Three pillars for recurrent ovarian cancer treatment

In recurrent ovarian cancer, oncologists rely on surgery, chemotherapy and maintenance therapy. At the 11th ICMC, experts from Charité and Mayo Clinic explained how such regimes interact.

Choosing the best possible therapy for patients

In recurrent ovarian cancer, oncologists rely on surgery, chemotherapy and maintenance therapy. At the 11th International Charité Mayo Conference, experts from the Charité Hospital, Berlin and the Mayo Clinic explained how such regimes interact.

With surgery, chemotherapy and maintenance therapy, three strategies are available to treat recurrent ovarian cancer. Dr. Rosalind Glasspool (Cancer Research, UK), Prof. Dr. Viola Heinzelmann (University Hospital Basel, Switzerland), Dr. Ana Oaknin (Vall d'Hebron Institute of Oncology, Spain) and Prof. Dr. Jalid Sehouli (Charité, Berlin) spoke about the details at a satellite symposium.

Surgical therapy in the era of pharmacological interventions

"When we think of surgery, we only have retrospective data or data from one centre," Sehouli knows. Often there is not a high level of evidence. The speaker emphasises that patients would benefit from maintenance therapies even after successful tumor resection.

The AGO DESKTOP III study provides new data on surgical outcome. 408 patients with platinum-sensitive late recurrence of ovarian cancer were included. The median overall survival was 53.7 months (surgery) versus 46.0 months (no surgery). If patients had no residual tumor postoperatively, their overall survival was significantly higher than in patients with macroscopically incompletely resectable cancer (61.9 months versus 28.8 months). The complete resection rate in the cohort was 74.2%.

Who benefits from surgery?

The AGO score has proven useful in selecting patients for surgical intervention, Sehouli reports. Patients with negative scores can still have a 50% chance of optimal tumor resection after secondary cytoreductive surgery. This is a crucial factor in counselling women with recurrent disease about further treatment options. Even when planning surgical interventions, it is important to consider postoperative strategies.

According to Sehouli, the decision is also based on the results of previous treatment and the patient's individual situation, but not on time factors, as is the case with chemotherapy. If women have an intestinal obstruction, a pleural effusion or ascites, for example, a PEG tube or a drainage should be considered. It is also important to clarify: Is this a palliative setting or is there a chance of longer, progression-free survival?

Chemotherapy versus maintenance therapy

Other pillars include chemotherapy and maintenance therapy. But how should doctors decide? Glasspool summarised key points from the randomised, placebo-controlled phase 3 ARIEL3 trial. The study included 564 patients with platinum-sensitive, high-grade serous or endometrioid ovarian, primary peritoneal or fallopian tube cancer. They had received at least two prior platinum-based chemotherapies - with complete or partial response. All participants were randomised 2:1 to a PARP inhibitor versus placebo.

Median progression-free survival in women with BRCA-mutated carcinoma was 16.6 months versus 5.4 months. In the recombination-deficient group, it was 13.6 versus 5.4 months. An exploratory intention-to-treat analysis showed that the median chemotherapy-free interval was significantly prolonged by PARP (14.3 months versus 8.8 months).

Time to initiation of first subsequent therapy was 12.4 months versus 7.2 months. The time to progression to subsequent therapy or death was reported by the authors as 12.4 months versus 7.2 months. And the time to the start of the second subsequent therapy was 22.4 months versus 17.3 months. Maintenance therapy with a PARP inhibitor leads to a clinically significant delay in subsequent treatments, Glasspool summarised.

She then presented key aspects of the phase 3 study ARIEL4. The target group was 349 platinum-sensitive, partially platinum-sensitive and platinum-resistant patients with recurrent ovarian cancer, with BRCA mutation and with two or more chemotherapies in their history. The ARIEL4 trial met its primary endpoint and showed a statistically significant improvement in progression-free survival with a PARP inhibitor versus chemotherapy (intention-to-treat population: 7.4 months versus 5.7 months).

In the concluding discussion, the speakers emphasised that today there is a much better prognosis for patients with recurrent ovarian cancer. The best possible treatment depends on the individual situation.

11th International Charité Mayo Conference, Satellite Symposium, 08.05.2021