Timothy L. Cannon, MD, is board certified in medical oncology and hematology, and has a special interest in managing gastrointestinal cancers. Dr. Cannon is the clinical director and moderator of Inova’s weekly molecular tumor board, which matches patients with targeted therapies based on molecular diagnostics. 



Tiffani A. DeMarco, MS, CGC, is a board-certified genetic counselor and genetic counseling manager at the Inova Translational Medicine Institute. She specializes in working with patients and family members at risk for hereditary cancers.


The Washington Post profiled a young woman with colon cancer that was raging out of control – until a new type of immunotherapy drug drove her cancer into remission.

That remarkable story isn’t the only one. Here at Inova, we recently treated a man with cancer of the small intestine. Chemotherapy wasn’t working, and we were running out of options. We tested his tumor and found a certain genetic signature, similar to the one found in the cancer of the woman in The Washington Post article.

Our patient’s cancer also responded to immunotherapy. Four months later, he has no symptoms and is back to lifting weights and playing basketball.

For years, cancer researchers have been talking about how targeted therapies could attack specific features of a person’s cancer. That talk has turned into action.

Immunotherapy Milestone

Immunotherapy uses parts of the patient’s own immune system to fight cancer. Until recently, these types of drugs have been approved to treat specific types of cancer, such as metastatic melanoma and non-small cell lung cancer.

But in May, the U.S. Food and Drug Administration (FDA) approved the immunotherapy drug Keytruda for treating tumors anywhere in the body, as long as they have a certain mutation (a kind of genetic glitch) that prevents the cells from repairing mismatched DNA.

That mutation can happen for a variety of reasons. Sometimes it develops by chance during a person’s lifetime. In other cases, though, the mutation is inherited. For example, the mismatch repair problem is often a feature of an inherited condition called Lynch syndrome.

Lynch syndrome significantly increases a person’s risk of colorectal cancer and, to a lesser degree, other cancers including those of the stomach, uterus and ovaries. People with Lynch syndrome are also more likely to develop cancer at a younger age. For many of these patients, immunotherapy could be an important weapon in the fight against cancer.

Personalized Cancer Care

For now, Keytruda is approved for people who have not responded to conventional treatment for their cancers. But that could change. Researchers are testing whether immunotherapy could be appropriate as a first-choice treatment for some people with cancer.

It’s an exciting time in the field of cancer treatment, as we move closer to customized therapies. For a number of years, genetic testing has allowed us to identify whether people have inherited genes that raise their cancer risk. In the last few years, we’ve moved toward testing tumors themselves.

By understanding the genetic changes present in those tumors, we can design more targeted treatments. Immunotherapy is still new, and it’s not always the best option. Right now, such treatments work only for a minority of people with cancer. But when immunotherapy works, it often works spectacularly – and we’re hopeful that more of these promising treatments will be developed and approved in the years to come.

At Inova, we believe in a personalized approach to cancer treatment. We hold weekly molecular tumor board meetings, for instance, to discuss care plans for patients who have not responded well to initial treatment. During these meetings, cancer doctors, nurses, genetic counselors and genetic researchers meet to talk about the patient’s history, symptoms, family history and the genetic features of his or her cancer.

If you’ve been diagnosed with cancer or are concerned about your risk of inherited cancer, we can help. Learn more about our personalized approach at the Inova Schar Cancer Institute, or reach out to the certified genetic counselors in our Cancer Genetics Program, the largest cancer genetics team in the region.


  1. Donna on June 10, 2018 at 12:54 pm

    Hello, my brother was diagnosed with colon cancer with lesions on his peritoneum in Dec. 2016. Thank goodness cancer has not spread. He is being treated at UPenn. Great hospital, like the doctor but saw your t.v. ad about using a person’s DNA to help fight their cancer and would like to find out if my brother would be a candidate. He is staying with me and we have his latest CAT Scan.

    • InovaNewsroom on June 29, 2018 at 2:41 pm

      Hello Donna – Please contact Inova Schar Cancer Institute at 571-472-4724 and they can provide more information about precision medicine available at Inova.

Leave a Comment