Treatment of Recurrent Low-grade Serous Ovarian Cancer With MEK Inhibitors: A Systematic Review

OBJECTIVE

Low-grade serous ovarian cancer (LGSC) represents 5% of all epithelial ovarian cancers. They are characterized by indolent growth and KRAS and BRAF mutations, differing from high-grade serous ovarian cancer both clinically and molecularly. LGSC has low response rates to traditional systemic therapies, including chemotherapy and hormonal therapy. The objective of this systematic review was to appraise the literature describing the efficacy of MEK inhibitors in the treatment of LGSC.

METHODS

A comprehensive search was conducted of the following databases: Medline ALL, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Sciences, ClinicalTrials.gov, International Clinical Trials Registry Platform (ICFRP), and International Standard Randomized Controlled Trials Number (ISRCTN) Registry. All studies investigating MEKi in the treatment of LGSC in the adjuvant or recurrent setting for patients 18 years of age or older were included. All titles/abstracts were then screened by 2 independent reviewers (A.K. and C.C.). The full-text articles were then screened. All disagreements were resolved by a third independent reviewer (T.Z.). Two independent reviewers (A.K. and C.C.) extracted data from the studies deemed eligible for final review.

RESULTS

A total of 2108 studies were identified in the initial search. Of these, a total of 4 studies met the eligibility criteria for systematic review. In these studies, 416 patients were treated with an MEKi alone. All patients included in the studies were being treated for LGSC in the recurrent setting. Varied results and efficacy of the MEKi were reported in each study.

CONCLUSIONS

The results highlighted in this systematic review demonstrate varied responses to MEKi for recurrent LGSC. Further research is needed in this field comparing the efficacy to current therapies, as well as to further evaluate the safety and toxicity profile with long-term use of MEKi.

Bevacizumab Treatment for Low-Grade Serous Ovarian Cancer: A Systematic Review

Serous epithelial ovarian cancer, classified as either high-grade (90%) or low-grade (10%), varies in molecular, histological, and clinicopathological presentation. Low-grade serous ovarian cancer (LGSOC) is a rare histologic subtype that lacks disease-specific evidence-based treatment regimens. However, LGSOC is relatively chemo-resistant and has a poor response to traditional treatments. Alternative treatments, including biologic therapies such as bevacizumab, have shown some activity in LGSOC. Thus, the objective of this systematic review is to determine the effect and safety of bevacizumab in the treatment of LGSOC. Following PRISMA guidelines, Medline ALL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase all from the OvidSP platform, ClinicalTrials.gov, International Clinical Trials Registry Platform, International Standard Randomised Controlled Trial Number Registry were searched from inception to February 2022. Articles describing bevacizumab use in patients with LGSOC were included. Article screening, data extraction, and critical appraisal of included studies were completed by two independent reviewers. The effect of bevacizumab on the overall response rate, progression-free survival, overall survival, and adverse effects were summarized. The literature search identified 3064 articles, 6 of which were included in this study. A total of 153 patients were analyzed; the majority had stage IIIC cancer (56.2%). The overall median response rate reported in the studies was 47.5%. Overall, bevacizumab is a promising treatment for LGSOC, with response rates higher than traditional treatment modalities such as conventional chemotherapy, and is often overlooked as a treatment tool. A prospective clinical trial evaluating the use of bevacizumab in LGSOC is necessary to provide greater evidence and support these findings.

Canadian Guideline on the Management of a Positive Human Papillomavirus Test and Guidance for Specific Populations

The purpose of this paper is to provide evidence-based guidance on the management of a positive human papilloma virus (HPV) test and to provide guidance around screening and HPV testing for specific patient populations. The guideline was developed by a working group in collaboration with the Gynecologic Oncology Society of Canada (GOC), Society of Colposcopists of Canada (SCC), and the Canadian Partnership Against Cancer. The literature informing these guidelines was obtained through a systematic review of relevant literature by a multi-step search process led by an information specialist. The literature was reviewed up to July 2021 with manual searches of relevant national guidelines and more recent publications. The quality of the evidence and strength of recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. The intended users of this guideline include primary care providers, gynecologists, colposcopists, screening programs, and healthcare facilities. The implementation of the recommendations will ensure an optimum implementation of HPV testing with a focus on the management of positive results. Recommendations for appropriate care for underserved and marginalized groups are made.

