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Mohs dermatologists and other surgeons should collaborate in the treatment of patients with squamous cell carcinoma to improve patient survival and recurrence rates, according to an expert who presented an outcomes poster at the annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery Foundation.
A collaborative approach to surgical management of squamous cell carcinomas (SCCs) that involves dermatologists will likely produce optimal outcomes in terms of improving survival and decreasing recurrence among patients, says the Chief of Mohs Surgery at Kaiser Permanente in San Rafael, Calif.
"Mohs dermatologists should share their techniques of tissue harvesting and processing with other surgeons," says Salvatore Iaquinta M.D., an otolaryngologist who presented retrospective data in a poster session regarding the use of Mohs surgery to manage SCCs of the head and neck at the recent annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery Foundation.
"Mohs has been proven with smaller lesions," Dr. Iaquinta says. "Dermatologists can show their colleagues in the operating room harvesting and mapping techniques. We can work together and use Mohs techniques to get 100 per cent of the margins analyzed. That way we know we've done the best possible surgery before closing a wound."
Typically, larger tumors are treated with the patient under general anesthesia in the operating room. Gross margin assessment is made with intra-operative frozen section analysis, even though it is associated with inferior tumor control when compared to Mohs. Smaller tumors are managed by Mohs dermatologists under local anesthesia in the outpatient setting. There, 100 percent of the peripheral and deep margins are analyzed, according to Dr. Iaquinta.
Larger lesions can also be managed with Mohs surgery without the precision of margin analysis being sacrificed, Dr. Iaquinta says. The key is that the clinicians removing the lesions need to be able to properly orient, mark, and map the specimen, Dr. Iaquinta says.
Dr. Iaquinta pointed to a study out of the Cleveland Clinic which saw collaboration between dermatologic surgeons and surgeons in facial plastic surgery/head and neck surgery to achieve marginal clearance during resection and reconstruction. Clinicians used Mohs micrographic analysis, rather than intra-operative frozen section margin analysis, to perform intra-operative margin assessment of cutaneous malignancies.[i]
"The biggest predictor of survival is that the surgical margins are clear," Dr. Iaquinta says. "If you are only looking at a couple of sections (of the tumor), you do not know if you are looking at enough pieces."
The research presented at the AAO-HNSF meeting described outcomes in 117 cases and also looked at the demographic characteristics of patients, such as immunocompromised status, as well as characteristics of tumors, such as bony or perineural invasion, and regional and local recurrence of SCC. As with most investigations, the vast majority of cutaneous SCCs occur in the sun-exposed areas of the head and neck.
Although the data from this particular series did not support it, previous investigations have found that bony or perineural invasion is predictive of poor survival, Dr. Iaquinta says. The patients in the series were mainly male (73 per cent) and elderly.
"Those are cases where the patients do not have a good prognosis, looking at the next five years," Dr. Iaquinta says.
Dr. Iaquinta and colleagues concluded that Mohs micrographic surgery for high-risk cutaneous SCCs is effective and that employing the Mohs technique in the operating room allowed a combination of extirpation and reconstruction as a single procedure. There was an average wound size of 13.74 cm2, and a five-year survival rate of 88%.
Dr. Iaquinta and colleagues contrasted their outcomes with that of a prospective study published nearly a decade ago which used wide local excision on 277 SCCs and used frozen-section analysis. In that study, patients were followed for a median of 22 months, and three-year overall disease-specific survival was 85%.[ii]
A limitation of using the Mohs technique for larger lesions, those over 6 cm, is that it can take about 90 minutes to process tissue while the process is much more rapid, usually about 30 minutes, with smaller lesions, Dr. Iaquinta says.
The use of Mohs micrographic surgery is superior in cases of recurrences, Dr. Iaquinta says.
Dr. Iaquinta has no relevant disclosures.
[i] Seth R, Revenaugh PC, Vidimos AT, Scharpf J, Somani AK, Fritz MA. Simultaneous intraoperative Mohs clearance and reconstruction for advanced cutaneous malignancies. Arch Facial Plast Surg. 2011;13(6):404-10.