Dealing with microscopic peritoneal metastases of epithelial ovarian cancer. A surgical challenge

Liquid biopsy in ovarian cancer in China and the world: current status and future perspectives

Ovarian cancer (OC) is the eighth most common cancer in women, but the mild, non-specific clinical presentation in early stages often prevents diagnosis until progression to advanced-stage disease, contributing to the high mortality associated with OC. While serum cancer antigen 125 (CA-125) has been successfully used as a blood-borne marker and is routinely monitored in patients with OC, CA-125 testing has limitations in sensitivity and specificity and does not provide direct information on important molecular characteristics that can guide treatment decisions, such as homologous recombination repair deficiency. We comprehensively review the literature surrounding methods based on liquid biopsies, which may provide improvements in sensitivity, specificity, and provide valuable additional information to enable early diagnosis, monitoring of recurrence/progression/therapeutic response, and accurate prognostication for patients with OC, highlighting applications of this research in China.

Ten-year treatment outcomes of consolidation hyperthermic intraperitoneal chemotherapy for ovarian cancer (HIPEC-KOV-03R)

OBJECTIVE

We aimed to evaluate the long-term efficacy of consolidation hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with primary epithelial ovarian cancer.

METHODS

This retrospective cohort study included patients who underwent second-look surgery either with or without HIPEC after having complete or partial response to primary cytoreductive surgery and adjuvant platinum-based chemotherapy between January 1991 and December 2003 at Seoul St. Mary's Hospital. The 10-year progression-free survival (PFS), overall survival (OS), and toxicity within postoperative 28 days were investigated.

RESULTS

A total of 87 patients were identified, 44 (50.6%) received second-look surgery with HIPEC whereas 43 (49.4%) received only second-look surgery. The 10-year PFS and OS were significantly longer in the HIPEC group compared with the control group (PFS, 53.6% vs. 34.9%, log-rank p=0.009; OS, 57.0% vs. 34.5%, log-rank p=0.025). Multivariable analysis identified HIPEC as an independent favorable prognostic factor for PFS (adjusted hazard ratio [HR]=0.42; 95% confidence interval [CI]=0.23-0.77; p=0.005) but not for OS (adjusted HR=0.58; 95% CI=0.32-1.07; p=0.079). The more common adverse events in the HIPEC group were thrombocytopenia (90.9% vs. 68.3%, p=0.005), elevated liver enzymes (65.9% vs. 29.3%, p=0.002), and wound complications (18.2% vs. 2.4%, p=0.032). However, these adverse events were reversible and did not delay subsequent consolidation chemotherapy.

CONCLUSION

The consolidation HIPEC demonstrated a significant improvement in 10-year PFS but not OS, with acceptable toxicity in patients with primary epithelial ovarian cancer. Further randomized controlled trials are warranted to confirm these results.

Folate Receptor Targeted Photodynamic Therapy: A Novel Way to Stimulate Anti-Tumor Immune Response in Intraperitoneal Ovarian Cancer

Photodynamic therapy (PDT) has shown improvements in cancer treatment and in the induction of a proper anti-tumor immune response. However, current photosensitizers (PS) lack tumor specificity, resulting in reduced efficacy and side effects in patients with intraperitoneal ovarian cancer (OC). In order to target peritoneal metastases of OC, which overexpress folate receptor (FRα) in 80% of cases, we proposed a targeted PDT using a PS coupled with folic acid. Herein, we applied this targeted PDT in an in vivo mouse model of peritoneal ovarian carcinomatosis. The efficacy of the treatment was evaluated in mice without and with human peripheral blood mononuclear cell (PBMC) reconstitution. When mice were reconstituted, using a fractionized PDT protocol led to a significantly higher decrease in the tumor growth than that obtained in the non-reconstituted mice (p = 0.0469). Simultaneously, an immune response was reflected by an increase in NK cells, and both CD4+ and CD8+ T cells were activated. A promotion in cytokines IFNγ and TNFα and an inhibition in cytokines TGFβ, IL-8, and IL-10 was also noticed. Our work showed that a fractionized FRα-targeted PDT protocol is effective for the treatment of OC and goes beyond local induction of tumor cell death, with the promotion of a subsequent anti-tumor response.

Can fluorescence-guided surgery improve optimal surgical treatment for ovarian cancer? A systematic scoping review of clinical studies

BACKGROUND

The predicament of achieving optimal surgical intervention faced by surgeons in treating ovarian cancer has driven research into improving intra-operative detection of cancer using fluorescent materials.

