patients with basal cell carcinoma |journal=J Invest Dermatol |volume=104 |issue=6 |pages=933–6 |date=June 1995 |pmid=7769261 |doi=10.1111/1523-1747.ep12606207 |url=}}

Basal-cell carcinomas can often come in association with other lesions of the skin, such as actinic keratosis, seborrheic keratosis, and squamous cell carcinoma.{{cite journal | vauthors = Fusco N, Lopez G, Gianelli U | title = Basal-Cell Carcinoma and Seborrheic Keratosis: When Opposites Attract | journal = International Journal of Surgical Pathology | volume = 23 | issue = 6 | pages = 464 | date = September 2015 | pmid = 26135529 | doi = 10.1177/1066896915593802 | s2cid = 206650583 }} In a small proportion of cases, basal-cell carcinoma also develops as a result of basal-cell nevus syndrome, or Gorlin Syndrome, which is also characterized by keratocystic odontogenic tumors of the jaw, palmar or plantar (sole of the foot) pits, calcification of the falx cerebri (in the center line of the brain) and rib abnormalities. The cause of this syndrome is a mutation in the PTCH1 tumor suppressor gene located in chromosome 9q22.3, which inhibits the hedgehog signaling pathway. A mutation in the SMO gene, which is also on the hedgehog pathway, also causes basal-cell carcinoma.{{cite journal | vauthors = Epstein EH, Shepard JA, Flotte TJ | title = Case records of the Massachusetts General Hospital. Case 3-2008. An 80-year-old woman with cutaneous basal-cell carcinomas and cysts of the jaws | journal = The New England Journal of Medicine | volume = 358 | issue = 4 | pages = 393–401 | date = January 2008 | pmid = 18216361 | doi = 10.1056/NEJMcpc0707893 }}

File:Basal cell carcinoma2.JPG

To diagnose basal-cell carcinomas, a skin biopsy is performed for histopathologic analyses. The most common method is a shave biopsy under local anesthesia. Most nodular basal-cell cancers can be diagnosed clinically; however, other variants can be very difficult to distinguish from benign lesions such as intradermal naevus, sebaceomas, fibrous papules, early acne scars, and hypertrophic scarring.{{cite web |url= http://www.skincancerguide.ca/basal/what_is_basal_cell_cancer.html |title=What Is Basal Cell Cancer |work = SkinCancerGuide |access-date=2009-02-18 |url-status=live |archive-url=https://web.archive.org/web/20090301043637/http://skincancerguide.ca/basal/what_is_basal_cell_cancer.html |archive-date=2009-03-01 }} Exfoliative cytology methods have high sensitivity and specificity for confirming the diagnosis of basal cell carcinoma when clinical suspicion is high but unclear usefulness otherwise.{{cite journal | vauthors = Ferrante di Ruffano L, Dinnes J, Chuchu N, Bayliss SE, Takwoingi Y, Davenport C, Matin RN, O'Sullivan C, Roskell D, Deeks JJ, Williams HC | title = Exfoliative cytology for diagnosing basal cell carcinoma and other skin cancers in adults | journal = The Cochrane Database of Systematic Reviews | volume = 2018 | pages = CD013187 | date = December 2018 | issue = 12 | pmid = 30521689 | pmc = 6517175 | doi = 10.1002/14651858.cd013187 }}

File:High-magnification micrograph of basal-cell carcinoma.jpg

Basal-cell carcinoma cells appear similar to epidermal basal cells and are usually well differentiated.{{cite web|url=https://www.medscape.com/answers/276624-100154/which-histologic-findings-are-characteristic-of-basal-cell-carcinoma-bcc|title=Which histologic findings are characteristic of basal cell carcinoma (BCC)?|website=Medscape|author=Robert S Bader}} Updated: Feb 21, 2019

In uncertain cases, immunohistochemistry using BerEP4 can be used, having a high sensitivity and specificity in detecting only BCC cells.{{cite journal|last1=Sunjaya|first1=Anthony Paulo|last2=Sunjaya|first2=Angela Felicia|last3=Tan|first3=Sukmawati Tansil|title=The Use of BEREP4 Immunohistochemistry Staining for Detection of Basal Cell Carcinoma|journal=Journal of Skin Cancer|volume=2017|year=2017|pages=1–10 |doi=10.1155/2017/2692604|pmid=29464122|pmc=5804366|doi-access=free}}

Basal-cell carcinoma can broadly be divided into three groups, based on the growth patterns.

