Top advances of the year: Ovarian cancer

Although cure rates remain low and effective screening strategies are elusive, the recent advances in systemic therapies over the past year highlighted in this review have prolonged survival for women with ovarian cancer. In 2022, the first antibody-drug conjugate for platinum-resistant ovarian cancer received accelerated US Food and Drug Administration (FDA) approval. Confirmatory studies examining the efficacy of mirvetuximab and other antibody-drug conjugates are underway. In the upfront setting, the first data establishing an overall survival benefit from poly(ADP-ribose) polymerase inhibitor maintenance was demonstrated after a 7-year follow-up period. In contrast, long-term updates from poly(ADP-ribose) polymerase inhibitor trials in the noncurative setting reported survival detriments, and the FDA withdrew the respective indications. Several trials attempted to improve upon the standard of care for platinum-sensitive ovarian carcinoma and those with rare ovarian cancer histologies (carcinosarcoma, clear cell carcinoma) but failed to demonstrate a clinically or statistically meaningful benefit. This leaves the open question of how to further optimize systemic therapy for advanced ovarian carcinoma to improve long-term survival and cure rates.

Effects of MFG-E8 expression on the biological characteristics of ovarian cancer cells via the AKT/mTOR/S6K signalling pathway

In this study, we assessed the effects of MFG-E8 on the biological characteristics of ovarian cancer cells and explored the underlying mechanisms. Human ovarian cancer SKOV3 cells were transfected with MFG-E8 siRNA or NC siRNA. CCK-8, cell adhesion, scratch-wound, and Transwell assays were used to detect changes in cell metastatic processes. Effects of MFG-E8 silencing on the proteins involved in AKT/mTOR/S6K signalling pathway were assessed using qRT-PCR and Western blotting. Transient silencing of MFG-E8 in SKOV3 cells decreased cell proliferation and downregulated the expression of CDK4, cyclin D1, and caspase-3 proteins. Cell adhesion, migration, and invasion were also suppressed. p-AKT, p-mTORC1, and p-p70S6K levels decreased following MFG-E8 knockdown. Hence, MFG-E8 enhances carcinogenesis and affects the AKT/mTOR/S6K signalling pathway in ovarian cancer cells. In conclusion, our results suggested that MFG-E8 could promote ovarian cancer via AKT/mTOR/S6K signalling pathway which improved our understanding of the molecular mechanisms involved in ovarian cancer.IMPACT STATEMENTWhat is already known on this subject? Milk fat globule-epidermal growth factor 8 (MFG-E8) is expressed in several types of cancers such as oesophageal, breast, and liver. However, the mechanism of MFG-E8 involving in EOC remains unknown. We previously found that MFG-E8 expression was related to pathological staging, tissue differentiation, platinum sensitivity, ascites state, and other clinicopathological characteristics.What the results of this study add? Due to a series of in vitro studies, we confirmed that MFG-E8 is involved in the process of proliferation, invasion and metastasis. Our results show that silencing MFG-E8 can significantly inhibit the expression of cyclin D1 and CDK4 in EOC SKOV3 cells. MFG-E8 enhances carcinogenesis and affects the AKT/mTOR/S6K signaling pathway in ovarian cancer.What the implications are of these findings for clinical practice and/or further research? Taken together, our findings suggest that MFG-E8 may be an oncogene in EOC and provide new insights into the mechanism of MFG-E8 in the progression of EOC.

Left Ventricular Ejection Fraction in Patients With Ovarian Cancer Treated With Avelumab, Pegylated Liposomal Doxorubicin, or Both

In the phase III JAVELIN Ovarian 200 trial, 566 patients with platinum-resistant/refractory ovarian cancer were randomized 1:1:1 to receive avelumab alone, avelumab plus pegylated liposomal doxorubicin (PLD), or PLD alone. Cardiac monitoring was included for all patients. We report left ventricular ejection fraction (LVEF) data from the trial. Grade ≥3 cardiac adverse events (AEs) occurred in 4 (2.1%), 1 (0.5%), and 0 patients in the avelumab, combination, and PLD arms, respectively. LVEF decreases of ≥10% to below institutional lower limit of normal at any time during treatment were observed in 1 (0.8%), 3 (1.9%), and 2 (1.5%) patients, respectively; 4 had subsequent assessments, and these showed transient decreases. No patient had a cardiovascular AE related to LVEF decrease. This analysis is, to our knowledge, the first analysis of LVEF in patients receiving immune checkpoint inhibitors.

CLINICALTRIALS.GOV IDENTIFIER

NCT02580058.

