The role of surgery in platinum-resistant ovarian cancer: A call to the scientific community

Homologous recombination proficient subtypes of high-grade serous ovarian cancer: treatment options for a poor prognosis group

Approximately 50% of tubo-ovarian high-grade serous carcinomas (HGSCs) have functional homologous recombination-mediated (HR) DNA repair, so-called HR-proficient tumors, which are often associated with primary platinum resistance (relapse within six months after completion of first-line therapy), minimal benefit from poly(ADP-ribose) polymerase (PARP) inhibitors, and shorter survival. HR-proficient tumors comprise multiple molecular subtypes including cases with CCNE1 amplification, AKT2 amplification or CDK12 alteration, and are often characterized as "cold" tumors with fewer infiltrating lymphocytes and decreased expression of PD-1/PD-L1. Several new treatment approaches aim to manipulate these negative prognostic features and render HR-proficient tumors more susceptible to treatment. Alterations in multiple different molecules and pathways in the DNA damage response are driving new drug development to target HR-proficient cancer cells, such as inhibitors of the CDK or P13K/AKT pathways, as well as ATR inhibitors. Treatment combinations with chemotherapy or PARP inhibitors and agents targeting DNA replication stress have shown promising preclinical and clinical results. New approaches in immunotherapy are also being explored, including vaccines or antibody drug conjugates. Many approaches are still in the early stages of development and further clinical trials will determine their clinical relevance. There is a need to include HR-proficient tumors in ovarian cancer trials and to analyze them in a more targeted manner to provide further evidence for their specific therapy, as this will be crucial in improving the overall prognosis of HGSC and ovarian cancer in general.

Clinical characteristics and treatment modalities in women with newly diagnosed advanced high-grade serous epithelial ovarian cancer in Taiwan

BACKGROUND

This study was designed to investigate the demographics, treatment patterns, and clinical outcomes of patients newly diagnosed with high-grade serous ovarian cancer (HGSOC) in 3 medical centers in Taiwan before the integration of poly (ADP-ribose) polymerase inhibitors in clinical practice.

METHODS

A retrospective analysis was conducted on data from patients diagnosed with HGSOC between January 2014 and December 2018 and followed-up for a minimum of 12 months after diagnosis. Descriptive statistics were used to analyze the data, while survival rates were evaluated using the Kaplan‒Meier method.

RESULTS

There were 251 patients included in the analysis, and 98.8% received platinum plus paclitaxel chemotherapy (PPCT). Primary cytoreductive surgery (PCS) and interval debulking surgery (IDS) were performed in 78.9% and 17.1% of patients, respectively. The percentage of optimal surgery was higher in the IDS cohort than in the PCS cohort (83.8% vs. 53.6%). Bevacizumab was used as initiation therapy in 16.7% of patients, and maintenance therapy was administered in 6.8%. Advanced age, IDS, and suboptimal surgery were independent poor prognostic factors associated with lower overall survival (OS). Patients with optimal surgery had significantly lower OS and progression-free survival in the IDS cohort than in the PCS cohort. The predictive accuracy was good for OS at the 1-year follow-up.

CONCLUSION

Advanced age, IDS, and residual disease are associated with poor OS in patients with HGSOC. Compared to PCS, IDS provides a higher likelihood of optimal surgery but results in a lower probability of survival for patients with HGSOC in Taiwan.

Evaluation of secondary cytoreduction surgery in platinum-resistant ovarian cancer patients within three-line recurrent: a multicenter, randomized controlled study

BACKGROUND

Epithelial ovarian cancer is the leading cause of death among gynecological malignancies. Platinum resistance remains a dilemma and bottleneck in treatment, and salvage chemotherapy has limited effectiveness. Recently, the role of secondary cytoreductive surgery (SCS) in patients with platinum-resistant recurrent ovarian cancer (ROC) has caused attention especially in patients with oligometastases. However, there is neither high-quality evidence-based evidence nor standardized criteria for selecting SCS for patients with platinum-resistant ROC until now.