1. Superficial basal-cell carcinoma, formerly referred to as in-situ basal-cell carcinoma, is characterized by a superficial proliferation of neoplastic basal-cells. This tumor is generally responsive to topic chemotherapy, such as imiquimod, or fluorouracil, although surgical treatment is better able to ensure complete removal and confirm that there is not an underlying more aggressive subtype that was not sampled in the initial biopsy.
2. Infiltrative basal-cell carcinoma, which also encompasses morpheaform and micronodular basal-cell cancer, is more difficult to treat with conservative methods, given its tendency to penetrate into deeper layers of the skin.
3. Nodular basal-cell carcinoma includes most of the remaining categories of basal-cell cancer. It is not unusual to encounter heterogeneous morphologic features within the same tumor.

File:Basal Cell Carcinoma, Nodular Pattern (6032028849).jpg

Nodular basal-cell carcinoma (also known as "classic basal-cell carcinoma") accounts for 50% of all BCC. It most commonly occurs on the sun-exposed areas of the head and neck.{{rp|748}}{{rp|646}} Histopathology shows aggregates of basaloid cells with well-defined borders, showing a peripheral palisading of cells and one or more typical clefts.Initially copied from: {{cite journal|last1=Paolino|first1=Giovanni|last2=Donati|first2=Michele|last3=Didona|first3=Dario|last4=Mercuri|first4=Santo|last5=Cantisani|first5=Carmen|title=Histology of Non-Melanoma Skin Cancers: An Update|journal=Biomedicines|volume=5|issue=4|year=2017|pages=71 |doi=10.3390/biomedicines5040071|pmid=29261131|pmc=5744095|doi-access=free}} Such clefts are caused by shrinkage of mucin during tissue fixation and staining.{{cite web|url=https://www.medscape.com/answers/276624-100154/which-histologic-findings-are-characteristic-of-basal-cell-carcinoma-bcc|title=Which histologic findings are characteristic of basal cell carcinoma (BCC)?|website=Medscape|author=Robert S Bader}} Updated: Feb 21, 2019 Central necrosis with eosinophilic, granular features may be also present, as well as mucin. The heavy aggregates of mucin determine a cystic structure. Calcification may be also present, especially in long-standing lesions. Mitotic activity is usually not so evident, but a high mitotic rate may be present in more aggressive lesions. Adenoidal BCC can be classified as a variant of NBCC, characterized by basaloid cells with a reticulated configuration extending into the dermis.

File:Palisading in basal cell cancer.jpg|Palisading

File:Nodular basal cell cancer with cleft.jpg|Cleft.

Other more specific subtypes of basal-cell carcinoma include:Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. {{ISBN|0-07-138076-0}}.{{cite book | last1 = James | first1 = William D. | last2 = Berger | first2 = Timothy G. |title=Andrews' Diseases of the Skin: clinical Dermatology |publisher=Saunders Elsevier |year=2006 |isbn=978-0-7216-2921-6 |display-authors=etal}}{{rp|646–50}}

There are mainly three patterns of aggressiveness, based mainly on the cohesion of cancer cells:From the "Glas classification" or "Sabbatsberg classification": {{cite journal|last1=Krynitz|first1=B.|last2=Olsson|first2=H.|last3=Lundh Rozell|first3=B.|last4=Lindelöf|first4=B.|last5=Edgren|first5=G.|last6=Smedby|first6=K.E.|title=Risk of basal cell carcinoma in Swedish organ transplant recipients: a population-based study|journal=British Journal of Dermatology|volume=174|issue=1|year=2016|pages=95–103 |doi=10.1111/bjd.14153|pmid=26333521|s2cid=43844922}}

File:BCC with squamous cell metaplasia with HE and BerEP4 staining.jpg

In suspected but uncertain BCC cells close to the resection margins, immunohistochemistry with BerEp4 can highlight the BCC cells.

