Surgical Resection Prolongs Survival for Patients Whose Melanoma Has Spread to the Abdomen
Surgical removal of melanoma that has metastasized to the abdomen appears to help patients live more than twice as long as those who receive only medical therapy, according to study results presented at the 2015 Clinical Congress of the American College of Surgeons. In more than 1,600 patients treated over 45 years, results showed an overall survival benefit from surgical treatment despite recent advances in systemic drugs to treat metastatic melanoma.
In the past, melanoma that spread to the liver or another abdominal organ was considered incurable and seldom received surgical resection. More recently, the availability of immune therapies for advanced melanoma gave physicians other medical treatment options besides chemotherapy.
“Some of these immunotherapy drugs can take a long time to work, however, and may not be effective for everyone,” said Gary B. Deutsch, MD, MPH, a surgical oncologist at North Shore–LIJ Health System. He performed the research while a surgical oncology fellow at John Wayne Cancer Institute at Providence Saint John's Health Center.
“We have been trying to gauge the role of surgical resection for metastatic melanoma since the development of systemic immunotherapy,” Dr. Deutsch continued. “Today, metastatic melanoma is discovered earlier in a number of patients, likely because of better imaging techniques, so surgeons may be able to intervene before it becomes futile.”
He said the research is the first comprehensive study of all major abdominal locations of melanoma metastases conducted to assess trends in surgical management and overall survival.
Study Details
In this study of 1,623 patients from the John Wayne Cancer Institute, overall survival was defined as how long the patient lived after diagnosis of stage IV melanoma. By measuring survival from this point, the researchers eliminated any variability in disease-free interval that can occur in patients with metastatic melanoma, Dr. Deutsch said.
All patients had abdominal metastases that might be operable and were referred for surgical evaluation. The liver was the sole site of cancer spread in 697 patients, gastrointestinal tract in 336, adrenal glands in 138, spleen in 109, and pancreas in 38. Another 305 patients had multiple sites of abdominal metastases. Metastases in 104 patients resulted from ocular melanoma rather than skin cancer.
Nearly one in four patients (392 of 1,623) underwent surgical resection of the metastasis. The operation was performed alone, combined with medical therapy, or in some cases included radiofrequency ablation or heat probe treatment to destroy cancer cells.
When the investigators combined all abdominal locations of melanoma metastasis, they found that the surgical group's median survival was 18 months compared to only 7 months for the nonsurgical group of 1,231 patients.
“With our long-term follow-up, we believe that select patients can live longer with surgical treatment,” Dr. Deutsch said.
To determine whether treatment era affected survival, the investigators divided patients into groups of before (1969–2003) and after (2003–2014) advances in systemic therapy. The latter group contained 320 patients. Contrary to what the researchers expected, treatment in the era of more effective systemic immunotherapy did not significantly affect survival compared to earlier treatment, said Anton J. Bilchik, MD, PhD, FACS, Professor of Surgery and Chief of Medicine at the John Wayne Cancer Institute.
Implications of Results
“Despite new immunotherapies, surgical resection provides the longest survival in patients with abdominal metastatic melanoma,” Dr. Bilchik said. “There is so much excitement about the new systemic immunotherapies, but there needs to continue to be multidisciplinary tumor boards to decide when to intervene surgically.”
Both Dr. Bilchik and Dr. Deutsch said surgical resection combined with medical therapy offers the chance to cure metastatic melanoma in selected patients. Patients may be candidates for curative surgical resection, according to Dr. Deutsch, if they have a long disease-free interval and a slow tumor doubling time, and are otherwise healthy.
In this study, individuals with gastrointestinal tract metastases who underwent complete, curative resection had the longest median survival of any patients—more than 2 years—Dr. Deutsch reported.
“Surgical resection can really make a difference in the patients with gastrointestinal tract metastases,” he said. “The operation can be performed laparoscopically, so it is minimally invasive.”
Even patients with gastrointestinal tract metastases who underwent palliative surgical resection to improve symptoms, such as bleeding and pain, had a slightly longer survival than patients who had no operation, Dr. Bilchik noted.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