OBJECTIVE

To provide a literature overview on the clinical use of intra-operative fluorescence-guided surgery for ovarian cancer, either for cytoreductive surgery or sentinel lymph node (SLN) biopsy.

METHODS

The systematic review included studies from June 2002 until October 2021 from PubMed, Web of Science, and Scopus as well as those from a search of related literature. Studies were included if they investigated the use of fluorescence-guided surgery in patients with a diagnosis of ovarian cancer. Authors charted variables related to study characteristics, patient demographics, baseline clinical characteristics, fluorescence-guided surgery material, and treatment details, and surgical, oncological, and survival outcome variables. After screening 2817 potential studies, 24 studies were included.

RESULTS

Studies investigating the role of fluorescence-guided surgery to visualize tumor deposits or SLN biopsy included the data of 410 and 118 patients, respectively. Six studies used indocyanine green tracer with a mean SLN detection rate of 92.3% with a pelvic and para-aortic detection rate of 94.8% and 96.7%, respectively. The sensitivity, specificity, and positive predictive value for micrometastases detection of OTL38 and 5-aminolevulinc acid at time of cytoreduction were 92.2% vs 79.8%, 67.3% vs 94.8%, and 55.8% vs 95.8%, respectively.

CONCLUSION

Fluorescence -guided surgery is a technique that may improve the detection rate of micrometastases and SLN identification in ovarian cancer. Further research is needed to establish whether this will lead to improved patient outcomes.

Evaluation of serum CA125-Tn glycoform in peritoneal dissemination and surgical completeness of high-grade serous ovarian cancer

BACKGROUND

Peritoneal dissemination is the predominant feature of malignant progression in ovarian cancer and is a major cause of poor surgical outcomes and clinical prognoses. Abnormal glycosylation of carbohydrate antigen 125 (CA125) may be involved in peritoneal implantation and metastasis. Here, we evaluated the clinical relevance of CA125-Tn glycoform in the assessment of high-grade serous ovarian cancer (HGSOC).

METHODS

A total of 72 patients diagnosed with HGSOC were included. Pre-treatment serum CA125-Tn levels were measured using an antibody-lectin enzyme-linked immunosorbent assay. The association of CA125-Tn with clinical factors was analyzed in all cases, whereas its association with peritoneal dissemination, residual disease, and progression-free survival was analyzed in stage III-IV cases.

RESULTS

Pre-treatment serum CA125-Tn levels were significantly higher in advanced-stage HGSOC patients than in early-stage patients (P = 0.029). In advanced-stage patients, the pre-treatment CA125-Tn level increased with an increase in Fagotti's score (P = 0.004) and with the extension of peritoneal dissemination (P = 0.011). The pre-treatment CA125-Tn level increased with the volume of residual disease (P = 0.005). The association between CA125-Tn level and suboptimal surgery remained significant even after adjustment for treatment type and stage. Pre-treatment CA125-Tn levels were also related to disease recurrence.

CONCLUSION

Serum CA125-Tn level could be a novel biomarker for peritoneal dissemination and a promising predictor of surgical completeness in ovarian cancer. Patients with lower CA125-Tn levels were more likely to have no residual disease. CA125-Tn could help surgeons to adopt optimized treatment strategies for patients with advanced ovarian cancer as a pre-treatment evaluator.

Residual Microscopic Peritoneal Metastases after Macroscopic Complete Cytoreductive Surgery for Advanced High-Grade Serous Ovarian Carcinoma: A Target for Folate Receptor Targeted Photodynamic Therapy?

Despite conventional treatment combining complete macroscopic cytoreductive surgery (CRS) and systemic chemotherapy, residual microscopic peritoneal metastases (mPM) may persist as the cause of peritoneal recurrence in 60% of patients. Therefore, there is a real need to specifically target these mPM to definitively eradicate any traces of the disease and improve patient survival. Therapeutic targeting method, such as photodynamic therapy, would be a promising method for such a purpose. Folate receptor alpha (FRα), as it is specifically overexpressed by cancer cells from various origins, including ovarian cancer cells, is a good target to address photosensitizing molecules. The aim of this study was to determine FRα expression by residual mPM after complete macroscopic CRS in patients with advanced high-grade serous ovarian cancer (HGSOC). A prospective study conducted between 1 June 2018 and 10 July 2019 in a single referent center accredited by the European Society of Gynecological Oncology for advanced EOC surgical management. Consecutive patients presenting with advanced HGSOC and eligible for complete macroscopic CRS were included. Up to 13 peritoneal biopsies were taken from macroscopically healthy peritoneum at the end of CRS and examined for the presence of mPM. In case of detection of mPM, a systematic search for RFα expression by immunohistochemistry was performed. Twenty-six patients were included and 26.9% presented mPM. In the subgroup of patients with mPM, FRα expression was positive on diagnostic biopsy before neoadjuvant chemotherapy for 67% of patients, on macroscopic peritoneal metastases for 86% of patients, and on mPM for 75% of patients. In the subgroup of patients with no mPM, FRα expression was found on diagnostic biopsy before neoadjuvant chemotherapy in 29% of patients and on macroscopic peritoneal metastases in 78% of patients. FRα is well expressed by patients with or without mPM after complete macroscopic CRS in patients with advanced HGSOC. In addition to conventional cytoreductive surgery, the use of a therapeutic targeting method, such as photodynamic therapy, by addressing photosensitizing molecules that specifically target FRα may be studied.

