Back in Town
James Thomas, MD, PhD, grew up in Union Grove and trained at The Medical College of Wisconsin. He has spent the last several years at Ohio State University, where he was in charge of a large clinical trials program.
In September, Dr. Thomas returned to his home state to lead cancer research efforts at Froedtert & The Medical College of Wisconsin. Working with Ming You, MD, PhD, and others, his goal is to help the Froedtert & The Medical College of Wisconsin Clinical Cancer Center obtain designation as a comprehensive cancer center from the National Cancer Institute.
“One aspect that drew me back to Wisconsin was the opportunity here at the Clinical Cancer Center, with its great facility and terrific staff,” he said. “The Clinical Cancer Center is emerging onto the national scene, and I want to be a part of bringing it into the upper echelon of cancer centers in the country.”
Other new drugs take advantage of irregularities in tumor blood vessels. And scientists are currently working on agents that target oddities in the way cancer cells metabolize fuel. “The normal way cells produce energy is by utilizing their mitochondria. Cancer cells tend to depend on a different process called glycolysis,” Dr. Thomas said. “Researchers are actively looking at ways to take advantage of this difference.”
In some cases, drugs can be targeted to very specific genetic mutations. Dr. Thomas pointed to the gastrointestinal stromal tumor (GIST), a type of sarcoma: “There is a specific mutated protein unique to GIST that drives the growth of this particular kind of cancer.” Targeted drug imatinib (Gleevec) inhibits this protein, dramatically increasing survival.
Unique Fingerprint
Increasingly, targeted drugs are allowing physicians to base care not just on cancer type, but on the molecular profile of individual tumors. “We now know that even one type of cancer is really many types of cancer, each with a unique fingerprint and susceptibility to targeted agents,” Dr. Thomas said.
For instance, in some women with breast cancer, estrogen receptor molecules exist on the surface of the cancer cells. When these molecules are present, estrogen is likely feeding the tumor. These women can be effectively treated using drugs that bind with and block the receptors.
Molecular profiling is also helping physicians know when to use drugs that are effective in a small number of patients. “About 5 percent of lung cancer tumors have a cancer cell mutation in the ALK gene,” Dr. Thomas said. “If your cancer has this mutation, crizotinib, a new agent under investigation, may be very effective — the key is picking out that 5 percent of patients.”
In many cases, molecular profiling is helping identify drugs that have a wide application. Targeted drug trastuzumab can be used to treat the minority of breast cancers with high levels of HER2 protein at the cell level — and also the minority of gastric cancers with the same protein overexpression.
“We may find the molecular signature of a tumor is actually more important than the site of origin of the cancer, because targeted drugs might work for some breast cancers, some lung cancers, some sarcomas, but not all of any one kind,” Dr. Thomas said. “We are crossing the boundaries between tumor types and relying more on the fundamental machinery driving these cells to be cancerous.”
Personalized Therapy
As new drugs target the inner workings of cancer cells with ever greater precision, physicians will increasingly be able to “personalize” therapy to individual patients.
“The ultimate goal is to be able to identify which targeted agents will work and which will not for a given patient,” Dr. Thomas said. “In the future, we will test people’s tumors to get their particular genetic signature, then design treatments that uniquely go after a patient’s personal tumor profile.”
Special Report 2011 866-680-0505 5
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