Basal-cell carcinoma is a common skin cancer and occurs mainly in fair-skinned patients with a family history of this cancer. Sunlight is a factor in about two-thirds of these cancers; therefore, doctors recommend sunscreens with at least SPF 30. However, a Cochrane review examining the effect of solar protection (sunscreen only) in preventing the development of basal-cell carcinoma or cutaneous squamous cell carcinoma found that there was insufficient evidence to demonstrate whether sunscreen was effective for the prevention of either of these keratinocyte-derived cancers.{{cite journal |vauthors = Sánchez G, Nova J, Rodriguez-Hernandez AE, Medina RD, Solorzano-Restrepo C, Gonzalez J, Olmos M, Godfrey K, Arevalo-Rodriguez I |title = Sun protection for preventing basal-cell and squamous cell skin cancers |journal = The Cochrane Database of Systematic Reviews |volume = 7 |pages = CD011161 |date = July 2016 |issue = 9 |pmid = 27455163 |doi = 10.1002/14651858.CD011161.pub2 |pmc=6457780}} The review did ultimately state that the certainty of these results was low, so future evidence could very well alter this conclusion. One-third occur in non-sun-exposed areas; thus, the pathogenesis is more complex than UV exposure as the cause.

The use of a chemotherapeutic agent such as 5-Fluorouracil or imiquimod can prevent the development of skin cancer. It is usually recommended to individuals with extensive sun damage, a history of multiple skin cancers, or rudimentary forms of cancer (i.e., solar keratosis).{{cite journal | vauthors = Weinstock MA, Thwin SS, Siegel JA, Marcolivio K, Means AD, Leader NF, Shaw FM, Hogan D, Eilers D, Swetter SM, Chen SC, Jacob SE, Warshaw EM, Stricklin GP, Dellavalle RP, Sidhu-Malik N, Konnikov N, Werth VP, Keri JE, Robinson-Bostom L, Ringer RJ, Lew RA, Ferguson R, DiGiovanna JJ, Huang GD | title = Chemoprevention of Basal and Squamous Cell Carcinoma With a Single Course of Fluorouracil, 5%, Cream: A Randomized Clinical Trial | journal = JAMA Dermatology | volume = 154 | issue = 2 | pages = 167–74 | date = February 2018 | pmid = 29299592 | pmc = 5839275 | doi = 10.1001/jamadermatol.2017.3631 }} It is often repeated every 2 to 3 years to further decrease the risk of skin cancer.{{citation needed|date=June 2012}}

The following methods are employed in the treatment of basal-cell carcinoma (BCC):

File:Basal Cell Carcinoma, Right cheek.jpg

Surgery to remove the basal-cell carcinoma affected area and the surrounding skin is thought to be the most effective treatment.{{Cite journal|last1=Thomson|first1=Jason|last2=Hogan|first2=Sarah|last3=Leonardi-Bee|first3=Jo|last4=Williams|first4=Hywel C.|last5=Bath-Hextall|first5=Fiona J.|date=November 17, 2020|title=Interventions for basal cell carcinoma of the skin|journal=The Cochrane Database of Systematic Reviews|volume=11|issue=12|pages=CD003412|doi=10.1002/14651858.CD003412.pub3 |pmid=33202063|pmc=8164471}} A disadvantage with standard surgical excision is a reported higher recurrence rate of basal-cell cancers of the face,{{cite book|url=http://www.nccn.org/professionals/physician_gls/PDF/nmsc.pdf|title=Basal Cell and Squamous Cell Skin Cancers|publisher=National Comprehensive Cancer Network|year=2009|series=NCCN Clinical Practice Guidelines in Oncology|pages=38|archive-url=https://web.archive.org/web/20090227133305/http://www.nccn.org/professionals/physician_gls/PDF/nmsc.pdf|archive-date=2009-02-27}} especially around the eyelids,{{cite journal |vauthors = Sigurdsson H, Agnarsson BA |title = Basal cell carcinoma of the eyelid. Risk of recurrence according to adequacy of surgical margins |journal = Acta Ophthalmologica Scandinavica |volume = 76 |issue = 4 |pages = 477–80 |date = August 1998 |pmid = 9716337 |doi = 10.1034/j.1600-0420.1998.760416.x |doi-access = free }} nose, and facial structures.{{cite journal |vauthors = Farhi D, Dupin N, Palangié A, Carlotti A, Avril MF |title = Incomplete excision of basal cell carcinoma: rate and associated factors among 362 consecutive cases | journal = Dermatologic Surgery |volume = 33 |issue = 10 | pages = 1207–14 |date = October 2007 |pmid = 17903153 | doi = 10.1111/j.1524-4725.2007.33255.x |s2cid = 19202086 }} There is no clear approach, nor clear research comparing the effectiveness of Mohs micrographic surgery versus surgical excision for BCC of the eye.{{cite journal | vauthors = Narayanan K, Hadid OH, Barnes EA | title = Mohs micrographic surgery versus surgical excision for periocular basal-cell carcinoma | journal = The Cochrane Database of Systematic Reviews | issue = 12 | pages = CD007041 | date = December 2014 | volume = 2014 | pmid = 25503105 | doi = 10.1002/14651858.CD007041.pub4 | pmc = 7390281 }}