Fluorescence guided surgery to improve peritoneal cytoreduction in epithelial ovarian cancer: A systematic review of available data

During surgery for advanced epithelial ovarian cancer (EOC), the most important prognostic factor is the absence of residual tumor. Invisible microscopic peritoneal metastasis (mPM) are not removed during surgery and can be responsible of peritoneal recurrences. The aim of this current systematic review is to assess the role of fluorescence in evaluating mPM in EOC. We performed a systematic review using bibliographic citations from PubMed, Clinical Trials.gov, Embase, Cochrane Library, and Web of Science databases. MeSH terms for fluorescence, EOC and peritoneal carcinomatosis were combined and not restricted to the English language. The final search was performed on September 1rst, 2021. The primary outcome was to determine the diagnostic accuracy of fluorescence. We also reviewed the different techniques used. Eighty-seven studies were identified. Of these, 10 were included for analysis. The sensitivity and specificity of fluorescence ranged between 66.7-100% and 54.2-100%, respectively. Most importantly, the negative predictive value (NPV) ranged from 90 to 100% Due to the heterogeneity of the studies, no consensus was reached concerning the optimal use of fluorescence in terms of type of dye, type and timing of injection and imager to use. No adverse event was reported. Fluorescence can safely be used in EOC to evaluate mPM with a high NPV. However, a randomized controlled trial is needed to homogenize current practice.

Tumor-Specific Imaging with Angiostamp800 or Bevacizumab-IRDye 800CW Improves Fluorescence-Guided Surgery over Indocyanine Green in Peritoneal Carcinomatosis

Complete surgical removal of lesions improves survival of peritoneal carcinomatosis and can be enhanced by intraoperative near-infrared fluorescence imaging. Indocyanine green (ICG) is the only near-infrared fluorescent dye approved for clinical use, but it lacks specificity for tumor cells, highlighting the need for tumor-selective targeting agents. We compared the tumor-specific near-infrared fluorescent probes Bevacizumab-IRDye 800CW and Angiostamp800, which target tumor angiogenesis and cancer cells, to ICG for fluorescence-guided surgery in peritoneal carcinomatosis of ovarian origin. The probes were administered to mice with orthotopic peritoneal carcinomatosis prior to conventional and fluorescence-guided surgery. The influence of neoadjuvant chemotherapy was also assessed. Conventional surgery removed 88.0 ± 1.2% of the total tumor load in mice. Fluorescence-guided surgery allowed the resection of additional nodules, enhancing the total tumor burden resection by 9.8 ± 0.7%, 8.5 ± 0.8%, and 3.9 ± 1.2% with Angiostamp800, Bevacizumab-IRDye 800CW and ICG, respectively. Interestingly, among the resected nodules, 15% were false-positive with ICG, compared to only 1.4% with Angiostamp800 and 3.5% with Bevacizumab-IRDye 800CW. Furthermore, conventional surgery removed only 69.0 ± 3.9% of the total tumor burden after neoadjuvant chemotherapy. Fluorescence-guided surgery with Angiostamp800 and Bevacizumab-IRDye 800CW increased the total tumor burden resection to 88.7 ± 4.3%, whereas ICG did not improve surgery at all. Bevacizumab-IRDye 800CW and Angiostamp800 better detect ovarian tumors and metastases than the clinically used fluorescent tracer ICG, and can help surgeons completely remove tumors, especially after surgery neoadjuvant chemotherapy.

