Predictive value of serum CA-125 levels in patients with persistent or recurrent epithelial ovarian cancer or peritoneal cancer treated with bevacizumab on a Gynecologic Oncology Group phase II trial

Treatment outcome analysis of bevacizumab combined with cyclophosphamide and oxaliplatin in advanced pseudomyxoma peritonei

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare peritoneal malignant tumor syndrome. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is its standard treatment. However, there are few studies and insufficient evidence regarding systemic chemotherapy of advanced PMP. Regimens for colorectal cancer are often used clinically, but there is no uniform standard for late-stage treatment.

AIM

To determine if bevacizumab combined with cyclophosphamide and oxaliplatin (Bev+CTX+OXA) is effective for treatment of advanced PMP. The primary study endpoint was progression-free survival (PFS).

METHODS

Retrospective analysis was conducted on the clinical data of patients with advanced PMP who received Bev+CTX+OXA regimen (bevacizumab 7.5 mg/kg ivgtt d1, oxaliplatin 130 mg/m² ivgtt d1 and cyclophosphamide 500 mg/m² ivgtt d1, q3w) in our center from December 2015 to December 2020. Objective response rate (ORR), disease control rate (DCR) and incidence of adverse events were evaluated. PFS was followed up. Kaplan-Meier method was used to draw survival curve, and log-rank test was used for comparison between groups. Multivariate Cox proportional hazards regression model was used to analyze the independent influencing factors of PFS.

RESULTS

A total of 32 patients were enrolled. After 2 cycles, the ORR and DCR were 3.1% and 93.7%, respectively. The median follow-up time was 7.5 mo. During the follow-up period, 14 patients (43.8%) had disease progression, and the median PFS was 8.9 mo. Stratified analysis showed that the PFS of patients with a preoperative increase in CA125 (8.9 vs 2.1, P = 0.022) and a completeness of cytoreduction score of 2-3 (8.9 vs 5.0, P = 0.043) was significantly longer than that of the control group. Multivariate analysis showed that a preoperative increase in CA125 was an independent prognostic factor for PFS (HR = 0.245, 95%CI: 0.066-0.904, P = 0.035).

CONCLUSION

Our retrospective assessment confirmed that the Bev+CTX+OXA regimen is effective in second- or posterior-line treatment of advanced PMP and that adverse reactions can be tolerated. A preoperative increase in CA125 is an independent prognostic factor of PFS.

Pazopanib based oral metronomic therapy for platinum resistant/refractory epithelial ovarian cancer: A phase II, open label, randomized, controlled trial

BACKGROUND

Treatment of patients with platinum resistant/refractory epithelial ovarian cancer (EOC) is an unmet need. We evaluated the role of oral metronomic therapy in this setting.

PATIENTS AND METHODS

Between October 2017 and September 2019 seventy five patients with platinum resistant/refractory EOC were enrolled. Patients received oral etoposide (50 mg, day 1 to 14, cyclophosphamide 50 mg, day 1 to 28, every 4 weeks (Arm A, n = 38). Patients in Arm- B (n = 37) received Pazopanib (400 mg once daily) in addition to etoposide and cyclophosphamide. Quality of life (QoL) was evaluated using the EORTC questionnaire. Serum VEGF and PDGF were estimated at baseline, after 3rd and 6th cycle. The primary endpoint was progression free survival (PFS). Secondary endpoints were overall survival (OS), toxicity and QoL.

RESULTS

Patients characteristics were well matched. Median PFS was higher in arm B, 5.1 months (95% CI 3.13 to10.33) compared to 3.4 months (95% CI 3.0 to 6.53) in arm A, p = 0.045. Median OS has 'not reached' in Arm B compared to 11.2 months (95% CI, 5.66 - not reached) in arm A, p = 0.032. Therapy was tolerated well; oral mucositis (p = 0.36) and fatigue (p = 0.08) being more in arm B. QoL assessment revealed modest improvement in 'symptom scales' in Arm B. Serum VEGF and PDGF levels decreased with therapy in both arms (Arm A-p < 0.0001, Arm B-p < 0.016).