For basal cell carcinoma excisions on the lower lip, the wound can be covered with a keystone flap. A keystone flap is achieved by creating a flap below the defect and pulling it superiorly to cover the wound. This can be performed if there is enough skin laxity to cover the defect and adequate blood supply to the flap.{{cite journal |url=https://jomi.com/article/290.6/Basal-Cell-Carcinoma-Excision-from-Lower-Lip-with-Keystone-Flap-Reconstruction |last=Hallock |first=G. |title=Basal Cell Carcinoma Excision from Lower Lip with Keystone Flap Reconstruction |journal=J Med Ins |date=2020 |volume=2023 |issue=10 |id=290.6 |doi=10.24296/jomi/290.6}}

For many new (primary) and all recurrent forms of basal cell carcinoma after previous surgery, especially on the head, neck, hands, feet, genitalia, and anterior legs (shins), Mohs surgery should be considered.{{cite journal |last1=Bichakjian |first1=CK |last2=Olencki |first2=T |last3=Olencki |first3=SZ |title=Basal Cell Skin Cancer, Version 1.2016, NCCN Clinical Practice Guidelines in Oncology |journal=J Natl Compr Canc Netw |date=2016 |volume=14 |issue=May |pages=574–597 |doi=10.6004/jnccn.2016.0065 |pmid=27160235 |doi-access=free }}{{cite journal |last1=Ad Hoc Task Force |last2=Connolly |first2=SM |last3=Baker |first3=DR |last4=Coldiron |first4=BM |title=AAD/ACMS/ASDSA/ASMS 2012 appropriate use criteria for Mohs micrographic surgery: a report of the American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery |journal=J Am Acad Dermatol |date=2012 |volume=67 |issue=4 |pages= 531–550|doi=10.1016/j.jaad.2012.06.009 |pmid=22959232 }}

Mohs surgery (or Mohs micrographic surgery) is an outpatient procedure, developed by Frederic E. Mohs in the 1930s, in which the tumor is surgically excised and then immediately examined under a microscope. It is a form of pathology processing called CCPDMA, which means that the entire surgical margin (both edges and deep) is examined. During the surgery, after each removal of tissue and while the patient waits, the tissue is examined for cancer cells. That examination dictates the decision for additional tissue removal. Mohs surgery is also used for squamous-cell carcinoma, melanoma, atypical fibroxanthoma, dermatofibrosarcoma protuberans, Merkel cell carcinoma, microcystic adnexal carcinoma, and multiple other skin cancers;{{Cite journal |last1=Mansouri |first1=Bobbak |last2=Bicknell |first2=Lindsay M. |last3=Hill |first3=Dane |last4=Walker |first4=Gregory D. |last5=Fiala |first5=Katherine |last6=Housewright |first6=Chad |date=2017-08-01 |title=Mohs Micrographic Surgery for the Management of Cutaneous Malignancies |url=https://www.sciencedirect.com/science/article/pii/S1064740617300275 |journal=Facial Plastic Surgery Clinics of North America |series=Facial Reconstruction Post-Mohs Surgery |volume=25 |issue=3 |pages=291–301 |doi=10.1016/j.fsc.2017.03.002 |pmid=28676157 }} usually with cure rates higher than for other surgical and non-surgical treatments.

