Extracapsular spread predicts survival in SLN+ melanoma

 

CHICAGO – Extracapsular extension, or extracapsular spread (ECS), has been recognized as a risk factor in melanoma patients with macrometastatic (N+) disease, but a study from the United Kingdom has found it may also be an important indicator of progression-free and overall survival in patients who have sentinel node positive (SLN+) micrometastatic disease, a researcher reported at the Society of Surgical Oncology Annual Cancer Symposium.

“There is limited published data on ECS in micrometastatic disease, although there is progression-free survival data published in the literature,” Michelle Lo, MBCHB, MRCS, of Norfolk and Norwich University Hospitals, in Norwich, England, said in presenting the results. “The goal of the study was to determine the incidence of ECS in the micrometastatic group and to determine the prognostic significance of this.”

The study found that the incidence of ECS in the N+ group was significantly higher than the SLN+ group, 52.4% vs. 16.2% (P less than .0001). ECS proved to be a significant prognostic indicator of disease-specific survival and overall survival for both N+ and SLN+ disease. “There was no statistical difference in Breslow thickness between the two groups regardless of ECS,” she said.

Both the N+ and SLN+ groups with ECS had more lymph nodes than the ECS-absent subgroups, Dr. Lo said. However, in the ECS-absent subgroups, N+ patients had twice the number of lymph nodes than SLN+ patients. “This would suggest that ECS is a high-risk phenotype from the outset of metastases rather than something that’s developed over time,” she said. “Our data is in line with international staging data.”

 

The ECS-absent SLN– disease group had the most favorable survival outcomes, while those with ECS-present N+ disease had the worst outcomes. The prognosis of ECS-present, SLN+ patients was statistically similar to the ECS-absent, N+ group, she said.

In patients with SLN+ disease, Breslow thickness and N-stage were independent prognostic indicators for progression-free survival (hazard ratio 2.4, P less than .0001) and disease-free survival (HR 2.3, P less than .0001), Dr. Lo noted that median progression-free survival in SLN+ and N+ disease was 20 and 10 months, respectively. “Within our cohort of patients with ECS present in the micrometastatic group, their disease progressed within 3 years,” she said.

A multivariate analysis showed the survival data from this study was consistent with American Joint Committee on Cancer staging criteria, Dr. Lo said. “ECS is well recognized in the macrometastatic group, but we demonstrated from our data that the incidence of ECS in the micrometastatic group is one in six. It’s an independent risk factor for disease progression and an independent risk factor for worst disease-specific and overall survival, and it upstages micrometastatic disease.” ECS upstages stage III disease in a fashion similar to that of ulceration in primary melanoma, she said.

“In the absence of data to suggest otherwise, we would still recommend completion lymph node dissection in our micrometastatic group where ECS is present, and we would advocate that ECS should be included as an independent staging variable in the future,” Dr. Lo said.

Dr. Lo and her coauthors reported having no financial disclosures.

SOURCE: Lo M, et al. SSO 2018 Abstract 70.

 

CHICAGO – Extracapsular extension, or extracapsular spread (ECS), has been recognized as a risk factor in melanoma patients with macrometastatic (N+) disease, but a study from the United Kingdom has found it may also be an important indicator of progression-free and overall survival in patients who have sentinel node positive (SLN+) micrometastatic disease, a researcher reported at the Society of Surgical Oncology Annual Cancer Symposium.

“There is limited published data on ECS in micrometastatic disease, although there is progression-free survival data published in the literature,” Michelle Lo, MBCHB, MRCS, of Norfolk and Norwich University Hospitals, in Norwich, England, said in presenting the results. “The goal of the study was to determine the incidence of ECS in the micrometastatic group and to determine the prognostic significance of this.”

The study found that the incidence of ECS in the N+ group was significantly higher than the SLN+ group, 52.4% vs. 16.2% (P less than .0001). ECS proved to be a significant prognostic indicator of disease-specific survival and overall survival for both N+ and SLN+ disease. “There was no statistical difference in Breslow thickness between the two groups regardless of ECS,” she said.

Both the N+ and SLN+ groups with ECS had more lymph nodes than the ECS-absent subgroups, Dr. Lo said. However, in the ECS-absent subgroups, N+ patients had twice the number of lymph nodes than SLN+ patients. “This would suggest that ECS is a high-risk phenotype from the outset of metastases rather than something that’s developed over time,” she said. “Our data is in line with international staging data.”

