WAIKOLOA, HAWAII — An incisional biopsy that fails to remove all of a pigmented skin lesion suspected of melanoma certainly isn't optimal, but it doesn't adversely affect overall or disease-free survival, Dr. Daniel G. Coit said at the annual Hawaii dermatology seminar sponsored by Skin Disease Education Foundation.
“A complete excisional biopsy is clearly the gold standard. But I would rather have an incomplete shave biopsy than no biopsy at all. Not getting all the tumor out is actually not all that terribly important in terms of outcome,” said Dr. Coit, a surgeon and coleader of the melanoma disease management team at Memorial Sloan-Kettering Cancer Center in New York, and member of the American Joint Committee on Cancer melanoma staging committee.
The key determinant of outcome in melanoma is not biopsy technique but rather tumor biology as expressed in factors including Breslow thickness, sentinel lymph node status, mitotic index, ulceration, and body site, he added. He also addressed the significance of the time interval between biopsy and definitive wide excision and the optimal margin of wide excision.
Regarding the clinical impact of biopsy technique, Dr. Coit cited a study by Dr. Barbara G. Molenkamp and colleagues at Vrije University Medical Center, Amsterdam, who reported on 471 patients who underwent initial complete or partial removal of what proved to be stage I/II melanoma. After reexcision and sentinel lymph node biopsy, patients were followed for a mean of more than 5 years.
The Dutch researchers found adjusted overall and disease-free survival were unaffected by whether the initial diagnostic biopsy was a wide or narrow excision, an excision with positive margins, or incisional. The presence of residual tumor—in 41 patients—did not adversely affect these key outcomes, either (Ann. Surg. Oncol. 2007;14:1424–30).
Similarly, when dermatologists at Case Western Reserve University, Cleveland, retrospectively studied 108 patients with invasive melanoma who initially underwent nonexcisional shave or punch biopsy then definitive wide excision, they found 88% of the initial biopsies were accurate as to Breslow depth (J. Am. Acad. Dermatol. 2003;48:420–4).
“If you take less than the whole lesion out, you should expect to be correct about 88% of the time. And that's not bad. It beats missing a melanoma altogether,” Dr. Coit said.
The Scottish Melanoma Group studied 986 patients with primary cutaneous melanoma whose surgical interval between diagnosis and definitive wide local excision ranged from less than 2 weeks to more than 92 days, with a median of 30 days. Surgical interval wasn't predictive of overall survival, disease-free survival, or local recurrence at a median follow-up of 5 years (Br. J. Dermatol. 2002;147:48–54).
“The interval from biopsy to definitive wide excision does not make a whit of difference other than dealing with patient anxiety, which is important. You can reassure your patients that, while we're doing everything to move them along, most of that is to deal with their anxiety. It will not [affect] the outcome of their melanoma,” Dr. Coit said.
There are good data from well-conducted prospective studies addressing the optimal width for excision margins. A recent meta-analysis of five randomized trials totaling 3,313 invasive melanoma patients showed no significant differences with wide as compared with narrow margins insofar as local recurrence, disease-specific survival, or overall survival (Arch. Surg. 2007;142:885–91).
The exception is melanoma in situ, for which there are no prospective data. The current recommendation is to aim for histologically negative margins, starting with a 0.5-cm margin beyond the visible disease. “Explain to patients with melanoma in situ that their disease may extend beyond that, and they may need to return,” said Dr. Coit.
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