An essential aspect of Mohs surgery is that the Mohs surgeon performs the surgery and personally reviews the Mohs pathology slides. Most standard excisions done in an office setting are sent to an outside laboratory for standard bread loafing methods of processing.{{cite journal |vauthors = Lane JE, Kent DE |title = Surgical margins in the treatment of nonmelanoma skin cancer and mohs micrographic surgery |journal = Current Surgery |volume = 62 | issue = 5 | pages = 518–26 | year = 2005 | pmid = 16125611 | doi = 10.1016/j.cursur.2005.01.003 }} With this method, it is likely that less than 5% of the surgical margin is examined, as each slice of tissue is only 6 micrometres thick, about 3 to 4 serial slices are obtained per section, and only about 3 to 4 sections are obtained per specimen.{{cite book | vauthors = Maloney ME, Torres A, Hoffman TJ |title=Surgical Dermatopathology |publisher=Blackwell |year=1999 |page= 113 |isbn=978-0-86542-299-5 }}

Cryosurgery is an old modality for the treatment of many skin cancers. When accurately utilized with a temperature probe and cryotherapy instruments, it can result in a very good cure rate. Disadvantages include lack of margin control, tissue necrosis, over or under-treatment of the tumor, and long recovery time. Overall, there are sufficient data to consider cryosurgery as a reasonable treatment for BCC. There are no good studies, however, comparing cryosurgery with other modalities, particularly with Mohs surgery, excision, or electrodesiccation and curettage so no conclusion can be made whether cryosurgery is as efficacious as other methods. Also, there is no evidence on whether curetting the lesions before cryosurgery affects the efficacy of treatment.{{cite journal |vauthors = Kokoszka A, Scheinfeld N |title = Evidence-based review of the use of cryosurgery in treatment of basal-cell carcinoma |journal = Dermatologic Surgery |volume = 29 |issue = 6 |pages = 566–71 |date = June 2003 |pmid = 12786697 |doi = 10.1046/j.1524-4725.2003.291511.x }} Several textbooks are published on the therapy, and a few physicians still apply the treatment to selected patients.{{cite web |url=http://www.webmd.com/cancer/cryosurgery-for-nonmelanoma-skin-cancer |title=Understanding Actinic Keratosis – Treatment |work = Web MD |access-date=2008-12-05 |url-status=live |archive-url=https://web.archive.org/web/20070811234338/http://www.webmd.com/cancer/Cryosurgery-for-nonmelanoma-skin-cancer |archive-date=2007-08-11 }}

Electrodesiccation and curettage (EDC, also known as curettage and cautery, simply curettage){{cite journal | vauthors = Telfer NR, Colver GB, Morton CA | title = Guidelines for the management of basal-cell carcinoma | journal = The British Journal of Dermatology | volume = 159 | issue = 1 | pages = 35–48 | date = July 2008 | pmid = 18593385 | doi = 10.1111/j.1365-2133.2008.08666.x | s2cid = 12365983 }} is accomplished by using a round knife, or curette, to scrape away the soft cancer. The skin is then burned with an electric current. This further softens the skin, allowing for the knife to cut more deeply with the next layer of curettage. The cycle is repeated, with a safety margin of curettage of normal skin around the visible tumor. This cycle is repeated 3 to 5 times, and the free skin margin treated is usually 4 to 6 mm. Cure rate is very much user-dependent and depends also on the size and type of tumor. Infiltrative or morpheaform BCCs can be difficult to eradicate with EDC. Generally, this method is used on cosmetically unimportant areas like the trunk (torso). Some physicians believe that it is acceptable to utilize EDC on the face of elderly patients over the age of 70. However, with increasing life expectancy, such an objective criterion cannot be supported. The cure rate can vary, depending on the aggressiveness of the EDC and the free margin treated. Some advocate curettage alone without electrodesiccation, and with the same cure rate.{{cite journal |vauthors = Barlow JO, Zalla MJ, Kyle A, DiCaudo DJ, Lim KK, Yiannias JA |title = Treatment of basal cell carcinoma with curettage alone |journal = Journal of the American Academy of Dermatology |volume = 54 |issue = 6 |pages = 1039–45 |date = June 2006 |pmid = 16713459 |doi = 10.1016/j.jaad.2006.01.041 }}