A molecular atlas of the human postmenopausal fallopian tube and ovary from single-cell RNA and ATAC sequencing

As part of the Human Cell Atlas Initiative, our goal is to generate single-cell transcriptomics (single-cell RNA sequencing [scRNA-seq], 86,708 cells) and regulatory (single-cell assay on transposase accessible chromatin sequencing [scATAC-seq], 59,830 cells) profiles of the normal postmenopausal ovary and fallopian tube (FT). The FT contains 11 major cell types, and the ovary contains 6. The dominating cell type in the FT and ovary is the stromal cell, which expresses aging-associated genes. FT epithelial cells express multiple ovarian cancer risk-associated genes (CCDC170, RND3, TACC2, STK33, and ADGB) and show active communication between fimbrial epithelial cells and ovarian stromal cells. Integrated single-cell transcriptomics and chromatin accessibility data show that the regulatory landscape of the fimbriae is different from other anatomic regions. Cell types with similar gene expression in the FT display transcriptional profiles. These findings allow us to disentangle the cellular makeup of the postmenopausal FT and ovary, advancing our knowledge of gynecologic diseases in menopause.

Retrospective Analysis of Total Parietal Peritonectomy Without Systematic Lymphadenectomy for Advanced Epithelial Ovarian Cancer

BACKGROUND/AIM

Total parietal peritonectomy (TPP) is a surgical procedure used for complete resection of microscopic peritoneal dissemination. This study analyzed the perioperative complications that developed when omitting systematic lymphadenectomy from TPP.

PATIENTS AND METHODS

We retrospectively analyzed perioperative complications in epithelial ovarian cancer patients with stage IIIB-IVB who underwent TPP during primary and interval cytoreductive surgeries between April 2018 and October 2021.

RESULTS

Thirty-three patients were enrolled in the study. The median patient age was 62 years. Of 31 patients (94%) with stage IIIC/IV disease, 24 (73%) had high-grade serous carcinoma. The median operative time and blood loss were 447 min and 2,831 ml, respectively. Complete tumor resection was performed in 30 patients (91%). Only five patients underwent partial lymphadenectomy for clinical metastatic lymph nodes. Further, grade 3 complications were observed in seven (21%) patients, and there were no fatal events in this study. Three patients (9%) had ureteric injuries, which was the most frequent complication in this study. Only one patient developed an intra-abdominal infection due to ascites. In this case, partial para-aortic and pelvic lymphadenectomies were performed.

CONCLUSION

TPP without systematic lymphadenectomy reduces the frequency of perioperative complications associated with ascites.

Current trends in chemotherapy for advanced ovarian cancer

Chemotherapy for advanced ovarian cancer has progressed over the past several decades with the introduction of cytotoxic agents. Various methods, including single agents, combination therapy and changes in the method of administration, have been validated in many clinical trials and have been combined in an attempt to improve the prognosis of advanced ovarian cancer. In recent years, molecular-targeted agents have been added to cytotoxic agents as a treatment option for maintenance therapy; however, their efficacy has been limited, and further development of treatment options is expected. The advent of poly(ADP-ribose) polymerase inhibitors has considerably improved prognosis and has affected treatment strategies for advanced ovarian cancer over the past few years. With the addition of the recently introduced immune checkpoint inhibitors, future treatment strategies for advanced ovarian cancer may become more complex. In this review, we introduce the latest advances in chemotherapy for advanced ovarian cancer and discuss future perspectives.

Multidetector computed tomography in diagnosing peritoneal metastases in ovarian carcinoma

Multidetector computed tomography (MDCT) of the abdomen is currently the imaging examination of choice for the staging and follow-up of ovarian carcinoma (OC). Peritoneal metastases (PMs) represent the most common pathway for the metastatic spread of OC. MDCT scanners, due to several advantages-including increased volume coverage, reduced scanning time, acquisition of thin slices and creation of multiplanar reformations, and three-dimensional reconstructions-provide useful information regarding the early and accurate detection of PMs. Detailed mapping of peritoneal carcinomatosis is feasible, with improved detection of sub-centimeter peritoneal implants and thorough evaluation of curved peritoneal surfaces.

Venous Thromboembolism in Patients Receiving Neoadjuvant Chemotherapy for Advanced Ovarian Cancer and Impact on Survival

OBJECTIVE

To determine the incidence of venous thromboembolism (VTE) in patients with ovarian cancer receiving neoadjuvant chemotherapy (NACT), identify risk factors for VTE, and assess the effect of VTE on treatment trajectory and overall survival.