METHODS

This multicenter, randomized, controlled clinical trial is to evaluate the value of SCS and to clarify reliable criteria of utilizing SCS in women with ROC, which is led by Gynecologic Oncology Group, Women's Hospital, Zhejiang University School of Medicine. Recruitment has started on January 1st, 2023, and is scheduled to end in December 2026. One hundred and forty participants with platinum-resistant ROC who meet the "RSCS criteria" will be randomized assigned at a ratio of 1:1 to either the experimental arm or the standard arm. Patients in the experimental arm will receive SCS followed by non-platinum single agent chemotherapy (paclitaxel, gemcitabine or liposomal adriamycin) for at least 4 cycles while patients in the standard arm will be provided with only non-platinum single agent chemotherapy. The primary outcome is progression-free survival. The secondary outcomes are overall survival, adverse events and health-related cancer-specific quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05633199.

Contrasting clinical characteristics and treatment patterns in women with newly diagnosed advanced-stage epithelial ovarian cancer in Australia, South Korea and Taiwan

OBJECTIVE

The real-world INFORM study analyzed sociodemographics, treatment patterns and clinical outcomes for patients with newly diagnosed advanced epithelial ovarian cancer (EOC) in Australia, South Korea (S.Korea) and Taiwan preceding incorporation of poly(ADP-ribose) polymerase inhibitors into clinical practice.

METHODS

Retrospective data from patients diagnosed with EOC (high-grade serous EOC for Taiwan) between January 2014 and December 2018 with ≥12 months follow-up from diagnosis were analyzed descriptively. Survival was evaluated by Kaplan-Meier with two-sided 95% confidence interval (CI).

RESULTS

Of the 987 patients (Australia, 223; S.Korea, 513; Taiwan, 251), 98% received platinum-based chemotherapy (CT). In S.Korea and Taiwan 76.0% and 78.9% respectively underwent primary cytoreductive surgery; in Australia, 56.5% had interval debulking surgery. Bevacizumab was included in primary/maintenance therapy for 22.4%, 14.6% and 6.8% of patients in Australia, S.Korea and Taiwan, respectively. Patients receiving bevacizumab were high-risk (reimbursement policy) and achieved similar real-world progression-free survival (PFS) compared with CT only. Overall, the median real-world PFS (months; 95% CI) was similar across Australia (16.0 [14.63-18.08]), S.Korea (17.7 [16.18-19.27]) and Taiwan (19.1 [17.56-22.29]).

CONCLUSION

This study reveals poor prognosis despite differences in demographics and treatment patterns for patients with EOC across Asia-Pacific suggesting the need for biomarker-driven novel therapies to improve outcomes.

ATR Inhibitors in Platinum-Resistant Ovarian Cancer

Platinum-resistant ovarian cancer (PROC) is one of the deadliest types of epithelial ovarian cancer, and it is associated with a poor prognosis as the median overall survival (OS) is less than 12 months. Targeted therapy is a popular emerging treatment method. Several targeted therapies, including those using bevacizumab and poly (ADP-ribose) polymerase inhibitor (PARPi), have been used to treat PROC. Ataxia telangiectasia and RAD3-Related Protein Kinase inhibitors (ATRi) have attracted attention as a promising class of targeted drugs that can regulate the cell cycle and influence homologous recombination (HR) repair. In recent years, many preclinical and clinical studies have demonstrated the efficacy of ATRis in PROC. This review focuses on the anticancer mechanism of ATRis and the progress of research on ATRis for PROC.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) for ovarian cancer in an Australian institution: lessons from 20 years' experience

Objectives

We report the 20-year experience of the largest Australian unit performing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for ovarian cancer and reflect on learning opportunities.

Methods

A retrospective review of all cases of CRS for ovarian cancer at St George Peritonectomy Unit from Jan 1998 to Jan 2018 was performed. Prospectively collected data include age, stage, histology, disease extent (PCI), completeness of cytoreduction (CC score), HIPEC regime, 30-day surgical morbidity, disease recurrence, and death. Survival was computed using Kaplan–Meier method and analysed using log-rank tests and Cox-proportional hazards models.

Results

Forty-one women with advanced ovarian cancer (11 primary stage III/IV, 30 recurrent) underwent CRS, 29 (71%) with HIPEC. Most (68%) had high-volume disease (PCI > 15). In 98%, CC0/CC1 (residual < 2.5 mm) was achieved. Fourteen (34%) had grade 3/4 complications, 1 patient (2%) died within 30 days and 2 patients (5%) died within 90 days. Progression-free and median overall survival was 30.0 and 67.0 months for primary cancer, and 6.7 and 18.1 months for recurrent cancer. Survival was associated with platinum-sensitivity, PCI ≤ 15, and CC score 0, but not HIPEC.

