Immunotherapy for advanced ovarian cancer more effectively treats tumors when administered immediately after chemotherapy. Sequential chemoimmunotherapy could improve disease control in stage IIIC/IV tubo-ovarian high-grade serous carcinoma (HGSC).1
Only approximately 35% of women with ovarian cancer experience long-term survival of 10 years or more.
This study examined pretreatment and posttreatment omental biopsies and blood samples from 54 patients undergoing platinum-based neoadjuvant chemotherapy and 6 patients undergoing primary debulking surgery. All patients were receiving treatment for stage IIIC/IV HGSC.
Women who received chemotherapy immediately prior to immunotherapy experienced increased activation of T cells within the tumors, as assessed by analysis of the tissue samples. The sequential chemoimmunotherapy, however, had a drawback in that it also promoted increased levels of PD-L1, a protein that allows tumors to evade the immune system.
Immunotherapy might be more effective if given immediately after chemotherapy, particularly if the immunotherapy incorporates a PD-L1 blockade. Inhibition of PD-L1 could allow the activated T cells to better attack the tumor cells.
“Our study suggests that to give patients the best results not only do the immunotherapy drugs need to be given straight after chemotherapy but they also have to able to block PD-L1,” explained Frances Balkwill, the Barts Cancer Institute at Queen Mary University of London, England, and senior author of the study.
“Clinical trials are now needed to test this theory. This same approach could also be extended to other kinds of cancer where the same types of chemotherapy are used, such as lung cancer.”
Results also indicated that patients who did not respond to chemotherapy still experienced increased levels of T cells. This suggests that sequential chemoimmunotherapy could help treat all patients with HGSC, regardless of response to chemotherapy.
“Sequential chemoimmunotherapy may improve disease control in advanced HGSC,” concluded the authors.
1. Böhm S, Montfort A, Pearce OM, et al. Neoadjuvant Chemotherapy Modulates the Immune Microenvironment in Metastases of Tubo-Ovarian High-Grade Serous Carcinoma. Clin Cancer Res. 2016 Jun 15. doi:10.1158/1078-0432.CCR-15-2657 [Epub ahead of print]