For sentinel node-positive melanoma treatment, location matters

Reuters Health - 21/02/2022 - Similar-risk melanoma patients with positive sentinel nodes are managed with nodal observation alone, nodal observation with adjuvant systemic therapy, or completion lymph node dissection (CLND) and adjuvant systemic therapy depending at least in part on the location of their treatment center, an international analysis found.

While most patients now receive nodal surveillance instead of CLND, and adjuvant systemic therapy use is increasing, significant geographic and center-level variation remains which merits further study, Dr. Kristy Broman of the University of Alabama at Birmingham and colleagues note in Annals of Surgery.

"We have good evidence to support a more minimal surgical approach for most patients with microscopic cancer in their lymph nodes, sparing patients additional surgery and long-term complications," Dr. Broman said. "This study shows that, unlike the pace of adoption that we see for many scientific innovations, these research findings were adopted very quickly, and quite broadly at major melanoma referral centers across the world."

"Taking the overall trends, we were surprised that there was still quite a bit of variation in the treatment provided for patients based on where they received care, which was not explained by how high-risk their melanoma was," she said. "Even within some institutions, we would find that a similar patient was just as likely to receive the most aggressive treatment (CLND and adjuvant systemic therapy) as they were the least aggressive strategy (observation alone). The reasons for this are not yet known."

Dr. Broman and colleagues studied data from 1,109 patients (median age, 61; 61%, men) treated at 21 referral centers in Australia, Europe, and the United States for sentinel lymph node (SLN)-positive melanoma from 2017-2019.

During the study period, use of CLND decreased from 28% to 8% and adjuvant systemic therapy use increased from 29% to 60%.

For both CLND and adjuvant systemic treatment, the most influential factors were nodal tumor size, stage.

However, patients treated in the United States, relative to Europe or Australia, were more likely to receive adjuvant systemic therapy, with or without CLND, the authors found.

"Basically, we did not find differences in nodal management (observation versus CLND) for U.S. versus non-U.S. (Europe/Australian) centers, but we did find greater use of adjuvant systemic therapy at U.S. centers," Dr. Broman said. "There were a lot of moving parts during the time period of study with respect to adjuvant therapy that would affect its availability including regulatory approvals and coverage by the respective payment systems for each country. I suspect there would be fewer country level differences in provision of adjuvant systemic therapy now than during the study period, though to my knowledge this has not been studied."

As Dr. Broman noted, treatment varied among centers in the management of stage IIIA patients with similar risks, including use of CLND with adjuvant systemic therapy versus nodal observation alone.

The authors conclude, "There has been an overall decline in CLND and simultaneous adoption of adjuvant systemic therapy for patients with SLN-positive melanoma though wide variation in practice remains. Accounting for differences in patient mix, location of care contributed significantly to the observed variation."

Dr. Broman said the team's future research includes "trying to get a more nuanced understanding of how patients and providers consider their treatment options in light of available evidence by conducting interviews with patients and providers about their recommendations and decisions. Second, we want to better understand the care delivery factors (things such as how organizations and treatment teams are structured, where providers get their information, and dissemination strategies that are used in health systems) that impact how new evidence gets implemented into practice, including not only what makes us providers start recommending a new therapy that is effective, but also what drives us to omit treatments that evidence shows are not beneficial for most patients."

Dr. Alain Algazi, Director, UCSF Head and Neck Medical Oncology commented on the study in an email to Reuters Health. "There have been several studies in the past demonstrating that CLND provides prognostic information, but it does not keep the cancer from coming back," he said. "So, if we have enough information to determine whether a patient could benefit from adjuvant therapy, we don't gain much from taking out a lot of lymph nodes with surgery."

"In contrast, with the development of safer medical therapies that really do reduce the risk of the cancer coming back, I think that our threshold for giving medicine to prevent recurrence is lower," he noted. "The main question that needs to be answered by large-scale studies is whether it is better to start medical therapy before or after surgery."

SOURCE: https://bit.ly/34PBj4I Annals of Surgery, online January 27, 2022.

By Marilynn Larkin



Posted on 21 February 202228 February 2022