Statistical Analysis
Sample characteristics were described using descriptive statistics. Frequencies and percentages were used to describe categorical variables. Medians and ranges were used to describe continuous variables due to nonsymmetrically distributed data. χ2 tests (or Fisher exact tests when low cell counts were present) for categorical variables and Wilcoxon signed rank tests for continuous variables were used to test for associations in bivariate comparisons between MMS and plastic surgery.
Results
A total of 7 physicians (1 fellowship-trained Mohs surgeon and 6 plastic surgeons) at our institution met the inclusion criteria. The Mohs surgeon performed a significantly higher number of flaps and grafts (n=276) than the plastic surgeons (n=17 combined; average per plastic surgeon, 2.83) on the nose or ears in a 12-month period (P<.05)(Table). The median final defect size was not significantly different between MMS (1.5 cm) and plastic surgery (1.8 cm)(P=.306). Flap repairs were more common in patients undergoing MMS (80%) vs plastic surgery (53%)(P=.022)(Figure). For flap repair, advancement flaps were used more commonly (MMS, 53%; plastic surgery, 35%) than transposition flaps (MMS, 27%; plastic surgery, 12%) by both specialties.
Patient age was similar between MMS (median, 74 years) and plastic surgery (median, 73 years) patients (P=.382), but a greater percentage of women were treated by plastic surgeons (53%) compared with Mohs surgeons (33%). The predominant skin tumor type for both specialties was basal cell carcinoma (MMS, 85%; plastic surgery, 76%). Dermatology was the largest referring specialty to both MMS (98%) and plastic surgery (53%). Family medicine referrals comprised a much larger percentage of cases for plastic surgery (24%) compared to MMS (1%).
Comment
This study supports and adds to recent studies and data regarding the utilization of MMS for the treatment of NMSCs. Although the percentage of all skin cancer surgery is increasing for dermatology, little has been reported on more complex repairs. This study highlights the volume and complexity of skin surgery performed by Mohs surgeons compared to our colleagues in plastic surgery.
Defect Size
The defect sizes prior to repair were not statistically different between the 2 types of surgeries, though the median size was slightly larger for plastic surgery (1.8 cm) compared to MMS (1.5 cm). These non–statistically significant differences may be explained by potentially larger tumors requiring repair by plastic surgeons in an operating room. Plastic surgeons, however, may be more likely to take a larger margin of clinically unaffected tissue as part of the initial layer. Plastic surgeons also may be less likely to curette the lesion prior to excision to obtain more clear tumor margins, possibly leading to more stages and a subsequently larger defect. Knowing the clinical sizes of these NMSCs prior to biopsy would have been beneficial to our study, but these data often were not available from the referring providers.