Lymph Node Test a Good Strategy for Melanoma: Study
Disease spread was detected and treated sooner, with better survival in patients who received 'sentinel node' biopsy
By Maureen Salamon
WEDNESDAY, Feb. 12, 2014 (HealthDay News) -- Testing a key lymph node in patients with the most dangerous form of skin cancer is the best approach to determine if the cancer has spread, new late-stage clinical research indicates.
The test could significantly improve survival among those whose affected lymph nodes are then removed, the researchers said.
Culminating nearly two decades of international research, the study provides the first long-term evidence affirming the value of a procedure known as "sentinel node biopsy" for intermediate and thick melanoma lesions, the study authors said.
The study compared melanoma patients during a 10-year period. Among people with intermediate-thickness lesions, those whose lymph nodes were removed after their sentinel node biopsy tested positive for cancer were 44 percent more likely to survive their melanoma, said study author Dr. Mark Faries. The other "watchful waiting" group of patients didn't have their nodes removed until the disease was later found to have spread.
"It makes sense: Those who were not treated up front had their melanoma spread from the sentinel lymph node to other lymph nodes in the area, [which can facilitate] a spread throughout the body," Faries said. "This study provides concrete evidence that everything we had assumed about the sentinel node procedure ... and lymph node treatment is true."
According to the American Cancer Society, lymph nodes are small structures that work as filters for harmful substances in the body. They contain immune cells that can help fight infection by attacking and destroying germs in lymph fluid.
The study by Faries, director of melanoma research at the John Wayne Cancer Institute in Santa Monica, Calif., and colleagues was published online Feb. 12 in the New England Journal of Medicine.
Melanoma is diagnosed in about 120,000 Americans each year and kills about 9,000 annually, according to the Skin Cancer Foundation. The strongest risk factor for the disease is intense, periodic exposure to ultraviolet light from sunshine or tanning beds, but other risk factors include fair skin and family history.
Initiated in 1994, the study randomly assigned about 2,000 patients with melanoma to two groups. The observation group had their lesion removed and their lymph nodes observed for recurrence, at which time they were removed. The biopsy group underwent lesion removal and a sentinel node biopsy, with immediate lymph node removal for patients whose cancer had spread to the sentinel node.
In melanoma, a sentinel node biopsy removes the lymph node nearest a lesion and tests it for evidence of cancer. If the sentinel node is unaffected, the cancer is highly unlikely to have spread to surrounding lymph nodes or distant sites in the body. The biopsy procedure is also used in other malignancies, particularly breast cancer.