Metastatic mortality hinges on risk stratification

May 29, 2013

While the control rate for uveal melanoma approaches 100%, disease-related mortality for this cancer has remained essentially unchanged over the past eight decades. According to Thomas M. Aaberg Jr., MD, identifying patients at greatest risk for metastasis and providing them with prophylactic treatment are key to altering mortality outcomes in the future.

East Lansing, MI-While the control rate for uveal melanoma approaches 100%, disease-related mortality for this cancer has remained essentially unchanged over the past eight decades. According to Thomas M. Aaberg Jr., MD, identifying patients at greatest risk for metastasis and providing them with prophylactic treatment are key to altering mortality outcomes in the future.

“The critical milestone in caring for patients with choroidal melanoma is reducing and ultimately, eliminating the risk of metastatic disease,” said Dr. Aaberg, founder and president, Retina Specialists of Michigan, Grand Rapids, MI, and assistant clinical professor of ophthalmology, Michigan State University, East Lansing.

“Today, we have relied on primary tumor detection and intervention and increased metastatic disease surveillance, but these efforts have not changed our mortality rates,” Dr. Aaberg said. “Alternatively, we can treat metastatic disease once it has been detected, but the few months of survival provided by the methods that have been used may not be outweighed by the incurred morbidity.

“While newer treatments for metastatic disease are being developed, I believe the most promising strategy would be to identify more precisely those patients at highest risk for progression and provide these specific patients with options for prophylactic treatment of micrometastatic disease,” he continued.

Identification of patients at high risk has also been challenging, as the current TNM staging system does not sufficiently differentiate patients at high risk from those at low risk. Molecular diagnostics, including analyses of chromosomal gains and losses, gene expression profiling, or some future method, holds promise for identifying patients at high risk of developing metastatic disease.

However, these techniques require tissue procurement through fine needle aspiration biopsy (FNAB). And, while FNAB is regarded as safe in terms of posing minimal risk of morbidity, there is controversy over whether it promotes metastasis.

In order to investigate that issue, the Collaborative Ocular Oncology Group founded by J. William Harbour, MD, undertook a case-control comparison of patients with choroidal melanoma who did and did not have biopsy. After stratifying them into prognostically similar groups based on TNM classification, they found no evidence that FNAB increases the risk of metastasis.

“As surgeons and physicians, it is our obligation to implement techniques for tissue procurement that minimize morbidity, maximize yield, and do not represent an appreciable risk to the patients’ vision or life,” Dr. Aaberg said.

This article was adapted from Dr. Aaberg’s presentation during Retina 2012 at the annual meeting of the American Academy of Ophthalmology.

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