METHODS

This is a retrospective cohort study of patients diagnosed with ovarian, fallopian tube, or primary peritoneal cancer treated with NACT between 2013 to 2016 in Alberta, Canada. The primary outcome was incidence of VTE during NACT. Secondary outcomes were risk factors for VTE and overall survival. Data related to patient demographics, cancer treatment, and incidence of VTE were collected. Statistical analyses included Kaplan-Meier estimates and univariate and multivariate Cox regression analysis.

RESULTS

A total of 284 patients were included in this study. Average age at diagnosis was 63.8 years. The incidence of VTE during NACT was 13.3%. Patients with VTE were less likely to undergo interval debulking surgery (58.3%) than patients without VTE (78.6%). Kaplan-Meier estimates demonstrated a decrease in overall survival in patients who had VTE during NACT (15.0 mo; 95% CI 14.5-16.5) compared with patients who did not (26.8 mo; 95% CI 22.8-30.9) (P < 0.0001). Multivariate analysis identified albumin <35 g/L, BMI >30 kg/m², and non-serous histology as risk factors for VTE.

CONCLUSION

The risk of VTE in this cohort was 13.3%, which was associated with decreased overall survival. These findings suggest that thromboprophylaxis may have a role in this patient population.

Survival and recurrence after intraperitoneal chemotherapy use: Retrospective review of ovarian cancer hospital registry data

Background

Intraperitoneal/intravenous chemotherapy (IP/IV) was associated with improved survival for ovarian cancer (OC) patients in several randomized clinical trials. However, the uptake of IP/IV in clinical practice is varied due to conflicting evidence about its impact on survival and recurrence. The aim of this study was to explore the uptake of IP/IV treatment and to evaluate its impact on survival and recurrence in OC patients.

Methods

Demographic and clinical information on OC patients (N = 2916) who underwent treatment for OC between 2000 and 2017 was obtained from the large healthcare system cancer registry. Duplicate records, grade 1, rare (eg, gelatinous carcinoma), and non‐epithelial (eg, granulosa cell carcinoma) tumors were excluded. Kaplan‐Meier survival curves were constructed to compare 5‐ and 10‐year survival based on the chemotherapy type, surgery type, and stage. Multivariable Gray's piecewise constant time‐varying coefficient models were fitted to evaluate the effect of IP/IV on adjusted hazard ratio (AHR) of OC survival and recurrence adjusting for potential confounders.

Results

The final sample consisted of 1846 OC patients, 14% (250/1846) of which received IP/IV chemotherapy. IP/IV was significantly associated with improved 10‐year survival (P < .001). Multivariable Gray's model demonstrated that IP/IV therapy significantly reduced the AHR of death (AHR = 0.39‐1.07, P < .001) with the beneficial effect gradually declining over time. Use of IP/IV chemotherapy had no impact on OC recurrence.

Conclusions

These findings demonstrated that only a small fraction of eligible patients underwent IP/IV chemotherapy. We report a significant 10‐year survival, but not necessarily recurrence benefit is associated with IP/IV chemotherapy compared to IV only, suggesting the need for novel ways of identifying patients who may benefit from IP/IV chemotherapy.

Systemic therapy for non-serous ovarian carcinoma

Ovarian cancer is one of the top ten most common cancers in women around the world, with high-grade serous epithelial cancer being the most frequent type. However, around a quarter of cases consist of non-serous epithelial ovarian cancer (EOC), which is a heterogeneous group of malignancies that includes endometroid, mucinous, clear cell carcinoma (CCC), and carcinosarcoma. Another relevant group of nonepithelial tumors are those arising from germ cells or sex-cord stromal cells, which account for about 10% of all ovarian cancers. Although there are similarities in the presentation, evaluation, and management of these tumors, they have unique characteristics in terms of epidemiology, tumor biology, tumor marker expression, and response to treatment, warranting a different approach to each one of them. Collectively, the treatment of most of EOC include surgical cytoreduction followed by adjuvant systemic platinum-based chemotherapy. The most common chemotherapy and route of administration for systemic treatment is paclitaxel plus carboplatin given intravenously. However, the treatment of EOC has been rapidly evolving and emerging targeted therapies such as poly (adenosine diphosphate-ribose) polymerase inhibitors, immune checkpoint inhibitors, and antiangiogenic agents are also available. On the other hand, non-EOC responds well to combination chemotherapy used to treat testicular cancer (bleomycin, etoposide, cisplatin) and has a good prognosis. Frontline chemotherapeutic regimen selection differs according to histological subtype, molecular alterations, and patient characteristics. Here, we review specific characteristics of non-serous and non-EOC emphasizing the peculiarities of systemic therapy for each subtype.