Some superficial cancers respond to local therapy with 5-fluorouracil, a chemotherapy agent. One can expect a great deal of inflammation with this treatment.[http://www.skincancer.org/bcc-treatment-options.html] {{webarchive|url=https://web.archive.org/web/20090520083646/http://www.skincancer.org/bcc-treatment-options.html|date=2009-05-20}} Chemotherapy often follows Mohs surgery to eliminate the residual superficial basal-cell carcinoma after the invasive portion is removed. 5-fluorouracil has received FDA approval.

Removing the residual superficial tumor with surgery alone can result in large and difficult-to-repair surgical defects. One often waits a month or more after surgery before starting the immunotherapy or chemotherapy to make sure the surgical wound has adequately healed. Some people{{who|date=November 2021}} advocate the use of curettage (see EDC below) first, followed by chemotherapy. These experimental procedures are not standard care.

Vismodegib and sonidegib are drugs approved for specially treating BCC, but are expensive and cannot be used in pregnant women.

Itraconazole, traditionally an anti-fungal medication, has also garnered recent attention for its potential use in the treatment of BCC, especially those that cannot be removed surgically. Possessing anti-Hedgehog pathway activity, there is clinical evidence that itraconazole has some efficacy either alone or when combined with vismodegib/sonidegib for primary and recurrent BCC. There is one case report of efficacy in metastatic BCC.{{cite journal|vauthors=Ip KH, McKerrow K | title = Itraconazole in the treatment of basal cell carcinoma: A case-based review of the literature | journal = Australasian Journal of Dermatology | pmid = 34160824 | doi = 10.1111/ajd.13655 | year = 2021| volume = 62 | issue = 3 | pages = 394–397 | s2cid = 235608763 }}

This technique uses the body's immune system to kill cancer cells. Improvement of the immune system works its way out up to the cancerous cells and treat the skin cancer.

Topical treatment with 5% Imiquimod cream (IMQ), with five applications per week for six weeks, has a reported 70–90% success rate at reducing, even removing, the BCC [basal-cell carcinoma]. Imiquimod has received FDA approval and topical IMQ is approved by the European Medicines Agency for the treatment of small superficial basal-cell carcinoma. Off-label use of imiquimod on invasive basal-cell carcinoma has been reported. Imiquimod may be used before surgery to reduce the size of the carcinoma.

Some advocate the use of imiquimod before Mohs surgery to remove the superficial component of the cancer.{{cite journal |vauthors = Butler DF, Parekh PK, Lenis A |title = Imiquimod 5% cream as adjunctive therapy for primary, solitary, nodular nasal basal-cell carcinomas before Mohs micrographic surgery: a randomized, double-blind, vehicle-controlled study |journal = Dermatologic Surgery |volume = 35 |issue = 1 |pages = 24–29 |date = January 2009 |pmid = 19018814 |doi = 10.1111/j.1524-4725.2008.34378.x |s2cid = 45091789 |doi-access = free }}

Research suggests that treatment using Euphorbia peplus, a common garden weed, may be effective.{{cite news | url=http://www.theage.com.au/news/Business/Peplins-skin-cancer-trial-a-success/2006/05/01/1146335660056.html | location=Melbourne | work=The Age | title=Peplin's skin cancer gel trial a success | date=1 May 2006 | url-status=live | archive-url=https://web.archive.org/web/20060616223341/http://www.theage.com.au/news/Business/Peplins-skin-cancer-trial-a-success/2006/05/01/1146335660056.html | archive-date=16 June 2006 }} Australian biopharmaceutical company Peplin[http://www.peplin.com Peplin] {{webarchive |url=https://web.archive.org/web/20080614224559/http://www.peplin.com/ |date=June 14, 2008 }} is developing this as topical treatment for BCC.