Photosensitized co-generation of nitric oxide and singlet oxygen Enhanced toxicity against ovarian cancer cells

Near micromolar concentrations of nitric oxide (NO) induce tumor cells death. However, an appropriate NO load has to be delivered selectively to the tumor site in order to avoid NO loss and secondary NO-induced effects. The encapsulation of millimolar concentrations of a NO source and an appropriate trigger of NO release within phospatidylcholine-based liposomes should provide an efficient tool for the selective release of the needed NO payload. In this work we report the photosensitized generation of singlet oxygen and NO from folate-targeted PEGylated liposomes, containing AlPcS4 as the sensitizer and S-nitrosoglutathione (GSNO), in millimolar amounts, as the NO source. Amounts of singlet oxygen detected outside the liposome when using PEGylated liposomes are near 200 % larger when GSNO is present inside the liposomes as compared to its absence. These liposomes, conjugated to folate, were found to enhance the photosensitized cytotoxicity to A2780CP20 ovarian cancer cells as compared to liposomes containing the sensitizer but no GSNO (30 % as compared to 70 % cell viability) under the conditions of this work. Fluorescense of AlPcS4 was observed inside cells incubated with folate-conjugated liposomes but not with liposomes without folate. The photosensitized activity enhancement by GSNO increased when light fluence or liposome concentration were increased. The majority of ovarian cancer patients are initially diagnosed with disseminated intra-abdominal disease (stages III-IV) and have a 5-year survival of less than 20%. This work suggests a novel ovarian cancer nodules treatment via the use of tumor-targeted liposome nanoparticles with the capability of generating simultaneously reactive oxygen and nitrogen species upon illumination with near-infrared light.

Confocal Imaging of Single-Cell Signaling in Orthotopic Models of Ovarian Cancer

Ovarian cancer (OVCA) is frequently detected at late stages of disease, often with dissemination throughout the peritoneal cavity surface, abdomen, and ascites fluid. Tumor signaling via mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) pathways can promote OVCA progression and depend on local microenvironmental cues. To better study OVCA in situ within native tissue contexts, here we describe confocal microscopy techniques to image mouse models of intraperitoneal disease at a single-cell resolution. As a proof of principle demonstration, examples are highlighted for simultaneously imaging tumor vascularization, infiltrating and often immunosuppressive immune cells (tumor-associated macrophages), and OVCA kinase activity.

Incomplete surgical staging in clinical early-stage ovarian cancer: guidelines versus daily practice

Background

Incomplete surgical staging of patients with early-stage epithelial ovarian cancer (EOC) has been reported in up to 98% of cases, when based on the International Federation of Obstetrics and Gynecology (FIGO) staging procedure. The aim of the present retrospective study was to clarify the reasons for incomplete staging.

Methods

The PRISMA (Prevention Recovery Information System for Monitoring and Analysis) technique was used to evaluate cases with FIGO I-IIa EOC based on incomplete staging from five gynecologic oncologic center hospitals in the Netherlands in the period 2010-2014.

Results

Fifty cases with an incomplete surgical staging of EOC according to national guidelines were included. The most common reasons for incomplete staging were insufficient random biopsies of the peritoneum (n = 34, 68%), and less than ten lymph nodes being resected and/or found at pathology (n = 16, 32%). The most mentioned reason for not performing biopsies was, besides forgetting to do so, believing that after careful inspection and palpation, taking biopsies is irrelevant and/or already are being taken while performing a hysterectomy (peritoneum of cul-de-sac, bladder). The value of contralateral pelvic lymph node dissection in case of a unilateral ovarian malignancy was also doubted, influencing the number of lymph nodes resected.

Conclusions

The most important reasons for incomplete staging in EOC are, besides omitting elements by accident, questioning the importance of obligatory elements of the staging procedure. A structured list of staging steps during surgery and more evidence-based consensus concerning these obligatory elements might increase the number of complete staging procedures in EOC.

Calcium Carbonate Microparticles as Carriers of 224Ra: Impact of Specific Activity in Mice with Intraperitoneal Ovarian Cancer

BACKGROUND

Patients with advanced-stage ovarian cancer face a poor prognosis because of recurrent peritoneal cavity metastases following surgery and chemotherapy. Alpha-emitters may enable the efficient treatment of such disseminated diseases because of their short range and highly energetic radiation. Radium-224 is a candidate α-emitter due to its convenient 3.6-day half-life, with more than 90% of the decay energy originating from α-particles. However, its inherent skeletal accumulation must be overcome to facilitate intraperitoneal delivery of the radiation dose. Therefore, ²²⁴Ra-labeled CaCO₃ microparticles have been developed.

OBJECTIVE

The antitumor effect of CaCO₃ microparticles as a carrier for ²²⁴Ra was investigated, with an emphasis on the ratio of activity to mass dose of CaCO₃, that is, specific activity.

