A combination of chemotherapy and immunotherapy could be effective in treating ovarian cancer.
A recent study identified why ovarian cancer often becomes treatment-resistant.
The study, published in Cell, noted there are 2 types of cells in ovarian tumors. The bad cells are called fibroblasts, which block chemotherapy, and the good cells, immune T cells, can reverse this resistance.
Researchers believe these findings could be used to create immunotherapy drugs to treat the cancer.
"Ovarian cancer is often diagnosed at late stages, so chemotherapy is a key part of treatment. Most patients will respond to it at first, but everybody develops chemoresistance and that's when ovarian cancer becomes deadly," said study author J. Rebecca Liu, MD. "In the past, we've thought the resistance was caused by genetic changes in tumor cells. But we found that's not the whole story.”
In the study, researchers examined tissue samples from patients with ovarian cancer, and studied the tumor’s microenvironment in cells and in mice.
Researchers discovered that fibroblasts can block platinum and cisplatin. The fibroblasts were able to keep platinum from accumulating in the tumor and kept the cancer cells from being killed by the drug.
However, when researchers added immune T cells to the fibroblasts, the tumor cells died.
"T cells are the soldiers of the immune system. We already know that if you have a lot of T cells in a tumor, you have better outcomes. Now we see that the immune system can also impact chemotherapy resistance," said study author Weiping Zou, MD, PhD.
An increased amount of immune T cells caused mice models to overcome chemotherapy resistance. Researchers used interferon in order to manipulate the pathways involved in cisplatin.
They believe that chemotherapy and immunotherapy could be an effective way to treat ovarian cancer.
"We can imagine re-educating the fibroblasts and tumor cells with immune T cells after chemoresistance develops," Dr Zou said.
"Then we could potentially go back to the same chemotherapy drug that we thought the patient was resistant to. Only now we have reversed that and it's effective again," Dr Liu concluded.