Lynn Schuchter, MD, of the University of Pennsylvania, Philadelphia, a designated ASCO expert, commented at the press briefing that the results might apply to a select group of patients concerned about lymphedema but not yet to the broader population. “I would say that this is a really important study, but it’s a relatively small one, and I don’t think we would make a complete change in our recommendations based on these data,” she offered. “I think we will wait to make definitive changes in our management until we have results from a larger study.”

The multinational MSLT2 trial with nearly 2,000 patients randomized is currently evaluating this issue and will provide much more definitive information, agreed Vernon Sondak, MD, Chair of the Cutaneous Oncology Department at Moffitt Cancer Center, Tampa, Florida, in an interview with The ASCO Post.

“We found out that in the early analysis of this German study, there was no obvious harmful impact of not doing a node dissection after a positive sentinel node biopsy. That’s a lot different than saying we don’t ever need to do a node dissection on our patients,” Dr. Sondak said.

Dr. Sondak considers the findings predictable, pointing out that microscopic disease can take years to become apparent. By taking out the sentinel node, he said, “we have reset the clock and are waiting for cancer in the other nodes, if it’s there, to show up. Hopefully, we can then intervene before it spreads.”

According to Dr. Sondak, most melanoma specialists have considered it safe to forego complete lymph node dissection after a positive sentinel node biopsy in select, low-risk patients. The question is determining who this low-risk group is, he said. “The safe patients would be those with the most to gain and the least to lose by not having complete lymph node dissection,” he pointed out. This is most likely to be the patient with minimal amounts of melanoma in the sentinel node, he added.

Clarifying Misconceptions

Dr. Sondak also clarified some misconceptions about complete lymph node dissection after a positive sentinel node biopsy. Both the incidence and morbidity associated with this surgery are less than those observed in the breast cancer setting or when the procedure is done for a macroscopic nodal metastasis from melanoma, he indicated. About 10% to 20% of complete lymph node dissection patients develop lymphedema, almost all of which is mild, when the procedure is done after a positive sentinel node biopsy. The incidence is higher among patients who are obese or have other risk factors and lower among younger, fit patients.

He also noted that upfront complete lymph node dissection produces less morbidity than the surgery that must be performed upon recurrence, which is usually more extensive and sometimes involves radiation.

In conclusion, Dr. Sondak said the DeCOG study does not definitively answer the question of which patients can forego complete lymph node dissection, but “it gives us a little more confidence as we talk to our patients… and that knowledge will be helpful. If we properly choose and inform our patients, then I think it’s safe, at least in the short run, to consider a close observation approach with frequent follow-up in select patients,” he said. ■

Disclosure: Drs. Schuchter and Sondak reported no potential conflicts of interest.