In a study reported in The Lancet Oncology, Stassen et al developed a model for the prediction of recurrence-free and melanoma-specific survival after sentinel lymph node biopsy (SLNB) in patients with melanoma.
Study Details
The study involved a development cohort of 4,071 patients aged > 13 years with stage pT1b or higher melanoma who underwent SLNB between October 1997 and November 2013 at melanoma centers in Berlin, Amsterdam, Rotterdam, and Warsaw. A validation cohort comprised 4,822 patients who underwent SLNB between January 1997 and December 2013 at the Melanoma Institute Australia in Sydney. In development of a predictive model for 5-year recurrence-free and melanoma-specific survival, potential risk factors assessed were sex, age, presence of ulceration, primary tumor location, histologic subtype, Breslow thickness, sentinel node status, number of sentinel nodes removed, maximum diameter of the largest sentinel node metastasis, and Dewar classification. Model performance was assessed by area under the time-dependent receiver operating characteristics curve (AUC).
Key Findings
In the development cohort of 4,071 patients, 889 (22%) had sentinel node–positive disease; in the validation cohort of 4,822 patients, 891 (18%) had sentinel node–positive disease.
In the development cohort, median follow-up was 4.8 years (interquartile range [IQR] = 2.3–7.8 years); 5-year recurrence-free survival was 73.5% (95% CI = 72.0%–75.1%) and 5-year melanoma-specific survival was 86.5% (95% CI = 85.3%–87.8%). Among patients with sentinel node–positive disease, the respective rates were 49.0% and 69.1%. Among patients with sentinel node–negative disease, the respective rates were 80.3% and 91.1%.
In the validation cohort, median follow-up was 5.0 years (IQR = 2.2–8.9 years); 5-year recurrence-free survival was 66.1% (95% CI = 64.6%–67.7%) and 5-year melanoma-specific survival was 83.3% (95% CI = 82.0%–84.6%). Among patients with sentinel node–positive disease, the respective rates were 43.0% and 65.5%. Among patients with sentinel node–negative disease, respective rates were 72.2% and 88.3%.
The final predictive model contained six factors: sentinel node status, Breslow thickness, presence of ulceration, age at SLNB, primary tumor location, and maximum diameter of the largest sentinel node metastasis. In the development cohort, AUCs were 0.80 (95% CI = 0.78–0.81) for prediction of recurrence-free survival and 0.81 (95% CI = 0.79–0.84) for prediction of melanoma-specific survival. In the validation cohort, AUCs were 0.73 (95% CI = 0.71–0.75) for prediction of recurrence-free survival and 0.76 (95% CI = 0.74–0.78) for prediction of melanoma-specific survival.
The investigators concluded, “Our prediction model and nomogram accurately predicted patient-specific risk probabilities for 5-year recurrence-free and melanoma-specific survival. These tools could have important implications for clinical decision-making when considering adjuvant treatments in patients with high-risk melanomas.”
Dirk J. Grünhagen, MD, PhD, of the Department of Surgical Oncology, Erasmus Medical Centre Cancer Institute, Rotterdam, Netherlands, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by Erasmus Medical Centre Cancer Institute. For full disclosures of the study authors, visit thelancet.com.
