Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of
skin cancer
Skin cancers are cancers that arise from the skin. They are due to the development of abnormal cells that have the ability to invade or spread to other parts of the body. There are three main types of skin cancers: basal-cell skin cancer (BCC) ...
.
[ It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it.][ It may also present as a raised area with ]ulceration
An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing o ...
. Basal-cell cancer grows slowly and can damage the tissue around it, but it is unlikely to spread to distant areas or result in death.
Risk factors include exposure to ultraviolet light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...
, having lighter skin, radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radi ...
, long-term exposure to arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, ...
and poor immune-system function.[ Exposure to UV light during childhood is particularly harmful.] Tanning beds
Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a ho ...
have become another common source of ultraviolet radiation. Diagnosis often depends on skin examination, confirmed by tissue biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disea ...
.
It remains unclear whether sunscreen affects the risk of basal-cell cancer. Treatment is typically by surgical removal.[ This can be by simple excision if the cancer is small; otherwise, ]Mohs surgery
Mohs surgery, developed in 1938 by a general surgeon, Frederic E. Mohs, is microscopically controlled surgery used to treat both common and rare types of skin cancer. During the surgery, after each removal of tissue and while the patient waits, ...
is generally recommended.[ Other options include ]electrodesiccation and curettage
Electrodesiccation and curettage (EDC, ED & C, or ED+C) is a medical procedure commonly performed by dermatologists, surgeons and general practitioners for the treatment of basal cell cancers and squamous cell cancers of the skin. It provides ...
, cryosurgery
Cryosurgery is the use of extreme cold in surgery to destroy abnormal or diseased tissue; thus, it is the surgical application of cryoablation. The term comes from the Greek words cryo (κρύο) ("icy cold") and surgery (''cheirourgiki'' – χ ...
, topical chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) as part of a standardized ...
, photodynamic therapy
Photodynamic therapy (PDT) is a form of phototherapy involving light and a photosensitizing chemical substance, used in conjunction with molecular oxygen to elicit cell death (phototoxicity).
PDT is popularly used in treating acne. It is used cl ...
, laser surgery
Laser surgery is a type of surgery that uses a laser (in contrast to using a scalpel) to cut tissue.
Examples include the use of a laser scalpel in otherwise conventional surgery, and soft-tissue laser surgery, in which the laser beam vapor ...
or the use of imiquimod
Imiquimod, sold under the brand name Aldara among others, is a medication that acts as an immune response modifier that is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis. Scientists at 3M's pharmaceuticals ...
, a topical immune-activating medication. In the rare cases in which distant spread has occurred, chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
or targeted therapy
Targeted therapy or molecularly targeted therapy is one of the major modalities of medical treatment ( pharmacotherapy) for cancer, others being hormonal therapy and cytotoxic chemotherapy. As a form of molecular medicine, targeted therapy blocks ...
may be used.[
Basal-cell cancer accounts for at least 32% of all cancers globally.] Of skin cancers other than melanoma, about 80% are basal-cell cancers. In the United States, about 35% of white males and 25% of white females are affected by BCC at some point in their lives.[
]
Signs and symptoms
Individuals with a 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
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can ...
. Infiltrative or morpheaform basal-cell cancers can present as a skin thickening or scar
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a n ...
tissue – making diagnosis difficult without using tactile sensation and a skin biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...
. It is often difficult to visually distinguish basal-cell cancer from acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
scar, actinic elastosis
Actinic elastosis, also known as solar elastosis, is an accumulation of abnormal elastin (elastic tissue) in the dermis of the skin, or in the conjunctiva of the human eye, eye, which occurs as a result of the cumulative effects of prolonged and e ...
, and recent cryodestruction inflammation
Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molec ...
.
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
Cause
The majority of basal-cell carcinomas occur on sun-exposed areas of the body.
Pathophysiology
''Basal-cell carcinoma'' is named after the basal cells that populate the lowest layer of the epidermis due to the histological
Histology,
also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...
appearance of the cancer cells under the microscope. Nevertheless, not all basal-cell carcinomas actually originate within the basal layer. Basal-cell carcinomas are thought to develop from the folliculo–sebaceous
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest num ...
–apocrine
Apocrine () glands are a type of exocrine gland, which are themselves a type of gland, i.e. a group of cells specialized for the release of secretions. Exocrine glands secrete by one of three means: holocrine, merocrine and apocrine. In apocri ...
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
Trichoblastomas are a skin condition characterized by benign neoplasms of the follicular germinative cells known as ''trichoblasts''.
''Trichoblastic fibroma'' is a term used to describe small nodular trichoblastomas that contain a conspicuous ...
(differential diagnosis can be challenging). It has been suggested that lesions diagnosed as 'trichoblastic carcinoma' may actually themselves be basal-cell carcinoma.