METHODS

Nude athymic mice were inoculated intraperitoneally with human ovarian cancer cells (ES-2) and treated with a single intraperitoneal injection of ²²⁴Ra-labeled CaCO₃ microparticles with varying combinations of mass and activity dose, or cationic ²²⁴Ra in solution. Survival and ascites volume at sacrifice were evaluated.

RESULTS

Significant therapeutic effect was achieved for all tested specific activities ranging from 0.4 to 4.6 kBq/mg. Although treatment with a mean activity dose of 1305 kBq/kg of cationic ²²⁴Ra prolonged the survival compared with the control, equivalent median survival could be achieved with ²²⁴Ra-labeled microparticles with a mean dose of only 420 kBq/kg. The best outcome was achieved with the highest specific activities (2.6 and 4.6 kBq/mg).

CONCLUSION

Radium-224-labeled CaCO₃ microparticles present a promising therapy against cancer dissemination in body cavities.

Polymeric Nanoparticle Delivery of Combination Therapy with Synergistic Effects in Ovarian Cancer

Treatment of ovarian cancer is challenging due to late stage diagnosis, acquired drug resistance mechanisms, and systemic toxicity of chemotherapeutic agents. Combination chemotherapy has the potential to enhance treatment efficacy by activation of multiple downstream pathways to overcome drug resistance and reducing required dosages. Sequence of delivery and the dosing schedule can further enhance treatment efficacy. Formulation of drug combinations into nanoparticles can further enhance treatment efficacy. Due to their versatility, polymer-based nanoparticles are an especially promising tool for clinical translation of combination therapies with tunable dosing schedules. We review polymer nanoparticle (e.g., micelles, dendrimers, and lipid nanoparticles) carriers of drug combinations formulated to treat ovarian cancer. In particular, the focus on this review is combinations of platinum and taxane agents (commonly used first line treatments for ovarian cancer) combined with other small molecule therapeutic agents. In vitro and in vivo drug potency are discussed with a focus on quantifiable synergistic effects. The effect of drug sequence and dosing schedule is examined. Computational approaches as a tool to predict synergistic drug combinations and dosing schedules as a tool for future nanoparticle design are also briefly discussed.

Microscopic Peritoneal Residual Disease after Complete Macroscopic Cytoreductive Surgery for Advanced High Grade Serous Ovarian Cancer

BACKGROUND

Epithelial ovarian cancers (EOC) are usually diagnosed at an advanced stage and managed by complete macroscopic cytoreductive surgery (CRS) and systemic chemotherapy. Peritoneal recurrence occurs in 60% of patients and may be due to microscopic peritoneal metastases (mPM) which are neither eradicated by surgery nor controlled by systemic chemotherapy. The aim of this study was to assess and quantify the prevalence of residual mPM after complete macroscopic CRS in patients with advanced high-grade serous ovarian cancer (HGSOC).

METHODS

A prospective study conducted between 1 June 2018 and 10 July 2019 in a single referent center accredited by the European Society of Gynecological Oncology for advanced EOC management. Consecutive patients presenting with advanced HGSOC and eligible for complete macroscopic CRS were included. Up to 13 peritoneal biopsies were taken from macroscopically healthy peritoneum at the end of CRS and examined for the presence of mPM. A mathematical model was designed to determine the probability of presenting at least one mPM after CRS.

RESULTS

26 patients were included and 26.9% presented mPM. There were no differences in characteristics between patients with or without identified mPM. After mathematical analysis, the probability that mPM remained after complete macroscopic CRS in patients with EOC was 98.14%.

CONCLUSION

Microscopic PM is systematically present after complete macroscopic CRS for EOC and could be a relevant therapeutic target. Adjuvant locoregional strategies to conventional surgery may improve survival by achieving microscopic CRS.

Photodynamic Diagnosis and Therapy for Peritoneal Carcinomatosis: Emerging Perspectives

Simple Summary

Peritoneal carcinomatosis, the formation of wide-spread metastases throughout the abdominal cavity, remains challenging to diagnose and treat. Photodynamic diagnosis and photodynamic therapy are promising approaches for the diagnosis and treatment of peritoneal carcinomatosis, which use photosensitizers for fluorescence detection or photochemical treatment of (micro) metastases. With the aim of highlighting the potential of this theranostic approach, this review outlines the clinical state of the art in the use of photodynamic diagnosis and therapy for peritoneal carcinomatosis, identifies the major challenges, and provides emerging perspectives from preclinical studies to address these challenges. We conclude that the development of novel illumination strategies and targeted photonanomedicines may aid in achieving more efficient cytoreductive surgery. In addition to combination treatments with chemo-, and radiotherapy, such approaches hold significant promise to improve the outlook of patients with peritoneal carcinomatosis.

