Recruiting the Immune System to Fight Cancer

Fighting cancer may become a lot simpler if researchers also take into account the microscale environment that develops inside tumor cells. Experts say that analysis of the way the immune system behaves at these locations may easily provide new targets for treatment.

In a new investigation, experts focused on breast cancer. Details of the work were presented in the first issue of Cancer Discovery, one of the American Association for Cancer Research's (AACR) most recent scientific journal.

The publication was inaugurate at the 102nd annual meeting of the AACR, which is being held in Orlando, Florida between April 2-6. The study itself was conducted by experts at the University of California in San Francisco (UCSF).

According to the scientists, a clear connection was established between patients' cancer recurrence and overall survival rates on one hand, and the amounts of two key types of immune system cells found in their tumors.

The UCSF team analyzed levels of macrophages and CD8+ T-cells, which are both tremendously important for underlying the actions of the immune system. Preclinical trials conducted at the university showed that recurrence rates can be diminished with a new approach.

If future therapies can prevent the recruitment of macrophage cells inside tumors then the chance of cancer returning will diminish considerably, ScienceDaily reports.

“Phase I clinical trials are blunt instruments because their goal is often limited to determining a safe dose for a new drug,” explains UCSF Department of Pathology professor Lisa Coussens, PhD.

“Using preclinical transgenic mouse models of cancer development, scientists cannot only help determine a safe dose for a new drug, but also identify biomarkers indicative of the biological response of the new drug,” she goes on to say.

“Identification of relevant biomarkers can then be translated to clinical studies and help to determine which patients are or are not responding to the drug,” the expert explains further.

In its studies, the team used a compound called PLX3397, which they say is currently undergoing trials for use in inhibiting macrophage recruitment into tumor cells. The chemical is manufactured by Plexxikon Inc.

“Understanding more about this tumor microenvironment response can help enhance the effectiveness of chemotherapy,” Coussens concludes.