Conclusion

This study reports outcomes for patients with advanced ovarian cancer patients treated in an Australian centre offering CRS and HIPEC. Whilst survival and morbidity outcomes were good for primary disease, they were poorer than predicted from the literature for cases of recurrent disease. The incorporation of evidence-based predictors of survival and multidisciplinary input are essential to achieve the best survival outcomes.

The surgical outcomes and perioperative complications of bowel resection as part of debulking surgery of advanced ovarian cancer patients

Background

To review the utilization of bowel resection in ovarian cancer surgery in our institution.

Methods

All ovarian cancer patients who received bowel resection between 2006/01 and 2018/12 were identified. Postoperative morbidities were assessed according to the Clavien–Dindo classification (CDC).

Results

There were 182 patients in the anastomosis group and 100 patients in the ostomy group, yielding a total of 282 patients. The median age was 57 years, and most patients had high-grade serous histology (88.7%). Forty-nine (17.3%) patients received neoadjuvant chemotherapy. During the operation, 78.7% of patients had ascites, and the median volume was 800 mL. Extensive bowel resection (at least two-segment) and upper abdominal operation were performed in 29 (10.2%) and 69 (24.4%) patients, respectively. The rectosigmoid colon was the most commonly resected (83.8%) followed by right hemicolectomy (5.9%) and small bowel resection (2.8%). No macroscopic residual disease was observed in 42.9% of the patients, whereas 87.9% had residual disease ≤ 1 cm. Among the entire cohort, 23.0% (65/282) experienced different complications. Severe complications (CDC 3–5) accounted for 9.2% of complications and were mostly categorized as pleural effusion requiring drainage (3.5%) followed by wound dehiscence requiring delayed repair in the operating room (1.8%). Nine patients experienced anastomotic leakage (AL): one in the ostomy group with extensive bowel resection and eight in the anastomosis group. The overall AL rate was 4.2% (9/212) per anastomosis.

Conclusions

The execution of bowel resection as part of debulking surgery in patients with newly diagnosed ovarian cancer resulted in a severe morbidity rate of 9.2%.

Secondary cytoreductive surgery for recurrent low-grade serous ovarian carcinoma: A systematic review and meta-analysis

OBJECTIVES

Low-grade serous ovarian cancer (LGSC) is a relatively chemo-resistant disease with limited effective treatment options for patients with recurrence. Secondary cytoreductive surgery (SCS) is commonly offered at recurrence, although any benefit this has on survival is not fully determined. This review evaluates the impact of SCS, including residual disease, on progression-free survival (PFS) and overall survival (OS) in recurrent LGSC.

METHODS

A comprehensive search of Medline ALL, Embase Classic + Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science was conducted to obtain studies evaluating optimal or complete SCS versus suboptimal SCS and the amount of residual disease in recurrent LGSC. Meta-analysis was performed and PFS and OS outcomes were calculated.

RESULTS

1Of 5296 studies screened, 350 progressed to full-text review, with 9 ultimately selected for inclusion in the systematic review. Two studies met criteria for meta-analysis of PFS and of OS. The presence of visible residual disease at the conclusion of SCS negatively impacted PFS (HR = 3.51, 95% CI = 1.72-7.14), whereas SCS with no residual disease significantly improved OS (HR = 0.4, 95% CI = 0.23-0.7) in patients with recurrent LGSC. Diffuse and extensive disease distribution was inversely linked to survival. In addition, SCS as an initial treatment for recurrent LGSC was associated with superior survival in comparison to chemotherapy. A short platinum-free interval was not associated with worse survival in this cohort.

CONCLUSIONS

Complete SCS, and to a lesser extent optimal SCS, are associated with improved PFS and OS in patients with recurrent LGSC. SCS may be a better initial treatment strategy than systemic chemotherapy for recurrent disease. Patients with recurrent LGSC should be evaluated for the role of SCS based on disease distribution and functional status, irrespective of the platinum-free interval. Prospective studies are needed to further study the role of SCS in patients with recurrent LGSC.