Predicting SLN Positivity in Patients With Thin Melanoma
Posted: Friday, November 2, 2018
Research by the Cleveland Clinic found that younger age and a Breslow thickness greater than 0.8 mm were associated with a higher risk of sentinel lymph nodes (SLNs) in patients diagnosed with thin melanoma. The report, published in the Journal of the American Academy of Dermatology, also demonstrated that the presence of dermal mitoses increased the risk of SLNs, ulceration, and an advanced Clark level. Interestingly, patients with dermal mitoses who lacked ulceration were also at greater risk for positive SLNs.
“While the new [American Joint Commission on Cancer] system has removed dermal mitotic rate from staging, continued evaluation of dermal mitotic rate could be valuable for guiding surgical decision making about SLN biopsies,” Ruzica Z. Conic, MD, of the Department of Dermatology and Plastic Surgery, Cleveland Clinic, and colleagues concluded.
Using the National Cancer Database, the authors identified 9,186 patients with cutaneous melanoma and a Breslow thickness less than 1.0 mm who received a SLN biopsy between 2004 and 2014. Patients younger than 60 years old (P < .001) with a Breslow thickness greater than or equal to 0.8 mm (P = .03) were at an increased risk of positive SLNs. The presence of dermal mitoses significantly increased the risk of positive SLNs by 95%, ulceration by 63%, and a Clark level of IV or V by 48%. Those who showed dermal mitosis but lacked ulceration had a 92% increased risk of positive SLNs compared with patients without dermal mitosis.