Oral Abstract Session

Prof Dr Els Van Nieuwenhuysen (University Hospitals Leuven) brings in this daily highlight some engaging presentations from the oral abstract session on gynaecological cancer at ASCO 2025. 

The TRUST trial aimed to determine the optimal timing of cytoreductive surgery for advanced ovarian cancer, following previous findings that interval debulking surgery is non-inferior to primary surgery. The study randomised 769 patients with resectable stage 3 and 4 epithelial ovarian cancer to either primary debulking surgery or chemotherapy followed by interval debulking surgery. While the trial did not meet its primary endpoint of OS, achieving a R0 resection (zero resection) remained a key determinant of improved progression-free survival (PFS), reinforcing the importance of making a maximal effort to achieve a R0 resection.

Another study, the PHENIX trial, evaluated the role of sentinel lymph node biopsy in early cervical cancer. This trial, involving 838 patients, compared radical hysterectomy with or without lymphadenectomy. The results showed that sentinel lymph node biopsy was non-inferior to lymphadenectomy in terms of DFS, with less surgical morbidity; however, the role in larger tumours remains uncertain.

The CALLA trial was a Phase 3 randomised study that assessed the combination of radiotherapy plus durvalumab against standard-of-care radiotherapy in patients with locally advanced cervical cancer. The trial did not show a statistically significant improvement in PFS for the durvalumab and radiotherapy combination compared to standard radiotherapy in this biomarker-unselected population. Among the 770 patients enrolled, 186 were evaluated for ctDNA levels. After treatment, ctDNA levels were lower in the durvalumab and chemoradiotherapy arm than in the radiotherapy-only arm. The presence of positive ctDNA at cycle 3 was associated with a poor prognosis, as 68% of patients who showed circulating ctDNA positivity subsequently progressed. This finding suggests that ctDNA positivity could be a useful prognostic marker in cervical cancer treatment. 

The KEYNOTE A18 trial presented final survival results for pembrolizumab combined with radiochemotherapy in locally advanced cervical cancer. This combination had already shown improved PFS with a manageable safety profile, leading to its approval. The trial included a high-risk population, with 83% of patients having lymph node metastases. The PFS benefit was maintained, with a hazard ratio of 0.72 in comparison to 0.70 at the first interim analysis. OS also showed a similar trend, with a final hazard ratio of 0.73, and no new safety concerns emerged. Based on these results, the addition of pembrolizumab to radiochemotherapy can now be considered a new standard of care for locally advanced cervical cancer.

The Phase III-I NGOT-OV44 trial (FIRST trial) investigated the combination of dostarlimab and niraparib as maintenance therapy in first-line advanced ovarian cancer. This follows previous trials which explored checkpoint inhibition and PARP inhibition in this setting. The trial, initially designed with three arms, dropped the chemotherapy and bevacizumab arms after the approval of first-line PARP inhibitors for maintenance. The primary endpoint was PFS, and baseline characteristics were well-balanced, with 20% of patients being BRCA-mutated. The addition of dostarlimab to first-line chemotherapy and maintenance niraparib resulted in a statistically significant, though clinically modest, improvement in PFS (hazard ratio of 0.85 and a median PFS difference of 1.4 months). PD-L1 positivity did not appear to influence the effect of dostarlimab, and no overall survival benefits were observed. Safety results were consistent with known toxicity profiles of these drugs, and there were no significant differences in quality-of-life assessments.

The ROSELLA phase 3 trial evaluated relacorilant plus NAB-paclitaxel versus NAB-paclitaxel monotherapy in platinum-resistant ovarian cancer patients who had received 1–3 prior lines of treatment. Relacorilant, a selective glucocorticoid receptor antagonist, aims to restore sensitivity to chemotherapy. A total of 381 patients were randomised 1:1, with prior bevacizumab as a requirement. ROSELLA met its primary endpoint, demonstrating statistically significant improvement in PFS, with a hazard ratio of 0.7 and a median PFS difference of one month. The PFS benefit was observed across subgroups, with a lower incidence of adverse events in the relacorilant arm. The overall safety profile was comparable between both arms..

These trials collectively contribute valuable insights into the treatment strategies for ovarian and cervical cancers, with a focus on optimising surgical approaches, reducing treatment-related morbidity, and identifying biomarkers for better prognosis and treatment decision-making.