Merkel Cell Carcinoma – a Rare and Aggressive Skin Cancer

Merkel cell carcinoma (MCC) is a rare but aggressive and lethal neuroendocrine carcinoma of the skin. Merkel cell carcinoma is more common in the elderly (age greater than 65) and mainly in Caucasians. MCC rarely occurs in patients with dark skin. Vast majority of these tumors present on sun exposed sites.

What causes Merkel Cell Carcinoma?

Excessive sunlight, prolonged ultraviolet radiation exposure, and photochemotherapy are all associated with an increased risk of MCC. Immunosupression due to solid organ transplant, HIV infection or chronic lymphocytic leukemia is also associated with merkel cell carcinoma.

Recently it has been suggested that a new virus named Merkel cell polyomavirus which was found in 8 out of 10 cases of merkel cell carcinoma may play role in etiology of Merkel cell carcinoma. [1]

Clinical Features:

Merkel cell carcinoma usually presents as firm, raised, reddish-blue or skin colored papule or nodule. Most initial lesions are less than 20 mm in diameter which grows rapidly with in 1-3 months. Ulceration of the lesion is rare. They re usually seen on sun exposed areas but not always. They are locally aggressive and later spread to distant lymph nodes in axilla, neck and groin.

Treatment for Merkel Cell Carcinoma

The current preferred treatment is surgical excision with sentinel lymph node biopsy followed by lymph node removal if biopsy comes positive. This may be followed by radiotherapy and this approach loco-regional control and disease free survival [2, 3]. Chemotherapy is not routinely recommended.

1. Feng H, Shuda M, Chang Y et al. Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science 2008; 319: 1096–100.
2. Mojica P, Smith D, Ellenhom JD. Adjuvant radiation therapy is associated with improved survival in Merkel cell carcinoma of the skin. J Clin Oncol 2007; 25:1043–7.
3. Eng TY, Boersma MG, Fuller CD et al. A comprehensive review of the treatment of Merkel cell carcinoma. Am J Clin Oncol 2007; 30: 624–36.

Merkel Cell Carcinoma

Merkel Cell Carcinoma also known as neuroendocrine carcinoma is a rare and very aggressive form of skin cancer.  They are thought to arise from the uncontrolled growth of Merkel cells in the skin. MCC can be lethal with overall 2 years survival rate of 50-70%, So immediate aggressive treatment is required.

More then 95% of cases occur is a individual over 50 years of age. It is slightly common in men, although some authors reports women outnumber men by 4:1. MCC occurs more commonly in whites and is very rare in patients with dark skin. They commonly occurs in sun exposed areas.

What causes Merkel cell carcinoma?

It is not clear what exactly causes MCC, but potential risk factors are extensive sun exposure as 90% of cases occur in sun exposed areas (50% on head and neck and 40% on the extremities). Arsenic exposure and PUVA therapy may also be a potential risk factor. It has also been associated with immunosupression including HIV and organ transplant patients. Recently in 2008 a virus namely Merkel cell polyomavirus, was discovered which is thought to be frequently involved in causing MCC.

Sign and symptoms of Merkel cell carcinoma

Merkel cell carcinoma (MCC) occurs commonly face, head and neck. The lesions are raised , firm, painless, reddish-blue or flesh colored nodules or tumor usually seen on sun exposed areas. They are asymptomatic and may grow rapidly ,measuring between 0.5 to 2 cm or more. They are usually symptoms-less but if it has spread to other parts of body you may notice lymph node swelling and pain. If you notice any changes in size and color of the mole or bumps contact your doctor immediately.

Treatment of Merkel cell carcinoma

Various chemotherapeutic regimens have been purposed but none has proven to be better in improving survival rate. Treatment modalities are usually based on the stage of the disease. If the disease is in early stage and is localized in a skin, surgical excision followed by radiation therapy is recommended as a primary treatment. If the cancer has spread to the lymph nodes surgical excision with radio therapy and if needed systemic chemotherapy is administered.

For a patients with distant metastasis involving organ, radiation therapy with chemotherapy may be required. But, it is still unclear whether chemotherapy improves the survival rate in patients with Merkel cell carcinoma. The purpose of treatment of metastasis disease is to improve the quality of patient life by relieving symptoms like pain and help patients live comfortably.

The prognosis of a patients depends on the stage of disease at the time of diagnosis. If the cancer has not spread to lymph nodes, 5 year survival rate is more then 90%.  If it has spread to lymph nodes, the 5 year survival rate is about 50%. The disease can reoccur in 50% of patients. It is important to keep in mind that these stats are based on the research of large group of patients and may not reflect each individual result or prognosis.