 

The ECS-absent SLN– disease group had the most favorable survival outcomes, while those with ECS-present N+ disease had the worst outcomes. The prognosis of ECS-present, SLN+ patients was statistically similar to the ECS-absent, N+ group, she said.

In patients with SLN+ disease, Breslow thickness and N-stage were independent prognostic indicators for progression-free survival (hazard ratio 2.4, P less than .0001) and disease-free survival (HR 2.3, P less than .0001), Dr. Lo noted that median progression-free survival in SLN+ and N+ disease was 20 and 10 months, respectively. “Within our cohort of patients with ECS present in the micrometastatic group, their disease progressed within 3 years,” she said.

A multivariate analysis showed the survival data from this study was consistent with American Joint Committee on Cancer staging criteria, Dr. Lo said. “ECS is well recognized in the macrometastatic group, but we demonstrated from our data that the incidence of ECS in the micrometastatic group is one in six. It’s an independent risk factor for disease progression and an independent risk factor for worst disease-specific and overall survival, and it upstages micrometastatic disease.” ECS upstages stage III disease in a fashion similar to that of ulceration in primary melanoma, she said.

“In the absence of data to suggest otherwise, we would still recommend completion lymph node dissection in our micrometastatic group where ECS is present, and we would advocate that ECS should be included as an independent staging variable in the future,” Dr. Lo said.

Dr. Lo and her coauthors reported having no financial disclosures.

SOURCE: Lo M, et al. SSO 2018 Abstract 70.

 

CHICAGO – Extracapsular extension, or extracapsular spread (ECS), has been recognized as a risk factor in melanoma patients with macrometastatic (N+) disease, but a study from the United Kingdom has found it may also be an important indicator of progression-free and overall survival in patients who have sentinel node positive (SLN+) micrometastatic disease, a researcher reported at the Society of Surgical Oncology Annual Cancer Symposium.

“There is limited published data on ECS in micrometastatic disease, although there is progression-free survival data published in the literature,” Michelle Lo, MBCHB, MRCS, of Norfolk and Norwich University Hospitals, in Norwich, England, said in presenting the results. “The goal of the study was to determine the incidence of ECS in the micrometastatic group and to determine the prognostic significance of this.”

The study found that the incidence of ECS in the N+ group was significantly higher than the SLN+ group, 52.4% vs. 16.2% (P less than .0001). ECS proved to be a significant prognostic indicator of disease-specific survival and overall survival for both N+ and SLN+ disease. “There was no statistical difference in Breslow thickness between the two groups regardless of ECS,” she said.

Both the N+ and SLN+ groups with ECS had more lymph nodes than the ECS-absent subgroups, Dr. Lo said. However, in the ECS-absent subgroups, N+ patients had twice the number of lymph nodes than SLN+ patients. “This would suggest that ECS is a high-risk phenotype from the outset of metastases rather than something that’s developed over time,” she said. “Our data is in line with international staging data.”

 

The ECS-absent SLN– disease group had the most favorable survival outcomes, while those with ECS-present N+ disease had the worst outcomes. The prognosis of ECS-present, SLN+ patients was statistically similar to the ECS-absent, N+ group, she said.

In patients with SLN+ disease, Breslow thickness and N-stage were independent prognostic indicators for progression-free survival (hazard ratio 2.4, P less than .0001) and disease-free survival (HR 2.3, P less than .0001), Dr. Lo noted that median progression-free survival in SLN+ and N+ disease was 20 and 10 months, respectively. “Within our cohort of patients with ECS present in the micrometastatic group, their disease progressed within 3 years,” she said.

A multivariate analysis showed the survival data from this study was consistent with American Joint Committee on Cancer staging criteria, Dr. Lo said. “ECS is well recognized in the macrometastatic group, but we demonstrated from our data that the incidence of ECS in the micrometastatic group is one in six. It’s an independent risk factor for disease progression and an independent risk factor for worst disease-specific and overall survival, and it upstages micrometastatic disease.” ECS upstages stage III disease in a fashion similar to that of ulceration in primary melanoma, she said.

“In the absence of data to suggest otherwise, we would still recommend completion lymph node dissection in our micrometastatic group where ECS is present, and we would advocate that ECS should be included as an independent staging variable in the future,” Dr. Lo said.

Dr. Lo and her coauthors reported having no financial disclosures.

SOURCE: Lo M, et al. SSO 2018 Abstract 70.