CHICAGO – Analysis of U.S. national cancer registry data shows that, contrary to expectation, the , Sean Condon, MD, reported at the annual meeting of the American College of Mohs Surgery.
Ditto for the use of Mohs in patients with the rare cutaneous malignancies for which published evidence clearly demonstrates Mohs outperforms wide local excision, which is employed seven times more frequently than Mohs in such situations.
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Dr. Sean Condon
“Mohs utilization did not increase after the Affordable Care Act [ACA], despite new health insurance coverage for 20 million previously uninsured adults,” Dr. Condon said. “Surprisingly, after the ACA we actually saw a decrease in Mohs use for melanoma in situ.”
Indeed, his retrospective study of more than 25,000 patients in the National Cancer Institute’s SEER (Surveillance, Epidemiology, and End Results) registries showed that the proportion of patients with melanoma in situ treated with Mohs declined from 13.9% during 2008-2009 – prior to ACA implementation – to 12.3% in 2011-2013, after the ACA took effect. That’s a statistically significant 13% drop, even though numerous published studies have shown outcomes in melanoma in situ are better with Mohs, said the dermatologist, who conducted the study while completing a Mohs surgery fellowship at the Cleveland Clinic. He is now in private practice in Thousand Oaks, Calif.
His analysis included 19,013 patients treated in 2008-2014 for melanoma in situ and 6,309 others treated for rare cutaneous malignancies deemed appropriate for Mohs according to the criteria formally developed jointly by the American Academy of Dermatology, the American College of Mohs Surgery, the American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery (J Am Acad Dermatol. 2012 Oct;67[4]:531-50). These rare malignancies include adnexal carcinoma, Merkel cell carcinoma, dermatofibrosarcoma, extramammary Paget disease, sebaceous adenocarcinoma, and leiomyosarcoma.
“These rare cutaneous malignancies were historically treated with wide local excision. However, numerous studies have lately shown that lower recurrence rates were found with Mohs compared with wide local excision,” Dr. Condon noted.
Nonetheless, the proportion of the rare cutaneous malignancies treated using Mohs was unaffected by implementation of the ACA. Nor was it influenced one way or the other by publication of the joint Mohs appropriate use criteria in 2012: The Mohs-treated proportion of such cases was 15.25% in 2010-2011 and 14.6% in 2013-2014.
Similarly, even though the appropriate use criteria identified melanoma in situ as Mohs appropriate, the proportion of those malignancies treated via Mohs was the same before and after the 2012 release of the criteria.
“It’s commonly thought that Mohs is overused. However, our study and our data clearly identify that Mohs is being underutilized for melanoma in situ and for rare cutaneous malignancies. This represents a knowledge gap for other specialties regarding best-practice therapy,” Dr. Condon said.
He and his coinvestigators searched for socioeconomic predictors of Mohs utilization by matching the nationally representative SEER data with U.S. census data. They examined the impact of three metrics: insurance status, income, and poverty. They found that low-income patients and those in the highest quartile of poverty were significantly less likely to have Mohs surgery for their melanoma in situ and rare cutaneous malignancies throughout the study years. Lack of health insurance had no impact on Mohs utilization for melanoma in situ but was independently associated with decreased likelihood of Mohs for the rare cutaneous malignancies. White patients were 2-fold to 2.4-fold more likely to have Mohs surgery for their rare cutaneous malignancies than were black patients.
“One can conclude that Mohs micrographic surgery may be skewed toward more affluent patients, and lower socioeconomic status areas have less Mohs access. So our data from this study support a role for targeted education and improved patient access to Mohs,” Dr. Condon said.
He noted that because the SEER registries don’t track squamous or basal cell carcinomas, it’s unknown whether Mohs is also underutilized for the higher-risk forms of these most common of all skin cancers.
Dr. Condon reported having no financial conflicts regarding his study, conducted free of commercial support.