CHICAGO – Significant variance exists in management of primary cutaneous melanoma, according to a national survey of 510 dermatologists.
Most dermatologists (36%) preferred a shave biopsy for lesions suspected of being melanoma, despite guidelines from the American Academy of Dermatology (AAD) and National Comprehensive Cancer Network (NCCN) guidelines that recommend narrow excision biopsy.
©The National Cancer Institute
In all, 31% of dermatologists used a narrow local excision (less than 5 mm margin), 13% saucerization/scoop shave biopsy, 11%, punch biopsy, 3% wide local excision, and 7% other.
“The guidelines and academy are all very clear that one of the goals of the biopsy is to obtain tumor depth, so we were surprised that a significant number of providers use shave biopsy or other methods that may leave a risk of not getting the correct depth,” study co-author Dr. Aaron S. Farberg, a melanoma clinical research fellow at the National Society for Cutaneous Medicine in New York City, said in an interview.
Notably, dermatologists in academic and dermatology-based group practices were significantly less likely than those in multispecialty or solo practice to use narrow excision (23% vs. 42%; P < .001).
Although treatment for melanoma evolves continuously, the authors observed that dermatologists remain at the forefront of melanoma management and play a critical role in patient decision making.
“This study suggests that a knowledge gap may exist representing an educational opportunity to more effectively disseminate and implement recommended approaches,” Dr. Farberg and Dr. Darrell Rigel, of New York University School of Medicine, reported in a poster presentation at the annual meeting of the American Society for Dermatologic Surgery.
The survey also revealed that dermatologists are going beyond suggested surgical margins when excising melanoma.
For malignant melanoma in situ (MMIS), 62% used a 5 mm or less margin, 36% a 6 mm to 10 mm margin, and 2% a 1.1 cm to 1.9 cm margin. For these lesions, the AAD recommends a 0.5 cm-1 cm (5 mm-10 mm) margin and the NCCN a 0.5 cm margin, Drs. Farber and Rigel reported.
Academic dermatologists were significantly more likely than all other practice types to refer patients with MMIS out for excision (18% vs. 10%; P < .05).
For invasive melanoma less than 1 mm in depth, both the AAD and NCCN recommend a 1 cm margin (10 mm). In all, 61% of dermatologists reported using 6 mm to 10 mm margins, with 34% opting for 1.1 cm to 1.9 cm margins, 3% at least 2 cm margins, and 2% no more than 5 mm margins.
No significant difference was found across provider types for treatment of melanomas less than 1 mm in depth.
For invasive melanoma greater than 1 mm in depth, 54% of respondents used 1.1 cm to 1.9 cm margins, with most (67%) referring the patient to another provider. Both national guidelines recommend 1 cm to 2 cm margins for melanomas 1 mm to 2 mm in depth and 2 cm margins for melanoma greater than 2 mm in depth.
Academic dermatologists were significantly more likely than other dermatologists to treat these lesions rather than to refer the patient out (51% vs. 30%; P < .001).
“This is exciting new data that suggests that there still is a variance in early melanoma management,” Dr. Rigel, past president of AAD and ASDS, said in an interview. “The data suggest more studies need to be done to better access why this is occurring.”
Dr. Hensin Tsao, who served on the 2011 AAD guideline working group and is co-chairing the AAD’s pending guideline update, said in an interview that, “Dr. Rigel is well respected in the field and the project will undoubtedly be submitted for publication and subject to further review. It is worthwhile to wait on the final published results and conclusions.”
He agreed, however, with the authors’ suggestion that there is significant variation in practice. Regarding the finding that 36% of respondents use a shave biopsy for suspicious lesions, the AAD guidelines recommend that the entire lesion be removed with a 1 mm to 3 mm margin, which can be accomplished by an elliptical or punch excision with sutures or shave removal to a depth below the anticipated plane of the lesion, Dr. Tsao, of Massachusetts General Hospital in Boston, said.
“It is quite possible that some of the respondents to the questionnaire interpreted ‘shave biopsy’ as a full shave disk excision,” he said. “That said, intentional and routine partial sampling of suspected melanomas would be at odds with the guidelines.”
It is not inappropriate to remove a suspicious lesion, if small enough, with a punch biopsy, Dr. Tsao said, adding, “Perhaps again, the respondents failed to distinguish between partial punch biopsy and punch excision.”