Variation in the Depth of Excision of Melanoma A Survey of US Physicians

Objective: To assess current practices and recommendations of US physicians regarding depth of excision for melanomas of varying histologic thicknesses. Design: A 2-page, 13-question survey of depth of excision practices for the treatment of melanoma was developed and distributed. Setting: Both private and academic settings. Participants: A total of 1184 US physicians (1000 dermatologists and 184 melanoma specialists) were sent the survey. The 184 melanoma specialists included dermatologists, oncologists, and surgeons working in pigmented lesion clinics. Main Outcome Measures: Depth of excision practices reported for melanomas of varying histologic thicknesses and comparison of treating physician groups. Results were tabulated, and descriptive frequencies were used to describe demographics and survey responses. Results: The final study analysis included 498 completed surveys. The overall response rate was 45% (498 of 1097 [1184 total respondents-87 ineligibles]). The response rate for the specialists was 63% (115 of 183 [184 total respondents-1 ineligible]), and for nonspecialist dermatologists it was 43% (383 of 892 [1000 total respondents- 108 ineligibles]). Specialists were more likely to practice in an urban setting than were nonspecialist dermatologists (78% vs 46%) (P<.001). Fifty-eight per-cent of nonspecialist dermatologists reported more than 400 patient visits per month compared with only 16% of specialists (P<.001). While specialists reported fewer patient visits per month, 51% reported diagnosing over 20 invasive melanomas in the previous year compared with 11% of nonspecialist dermatologists. There was no significant difference in excision depth reported among the specialties for melanoma in situ (P =.15). For invasive melanoma, significant differences were observed among treating groups, with the greatest incongruence reported for thin invasive melanoma (<0.50 mm, P=.02; 0.50-0.75 mm, P<.001; and 0.76-1.00 mm, P<.001). Specialist nondermatologists consistently reported excising more deeply than specialist dermatologists and nonspecialist dermatologists. More specialist nondermatologists report excising to the fascia for thin invasive melanoma than do both specialist and nonspecialist dermatologists. For thicker melanomas (>1.00 mm), differences in excision depths among treating physician groups decreased: most physicians in each group reported excising to the fascia. Conclusions: There is considerable variation among physician groups with regard to depth of excision practices for the treatment of melanoma. Given the current lack of clinical data available, studies assessing depth of excision and patient outcomes are needed to better define our surgical management of melanoma.