Abstract

Peritoneal carcinomatosis occurs frequently in patients with advanced stage gastrointestinal and gynecological cancers. The wide-spread peritoneal micrometastases indicate a poor outlook, as the tumors are difficult to diagnose and challenging to completely eradicate with cytoreductive surgery and chemotherapeutics. Photodynamic diagnosis (PDD) and therapy (PDT), modalities that use photosensitizers for fluorescence detection or photochemical treatment of cancer, are promising theranostic approaches for peritoneal carcinomatosis. This review discusses the leading clinical trials, identifies the major challenges, and presents potential solutions to advance the use of PDD and PDT for the treatment of peritoneal carcinomatosis. While PDD for fluorescence-guided surgery is practically feasible and has achieved clinical success, large randomized trials are required to better evaluate the survival benefits. Although PDT is feasible and combines well with clinically used chemotherapeutics, poor tumor specificity has been associated with severe morbidity. The major challenges for both modalities are to increase the tumor specificity of the photosensitizers, to efficiently treat peritoneal microtumors regardless of their phenotypes, and to improve the ability of the excitation light to reach the cancer tissues. Substantial progress has been achieved in (1) the development of targeted photosensitizers and nanocarriers to improve tumor selectivity, (2) the design of biomodulation strategies to reduce treatment heterogeneity, and (3) the development of novel light application strategies. The use of X-ray-activated PDT during whole abdomen radiotherapy may also be considered to overcome the limited tissue penetration of light. Integrated approaches that take advantage of PDD, cytoreductive surgery, chemotherapies, PDT, and potentially radiotherapy, are likely to achieve the most effective improvement in the management of peritoneal carcinomatosis.

EpCAM-Binding DARPins for Targeted Photodynamic Therapy of Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy due to late detection associated with dissemination throughout the abdominal cavity. Targeted photodynamic therapy (tPDT) aimed at epithelial cell adhesion molecule (EpCAM), overexpressed in over 90% of ovarian cancer metastatic lesions, is a promising novel therapeutic modality. Here, we tested the specificity and activity of conjugates of EpCAM-directed designed ankyrin repeat proteins (DARPins) with the photosensitizer IRDye 700DX in in vitro and in vivo ovarian cancer models. EpCAM-binding DARPins (Ec1: Kd = 68 pM; Ac2: Kd = 130 nM) and a control DARPin were site-specifically functionalized with fluorophores or IRDye 700DX. Conjugation of anti-EpCAM DARPins with fluorophores maintained EpCAM-specific binding in cell lines and patient-derived ovarian cancer explants. Penetration of DARPin Ec1 into tumor spheroids was slower than that of Ac2, indicative of a binding site barrier effect for Ec1. DARPin-IRDye 700DX conjugates killed EpCAM-expressing cells in a highly specific and illumination-dependent fashion in 2D and 3D cultures. Furthermore, they effectively homed to EpCAM-expressing subcutaneous OV90 xenografts in mice. In conclusion, the high activity and specificity observed in preclinical ovarian cancer models, combined with a high specificity in patient material, warrant a further investigation of EpCAM-targeted PDT for ovarian cancer.

A global approach for the development of photodynamic therapy of peritoneal metastases regardless of their origin

Surgical management of peritoneal metastases raises the problem of the theoretical spread of the entire peritoneal surface. Intraperitoneal photodynamic therapy (IntraPDT) has been limited by the lack of specificity of photosensitizers (PS) and difficulties to bring light into the abdominal cavity. Recent data in ovarian cancer may give development opportunities for IntraPDT. Intraperitoneal PDT could be an option but the level of evidence of research in this topic must increase. Our opinion is that the most important is to have a realistic idea of what we can objectively expect from PDT and the feasibility of its daily application. At the time of personalized medicine, it is mandatory to select population eligible for a targeted PS administration and who could benefit from the process. The design of a specific PS for each subtype of cancers seems essential to avoid side effects on healthy tissue. On the contrary, our progress on lighting solutions can be beneficial for all patients with an indication of IntraPDT regardless of the origin of PM. A common lighting system developed for all cancers eligible for IntraPDT could be adapted with light source of specific wavelength to activate dedicated PS.