CONCLUSION

Addition of pazopanib to etoposide and cyclophosphamide could be a novel oral combination for metronomic therapy for platinum resistant/refractory EOC.

TRIAL REGISTRATION

CTRI/2017/10/010219.

Prognostic relevance of high pretreatment CA125 levels in primary serous ovarian cancer

The objective of the present study was to analyze the prognostic relevance of pretreatment serum CA125 ≥500 U/ml and its role as a non-invasive factor for estimating optimal cytoreduction (≤1 cm) in primary serous ovarian cancer. Clinicopathological parameters and CA125 levels prior to primary cytoreductive surgery were retrospectively evaluated in all 261 consecutive patients with primary epithelial ovarian cancer from a single centre. Inclusion criteria were existing preoperative CA125 level, serous ovarian cancer and performed full primary treatment (surgery/platinum-based chemotherapy). A total of 136 patients met the criteria. Among them, 74 patients had CA125 ≥500 U/ml. The other 62 patients that met the aforementioned criteria and had CA125 <500 U/ml were defined as controls. The present study tested cut-off CA125 values to detect subgroups affecting prognosis. The goal was to evaluate patients with optimal cytoreduction (R≤1 cm). Univariate analyses were performed with PASW to identify clinicopathological parameters associated with the pretreatment CA125 level. For survival analyses, a cut-off-value of CA125 ≥500 U/ml was used to identify the association between preoperative CA125 levels, resection status and prognosis. To test significant differences between examined groups, Student's t-test and the Mann-Whitney test were used. P<0.05 was considered to indicate a statistically significant difference. Significantly worse prognosis in terms of overall survival (P=0.023) and progression-free survival (P=0.011) was detected in the CA125 ≥500 U/ml group of optimally cytoreduced patients compared with in the CA125 <500 U/ml group. The complete cytoreduction rate was higher in CA125 <500 U/ml (33.9%) vs. CA125 ≥500 U/ml (21.6%). A CA125 level >1,404 U/ml had a higher rate of suboptimal cytoreduction (32.4%) compared with lower CA125 levels. A pretreatment CA125 level ≥500 U/ml had significantly worse prognostic impact after optimal cytoreduction compared with CA125 <500 U/ml. The higher the CA125 level the higher the suboptimal cytoreduction rate. Patients with CA125 ≥500 U/ml may be candidates for an initial laparoscopic approach to specify resectability and to determine how to proceed. Overall, CA125 levels appear to be helpful in predicting suboptimal cytoreductive surgery for patients with primary ovarian cancer, but should be interpreted together with clinical and radiologic findings. This may improve defining the optimal treatment strategy in these patients.

Bevacizumab use in the frontline, maintenance and recurrent settings for ovarian cancer

On 13 June 2018, Genentech, Inc. issued a press release announcing that the US FDA had approved the antiangiogenesis drug, bevacizumab, in combination with chemotherapy for frontline and maintenance therapy for women with newly diagnosed ovarian cancer. Regulatory approval was based on the National Cancer Institute-sponsored Gynecologic Oncology Group (GOG) protocol 0218, the Phase III, randomized, placebo-controlled, double-blind, multi-center and multi-national clinical trial that met its primary end point, progression-free survival. Bevacizumab is now approved in the frontline, platinum-sensitive recurrent and platinum-resistant recurrent settings for epithelial ovarian cancer. This review will address the broad range of clinical trials addressing the efficacy of bevacizumab use in ovarian cancer.