Identifying Borderline Ovarian Tumor Recurrence Using Routine Ultrasound Follow-Up

Borderline ovarian tumors (BOTs) are non-invasive tumors frequently diagnosed in young patients. Surgical removal of the uterus, fallopian tubes, ovaries, and omentum is considered definitive management, however fertility-sparing approach is a recognized option. Surveillance is important due to known recurrence, but there is controversy over the effectiveness of follow-up modalities. The objective is to determine the efficacy of ultrasound screening in identifying tumor recurrence. This retrospective chart review evaluated all patients consulted and/or treated surgically at our institution from January 2015 to June 2020 diagnosed with BOT. Patients were excluded if concurrently diagnosed with another gynecologic malignancy, did not have yearly ultrasound follow-up, or were lost to follow-up. This study included 56 patients, 17 of whom underwent fertility preserving surgery. The overall rate of recurrence was 10.7%; with recurrence rates of 23.5% for the fertility preserving surgery population and 5.1% for the definitive surgery population. Ultrasound first identified 5 of the 6 (83.3%) recurrences. Overall time to recurrence was 51.5 months. In conclusion, recurrences were identified on routine ultrasound screening prior to symptom onset or detection via physical exam in 83.3% of cases. While the best modality of follow-up remains controversial, this review provides evidence supporting the use of routine ultrasound follow-up for early detection of BOT recurrence.

Innovations in the Management of Vaginal Cancer

Primary vaginal cancer is a rare gynecologic malignancy. Given the rarity of the disease, standardized approaches to management are limited, and a great variety of therapeutic conditions are endorsed. This paper reviews advances in surgical approaches, radiation, chemoradiation, and immunotherapy. Advances in surgical management including the increasing use of laparoscopic and endoscopic approaches, as well as the novel techniques in vaginal reconstruction, are reviewed. Concurrent chemoradiation remains a mainstay of treatment for vaginal cancer and has improved local control of disease and overall survival. Additionally, with metastatic disease or situations where toxicity from CCRT is unacceptable, systemic therapies including immunotherapy approaches are reviewed.

Does Radical Hysterectomy for Clinically Apparent Stage II Endometrial Cancer Affect Risk of Local Recurrence?

OBJECTIVE

Compare recurrence-free survival (RFS) and morbidity between radical hysterectomy (RH) and simple hysterectomy (SH) for clinically diagnosed stage II endometrial cancer.

METHODS

A multicentre, retrospective study, from 2000 to 2015, involving patients with endometrial cancer with cervical involvement preoperatively and stromal invasion on final pathology. Wilcoxon rank-sum test, Fisher exact test, Kaplan-Meier survival functions, and Cox proportional hazards models were used for analysis.

RESULTS

Ninety of 1613 patients had clinical stage II endometrial cancer; 57 underwent RH and 33 underwent SH, with no difference in adjuvant treatment or morbidity. About half of patients (51%) had pathologic stage III-IV disease. Mean follow-up was 3.3 and 3.8 years for SH and RH, respectively. Thirty-three percent of patients with RH and SH experienced a recurrence. Most recurrences were distant: 90% with SH and 79% with RH. There was no difference in RFS between groups (2-year: SH 65% vs. RH 75%; 5-year: SH 54% vs. RH 63%; P = 0.72). Controlling for stage, adjuvant treatment, and margin status, RH was not associated with RFS (HR 0.62; 95% CI 0.28-1.35). Among 44 patients with pathologic stage II disease, 7 had a recurrence (4 SH and 3 RH); 6 of 7 had distant recurrences.

CONCLUSIONS

Fifty-one percent of patients with clinical stage II endometrial cancer had advanced disease on final pathology, highlighting the importance of surgical staging. RH was not associated with RFS or reduced morbidity. Most recurrences were distant. Although RH could be performed to achieve negative surgical margins, SH may be sufficient for central, small tumours given the high risk of advanced disease and distant recurrence. Research efforts should further elucidate the ideal management of these patients.

A comparison of mechanical properties of materials used in aortic arch reconstruction

BACKGROUND

Differences in the mechanical properties of aortic tissues and replacement materials can have unwanted hemodynamic effects leading to graft failure. The aim of this experimental study was to compare the mechanical properties of different graft-patch materials used in aortic arch reconstruction with those of healthy and dilated human ascending aortas (AAs).

METHODS

Four square samples were taken from 30 healthy (n = 120) and 14 dilated (n = 56) AA rings and from 34 human pericardial sections (fresh [n = 68] and Carpentiers solution fixed [n = 68]). In addition, square samples from commercial bovine pericardium (n = 14) were also compared with woven Dacron grafts (n = 24) and tested biaxially. Stress-strain curves (0% to 30%) were generated using a biaxial tensile tester to quantify the anisotropic properties and stiffness of the materials at 37 degrees C.

RESULTS

We found significant differences in stiffness and anisotropy among all material types. Fresh and fixed human pericardia, bovine pericardium, and Dacron were 9.5, 7.1, 16.4, and 18.4 times stiffer than dilated AAs, which was 1.3 times stiffer than healthy AAs under physiologic stretch. Only dilated and healthy AAs showed an increase in anisotropic properties with increasing strain.

CONCLUSIONS

The significant differences in the mechanical properties among all materials we found are intended to increase the awareness of these differences in materials used in aortic reconstruction surgery. This finding suggests that improvements are needed in prosthetic material design to better mimic native tissue.