'Precision medicine' now being used in treatment of local cancer patients
Donna Carr calls herself “pretty lucky.”
Though the 67-year-old certified nursing assistant from Niantic is battling a unique type of cancer that’s spawned tumors in various parts of her body, she’s feeling better after four months of treatment with a chemotherapy drug specifically designed for her.
“They can’t cure it, but they can keep it under control,” she said Thursday. “I get tired from the treatment, but I can drive and I can still function, and all that pain I had has been mostly eliminated.”
To design Carr’s treatment, her doctor at Lawrence + Memorial Cancer Center in Waterford sent cells from a biopsy of one of her tumors to the laboratory at Yale New Haven Hospital for genomic sequencing, then chose her medication based on the results. The genomic test, which looks for specific mutations in the DNA of cancerous tumors, was available only at major medical centers up until a few years ago, but has now become a regular part of care for many cancer patients in southeastern Connecticut and across the country. At L+M Cancer Center, it became routine after L+M joined the Yale New Haven Health network last year.
Now, figuring out the unique molecular code of a cancer tumor’s DNA is one of the most common examples that so-called “precision medicine” has moved beyond futuristic speculation and academic and research arenas.
“This treatment is becoming widely available in many more community settings,” said Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society.
At Eastern Connecticut Hematology & Oncology Associates, a private practice located at The William W. Backus Hospital in Norwich, Dr. Susan Johnson said genomic testing is becoming “more and more routine,” especially for hard-to-treat cancers. She estimates that about 50 patients per year there with advanced cancers are having DNA analysis of up to 400 genes in tests on tumor samples sent to a private lab. The results, she said, are used to identify drugs created specifically to act on those mutations, stopping the tumor from continuing to spread.
“It’s really transforming care and opening up new options for patients, especially those who have run out of other options,” said Johnson, who is director of research at the oncology practice.
Dr. Richard Hellman, medical director of L+M Cancer Center, said having the capability to do genomic testing is especially welcome when he’s treating patients like Carr and determining which of a suite of new drugs will work best.
“In cases such as this,” he said, “we must cast a wide net using multiple platforms to identify any potential targets when we are not absolutely certain as to the tumor’s true cell of origin. Identifying ‘driver mutations’ has become the standard of care for many malignancies.”
The benefits of genomic testing have been well known and in use for patients with breast cancer, the most common type of cancer, for several years, said Dr. Jane Kanowitz, medical oncologist at the L+M center. Now, expanding the availability of the tests to patients with other types of cancers not only helps more doctors identify new drugs to prescribe, but also which ones not to. That information is particularly important considering the debilitating side effects of some of the more generalized, unspecific chemotherapy drugs.
“Each tumor has a unique signature, just like each person has a distinct fingerprint and psychological makeup,” Kanowitz said. “Knowing that molecular arrangement can be used to predict the behavior of tumors and who’s going to benefit from specific treatments, and who’s only going to get the toxic effects. Our goal now is to do this test for patients with most solid tumors.”
Rapid advancements
At the Tumor Profiling Laboratory at Yale New Haven Hospital, Dr. Janina Longtine said that across the Yale New Haven Network, which extends from Greenwich to Westerly, all patients with stage 2 or higher melanoma, lung or colon cancer — the fifth, second and fourth most common types, according to the National Institutes of Health — are having 50-gene panel tests done to find target mutations. Next month, that is slated to increase to a 148-gene panel test, according to Kanowitz.
Longtine said the use of genomic testing in cancer care has advanced rapidly over the 14 years since the human genome was first sequenced. The first tests offered would look for just one or two genes prone to cancerous mutations, she said, but now advances in technology and understanding of tumors has expanded the numbers of genes routinely being sequenced, she said.
“Now, with one test, we can look at 50 genes for hot spots,” said Longtine, the vice chairwoman of pathology, laboratory medicine and tumor profiling at Yale New Haven. For patients with more advanced disease, she added, 400-gene panel testing is offered. In all, the lab is conducting about 90 of these tests per month, with each test taking three to four days.
At the Hartford HealthCare Cancer Institute, part of the same network as Backus hospital, 300- to 400-gene panel testing is being made available for patients with advanced cancer, said Dr. Peter Yu, physician-in-chief. The test costs about $1,500 and is not covered by most insurance, he said, but Hartford HealthCare this month began offering the treatment free of charge to 200 breast cancer patients. It is also offering the free tests to 12 lung cancer patients.
“Insurance still sees this as an experimental test,” Yu said. “This is where the field is getting ahead of itself. But we are poised to take the next step.”
Hartford Hospital is sending the samples to the lab at its affiliate, Memorial Sloan Kettering Cancer Center in New York, but is planning to expand its lab to do tests in house, Yu added.
One of the factors contributing to the rapid expansion of genomic testing for cancer is the development of new cancer drugs that target specific mutations, according to Dr. Longtine. In some cases, those drugs are replacing older chemotherapy drugs that would target all fast-growing cells and cause the telltale hair loss, nausea and other side effects long associated with cancer treatment.
“These new drugs inhibit or put the brakes on the growth of the tumor,” said Kanowitz, adding that some of the new medications mimic the body’s own antibodies. “They block the signal being transmitted to the nucleus or brain of the cancer cell.” Many patients, she said, are staying cancer-free for longer because of the new drugs.
But the new drugs can be expensive, Dr. Yu noted, costing as much as $10,000 per month. That’s why precise genetic testing must be done first.
“You need to know exactly what the mutations are for this whole thing to work,” he said.
While the reimbursement for the 300- to 400-gene tests is a problem, Medicare does reimburse $602 for the 50-gene tests, and some private insurance companies are also covering the 50-gene test it because it is one of the care guidelines endorsed by the National Comprehensive Cancer Network, Longtine said. The 148-gene test slated to begin next month will also be covered by Medicare, according to Kanowitz.
'Cancers are smart'
To conduct the tests, samples taken from a patient’s tumor are sent to the New Haven lab, where they are undergo a process to extract the DNA and fix it onto slides sent through a robotic analyzing machine.
“We can run samples from up to eight patients at the same time, each with a bar code imbedded into the sample,” Longtine said, as white-coated lab staff examined panels of slides. “You can have a lung and colon and melanoma cancers tested all at the same time.”
She checked the written report on one of the sample results.
“This patient has four different cancer-related mutations in their tumor,” she said.
While the test is helping guide more precise treatments, she said, cancer remains a tricky disease to cure completely.
“Cancers are smart, and sometimes they develop additional mutations that can escape treatment,” she said. “Sometimes you have to have a second round of the tests to find a new therapy.”
Dr. Lichtenfeld of the American Cancer Society cautioned that the genomic testing isn’t helpful in all cases. Tumors change over time, and some mutations can be missed if the sampling doesn’t extract enough of the tumor.
“Is it really going to impact the care of the patient, or is it more of a selling point?” he asked. In some cases, he said, the value of the tests for specific patients is “overpromised and underdeveloped.” He agreed, however, that using the test to identify mutations in breast, lung, colon and melanoma tumors has been shown to have the greatest value, because of specific drugs available for those types.
“You have to be very thoughtful about where you apply this technology,” he said.
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