Development of a near infrared protein nanoprobe targeting Thomsen-Friedenreich antigen for intraoperative detection of submillimeter nodules in an ovarian peritoneal carcinomatosis mouse model

The epithelial ovarian cancer is one of the most lethal gynecological malignancy due to its late diagnostic and many relapses observed after first line of treatment. Once diagnose, the most important prognostic factor is the completeness of cytoreductive surgery. To achieve this goal, surgeons have to pinpoint and remove nodules, especially the smallest nodules. Recent advances in fluorescence-guided surgery led us to develop a recombinant lectin as a nanoprobe for the microscopic detection of nodules in the peritoneal cavity of tumor-bearing mice. This lectin has an intrinsic specificity for a carcinoma-associated glycan biomarker, the Thomsen-Friedenreich antigen. In this study, after its labelling by a near infrared dye, we first demonstrated that this nanoprobe allowed indirect detection of nodules already implanted in the peritoneal cavity, through tumor microenvironment targeting. Secondly, in a protocol mimicking the scattering of cells during surgery, we obtained a direct and long-lasting detection of tumor cells in vivo. This lectin as already been described as a nanocontainer able to do targeted delivery of a therapeutic compound to carcinoma cells. Future developments will focus on the combination of the nanoprobe and nanocontainer aspects in an intraperitoneal nanotheranostic approach.

Cooperation therapy between anti-growth by photodynamic-AIEgens and anti-metastasis by small molecule inhibitors in ovarian cancer

Metastasis is one of the main causes of death and treatment failure in ovarian cancer. Some small molecule inhibitors can effectively inhibit the metastasis of primary tumors. However, they do not kill the primary tumor cells, which may lead to continuous proliferation. Herein, we have prepared a multifunctional nanoparticles named TPD@TB/KBU2046, which consisted of three functional moieties: (1) KBU2046 (small molecule inhibitor) that can inhibit the metastasis of the primary tumors, (2) TB (photodynamic-AIEgens) that may suppress the growth of the primary tumors, and (3) TPD, which contains TMTP1 (a targeting peptide, which specifically binds to highly metastatic tumor cells) that can enhance the TB/KBU2046 dosage in the tumor site. Methods: The TPD@TB/KBU2046 was prepared by nano-precipitation method. We linked the targeting peptide (TMTP1) to the nanoparticles via amidation reaction. TPD@TB/KBU2046 nanoparticles were characterized for encapsulation efficiency, particle size, absorption spectra, emission spectra and ROS production. The combinational efficacy in image-guided anti-metastasis and photodynamic therapy of TPD@TB/KBU2046 was explored both in vitro and in vivo. Results: The TPD@TB/KBU2046 showed an average hydrodynamic size of approximately 50 nm with good stability. In vitro, TPD@TB/KBU2046 not only inhibited the metastasis of the tumors, but also suppressed the growth of the tumors under AIEgens-mediated photodynamic therapy. In vivo, we confirmed that TPD@TB/KBU2046 has the therapeutic effects of anti-tumor growth and anti-metastasis through subcutaneous and orthotopic ovarian tumor models. Conclusion: Our findings provided an effective strategy to compensate for the congenital defects of some small molecule inhibitors and thus enhanced the therapeutic efficacy of ovarian cancer.

Upfront debulking surgery versus interval debulking surgery for advanced tubo-ovarian high-grade serous carcinoma and diffuse peritoneal metastases treated with peritonectomy procedures plus HIPEC

BACKGROUND

Whether patients with advanced tubo-ovarian high-grade serous cancer (HGSC) fare better after upfront debulking surgery (UDS) or neoadjuvant chemotherapy with interval debulking surgery (NACT-IDS) remains controversial.

METHODS

We studied patients with HGSC who underwent UDS or NACT-IDS between July 2000 and December 2015, with peritonectomy procedures combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Clinical reports were included peritoneal cancer index (PCI), NACT responses, surgical complexity score (SCS), completeness of cytoreduction (CC), complete follow-up with timing, site, and treatment of recurrence. Outcome measures were morbidity, progression-free survival (PFS), PFS2, and overall survival during a mean 5-year follow-up.

RESULTS

A total of 34 patients (23.6%) underwent UDS and 110 (76.4%) NACT-IDS both combined with HIPEC. At a median 66.3-month follow-up, patients who underwent UDS or NACT-IDS had similar outcomes. NACT subgroup responses correlated with PCI, SCS, morbidity, and CC. Patients who underwent UDS had lower recurrence rates than those who responded partly or poorly to NACT (PFS, P < .04; PFS2, P < .01). Despite HIPEC, the peritoneal disease recurred in 42.5% of the overall patients.