Successful Treatment Of Basal Cell Carcinoma With Imiquimod Cream

Researcher at North Queensland Centre for Cancer Research,James Cook University,Queensland,Australia found out some good success rate in treating superficial basal cell carcinoma with Imiquimod cream.

Superficial basal cell carcinoma comprise up to 25% of all histological sub-types. They are more likely to occur on younger persons and females and although generally more common on the trunk, also occur frequently on the exposed areas of the head and neck especially in areas of high sun exposure. In the last decade, new treatment options such as topical applications that modify the immune response have been trialed for effectiveness in treating these lesions.
Imiquimod 5% cream has been shown to stimulate the innate and cell mediated immune system. The short-term success of imiquimod 5% cream in randomized controlled trials comparing different treatment regimes and dosing as a treatment for small superficial basal cell carcinoma (BCC) not on the face or neck is in the range of 82% for 5 times per week application.
A high proportion of participants with good response rates to topical treatment (58%–92%) experience local side effects such as itching and burning, less commonly erosion and ulceration, but the proportion of participants ceasing treatment has not been high.

To date one long-term study indicates a treatment success rate of 78%–81% and that initial response is a predictor of long-term outcome. Recurrences tend to occur within the first year after treatment. Future research will compare this preparation to the gold standard treatment for superficial BCC – surgical excision.

Any Doubtful Non Itchy Painless Mass Could Be Skin Cancer

When cells of the skin multiply in a haphazard manner,they form small masses on the skin, and these are known as skin cancer.

There are mainly three types of skin cancer. The most common are squamous cell carcinoma and basal cell carcinoma. Squamous cell carcinoma present ulcerated masses on the lower half of the face, while basal cell carcinoma are skin coloured, pearly white or coloured masses on the upper half of the face. Both can be cured by surgical method.

Melanoma, on the other hand, is the most lethal cancers. They are like coloured moles, which grow repidly,can bleed,are itchy or change colour. They have to be excised very early. Any doubtful lesion or mass on the skin which doesn’t itch, painless has to be checked to rule out skin cancer.

Skin cancer is diagnosed clinically and confirmed by histopathological examination. If you have doubt or if you suspect of skin cancer it is better to consult a dermatologist as soon as possible for quick management and treatment.

New Drug For Skin Cancer Approaching Commercialization

A drug that is activated by light can be a quick, simple, and cheap treatment for tens of thousands of patients with skin cancer in Sweden alone. Researcher Leif Eriksson’s team at Örebro University in Sweden has now received about SEK 4 million from government research financiers, the Swedish Research Council and Vinnova, to further develop and commercialize the method.

The new drug that the Örebro researchers have developed is based on the use of photo-dynamic therapy in cancer treatment. In short, this is a drug that after reorganization in the cell is activated by light, which in turn leads to chemical reactions that effectively kills cancer cells.

With this method, a majority of the some 30,000 new cases of skin cancer discovered each year in Sweden alone could be treated quickly, simply, and cost effectively. This is also true for pre-stages of skin cancer, so-called actinic keratosis.

“It’s extremely gratifying that two of the most important research financiers in Sweden so actively support our research,” says Leif Eriksson, professor of biophysical and theoretical chemistry at Örebro University.

Leif Eriksson’s drug research has grown out of the Örebro Life Science Center (OLSC), an interdisciplinary, internationally acclaimed research node at Örebro University. Research on new forms of treatment for skin tumors is also being conducted in collaboration with Associate Professor Lennart Löfgren at the Center for Head and Neck Oncology at Örebro University Hospital.

“Our drug, and the new treatment concept we are developing together with researchers in Belfast, has tremendous potential. In the coming year we will also see further patents as a direct result of the collaboration with other research teams within the OLSC, including treatments for atherosclerosis and autoimmune disorders such as rheumatism,” says Leif Eriksson.

The development of new drugs is being carried out with the aid of advanced computer modeling – a method that has proven to be highly successful.

“We provide the expertise in the theoretical description of new drugs. In our research we aim to describe at a detailed level what they should look like, what properties they should have to match the right targets in the body, what happens if we alter the molecules in different ways, etc. We then put this together through collaboration with experimental or clinically active research teams within OLSC and at the hospital, which makes the research exciting and dynamic,” says Leif Eriksson

Adapted from materials provided by Vetenskapsrådet (The Swedish Research Council), via AlphaGalileo