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From the lengthy study carried out by his group we can see the need for widening our margins, along with the impact it has in recurrence rates as early as 1 year or as late as 10 years later.
This could be practice-changing, as it would call for wider margins for both in situ and invasive melanoma that arises in already sun-damaged skin from the head and neck. I believe that considering the rate of late recurrences (after 5 years), this would also call for awareness on the part of both physicians and patients to continue follow-up after the usual 5 years.
Time and time again new published data have demonstrated that “one size does not fit all" and that we have to be conscious of this when holding conversations with our patients.
Melanomas arising in chronically sun-damaged skin on the head and neck that receive staged excision with comprehensive permanent section margin control lead to lower recurrence rates than with traditional techniques, according to a new study.
"A 'cookbook solution' of set margins results in higher recurrence rates in melanoma; patients who have melanoma arising in the head and neck area need to see a specialist to map out the true margins," the lead author of the study, , of the University of Michigan in Ann Arbor, told 鶹ý.
Melanoma arising in sun-damaged skin behaves differently than in other parts of the body, he explained. This type of melanoma most often appears in the head and neck, and melanoma arising on head and neck is difficult to assess.
Most melanomas on the trunk and extremities can be excised with standard margins and tissue-processing techniques, with high rates of local control. Melanoma in sun-damaged skin of the head and neck, however, is often characterized by poorly defined clinical margins and unpredictable extension. This may be due to higher melanocytic density compared with other areas of the body, Moyer said.
The problem in head and neck melanoma is that margins are irregular, not discrete, and not dictated by size. "If we take a standard margin, a large percentage of the time we will not get a clear margin. A defined method of mapping out margins, such as the technique we used, will give the best recurrence rates."
For the study, published in , Moyer and colleagues investigated the local recurrence rates and margin to clearance endpoints using with comprehensive hematoxylin-eosin–stained permanent section margin control, the so-called "square" staged excision technique. The observational cohort study performed from 1997 to 2006, with a median follow-up of 9.3 years, included 806 patients, median age of 65, with 834 melanomas in the head and neck.
The estimated local recurrence rates were 1.4% at 5 years, 1.8% at 7.5 years, and 2.2% at 10 years. For each 50 mm2 increase in the size of the clinical lesion, there was a 9% increase in the rate of local recurrence.
The mean margin from lesion to clearance for melanoma in situ was 9.3 mm compared with 13.7 mm for invasive melanoma. This contrasts with the standard margin recommendation in of 5 to 10 mm for melanoma in situ and 10 mm for invasive melanoma with a Breslow depth of 1 mm or less. For melanoma in situ, margins were clear after 5 mm or less in 232 excisions (41.1%) and after 10 mm or less in 420 excisions (74.5%). For invasive melanoma, margins were clear after 5 mm or less in eight excisions (3%) and after 10 mm or less in 141 excisions (52.2%).
Factors associated with a greater margin to clearance included increasing lesion size, invasive versus in situ disease, and incompletely excised versus primary or recurrent lesions.
Patient satisfaction with the final reconstructive results was "high," the researchers said. In a survey of 320 patients, 94% said they were very satisfied or somewhat satisfied with their reconstruction results. "No association was found between subjective reconstructive outcomes and the size of the area reconstructed," the authors stated, noting that there had been some concern that a more aggressive local incision approach to melanoma in the head and neck might result in unacceptably high morbidity.
The study's strengths, Moyer said, include its large population (more than 800 patients) and long follow-up (9 years) -- had a smaller numbers of patients and shorter follow-up.
"The reality is that most of these melanomas are treated in early stages. If we treat them earlier, this impacts survival. Once a patient with this type of melanoma develops a deep melanoma, it is more difficult to manage.
"There is no question that patients who have melanoma are at increased risk of developing a new melanoma and a recurrence if margins are not adequately managed. Even if we map margins and do the best resection, these patients are still at risk of a new melanoma and non-melanoma skin cancer. These patients need routine skin exams, as well as information on how to do self-exams."
Moyer noted that more than one-third of the recurrences developed after 5 years, indicating that long-term follow-up is necessary to assess local recurrence.
He said that new NCCN guidelines for melanoma are expected within about a year, and he recommended that the panel involved should consider techniques for formally mapping the margins in head and neck melanoma, rather than using the current recommended set margins.
Moyer reported having no disclosures.
Primary Source
JAMA Dermatology
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