Do all patients with recurrent ovarian cancer need systemic therapy?

Clinical and molecular features of platinum resistance in ovarian cancer

Ovarian cancer is the most lethal of all the gynecological tumors despite remarkable advances in our understanding of its molecular biology. The cornerstone treatment remains cytoreductive surgery followed by platinum-based chemotherapy. Recently, the addition of targeted therapies, such as PARP inhibitors, as first-line maintenance has led to outstanding improvements, mainly in BRCA mutated and homologous recombination deficient tumors. However, a significant proportion of patients will experience recurrence, primarily due to platinum resistance, which ultimately result in fatality. Among these patients, primary platinum-resistant have a particularly dismal prognosis due to their low response to current available therapies, historical exclusion from clinical trials, and the absence of validated biomarkers. In this review, we discuss the concept of platinum resistance in ovarian cancer, the clinical and molecular characteristics of this resistance, and the current and new treatment options for these patients.

A Preliminary Exploration Using Imaging Methods to Predict the Possibility of the Recurrence of Serous Ovarian Cancer in Patients Undergoing Total Resection

Background

The purpose of our research was to explore the value of preoperative CT and MRI examinations and clinical indicators in the prediction of recurrence of ovarian serous carcinoma in patients who underwent satisfactory staging surgery.

Procedure

Detailed inclusion and exclusion criteria were installed to screen all patients collected and the eligible patients were divided into two groups. The CT and MRI features and some clinical characteristics of two groups were analyzed, in addition, the apparent diffusion coefficient (ADC) value in tumor solid region was measured. Univariate analysis was used in this study.

Results

There were 78 patients with histologically proven ovarian serous carcinoma. According to the strict inclusion and exclusion criteria, we retained 29 patients (recurrence group: 11 patients, no recurrence group: 18 patients). For the peritoneal implantation metastasis in CT or MRI images and Ki67 proliferation index (Ki67 PI), the differences between two cohorts were statistically significant (P < 0.05). The rate of peritoneal metastasis in the recurrence cohort (10/11, 91%) was higher than that in the no recurrence cohort (7/18, 39%). Patients with high Ki67 PI expression had lower recurrence risk than those with low Ki67 PI expression, HR=0.172 (95%CI: 0.050-0.589, P=0.005), and patients without peritoneal planting had lower recurrence risk than those with it, HR=9.373 (95%CI: 1.194-73.551, P=0.033). For FIGO III patients, ipsilateral fallopian tube involvement was statistically significant between the two groups (P < 0.05). The differences in the other preoperative imaging characteristics of ovarian serous cancer, including the volume; capsule of the mass; main components; ADC value; cystic change; bleeding; degree of enhancement of the mainly solid region in 3 periods; and range of tumor involvement in the ovary, uterus, bladder, bowel, and pelvic wall, were not statistically significant. In addition, the differences in the other clinical indicators (i.e., age, FIGO stage) between the two cohorts were not statistically significant.

Conclusions

In CT and MRI examinations before surgery, peritoneal implantation metastasis was suggestive of the possibility of the recurrence of serous ovarian carcinoma in the near future. In addition to that, ipsilateral fallopian tube involvement and Ki67 PI may also indicate the possibility of recurrence (the former was only applicable to FIGO III patients).

Treatment of Recurrent Epithelial Ovarian Cancer

Epithelial ovarian cancer is the most common cause of death from gynecological tumors. Most patients with advanced ovarian cancer develop recurrence after concluding first-line therapy, making further lines of therapy necessary. The choice of therapy depends on various criteria such as tumor biology, the patient's general condition (ECOG), toxicity, previous chemotherapy, and response to chemotherapy. The platinum-free or treatment-free interval determines the potential response to repeat platinum-based therapy. If patients have late recurrence, i.e. > 6 months after the end of the last platinum-based therapy (i.e., they were previously platinum-sensitive), then they are usually considered suitable for another round of a platinum-based combination therapy. Patients who are not considered suitable for platinum-based chemotherapy are treated with a platinum-free regimen such as weekly paclitaxel, pegylated liposomal doxorubicin (PLD), gemcitabine, or topotecan. Treatment for the patient subgroup which is considered suitable for platinum-based therapy but cannot receive carboplatin due to uncontrollable hypersensitivity reactions may consist of trabectedin and PLD. While the use of surgery to treat recurrence has long been a controversial issue, new findings from the DESKTOP III study of the AGO working group have drawn attention to this issue again, particularly for patients with a platinum-free interval of > 6 months and a positive AGO score. Clinical studies have also shown the efficacy of angiogenesis inhibitors such as bevacizumab and the PARP inhibitors olaparib, niraparib and rucaparib. These drugs have substantially changed current treatment practice and expanded the range of available therapies. It is important to differentiate between purely maintenance therapy after completing CTX, continuous maintenance therapy during CTX, and the therapeutic use of these substances. The PARP inhibitors niraparib, olaparib and rucaparib have already been approved for use by the FDA and the EMA. The presence of a BRCA mutation is a predictive factor for a better response to PARP inhibitors.