Radiation therapy can be delivered either as external beam radiotherapy or as brachytherapy (mostly internal radiotherapy). Although radiotherapy is generally used in older patients who are not candidates for surgery, it is also used in cases where surgical excision will be disfiguring or difficult to reconstruct (especially on the tip of the nose, and the nostril rims). Radiation treatment with external radiation often takes as few as 5 visits to as many as 25 visits. Usually, the more visits scheduled for therapy, the less complication or damage is done to the normal tissue supporting the tumor. Radiotherapy can also be useful if surgical excision has been done incompletely or if the pathology report following surgery suggests a high risk of recurrence, for example, if nerve involvement has been demonstrated. The cure rate can be as high as 95% for small tumors, or as low as 80% for large tumors. A variation of an external brachytherapy is the epidermal radioisotope therapy (e.g. with ¹⁸⁸Re in the form of the Rhenium-SCT). It is used in accordance with the general indications for brachytherapy and especially complex localisations or structures (e.g. earlobe) as well as the genitals.{{Cite journal|last1=Castellucci|first1=Paolo|last2=Savoia|first2=F.|last3=Farina|first3=A.|last4=Lima|first4=G. M.|last5=Patrizi|first5=A.|last6=Baraldi|first6=C.|last7=Zagni|first7=F.|last8=Vichi|first8=S.|last9=Pettinato|first9=C.|last10=Morganti|first10=A. G.|last11=Strigari|first11=L.|date=2020-11-02|title=High dose brachytherapy with non sealed 188Re (rhenium) resin in patients with non-melanoma skin cancers (NMSCs): single center preliminary results.|url=https://doi.org/10.1007/s00259-020-05088-z|journal=European Journal of Nuclear Medicine and Molecular Imaging|volume=48|issue=5|pages=1511–21 |doi=10.1007/s00259-020-05088-z|pmid=33140131|pmc=8113182 }}

Usually, recurrent tumors after radiation are treated with surgery, and not with radiation. Further radiation treatment will further damage normal tissue, and the tumor might be resistant to further radiation. Radiation therapy may be contraindicated for treatment of nevoid basal-cell carcinoma syndrome. A 2008 study reported that radiation therapy is appropriate for primary BCCs and recurrent BCCs, but not for BCCs that have recurred following previous radiation treatment.

Photodynamic therapy (PDT) is a new modality for the treatment of basal-cell carcinoma, which is administered by application of photosensitizers to the target area. When these molecules are activated by light, they become toxic, therefore destroying the target cells. Methyl aminolevulinate is approved by the EU as a photosensitizer since 2001. This therapy is also used in other skin cancer types.{{cite journal |doi=10.1088/0034-4885/71/5/056701 |title=Lasers in medicine |journal=Reports on Progress in Physics |volume=71 |issue=5 |pages=056701 |year=2008 |last1=Peng |first1=Qian |last2=Juzeniene |first2=Asta |last3=Chen |first3=Jiyao |last4=Svaasand |first4=Lars O |last5=Warloe |first5=Trond |last6=Giercksky |first6=Karl-Erik |last7=Moan |first7=Johan |bibcode=2008RPPh...71e6701P |s2cid=119815301 }} A 2008 study reported that PDT was a good treatment option for primary superficial BCCs and reasonable for primary low-risk nodular BCCs, but was a "relatively poor" option for high-risk lesions.

Prognosis is excellent if the appropriate method of treatment is used in early primary basal-cell cancers. Recurrent cancers are much harder to cure, with a higher recurrence rate with any method of treatment. Although basal-cell carcinoma rarely metastasizes, it grows locally with invasion and destruction of local tissues. The cancer can impinge on vital structures like nerves and result in loss of sensation or loss of function or rarely death. The vast majority of cases can be successfully treated before serious complications occur. The recurrence rate for the above treatment options ranges from 50 percent to 1 percent or less.

