New melanoma classification system may help predict treatment course
Accurate staging in melanoma is critical, and researchers at Cedars-Sinai in California have proposed a new six-stage system they believe can improve staging accuracy, and eventually help fine-tune personalized treatment. The findings were published in JAMA Surgery (online Sept. 1, 2021; doi:10.1001/jamasurg.2021.4298).
“We wanted to develop a simple and practical system that more accurately reflects a patient’s prognosis, which may inform what treatment they might need after surgery and whether they may benefit from joining a clinical trial,” noted Anthony Nguyen, MD, PhD, in a news release. He is a resident in the department of radiation oncology at Cedars-Sinai in Los Angeles, Calif.
The researchers questioned whether or not the current nodal classification system is precise enough to estimate melanoma prognosis. They note the existing nodal staging for cutaneous melanoma references nine distinct stages and was developed primarily for patients undergoing completion lymph node dissection for node-positive disease.
In a study of data from 105,785 patients with melanoma collected in the U.S. National Cancer Database, the researchers used agnostic recursive partitioning analysis (RPA) to identify the lymph node characteristics most closely associated with prognosis. Factors included the number of lymph nodes with cancer, whether the lymph nodes were microscopic or large enough to be seen and felt, and whether cancer had spread to areas outside of the lymph nodes.
The proposed new system has six tiers with increasing risk of death as the stage increases. The authors found this new system was more accurate at assigning prognoses to melanoma patients with lymph node spread, even in patients undergoing more limited lymph node removal consistent with the current standard of care.
In the press release, Dr. Nguyen said: “The current lymph node staging system for melanoma was developed primarily for patients who receive more extensive lymph node surgery. Two recent clinical trials have shown that certain patients can undergo more limited lymph node surgery without compromising their survival. It was reassuring to see that our staging system will be applicable to modern practice.”