June 15, 2016, American Association for Cancer Research -- Bottom Line: Metastatic ovarian cancer patients treated with chemotherapy prior to surgery had altered immune cells in their tumors, and specific alterations identified suggest that immunotherapy given after chemotherapy may help in preventing the cancer from coming back.

Journal in Which the Study was Published: Clinical Cancer Research, a journal of the American Association for Cancer Research.

Author: Frances R. Balkwill, PhD, professor of cancer biology at Barts Cancer Institute in Queen Mary University of London, United Kingdom.
Background: "We are studying a type of ovarian cancer called high-grade serous ovarian cancer (HGSC), which is quite difficult to treat for two main reasons: first, it is often detected after it has spread quite extensively in the body; and second, although the disease can respond well to the first chemotherapy treatments, it often relapses and becomes more difficult to treat. Therefore we need to find other treatment options after the initial treatment is given," said Balkwill.

Prior preclinical research in mice suggests that when chemotherapy destroys cancer cells, it also stimulates immune cells in the cancer that can kill cancer cells, she explained. "We wanted to study whether this was also true in cancer patients, and whether it occurred with the chemotherapy used to treat women with ovarian cancer," Balkwill added.

How the Study Was Conducted: Balkwill and colleagues collected pre- and post-chemotherapy biopsies and blood samples from 54 patients with advanced-stage HGSC who underwent platinum-based neoadjuvant (given prior to surgery) chemotherapy, and from six patients who underwent surgery without prior chemotherapy.

The researchers analyzed the samples using immunohistochemistry and RNA sequencing to study the changes in the tumor immune microenvironment of patients who received and did not receive chemotherapy, and changes before and after chemotherapy. Patients were categorized into those who had a good response and those who had a poor response to chemotherapy, based on a recently approved chemotherapy response score that correlates with progression-free and overall survival.

Results: They found that in patients who received chemotherapy, there was evidence of activation of certain types of T cells that can fight cancer cells, while the number of a type of T cell that suppresses the immune system decreased. The results were more pronounced in those who had a good response to chemotherapy, compared with those who had a poor response to chemotherapy.

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