Dr Van Akkooi on the Prognostic Value of Minimal Sentinel Node Tumor Burden in Melanoma

Alexander C. Van Akkooi, MD, PhD, FRACS, chair, Melanoma Surgery, Melanoma Institute Australia; associate professor, the University of Sydney, Australia, discusses the prognostic value of minimal sentinel node tumor burden in melanoma, as evaluated in the prospective EORTC-1208-MG registry study (NCT01942603).

The aim of the trial was to evaluate the outcomes of patients with minimal sentinel node tumor burden who were managed without complete lymph node dissection. Investigators hypothesized that the cumulative incidence of distant metastasis at 5 years would be less than 20% in patients with pT2-pT3 tumors. The primary analysis revealed that the cumulative distant metastasis free survival (DMFS) rate in this cohort was 15% (90% CI, 10%-21%) at a median follow-up of 4.5 years, though this result did not meet the study’s primary end point of statistical significance, Van Akkooi reports. The subgroup of patients with AJCC stage IIIA tumors and minimal tumor burden who chose observation had a 5-year DMFS rate of 8.2% (95% CI, 2.8%-17.4%), he notes.

A notable finding was the high rate of discrepancy upon central pathology review, which indicated significant overdiagnosis of sentinel node metastasis in many cases, Van Akkooi continues. Patients who were reclassified following the central review demonstrated a high DMFS rate at 5 years, suggesting that the central pathology review was accurate and that some patients initially diagnosed with minimal tumor burden had an even more favorable prognosis than anticipated, he adds.

The study further identified that sentinel tumor burden, along with AJCC stage, were independent prognostic factors, suggesting the possibility of refining future staging systems, Van Akkooi says. Incorporating these factors may allow for better prognostication and may potentially spare low-risk stage III patients from the toxicity associated with adjuvant therapies, he explains. These findings could influence future clinical guidelines by shifting management strategies for patients with minimal tumor burden towards less invasive approaches, especially for those in earlier stages of disease, Van Akkooi concludes.