Merkel cell cancer
Merkel cellcancer, also called Merkel cell carcinoma, trabecular cancer, Apudoma of skin, or Small cell neuroepithelial tumor of the skin, is a rare and highly aggressive cancerwhere malignantcancer cells develop on or just beneath the skinand in hair follicles. This cancer is a type of neuroendocrine tumor, like small cell lung cancer. Once it has metastasized to the lymph nodes, the 5-year survival rate for a patient is about 50 percent. A small tumor (less than 2 cm) that has not metastasized to the lymph nodes reported a 5-year survival rate of more than 90 percent; however, at the time of diagnosis of MCC the 5-year survival was 64 percent. Up to half of patients suffer a recurrence.cite journal |author=Allen PJ, Bowne WB, Jaques DP, Brennan MF, Busam K, Coit DG |title=Merkel cell carcinoma: prognosis and treatment of patients from a single institution |journal=J. Clin. Oncol. |volume=23 |issue=10 |pages=2300–9 |year=2005 |pmid=15800320 |doi=10.1200/JCO.2005.02.329]
It occurs most often on the face, head, and neck. It usually appears as firm, painless,
nodules, or tumors. These flesh-colored, red, or blue tumors vary in size from 5 mm (less than a quarter of an inch) to more than 5cm (2 inches). The tumor grows rapidly. About half of all Merkel cell cancers occur on the sun-exposed areas of the head and neck, while one-third begin on the legs, and 15% occur on the arms. The cancer may also begin on other parts of the body, such as the trunk.
From initial onset, Merkel cell cancer
metastasizes quickly and spreads to other parts of the body, tending towards the regional lymph nodes. The tumor tends to invade underlying subcutaneous fat, fascia, and muscle. It can also metastasize to the liver, lungs, brainor bones.
A newly discovered virus called
Merkel cell polyomavirus(MCV) is suspected to contribute to the development of the majority of MCC. Approximately 80% of MCC tumors have this virus integrated in a monoclonalpattern [http://www.sciencemag.org/cgi/content/abstract/1152586] [http://www.nytimes.com/2008/01/17/health/research/17cnd-virus.html?ref=health] , indicating that the infection was present in a precursor cell before it became cancerous. Polyomaviruses have been known to be cancer viruses in animals since the 1950s [http://www.time.com/time/magazine/article/0,9171,864777-3,00.html] , but this is the first polyomavirus strongly suspected to cause tumors in humans. Like other tumor viruses, most people who are infected with MCV probably do not develop MCC; it is unknown what other steps are required for the development of MCC.cite web |url=http://news.theage.com.au/new-virus-linked-to-rare-but-lethal-skin-cancer/20080119-1muc.html|title=New virus linked to rare but lethal skin cancer|Publisher=The Age|accessdate=2008-02-26 |format= |work=] Ultraviolet light (sun) exposure probably contributes to MCC development in a large number of cases. MCC also occurs more frequently than expected among immunosuppressed patients, such as transplant patients, AIDS patients and elderly persons, indicating that the tumor is under immune control [http://www3.interscience.wiley.com/cgi-bin/fulltext/114266344/HTMLSTART] . At least 20% of MCC tumors are not infected with MCV suggesting that MCC may have multiple causes.
This type of cancer occurs mostly in — though is not restricted to — Caucasians between 60 and 80 years of age. It occurs about twice as often in males as in females. There are roughly 1200 new cases diagnosed a year in the United States, compared to 60,000 new cases of
melanomaand over 1 million new cases of nonmelanoma skin cancer.cite journal |author=Hodgson NC |title=Merkel cell carcinoma: changing incidence trends |journal=J Surg Oncol |volume=89 |issue=1 |pages=1–4 |year=2005 |pmid=15611998 |doi=10.1002/jso.20167] Merkel cell cancer can be mistaken for another cancer like basal cell carcinoma, squamous cell carcinoma, malignant melanoma, lymphoma, or small cell carcinoma, or may appear to be a benign cyst. Researchers believe that exposure to sunlightor ultraviolet lightmay increase a person’s risk of this disease. Immune suppressioncan profoundly increase one's risk of developing Merkel cell cancer. According to a recent study in the Lancet, Merkel cell carcinoma occurs 13.4 times more often in people with advanced HIVas compared to the general population. Solid organ transplant recipients have similarly increased risk.
Because Merkel cell cancer is uncommon and is difficult to diagnose, patients may want a second opinion about the diagnosis and treatment plan before starting treatment. However, early diagnosis and treatment of Merkel cell cancer are important factors in decreasing the chance of its spreading, after which it is difficult to cure.
