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Better understanding of the pathogenesis of the disease and its interaction with the immune system indicates that a closer look should be taken at the concept of surgery for some patients.
Vancouver, British Columbia - Although surgery often is not a consideration for metastatic melanoma as most patients are believed to have multiple sites and a number of distant metastases, perhaps physicians should not dismiss surgical resection as a viable treatment option.
Speaking at the sixth World Congress on Melanoma, Richard Essner, M.D., director of molecular therapeutics at the John Wayne Cancer Institute in Santa Monica, Calif., expressed his viewpoint regarding surgical treatment of melanoma. He suggests that better understanding of the pathogenesis of the disease and its interaction with the immune system indicates that a closer look should be taken at the concept of surgery for some patients.
"At our institute, in well selected patients, we have been able to obtain better survival with surgical resection, compared to non-surgical management," Dr. Essner explains.
"The development of PET, and more sophisticated and accurate CT and MRI have made us better able to stage our patients. With these techniques, we have also been able to identify patients who have disease that is limited to only a few sites. Indeed, if there truly is immune interaction between melanoma and the host, removing the tumor can perhaps give the immune system an advantage, and surgery should have more of a role in the care of our patients."
By 1965, it was known that resection of a variety of different solid tumors that had spread to the lung could achieve a five-year survival of about 30 percent. Very consistent long-term survival has also been shown in a number of large single institution studies of melanoma and from the international lung metastasis registry.
Conventional imaging has been around for about 40 years but positron emission tomography (PET) scanning only became popular for use in melanoma patients in the last 10 years. Dr. Essner says he and colleagues used conventional CT or MRI, followed by full-body PET scan, with the PET images subsequently examined by different radiologists blinded to the results of the other scans.
"The treatment plan was changed in up to 68 percent of our patients as a result of having the PET scan following conventional CT or MRI. Although I don't think PET is the perfect test, in combination with a variety of other scans, it certainly can be very useful."
Last year, Dr. Essner says he and fellow researchers looked at 1,574 patients over a 30-year period with stage four disease; these patients had undergone surgical resection. Equally divided between men and women, the patients averaged 50 years of age and had a variety of primary disease sites.
A majority of the patients had only one metastasis, but 14 percent had four or more metastases to such sites as skin, lymph node, brain, GI and adrenal glands. About 6 percent of the patients had very low-risk primaries that ultimately developed distant metastases, suggesting the importance of following all patients with melanoma.
"The patients were subsequently divided into what were considered to be favorable or less favorable sites for surgery. Generally, lung, GI tract, skin or distant lymph nodes were considered favorable sites to remove," Dr. Essner tells Dermatology Times. "The median survival for this group was about 30 to 35 months with no difference in survival time based on the disease site involved."
Differences in outcome were related to the number of metastases, the disease-free interval from initial disease and the presence or absence of prior lymph node metastases. Patients who had less favorable sites of disease such as adrenal glands, brain and liver still had a median survival of 18 months after surgical resection.
Dr. Essner says retrospective studies from around the world show that in order for surgery to be effective, tumors must be completely resected.
"If 95 percent of the tumor is removed, these patients receive no survival benefit from the operation, although surgery for palliation of symptoms can be accomplished with incomplete removal of metastases," he says.
If surgical intervention truly has a positive bearing on outcome of the disease process in melanoma patients, it should be considered more often as a treatment option for such patients.
Disclosures: Dr. Essner reports no conflicts of interest.