I have a friend that is presently being treated for Merkel cell carcinoma and started radiation about a month ago. So I thought I might write a little about it. Your first thought might be, “What is a Merkel cell?” I’ve never heard of it. A merkel cell lies on the outermost layer of the skin. They were identified in the 1800’s by a Friedrick Merkel, a German anatomist. Over the last 100 years their complete function has not been identified but they are found over the body in varying amounts with the highest density on the fingertips, lips, and face where touch sensitivity is at its greatest. They have also been found to produce hormones but the function of this is still unknown. So this is still very new territory.
Merkel cell carcinoma has been rare but, like melanoma, the numbers of occurrences has been increasing rapidly. Diagnosis can be a little random since doctors are rarely looking for it when it is found. Most of the time it is discovered when a biopsy is being performed for another form of skin cancer and it turns up. It is a like going for a walk and hearing hoof beats behind you. You turn to look at the horse you expected but instead you find a Zebra. An early diagnosis can mean minimal treatment and an assurance of being cured. But it is aggressive and can metastasize in its early stage.
The cause of Merkel cell carcinoma is still a mystery though a few pieces of the puzzle are beginning to come to light. Like melanoma sunlight is a factor to its growth, so yet another reason to follow the safety precautions we recommend with melanoma prevention. Patients with suppressed immune symptoms are at a greater risk of developing this particular cancer as well. Buts those whose immune system were able to heal their primary tumor without intervention fair better since their immune system was strong enough to fight it off. In 2008 a common virus, polyomavirus, has been found in a vast majority of the cancer cells, at least 80% of the time. This virus rarely causes any symptoms other then the cases where it contributes to triggering the MCC.
The treatment options are not dissimilar to melanoma. When the risk of the tumor spreading is relatively low surgery alone can be all that is recommended. Though often a series of radiation treatment sessions can be added to insure the risk of local recurrence is minimized even more. It may be possible to remove the tumor with a Mohs micrographic surgery when on the face and there is a need to limit the margin it 1cm. Since such a small margin is taken radiation is almost always recommended in this case. Chemotherapy can be used initially but the MCC develops resistance to these drugs very rapidly. Immune therapy started to advance about 10 years ago and in the last 5 years a version using immune checkpoint inhibitors show the best result when a skin cancer of any kind metastasizes. There are presently 4 drugs which do this and can be used individually or in conjunction with the others or in conjunction with other treatments.
The prognosis and chances of beating the disease are unique to each individual. How early it was discovered and the state of a person’s immune system is a key contributing factor to chances of survival.