Profile of bevacizumab in the treatment of platinum-resistant ovarian cancer: current perspectives

Patients with platinum-resistant ovarian cancer have progression of disease within 6 months of completing platinum-based chemotherapy. While several chemotherapeutic options exist for the treatment of platinum-resistant ovarian cancer, the overall response to any of these therapies is ~10%, with a median progression-free survival of 3–4 months and a median overall survival of 9–12 months. Bevacizumab (Avastin), a humanized, monoclonal antivascular endothelial growth factor antibody, has demonstrated antitumor activity in the platinum-resistant setting and was recently approved by US Food and Drug Administration for combination therapy with weekly paclitaxel, pegylated liposomal doxorubicin, or topotecan. This review summarizes key clinical trials investigating bevacizumab for recurrent, platinum-resistant ovarian cancer and provides an overview of efficacy, safety, and quality of life data relevant in this setting. While bevacizumab is currently the most studied and clinically available antiangiogenic therapy, we summarize recent studies highlighting novel alternatives, including vascular endothelial growth factor-trap, tyrosine kinase inhibitors, and angiopoietin inhibitor trebananib, and discuss their application for the treatment of platinum-resistant ovarian cancer.

Current approaches and challenges in managing and monitoring treatment response in ovarian cancer

Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Treatment of recurrent ovarian cancer remains a challenge despite advances in surgical and chemotherapeutic options. A goal of many providers is to detect recurrences as early as possible and initiate treatment though there is controversy as to whether this impacts outcome. Elevations in CA125 and radiological findings may precede symptoms of recurrence by several months. While detection of recurrences by physical exam alone is unusual, a thorough exam in conjunction with reported symptoms and elevated CA125 is sufficient to detect 80-90% of recurrences. A spiral CT scan may be used to confirm recurrence in the setting of asymptomatic CA125 elevation and a PET/CT can yield additional insight if the CT is inconclusive. Initiating chemotherapy prior to the development of symptoms, even in the setting of elevated CA125, does not impact overall survival primarily because the efficacy of available treatments in the recurrent setting is poor. More information about tumor biology and ways to predict which patients will benefit from available treatment options is required. Consequently, the approach to post-treatment surveillance should be individualized taking into account the clinical benefit of the second-line therapy, versus the costs and morbidity of the surveillance method.

Current status of bevacizumab in advanced ovarian cancer

Ovarian cancer is the most lethal gynecological cancer, mainly because of the delay in diagnosis. Recently, much effort has been put into investigating and introducing novel targeted agents into clinical practice, with the aim of improving prognosis and quality of life. Angiogenesis is a possible target. The aim of this review is to investigate the most common molecular pathways of angiogenesis, which have provided novel targets for tailored therapy in patients with ovarian cancer. These therapeutic strategies include monoclonal antibodies and tyrosine-kinase inhibitors. These drugs have as molecular targets vascular endothelial growth factor, vascular endothelial growth factor receptors, platelet-derived growth factor, fibroblast growth factor, and angiopoietin. Bevacizumab was investigated in several Phase III studies, with interesting results. Today, there is strong evidence for introducing bevacizumab in the treatment of patients with advanced and recurrent ovarian cancer. Nevertheless, further investigations and large clinical trials are needed to understand the safety and effectiveness of bevacizumab, the optimal duration and timing of treatment, and activity in association with other chemotherapeutic and targeted agents. It also is necessary to identify biologic factors predictive of efficacy to choose the most appropriate antiangiogenic agent in the integrated treatment of epithelial ovarian cancer.

The combination of intravenous bevacizumab and metronomic oral cyclophosphamide is an effective regimen for platinum-resistant recurrent ovarian cancer

OBJECTIVE

To determine the efficacy, progression-free survival (PFS) and overall survival (OS) for the combination of intravenous bevacizumab and oral cyclophosphamide in heavily pretreated patients with recurrent ovarian carcinoma.

METHODS

A retrospective review was performed for all patients with recurrent ovarian carcinoma treated with intravenous bevacizumab 10 mg/kg every 14 days and oral cyclophosphamide 50 mg daily between January 2006 and December 2010. Response to treatment was determined by Response Evaluation Criteria in Solid Tumors criteria and/or CA-125 levels.

