Chemotherapy has the potential to make cancer cells more susceptible to immunotherapy.
Findings from a recent study suggest that chemotherapy prior to surgery could potentially make metastatic ovarian cancer more receptive to immunotherapy.
Chemotherapy has been shown to alter immune cells in tumors that could make the cells more vulnerable to immunotherapy and prevent relapse.
"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,” said researcher Frances R. Balkwill, PhD. “Therefore, we need to find other treatment options after the initial treatment is given.”
In preclinical trials, chemotherapy was found to destroy cancer cells and stimulate immune cells to kill cancerous cells in mice. Included in the study, published in Clinical Cancer Research, were pre- and post-chemotherapy biopsies, plus blood samples from patients with advanced-stage HGSC.
There were 54 patients who received treatment with platinum-based neoadjuvant chemotherapy and 6 patients who had surgery without chemotherapy. Researchers analyzed changes in tumor immune microenvironment in both groups of patients.
The patients were said to either have a positive or a poor response to chemotherapy. Researchers discovered that patients who had chemotherapy prior to surgery had types of T cells that fight cancer cells and decreased levels of T cells that suppress the immune system, according to the study.
"Our study showed that chemotherapy altered the immune cells called T cells that are found in metastatic ovarian cancer samples in a way that suggested they were better able to fight the cancer after the treatment," Dr Balkwill said. “Our research provides evidence that immunotherapy may be more effective if given straight after chemotherapy.”
The researchers also found that patients who received chemotherapy had reduced levels of cytokines that promote cancer growth, which has the potential to increase the efficacy of immunotherapy drugs. The addition of immune checkpoint blockade treatments can stop PD-L1 from preventing T cells from recognizing and destroying cancer cells, the researchers wrote.
"The chemotherapies, carboplatin and paclitaxel, given in our study are also used to treat many different cancer types,” Dr Balkwill concluded. “It will, therefore, be very interesting and potentially promising if similar effects are seen in other cancer types, such as lung cancer.”