Combination Therapy Could Stop Cancer in its Tracks

Combining chemotherapy with immune blocker could prevent cancer from growing back.

A new approach to therapy may prevent cancer recurrence in some patients.

A study published recently in Cancer Research finds that administering a drug that stops part of the immune system from repairing damaged cells could stop the disease from coming back in some people.

Scientists funded by Cancer Research UK noted that chemotherapy can produce an onslaught of white blood cells that gather around blood vessels in treated tumors. These M2 macrophage cells are able to repair the damaged tissue to build new blood vessels, which can help the tumor to re-grow following treatment.

Researchers found in a mouse model of cancer that administering a drug that blocks the repair cells can decrease reduce how quickly tumors grow back after chemotherapy.

"Scientists already knew that the body's drive to heal itself can sometimes backfire when the immune system reacts to tissue damage. Our research shows that treating tumors with chemotherapy can activate this part of the immune system, and this then helps tumors re-grow afterwards,” said lead author Professor Claire Lewis from the University of Sheffield Department of Oncology. "But combining chemotherapy with a drug that switches off this part of the body's repair system slowed the growth of tumors after chemotherapy. This could be particularly important for patients who can't have surgery and, therefore, need chemotherapy to help them live for as long as possible."

The findings still need to be confirmed in clinical trials with patients, such as recipients of bone marrow transplants, to see if the drug can help stop cancer from returning.

"Chemotherapy is a cornerstone cancer treatment that saves thousands of lives, but sometimes tumors come back, reducing patients' chances of survival,” said Áine McCarthy, PhD, science communications officer at Cancer Research UK. “We don't understand all the reasons why tumors do come back, but this study sheds new light on the role of the immune system in causing tumors to grow again and, importantly, identifies a drug that could block this happening if given at the same time as chemotherapy. But this is early research carried out in mice and more work is needed to see if blocking M2 macrophages can also slow down tumors re-growth in patients."