Three physicians at a prominent California hospital network are calling for reforms regarding the way tissue specimens are handled for cancer testing. The doctors—Scripps Health pathologist Kelly Bethel, M.D., surgeon Laura Goetz, M.D., and cardiologist and Scripps Chief Academic Officer Eric Topol, M.D., believe the changes in cancer testing wrought by molecular pathology require changes in handling specimens. Traditionally, tumor tissue specimens are preserved in a combination of formalin and paraffin. However, the trio argues in the most recent issue of the Journal of the American Medical Association that such preparation methods damage DNA, making gene sequencing difficult, if not impossible. “We need to completely rethink the way we have collected and stored cancer tissue samples for decades,” Topol said. “It’s becoming increasingly clear that obtaining an accurate map of a tumor’s DNA can be the key to determining the specific mutations that are driving a person’s cancer, how best to treat it, and how likely it is to recur.” ‘Tipping Point’ In the article, the doctors argue that the practice of pathology has arrived at a “tipping point” when it comes to cancer testing. “Deciding how best to obtain samples and how best to process them for whole genome […]
Three physicians at a prominent California hospital network are calling for reforms regarding the way tissue specimens are handled for cancer testing.
The doctors—Scripps Health pathologist Kelly Bethel, M.D., surgeon Laura Goetz, M.D., and cardiologist and Scripps Chief Academic Officer Eric Topol, M.D., believe the changes in cancer testing wrought by molecular pathology require changes in handling specimens.
Traditionally, tumor tissue specimens are preserved in a combination of formalin and paraffin. However, the trio argues in the most recent issue of the Journal of the American Medical Association that such preparation methods damage DNA, making gene sequencing difficult, if not impossible.
“We need to completely rethink the way we have collected and stored cancer tissue samples for decades,” Topol said. “It’s becoming increasingly clear that obtaining an accurate map of a tumor’s DNA can be the key to determining the specific mutations that are driving a person’s cancer, how best to treat it, and how likely it is to recur.”
‘Tipping Point’
In the article, the doctors argue that the practice of pathology has arrived at a “tipping point” when it comes to cancer testing. “Deciding how best to obtain samples and how best to process them for whole genome or exome sequencing is a pivotal yet unresolved issue with several layers of complexity,” they wrote, adding that a “fundamental change in how cancer specimens are handled” may soon be at hand.
As an alternative, the doctors suggest that freezing specimens for preservation might be a better way to proceed, although they noted that process might require larger or more numerous biopsy samples. They also urged randomized clinical trials comparing the efficacy of current specimen collections and alternative methods.
The trio also suggested that the additional costs of freezing samples and collecting and storing more of them should be balanced against the patient benefits of complete genetic evaluations of tumors.
The article was praised by the College of American Pathologists, although President Stanley Robboy, M.D., urged a deliberative process.
“This type of change will require discussion about new operative standards, which will need the cooperation of surgeons, pathologists, ethicists, and, of course, appropriate patient consents. It’s these types of implications we will need to consider and incorporate as a progressive health care agenda is moved forward,” he said.
