Sentinel Node Positivity Less Likely in Presence of Melanoma Regression

Micrograph of an invasive nodular melanoma

Metastasis to sentinel lymph nodes was significantly lower among patients with melanoma with histologic regression of their disease compared with those without regression, according to the results of a recently published meta-analysis.

“The results of this meta-analysis may be useful when deciding to offer sentinel lymph node biopsy to patients with regressions of melanomas,” wrote researchers led by Simone Ribero, MD, of the University of Turin, Italy, in JAMA Dermatology. “It may help clinicians make a final selection of the most appropriate patients for this procedure.”

According to the study, sentinel lymph node biopsy (SLNB) has been recommended for melanomas of 1 mm to 4 mm thickness since 2009, but, more recently, this recommendation has been extended to thinner melanomas as well. Ribero and colleagues designed this study to provide additional guidance to clinicians on how to select patients with thin melanomas for this procedure.

“Given the lack of evidence-based guidelines by which to stratify thin melanomas for this procedure, the selection criteria in fact vary widely between institutions and countries,” the researchers explained.

To find out more, they conducted a review of relevant literature from January 1990 to June 2014 that discussed odds ratios (ORs) or data on sentinel lymph node positivity and histologic regression of melanoma. Their analysis included 14 studies and 10,098 patients.  

Combined data from these studies showed that patients with histologic regression had a significantly lower likelihood of sentinel lymph node positivity (OR, 0.56 [95% confidence interval (CI), 0.41–0.77]) compared with patients without disease regression.

When the researchers examined the quality of the studies used in their analysis they found that patients with regression in high-quality studies had an even lower likelihood for node positivity (OR, 0.48 [95% CI, 0.32–0.72]) compared with low-quality studies (OR, 0.73 [95% CI, 0.53–1.00]).

In an accompanying editorial, Claus Garbe, MD, of the University Hospital Tübingen, Germany, wrote that the results of this study give “a clear answer to the question whether patients with thin melanoma and regression should undergo SLNB: The answer is ‘No.’”

According to Garbe, “this will change the treatment of patients with melanoma in a considerable number of skin cancer centers.”