Overexposure to sun leads to the formation of thymine dimer
Pyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions, commonly associated with direct DNA damage. Ultraviolet light (UV; particularly UVB) induces the formation of covalent linkages bet ...
s, a form of DNA damage. While DNA repair
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA da ...
removes most UV-induced damage, not all crosslinks are excised. There is, therefore, cumulative DNA damage leading to mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA replication, DNA or viral repl ...
s. Apart from the mutagenesis, overexposure to sunlight depresses the local immune system
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splint ...
, possibly decreasing immune surveillance for new tumor cells.
Basal-cell carcinomas can often come in association with other lesions of the skin, such as actinic keratosis
Actinic keratosis (AK), sometimes called solar keratosis or senile keratosis, is a pre-cancerous area of thick, scaly, or crusty skin.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . Actinic k ...
, seborrheic keratosis
A seborrheic keratosis is a non-cancerous (benign) skin tumour that originates from cells, namely keratinocytes, in the outer layer of the skin called the epidermis. Like liver spots, seborrheic keratoses are seen more often as people age.
The tum ...
, squamous cell carcinoma. 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
The falx cerebri (also known as the cerebral falx) is a large, crescent-shaped fold of dura mater that descends vertically into the longitudinal fissure between the cerebral hemispheres of the human brain,Saladin K. "Anatomy & Physiology: The Uni ...
(in the center line of the brain) and rib abnormalities. The cause of this syndrome is a mutation in the PTCH1
Protein patched homolog 1 is a protein that is the member of the patched family and in humans is encoded by the ''PTCH1'' gene.
Function
PTCH1 is a member of the patched gene family and is the receptor for sonic hedgehog, a secreted molecule ...
tumor suppressor gene
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or re ...
located in chromosome 9q22.3, which inhibits the hedgehog signaling pathway
The Hedgehog signaling pathway is a signaling pathway that transmits information to embryonic cells required for proper cell differentiation. Different parts of the embryo have different concentrations of hedgehog signaling proteins. The pathwa ...
. A mutation in the SMO gene, which is also on the hedgehog pathway, also causes basal-cell carcinoma.
Diagnosis
To diagnose basal-cell carcinomas, a skin biopsy
Skin biopsy is a biopsy technique in which a skin lesion is removed to be sent to a pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician's office, and results are often available in 4 to 10 days. ...
is performed for histopathologic analyses. The most common method is a shave biopsy under local anesthesia
Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It ...
. 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, sebaceoma
Sebaceoma (also known as a "sebaceous epithelioma") is a cutaneous condition that appears as a yellow or orange papule.
See also
* Sebaceous carcinoma
* Sebaceous adenoma
* Skin lesion
A skin condition, also known as cutaneous condition, is ...
s, fibrous papules, early acne scars, and hypertrophic scar
A hypertrophic scar is a cutaneous condition characterized by deposits of excessive amounts of collagen which gives rise to a raised scar, but not to the degree observed with keloids. Like keloids, they form most often at the sites of pimples, b ...
ring. 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.
Characteristics
Basal-cell carcinoma cells appear similar to epidermal basal cells, and are usually well differentiated.
In uncertain cases, immunohistochemistry using BerEP4
BerEp4 (also Ber-EP4) is a histologic stain mainly used to aid in the diagnosis of basal cell carcinoma (BCC). It is an antibody to EpCAM (epithelial cell adhesion molecule
Epithelial cell adhesion molecule (EpCAM), also known as CD326 among o ...
can be used, having a high sensitivity and specificity in detecting only BCC cells.
Main classes
Basal-cell carcinoma can broadly be divided into three groups, based on the growth patterns.
# Superficial basal-cell carcinoma, formerly referred to 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
Imiquimod, sold under the brand name Aldara among others, is a medication that acts as an immune response modifier that is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis. Scientists at 3M's pharmaceuticals ...
, or fluorouracil
Fluorouracil (5-FU), sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pan ...
, 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.
# 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.
# 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.
Nodular basal-cell carcinoma
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. 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: ] Such clefts are caused by shrinkage of mucin during tissue fixation and staining. 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 subtypes
Other more specific subtypes of basal-cell carcinoma include:[Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. .]
Aggressiveness patterns
There are mainly three patterns of aggressiveness, based mainly the cohesion of cancer cells:[From the "Glas classification" or "Sabbatsberg classification": ]
Differential diagnoses
Radicality
In suspected but uncertain BCC cells close to the resection margin
A resection margin or surgical margin is the margin of apparently non-tumorous tissue around a tumor that has been surgically removed, called " resected", in surgical oncology. The resection is an attempt to remove a cancer tumor so that no por ...
s, immunohistochemistry with BerEp4
BerEp4 (also Ber-EP4) is a histologic stain mainly used to aid in the diagnosis of basal cell carcinoma (BCC). It is an antibody to EpCAM (epithelial cell adhesion molecule
Epithelial cell adhesion molecule (EpCAM), also known as CD326 among o ...
can highlight the BCC cells.