The nose and the temporal region are the most common areas of basal-cell carcinoma of the face.{{cite journal |vauthors=Saeidi A, Gülses A, Jamil M, Alolayan A, Elsayed S, Wiltfang J, Flörke C |title=Retrospective Analysis of Clinicopathological Characteristics of Surgically Treated Basal Cell Carcinomas of the Face: A Single-Centre Maxillofacial Surgery Experience |journal=J Clin Med |volume=13 |issue=18 |date=September 2024 |page=5470 |pmid=39336956 |pmc=11432292 |doi=10.3390/jcm13185470 |doi-access=free |url=}} When completely excised, the recurrence rate for basal-cell carcinoma is relatively low. However, when recurrence occurs among surgically treated basal-cell carcinomas of the face, there is a strong correlation with tumor thickness.

Basal-cell cancer is a very common skin cancer. It is much more common in fair-skinned individuals with a family history of basal-cell cancer and increases in incidence closer to the equator or at higher altitudes. It is very common among elderly people over the age of 80.{{cite journal |vauthors=Lubeek SF, van Vugt LJ, Aben KK, van de Kerkhof PC, Gerritsen MP |title=The epidemiology and clinicopathological features of basal cell carcinoma in patients 80 years and older: a systematic review |journal=JAMA Dermatol |volume=153 |issue=1 |pages=71–78 |date=2017 |pmid=27732698 |doi=10.1001/jamadermatol.2016.3628 |s2cid=8964342 |url=}} There are approximately 800,000[http://www.skincancer.org/basal/index.php Skin Cancer Foundation: Basal-Cell Carcinoma] {{webarchive |url=https://web.archive.org/web/20060619050800/http://www.skincancer.org/basal/index.php |date=2006-06-19 }} new cases yearly in the United States alone. Up to 30% of white people develop basal-cell carcinomas in their lifetime.{{cite journal |vauthors = Wong CS, Strange RC, Lear JT |title = Basal cell carcinoma |journal = BMJ |volume = 327 |issue = 7418 |pages = 794–98 |date = October 2003 |pmid = 14525881 |pmc = 214105 |doi = 10.1136/bmj.327.7418.794 }} In Canada, the most common skin cancer is basal-cell carcinoma (as much as one-third of all cancer diagnoses), affecting 1 in 7 individuals over a lifetime.{{cite web |url=http://www.cancercare.on.ca/cms/one.aspx?pageId=9684 |title = Epidemiology of Skin Cancer |work = BC Cancer Agency |access-date=2011-06-25 |url-status=live |archive-url=https://web.archive.org/web/20110514103530/http://www.cancercare.on.ca/cms/one.aspx?pageId=9684 |archive-date=2011-05-14 }} This tumor accounts for approximately 70% of non-melanoma skin cancers. In 80 percent of all cases, basal-cell carcinoma affects the head or neck skin.

Most sporadic BCC arises in small numbers on sun-exposed skin of people over age 50, although younger people may also be affected. The development of multiple basal-cell cancer at an early age could be indicative of nevoid basal-cell carcinoma syndrome, also known as Gorlin syndrome.{{Cite book|doi=10.1007/978-3-211-69500-5_45 |chapter=Nevoid Basal Cell Carcinoma (Gorlin) Syndrome |title=Neurocutaneous Disorders Phakomatoses and Hamartoneoplastic Syndromes |pages=669–94 |year=2008 |last1=Gorlin |first1=Robert J |isbn=978-3-211-21396-4 }}

{{reflist|group=notes}}

{{Reflist}}

{{Medical resources

| DiseasesDB = 1264

| ICD10 = C44 (ILDS C44.L21)

| ICD9 = {{ICD9|173}}

| ICDO = {{ICDO|8090|3}}-8093/3

| OMIM = 605462

| MedlinePlus = 000824

| eMedicineSubj = med

| eMedicineTopic = 214

| MeshID = D002280

}}

{{Diseases of the skin and appendages by morphology}}

{{Tumor histology}}

{{Skin tumors, epidermis}}

{{DEFAULTSORT:Basal-Cell Carcinoma}}

Category:Epidermal nevi, neoplasms, and cysts

Category:Histopathology

Category:Carcinoma

Category:Wikipedia medicine articles ready to translate

Category:Dermal and subcutaneous growths