Highlights on Ovarian Cancer (ESGO)
Presented by Prof Mireille Langouo Fontsa (Institut Jules Bordet)
Professor Mireille Langouo Fontsa, medical oncologist at the Institut Jules Bordet, offers a comprehensive summary of the pivotal findings on ovarian cancer unveiled at the ESGO congress.
The first scientific session, presented by Professor Toon Van Gorp, discusses the benefits of neoadjuvant treatment in stage 4 ovarian cancer. The optimal timing for surgery is crucial since 20-30% of newly diagnosed ovarian cancer cases are stage 4. The non-inferiority of neoadjuvant chemotherapy was demonstrated in the CHORUS and the EORTC 55971 trial, but it may benefit stage 4 patients. Achieving complete resection without residual disease is an independent prognostic factor for improved outcomes, regardless of neoadjuvant chemotherapy before surgery. Only 19% of patients underwent complete resection, so the data from the TRUST trial are awaited to address selection biases in neoadjuvant therapy. The AGO meta-analysis revealed that the absence of residual disease increased PFS by up to 7 months and OS by 30 months. As stated in the ESMO2023 guideline, the key question lies in the extent to which complete debulking of the tumour is achievable. Patient selection is critical in determining the need for neoadjuvant chemotherapy, even in stage 4. In this context, the use of preoperative imaging techniques is discussed to identify patients with unresectable distant parenchymal metastases and whole-body DW-MRI has shown superior outcomes in detection. Since surgery and preoperative imaging significantly contribute to survival, even in stage 4, treatment should be sought in expert centres.
Professor Kristina Lindemann’s presentation addresses the subsequent line of treatment after the failure of PARP inhibition in oligoprogressive patients. Despite the impressive clinical benefits of PARPi, approximately 50% of patients experience disease recurrence. Progression in PARP inhibition differentiates patients into oligoprogressive and non-oligoprogressive groups, with the former having 1-5 sites of metastasis. The number of metastatic sites is associated with the outcome, with a PFS of 40.5 months observed in patients with one site of metastasis compared to 6 months in those with more than one site. Regarding the site of metastasis, lymph node-only recurrences have a better outcome compared to external lymph node metastasis. Retrospective analysis of studies indicates that local treatment, either through surgery or radiotherapy, improves PFS and DFS in oligoprogressive patients. The efficacy of chemotherapy diminishes with increasing treatment lines, and the impact of PARPi on subsequent therapy efficacy is discussed due to its potential to increase resistance to subsequent lines of treatment. Careful patient selection and duration of therapy with PARPi are essential.
Professor Isabelle Ray-Coquard discusses the role of checkpoint inhibition in ovarian cancer, drawing parallels with its success in endometrial and cervical cancer. However, single-agent checkpoint inhibition has not shown positive outcomes. Combining checkpoint inhibitors with chemotherapy, as in the JAVELIN-200 trials, did not demonstrate additional benefit. Similarly, adding bevacizumab to chemotherapy and checkpoint inhibitors in the IMAGYN 050 trial did not improve PFS or OS. After these failures, it’s important to analyse specific subgroups that might benefit from treatment. Some phase 2 trials indicate potential benefits of PD-1 or PD-L1 inhibition in clear cell carcinoma patients. However, trials such as ATALANTE and ANITA did not show any benefit from checkpoint inhibition. Preliminary results from the DUO-O trial suggest potential benefits of adding bevacizumab and a PARPi to chemotherapy for HRD-negative patients, though data are still immature. Alternative immunotherapy approaches need to be considered beyond traditional checkpoint inhibition in ovarian cancer.
References:
Van Gorp T., 2024, FIGO IV – When Is the Best Time to Opt for Neoadjuvant Treatment. ESGO2024
Lindemann K., 2024, Challenges in the PARPi Era: From Oligo-Progression to Impact of PARPi in Subsequent Lines. ESGO2024
Ray-Coquard I., 2024, Still Looking for the Gear to Bring Immunotherapy in the Ovarian Cancer Treatment. ESGO2024