Prevention
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. 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
Fluorouracil (5-FU), sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pan ...
or imiquimod
Imiquimod, sold under the brand name Aldara among others, is a medication that acts as an immune response modifier that is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis. Scientists at 3M's pharmaceuticals ...
can prevent the development of skin cancer. It is usually recommended to individuals with extensive sun damage, history of multiple skin cancers, or rudimentary forms of cancer (i.e., solar keratosis). It is often repeated every 2 to 3 years to further decrease the risk of skin cancer.
Treatment
The following methods are employed in the treatment of basal-cell carcinoma (BCC):
Standard surgical excision
Surgery to remove the basal-cell carcinoma affected area and the surrounding skin is thought to be the most effective treatment. A disadvantage with standard surgical excision is a reported higher recurrence rate of basal-cell cancers of the face, especially around the eyelids, nose, and facial structures. There is no clear approach, nor a clear research comparing the effectiveness of Mohs micrographic surgery versus surgical excision for BCC of the eye.
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.
Mohs surgery
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.
Mohs surgery
Mohs surgery, developed in 1938 by a general surgeon, Frederic E. Mohs, is microscopically controlled surgery used to treat both common and rare types of skin cancer. During the surgery, after each removal of tissue and while the patient waits, ...
(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
Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on th ...
, melanoma, atypical fibroxanthoma
Atypical fibroxanthoma of the skin is a low-grade malignancy related to malignant fibrous histiocytoma, which it resembles histologically.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology'' ...
, dermatofibrosarcoma protuberans
Dermatofibrosarcoma protuberans (DFSP) is a rare locally aggressive malignant cutaneous soft-tissue sarcoma. DFSP develops in the connective tissue cells in the middle layer of the skin (dermis). Estimates of the overall occurrence of DFSP in the ...
, Merkel cell carcinoma
Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer occurring in about 3 people per 1,000,000 members of the population. It is also known as cutaneous APUDoma, primary neuroendocrine carcinoma of the skin, primary small cell carcin ...
, microcystic adnexal carcinoma
Microcystic adnexal carcinoma (MAC) is a rare sweat gland cancer, which often appears as a yellow spot or bump in the skin. It usually occurs in the neck or head, although cases have been documented in other areas of the body. Most diagnosis occur ...
, and multiple other skin cancers; usually with cure rates higher than for other surgical and non-surgical treatments.
An essential aspect of Mohs surgery
Mohs surgery, developed in 1938 by a general surgeon, Frederic E. Mohs, is microscopically controlled surgery used to treat both common and rare types of skin cancer. During the surgery, after each removal of tissue and while the patient waits, ...
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 method of processing. With this method, it is likely that less than 5% of the surgical margin
A resection margin or surgical margin is the margin of apparently non-tumorous tissue around a tumor that has been surgically removed, called " resected", in surgical oncology. The resection is an attempt to remove a cancer tumor so that no portio ...
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.
Cryosurgery
Cryosurgery
Cryosurgery is the use of extreme cold in surgery to destroy abnormal or diseased tissue; thus, it is the surgical application of cryoablation. The term comes from the Greek words cryo (κρύο) ("icy cold") and surgery (''cheirourgiki'' – χ ...
is an old modality for the treatment of many skin cancers. When accurately utilized with a temperature probe and cryotherapy
Cryotherapy, sometimes known as cold therapy, is the local or general use of low temperatures in medical therapy. Cryotherapy may be used to treat a variety of tissue lesions. The most prominent use of the term refers to the surgical treatment, s ...
instruments, it can result in 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
Mohs surgery, developed in 1938 by a general surgeon, Frederic E. Mohs, is microscopically controlled surgery used to treat both common and rare types of skin cancer. During the surgery, after each removal of tissue and while the patient waits, ...
, excision, or electrodesiccation and curettage so that 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. Several textbooks are published on the therapy, and a few physicians still apply the treatment to selected patients.
Electrodesiccation and curettage
Electrodesiccation and curettage
Electrodesiccation and curettage (EDC, ED & C, or ED+C) is a medical procedure commonly performed by dermatologists, surgeons and general practitioners for the treatment of basal cell cancers and squamous cell cancers of the skin. It provides ...
(EDC, also known as curettage and cautery, simply curettage) 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.
Chemotherapy
Some superficial cancers respond to local therapy with 5-fluorouracil
Fluorouracil (5-FU), sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pan ...
, a chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
agent. One can expect a great deal of inflammation with this treatment. Chemotherapy often follows Mohs surgery to eliminate the residual superficial basal-cell carcinoma after the invasive portion is removed. 5-fluorouracil
Fluorouracil (5-FU), sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pan ...
