Early Detection and Surgery for Melanoma in Lymph Nodes May Increase Survival
For some melanoma patients, detecting the cancer in the lymph nodes and removing the nodes early in treatment may reduce recurrences and help patients live longer, researchers said while presenting preliminary findings from a clinical trial at the American Society of Clinical Oncology (ASCO) annual meeting in Orlando, Fla., May 13th-17th.
A simple outpatient procedure called a sentinel node biopsy (SNB), which is used to determine a patient's prognosis, can detect the cancer's spread before clinical signs appear, they said.
Melanoma is the most deadly of skin cancers, and it spreads to lymph nodes in about 20 percent of cases. Several previous trials have failed to show that the early detection of affected nodes and surgery can extend a patient's life.
This study reports that among patients with intermediate-stage melanoma and affected nodes, the survival rate over 7 years was 69 percent for the screening/surgery group compared with 48 percent for patients who had the surgery later, when their tumors were large enough to be felt during a physical exam.
In addition, patients in the screening/surgery group were 6 percent less likely to experience a recurrence over 5 years compared with those in the "watch and wait" group, according to findings from the Multicenter Selective Lymphadenectomy Trial (MSLT), an international randomized phase III study involving 2,000 patients.
"These results show we can identify a large subgroup of patients with melanoma who can benefit from the early removal of their lymph nodes," said Dr. Donald Morton of the John Wayne Cancer Institute, who leads the MSLT and presented the findings.
In the early 1990s, Dr. Morton developed SNB, which detects melanoma cells in a lymph node near the tumor, to identify patients who might be candidates for a radical surgery called a lymphadenectomy.
"I see no reason to delay the removal of tumor-involved lymph nodes if we can identify those patients at the time of diagnosis," Dr Morton said. He emphasized that only patients with metastatic lymph nodes can benefit from the surgery.
Delay may allow the cancer to spread to more nodes and to distant organs, Dr. Morton noted. The SNB group averaged 1.6 affected nodes at surgery compared with 3.4 for the other group. The prognosis worsens as more nodes are involved.
"The number of affected lymph nodes is important," said Dr. Mohammed Kashani-Sabet of the University of California, San Francisco. "These findings show that by removing metastatic nodes when they're microscopic, you can affect prognosis."
This was the third of five planned analyses from MSLT, which began in 1994 and was funded by an NCI grant.
"The interim results are further evidence that doctors should be doing SNB for the staging and treatment of patients in the early stages of melanoma," said Dr. Scott Saxman of NCI's Cancer Therapy Evaluation Program.
By Edward R. Winstead