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Current melanoma treatment guidelines recommend complete lymph node dissection (CLND), following a positive sentinel lymph node (SLN) biopsy. However, in many situations, a complete dissection fails to reveal further lymph node involvement, Robert H. I. Andtbacka, MD, CM, notes. To help cull out which patients require further surgery, the phase III MSLT-II trial is comparing CLND with observation plus nodal ultrasound for patients with melanoma following a positive SLN biopsy.
In the MSLT-I study, patients with melanoma underwent a wide excision followed by observation or SLN biopsy, which could lead to a CLND. For the entire population, a significant treatment-related difference in the primary endpoint of melanoma-specific survival was not observed. However, the secondary endpoint of improvement in disease free-survival was noted with biopsy-based management.
Patients with melanoma of intermediate thickness and nodal metastases experienced a significant prolongation in survival with SLN biopsy, Andtbacka notes. These results suggest that SLN dissection may have therapeutic properties, leading to the design of MSLT-II. The number of patients with multiple positive lymph nodes is considerably less than those with a single positive node, suggests Merrick I. Ross, MD.
For patients with metastatic disease, lymph node dissection can provide quality of life improvement and regional control. Additionally, it lessens the risk of local recurrence, Ross nodes. Studies suggest that lymphedema and other morbidity is less when CLND is performed on micrometastatic disease compared with macrometastatic, notes Andtbacka.
For patients with in-transit metastases, even if the disease is not palpable the risk of microscopic nodal involvement is still 40% or higher. As a result, for patients with single in-transit metastases, Andtbacka believes that dissection is a valid option. However, when multiple recurrences are present, surgery becomes more challenging.