Surgery is the usual treatment for Merkel cell cancer. The
tumoris removed along with a border of healthy tissue surrounding it. Nearby, or regional, lymph nodes are often removed because they may contain cancer cells. Sometimes the doctor performs a sentinel lymph node biopsy. In this procedure, the doctor injects a dye or radioactive substance near the tumor. This material flows into the first lymph nodes where cancer is likely to spread (the sentinel nodes). These nodes are then removed and checked for cancer cells. This procedure has been demonstrated to be an important prognostic indicator. Results help dictate the use of appropriate adjuvant therapy, if necessary.
Radiation and chemotherapy
Adjuvant radiotherapyhas been shown to be effective in reducing recurrence and increasing five year survival of patients with Merkel Cell Carcinoma. Patients who present with no metastases and a negative sentinel lymph node biopsy have a good prognosis when treated with surgery and radiotherapy - approximately 90% survival at five years.
Merkel cell cancer that has metastasized may respond to treatment with chemotherapy and/or radiation. This therapy usually does not cure the disease, but can be effective in shrinking the tumor if the tumor is too large to be removed, or is located in a place where removal would be difficult or dangerous.
entinel lymph node biopsy
Sentinel lymph node biopsy detects MCC spread in one third of patients whose tumors would have otherwise been clinically and radiologically understaged and who may not have received treatment to the involved node bed. There was a significant benefit of adjuvant nodal therapy, but only when the SLNB was positive. Thus, SLNB is important for both prognosis and therapy and should be performed routinely for patients with MCC. In contrast, computed tomographic scans have poor sensitivity in detecting nodal disease as well as poor specificity in detecting distant disease.cite journal |author=Gupta SG, Wang LC, Peñas PF, Gellenthin M, Lee SJ, Nghiem P |title=Sentinel lymph node biopsy for evaluation and treatment of patients with Merkel cell carcinoma: The Dana-Farber experience and meta-analysis of the literature |journal=Arch Dermatol |volume=142 |issue=6 |pages=685–90 |year=2006 |pmid=16785370 |doi=10.1001/archderm.142.6.685 |url=http://archderm.ama-assn.org/cgi/content/full/142/6/685]
Famous people who have had Merkel cell cancer
David BrudnoyBoston talk radio host
Al CopelandNew Orleans Entrepreneur, Powerboat Racer.
Max PerutzNobel-prize winning chemist
Lindsay ThompsonFormer Premier of Victoria, Australia
Edward UtleyPresident of Geico
Joe ZawinulJazz-Fusion Pioneer
* [http://groups-beta.google.com/group/merkelcell/web?hl=en Merkel Cell Cancer Discussion Group]
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Look at other dictionaries:
Merkel cell cancer — A rare type of cancer that forms on or just beneath the skin. Merkel cell cancer is divided into three types called trabecular, intermediate, and small cell … English dictionary of cancer terms
Merkel cell polyomavirus — Virus classification Group: Group I (dsDNA) Family: Polyomaviridae Genus: Polyomavirus … Wikipedia
Merkel cell carcinoma — Classification and external resources Micrograph of a Merkel cell carcinoma. H E stain. ICD 10 C … Wikipedia
Merkel cell — Neuron: Merkel cell Diagram of human skin. In humans, Merkel cells (yellow dot) are found clustered beneath the epidermal ridges (aka fingerprints) … Wikipedia
Merkel cell carcinoma — An infrequent but highly malignant type of skin cancer. Characteristically starts in a sun exposed area (of the head, neck, arms or legs) in whites 60 80 years of age as a firm, painless, shiny lump that can be red, pink, or blue in color and… … Medical dictionary
stage I Merkel cell carcinoma — is divided into stages IA and IB. In stage IA, the cancer is smaller than 2 centimeters in diameter and has not spread to lymph nodes or other parts of the body. In stage IB, the cancer is 2 centimeters or larger in diameter and has not spread to … English dictionary of cancer terms
stage II Merkel cell carcinoma — The cancer may be any size and has spread to nearby lymph nodes, but has not spread to other parts of the body … English dictionary of cancer terms
stage III Merkel cell carcinoma — The cancer may be any size and has spread beyond nearby lymph nodes to other parts of the body … English dictionary of cancer terms
Carcinoma, Merkel cell — An infrequent but highly malignant type of skin cancer. Characteristically starts in a sun exposed area (of the head, neck, arms or legs) in whites 60 80 years of age as a firm, painless, shiny lump that can be red, pink, or blue in color and… … Medical dictionary
Merkel — may refer to: Surnames Angela Merkel (born 1954), the current Chancellor of Germany Alexander Merkel (born 1992), German footballer Charles Emanuel Merkel, (1872 1955), American inventor, manufacturer Crawford Merkel, American bobsledder Earl… … Wikipedia