Ovarian cancer is often called the “silent killer” because its symptoms are difficult to detect until the cancer has developed into later, deadlier stages. Since it is commonly detected only at an advanced stage, chemotherapy and surgery regularly fail to prevent ovarian cancer from recurring. The five-year survival rate for stage IV invasive epithelial ovarian cancer is a mere 17 percent.
However, preliminary clinical trials show that an experimental personalized vaccine is safe and could extend the lives of advanced-stage ovarian cancer patients.
The treatment is a personalized immunotherapy targeted to address individual patients..
After both the tumor cells and the parts of a the patients’ immune system known as dendritic cells are harvested, the dendritic cells are taught to identify and attack the tumor cells. They are reintroduced as a personalized vaccine into the patient’s body, where the dendritic cells interact with the patient’s T cells, the immune system’s front line. The T cells then learn to identify and attack malignant cells as well.
Ten patients with advanced ovarian cancer received the personalized treatment along with cyclophosphamide and bevacizumab, other cancer medications. Eight survived beyond two years. Out of another 10 who received the same treatment, excluding the cyclophosphamide, 30 percent were alive after two years. In contrast to the survival rate of the cohort with the full treatment, only half of a control group of 56 patients who received only chemotherapy survived to the two-year mark.
The vaccine has been found to be remarkably safe in conjunction with the other medications — the worst side effects reported were small spells of tiredness and flu-like symptoms.
The use of personalized vaccines is far from widespread. Otis Brawley, chief medical officer of the American Cancer Society, is hopeful, and he has noted that the study “justifies a larger clinical trial.” However, he has also cautioned that survival analysis may be susceptible to biases and that there may be “better-proven” conventional therapies preferable to an “unknown” immunotherapy.
Either way, continued innovation in oncology continues to give patients of the “silent killer” hope.