RESULTS

Sixty-six eligible patients were identified. Median age was 53 years. Fifty-five patients (83%) had undergone optimal cytoreduction. All patients were primarily or secondarily platinum resistant at the time of administration of bevacizumab and cyclophosphamide. The median number of prior chemotherapy treatments was 6.5 (range, 3 to 16). Eight patients (12.1%) had side effects which required discontinuation of bevacizumab and cyclophosphamide. There was one bowel perforation (1.5%). Overall response rate was 42.4%, including, complete response in 7 patients (10.6%), and partial response in 21 patients (31.8%), while 15 patients (22.7%) had stable disease and 23 patients (34.8%) had disease progression. Median PFS for responders was 5 months (range, 2 to 14 months). Median OS from initiation of bevacizumab and cyclophosphamide was 20 months (range, 2 to 56 months) for responders and 9 months (range, 2 to 51 months) for non-responders (p=0.004).

CONCLUSION

Bevacizumab and cyclophosphamide is an effective, well-tolerated chemotherapy regimen in heavily pretreated patients with recurrent ovarian carcinoma. This combination significantly improved PFS and OS in responders. Response rates were similar and favorable to the rates reported for similar patients receiving other commonly used second-line chemotherapeutic agents.

Recurrence patterns after extended treatment with bevacizumab for ovarian, fallopian tube, and primary peritoneal cancers

OBJECTIVE

To evaluate patterns of recurrence for ovarian, fallopian tube, and primary peritoneal cancer patients undergoing extended treatment with bevacizumab (BEV).

METHODS

A retrospective review of patients with primary ovarian, fallopian tube, or peritoneal cancer treated with BEV alone or in combination with other chemotherapy from 2001 to 2011 was performed. Qualified patients were identified by chemotherapy records. Electronic medical records, labs, and imaging reports were reviewed and abstracted.

RESULTS

Of 108 patients identified, 89 patients met study criteria by having disease progression either during treatment with BEV or after discontinuing BEV without initiating any other treatment. Patients on extended BEV therapy (>12 cycles) were more likely to recur in extra-visceral sites (p=0.04), especially in lymph nodes (p=0.0002), and presented with fewer symptoms at time of recurrence (p=0.02), compared to patients who had received ≤ 12 cycles. CA-125 becomes less reliable for the detection of recurrent disease with extended BEV therapy (p=0.03 for ≤12 cycles vs. p=0.08 for >12 cycles). Radiology was superior to CA-125, symptom, and physical exam, in detecting recurrence with extended BEV therapy (all p<0.0001).

CONCLUSIONS

Extended treatment with BEV in ovarian, fallopian tube, and peritoneal cancers results in alterations in the patterns of recurrence. Radiologic imaging is more reliable than CA-125, symptoms, or physical exam, in identifying recurrent disease in patients undergoing BEV treatment. As novel targeted therapies continue to be employed, guidelines for gynecologic cancer surveillance must continue to be reexamined.

Antiangiogenic agents as a maintenance strategy for advanced epithelial ovarian cancer

Bevacizumab is the first antiangiogenic agent to have demonstrated benefit as first-line and maintenance therapy in epithelial ovarian cancer (EOC), with the Gynecologic Oncology Group 218 and ICON 7 phase III trials revealing significantly prolonged progression-free survival (PFS) for carboplatin/paclitaxel plus bevacizumab followed by bevacizumab maintenance versus carboplatin/paclitaxel alone. Results are forthcoming from several phase III maintenance trials of investigational antiangiogenic agents, each evaluating PFS as the primary endpoint: AGO-OVAR12/LUME-Ovar1 (nintedanib [BIBF 1120]), AGO-OVAR16 (pazopanib), and TRINOVA-1, -2, and -3 (AMG 386). Here we review available data and ongoing clinical trials of investigational antiangiogenic agents as maintenance therapy for EOC. Current controversies, including uncertainties regarding the (1) most appropriate clinical trial endpoints, (2) optimal dosing, duration, and timing of therapy (e.g., with first-line chemotherapy and/or as maintenance monotherapy), and (3) feasibility, tolerability, and cost of adding these agents to platinum/taxane regimens are also highlighted.