Merkel cell cancer

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Merkel cell cancer, also called Merkel cell carcinoma or trabecular cancer, is a rare and highly aggressive cancer where malignant cancer cells develop on or just beneath the skin and in hair follicles. This cancer is a type of neuroendocrine tumor, like small cell lung cancer. Merkel cell carcinoma is the most serious form of skin cancer. One third to one half of all patients with Merkel cell cancer eventually die of the disease.

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, brain or bones.

1 Epidemiology
2 Treatment
- 2.1 Surgery
- 2.2 Radiation and chemotherapy
3 See also
4 External links

[edit] Epidemiology

This type of cancer occurs mostly in -- though 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 1000 cases a year in the United States. Merkel cell cancer can be mistaken for another cancer like basal cell carcinoma, squamous cell carcinoma, malignant melanoma, lymphoma, small cell carcinoma or may appear to be a benign cyst. Researchers believe that exposure to sunlight or ultraviolet light may increase a person’s risk of this disease.

Immune suppression can 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 HIV as compared to the general population. Solid organ transplant recipients have similarly increased risk.

[edit] Treatment

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 spread. It is difficult to cure once it has spread.

[edit] Surgery

Surgery is the usual treatment for Merkel cell cancer. The tumor is 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.

[edit] Radiation and chemotherapy

Adjuvant radiotherapy has 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.