For good reason the most feared form of skin cancer is malignant melanoma. Your dermatologist or primary physician is usually first when it comes to diagnosing these skin cancers. However, once the diagnosis of malignant melanoma is made, there is new and compelling evidence that selectively treating the adjacent lymph nodes along with the melanoma can improve the chances of cure. This article describes the role of the sentinel node biopsy (SNB) in providing the optimal treatment of malignant melanoma. For nearly ten years, several of surgeons at Colorado Otolaryngology Associates have worked with regional specialists in melanoma performing SNB for patients with head and neck malignant melanoma as well as providing further surgical treatment depending on the findings at biopsy.
First, however, we’ll present some background information on malignant melanoma which is worth knowing.
About 60,000 new cases of malignant melanoma occurred in 2007 in the United States. Of these, 30% occurred in the head and neck region, realizing that the head and neck region accounts for only 9% of the body surface area. Over the last 30 years, the incidence of melanoma has been increasing at a pace of 5% per year. If you are a white male over the age of 70, your chances of getting a melanoma are greater than the overall risk of a male getting prostate cancer. In fact, the rate is equivalent to the overall risk of a woman getting breast cancer.
It is not, however, just older men who are at risk. This cancer is increasing in frequency in all ages of white men and women. Melanoma also occurs in Hispanics, Blacks, and American Indians, albeit at a lower rate.
Cure rates have, fortunately, been going up in recent years from 80% to 88% survival. This is largely due to increased awareness and early treatment. Nonetheless, advanced melanomas still occur regularly and remain much less curable. The risk of getting a melanoma goes up if
There is evidence from Australia that using sunscreens and reducing exposure to sunlight reduces the incidence of melanoma. There is also evidence, though, that prior exposure to sunlight is the more important factor and for that reason the most effective thing to do for most of us is to get a thorough check of our skin on a regular basis by our dermatologist or primary care physician.
Melanomas are very curable if treated surgically when they are shallow. Once the melanoma invades deeper than 1 millimeter, though, the chance of spread to adjacent lymph nodes goes up and the rate of cure goes down. This is where the sentinel node biopsy comes in. Although chemotherapy and radiation therapy have a role in certain patients, surgical management remains the mainstay in this type of cancer.
This is what happens when a sentinel node biopsy is performed. On the day that the melanoma is to be excised the area of the melanoma is injected with aradioactive material which will spread to adjacent lymph nodes near that part of the body. This lymph node or nodes are known to be the ones most likely to contain metastatic melanoma if it has spread. Because the lymph node is expressing a low level of radioactivity, a “gamma probe” which detects the low level of radioactivity and an x-ray help guide the removal of this lymph node. This lymph node is removed at the time that we excise the melanoma. If there is spread to this sentinel lymph node, we return to the operating room on a later day to remove all the adjacent lymph nodes in that part of the body. A recent study showed that by doing this technique, the cure rate can be increased by20%. This makes it a very valuable tool and is worth going through the extra effort.
Performing the excision of a melanoma and removing the adjacent lymph nodes in the head and neck region poses some logistical difficulties which are not present at other sites in the body. For example, melanomas and lymph nodes may be very close to critical cosmetic and functional structures in the head and neck like the mouth, the eye, the nose and the nerves which make the face move. For that reason performing these surgeries in the head and neck can be particularly challenging. Fortunately, there are several surgeons at Colorado Otolaryngology Associates with extensive experience in performing these procedures.
Although melanomas are increasing in frequency in the United States, the cure rates are going up. If you are someone with a history of blistering sunburns, have light skin and freckles, have multiple moles, or have a family history of malignant melanoma, you should see your dermatologist or primary physician regularly for a close evaluation of your skin.
If you are diagnosed with a melanoma, expect to be referred to a specialist who can both remove the melanoma as well as deal with the adjacent lymph nodes. A sentinel node biopsy for malignant melanoma is a new proven technique which increases the likelihood of cure.