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 inmunotherapy or chemotherapy to make sure the surgical wound has adequately healed. Some people 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
Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis. It may be given by mo ...
, 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
Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis. It may be given by mo ...
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
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
BCC.
Immunotherapy
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
Imiquimod, sold under the brand name Aldara among others, is a medication that acts as an immune response modifier that is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis. Scientists at 3M's pharmaceuticals ...
cream (IMQ), with five applications per week for six weeks has a reported 70–90% success rate at reducing, even removing, the BCC asal-cell carcinoma Imiquimod
Imiquimod, sold under the brand name Aldara among others, is a medication that acts as an immune response modifier that is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis. Scientists at 3M's pharmaceuticals ...
has received FDA approval, and topical IMQ is approved by the European Medicines Agency for treatment of small superficial basal-cell carcinoma. Off label use of imiquimod
Imiquimod, sold under the brand name Aldara among others, is a medication that acts as an immune response modifier that is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis. Scientists at 3M's pharmaceuticals ...
on invasive basal-cell carcinoma has been reported. Imiquimod may be used prior to surgery in order to reduce the size of the carcinoma.
Some advocate the use of imiquimod prior to Mohs surgery to remove the superficial component of the cancer.
Research suggests that treatment using Euphorbia peplus
''Euphorbia peplus'' (petty spurge, radium weed, cancer weed, or milkweed), is a species of ''Euphorbia'', native to most of Europe, northern Africa and western Asia, where it typically grows in cultivated arable land, gardens and other disturbe ...
, a common garden weed, may be effective. Australian biopharmaceutical company Peplin is developing this as topical treatment for BCC.
Radiation
Radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radi ...
can be delivered either as external beam radiotherapy
External beam radiotherapy (EBRT) is the most common form of radiotherapy (radiation therapy). The patient sits or lies on a couch and an external source of ionizing radiation is pointed at a particular part of the body. In contrast to brachyt ...
or as brachytherapy
Brachytherapy is a form of radiation therapy where a sealed radiation source is placed inside or next to the area requiring treatment. ''Brachy'' is Greek for short. Brachytherapy is commonly used as an effective treatment for cervical, prost ...
(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. Cure rate can be as high as 95% for small tumor, or as low as 80% for large tumors. A variation of an external brachytherapy
Brachytherapy is a form of radiation therapy where a sealed radiation source is placed inside or next to the area requiring treatment. ''Brachy'' is Greek for short. Brachytherapy is commonly used as an effective treatment for cervical, prost ...
is the epidermal radioisotope therapy (e.g. with 188Re in form of the Rhenium-SCT). It is used in accordance to the general indications for brachytherapy
Brachytherapy is a form of radiation therapy where a sealed radiation source is placed inside or next to the area requiring treatment. ''Brachy'' is Greek for short. Brachytherapy is commonly used as an effective treatment for cervical, prost ...
and especially complex localisations or structures (e.g. earlobe) as well as the genitals.
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
Photodynamic therapy
Photodynamic therapy (PDT) is a form of phototherapy involving light and a photosensitizing chemical substance, used in conjunction with molecular oxygen to elicit cell death (phototoxicity).
PDT is popularly used in treating acne. It is used cl ...
(PDT) is a new modality for treatment of basal-cell carcinoma, which is administrated by application of photosensitizers
Photosensitizers produce a physicochemical change in a neighboring molecule by either donating an electron to the substrate or by abstracting a hydrogen atom from the substrate. At the end of this process, the photosensitizer eventually returns t ...
to the target area. When these molecules are activated by light, they become toxic, therefore destroy the target cells. Methyl aminolevulinate is approved by EU as a photosensitizer since 2001. This therapy is also used in other skin cancer types. The 2008 study reported that PDT was a good treatment option for primary superficial BCCs and reasonable for primary low-risk nodular BCCs but a "relatively poor" option for high-risk lesions.
Prognosis
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 recurrent rate with any methods 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
Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...
. 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.
Epidemiology
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 altitude. It is very common among elderly people over the age of 80. There are approximately 800,000 new cases yearly in the United States alone. Up to 30% of white people develop basal-cell carcinomas in their lifetime.[ 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.
In the United States approximately 3 out of 10 White people develop a basal-cell carcinoma during their lifetime.] This tumor accounts for approximately 70% of non-melanoma skin cancers. In 80 percent of all cases, basal-cell carcinoma affects the skin of head and neck. Furthermore, there appears to be an increase in the incidence of basal-cell cancer of the trunk in recent years.
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.
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{{DEFAULTSORT:Basal-Cell Carcinoma
Epidermal nevi, neoplasms, and cysts
Histopathology
Carcinoma
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Dermal and subcutaneous growths