Surgical techniques in Mohs micrographic surgery and Mohs surgery with immunohistochemistry for melanoma widely differ across geographic areas despite static National Comprehensive Cancer Network guidelines, according to researchers in JAMA Dermatology.
“This shift in surgical practice (ie, the increasing use of Mohs surgery) requires more rigorous investigation in the form of clinical trials to ensure patients are receiving the safest and most efficacious treatment available,” according to Joseph F. Sobanko, MD, at the department of dermatology at the Hospital of the University of Pennsylvania in Philadelphia, and colleagues.
Researchers used patient claim data for surgical excision of melanomas from the Optum Clinformatics Data Mart for January 2001 through December 2016 and identified 79,108 patients. The researchers also compared their review data with data from the SEER registries from 2003 through 2009.
The median age of the cohort was 63 years (interquartile range, 51-73 years) with 59.9% men (n = 47,407). A total of 4,061 patients (5.1%) were treated with Mohs surgery of which 64.5% were men (n = 2,621) and 35.4% women (n = 1,439). In 75,047 patients treated with conventional excision, 59.7% were men (n = 44,786) and 40.3% women (n = 30,248).
The use of Mohs surgery to treat melanoma increased from 2.6% in 2001 to 7.9% in 2016, according to researchers. The odds of using Mohs surgery for melanoma increased by 1.02 times per calendar year (95% CI, 1.01-1.03).
Researchers found a significant association in the geographic census division of the patient and the odds of having Mohs surgery overall. For example, for 2013 through 2016, the East South Central region used Mohs surgery in 8.8% of melanoma excisions compared with 2.6% of melanoma excisions in the New England region (P < .001).
Patients with head and neck melanomas (OR = 2.51; 95% CI, 2.32-2.71) had higher odds of receiving Mohs surgery along with female patients (OR = 1.12; 95% CI, 1.04-1.22).
Additionally, having a higher household income and patients who attained a higher level of education were associated with higher odds of receiving Mohs surgery.
The use of immunohistochemistry (IHC) associated with Mohs surgery increased 442%, from 8.8% in 2001 to 38.9% in 2016. The odds increased by 1.13 per year for receiving Mohs surgery in conjunction with IHC (95% CI, 1.10-1.15).
Similarly, patients with head and neck melanomas, female patients, those with higher incomes and higher educational attainment were more likely to have their melanoma treated with Mohs surgery and IHC.
The researchers found a greater than threefold variation in Mohs surgery for melanoma use between the lowest use of 1.8% in the New England census division and highest use at 6.8% in the Mountain division during the 2001 to 2016 timeframe.
In the comparison of data from 2001 to 2004 and 2014 to 2016, the use of Mohs surgery for melanoma increased in all but one geographic census division and the use of IHC with Mohs surgery increased in all geographic census divisions.
“This surgical treatment of melanoma is in United States is evolving in the face of static National Comprehensive Cancer Network guidelines and no new randomized clinical trial data,” Sobanko and colleagues wrote.
“Given the increasing use of Mohs surgery to surgically excise melanomas, there is greater urgency to evaluate the safety and efficacy of comprehensive margin assessment surgery compared with wide local excision with randomized prospective trials,” they wrote.
Contrasting recommendations on when comprehensive margin assessment surgery for melanoma is appropriate may contribute to the variation in practice patterns in the U.S., according to researchers. – by Abigail Sutton
Disclosure: Sobanko reports no relevant financial disclosures. Please see the full study for all other authors’ relevant financial disclosures.