CONCLUSION

In patients with primary HGSC who undergo UDS or NACT-IDS, despite similar outcomes, peritonectomy procedures combined with HIPEC seem unable to prevent peritoneal recurrence.

Characterizing the landscape of peritoneal exosomal microRNAs in patients with ovarian cancer by high-throughput sequencing

In the present study, differentially expressed microRNAs (miRNAs) in peritoneal exosomes that were isolated from 10 patients with epithelial ovarian cancer (EOC) with metastasis in the abdominal cavity and 10 participants without cancer (NC) were identified. These differentially expressed miRNAs that were revealed by next-generation sequencing were categorized by Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of their target genes. Notably, two miRNAs that were associated with EOC-miR-149-3p and miR-222-5p-were identified. There were significant differences in expression of miR-149-3p and miR-222-5p between EOC and NC samples, and the effect of the expression level of the two miRNAs on the patient survival was identified using publicly available data from The Cancer Genome Atlas. There is an association between these two miRNAs and EOC, that was further verified by reverse transcription-quantitative polymerase chain reaction in peritoneal exosomes from 10 patients with EOC and NC participants. These results indicated that miR-149-3p and miR-222-5p might be novel biomarkers for evaluating the prognosis of patients with EOC and that these two miRNAs might have potential therapeutic values.

Imaging and therapy of ovarian cancer: clinical application of nanoparticles and future perspectives

Despite significant advances in cancer diagnostics and treatment, ovarian cancers (OC) continue to kill more than 150,000 women every year worldwide. Due to the relatively asymptomatic nature and the advanced stage of the disease at the time of diagnosis, OC is the most lethal gynecologic malignancy. The current treatment for advanced OC relies on the synergistic effect of combining surgical cytoreduction and chemotherapy; however, beside the fact that chemotherapy resistance is a major challenge in OC management, new imaging strategies are needed to target microscopic lesions and improve both cytoreductive surgery and patient outcomes. In this context, nanostructured probes are emerging as a new class of medical tool that can simultaneously provide imaging contrast, target tumor cells, and carry a wide range of medicines resulting in better diagnosis and therapeutic precision. Herein we summarize several exemplary efforts in nanomedicine for addressing unmet clinical needs.

Hypocrellin B-loaded, folate-conjugated polymeric micelle for intraperitoneal targeting of ovarian cancer in vitro and in vivo

Photodynamic therapy (PDT) is considered an innovative and attractive modality to treat ovarian cancer. In the present study, a biodegradable polymer poly (ethylene glycol) (PEG)‐poly (lactic acid)(PLA)‐folate (FA‐PEG‐PLA) was prepared in order to synthesize an active‐targeting, water‐soluble and pharmacomodulated photosensitizer nanocarrier. Drug‐loading content, encapsulation efficiency, in vitro and in vivo release were characterized, in which hypocrellin B (HB)/FA‐PEG‐PLA micelles had a high encapsulation efficiency and much slower control release for drugs compared to free drugs (P < .05). To evaluate the targeting ability of the HB/FA‐PEG‐PLA micelles, a cellular uptake study in vitro was carried out, which showed significantly enhanced uptake of HB/FA‐PEG‐PLA micelles in SKOV3 (FR+) compared to A2780 cancer cells (FR−). The enhanced uptake of HB/FA‐PEG‐PLA micelles to cancer cells resulted in a more effective post‐PDT killing of SKOV3 cells compared to plain micelles and free drugs. Binding and uptake of HB/FA‐PEG‐PLA micelles by SKOV3 cells were also observed in vivo after ip injection of folate‐targeted micelles in tumor‐bearing ascitic ovarian cancer animals. Drug levels in ascitic tumor tissues were increased 20‐fold (P < .001), which underscored the effect of a regional therapy approach with folate targeting. Furthermore, the HB‐loaded micelles were mainly distributed in kidney and liver (the main clearance organs) in biodistribution. These results showed that our newly developed PDT photosensitizer HB/FA‐PEG‐PLA micelles have a high drug‐loading capacity, good biocompatibility, controlled drug release, and enhanced targeting and antitumor effect, which is a potential approach to future targeting ovarian cancer therapy.

[Microscopic peritoneal metastases of epithelial ovarian cancers. Clinical relevance, diagnostic and therapeutic tools]

Understanding the biology and progression mechanisms of peritoneal metastases in ovarian epithelial cancers (EOC) is important because peritoneal carcinomatosis is present or will occur during surveillance of a majority of patients. Despite the clinical remission achieved after complete macroscopic cytoreductive surgery and platinum-based chemotherapy, 60% of patients will develop peritoneal recurrence. This suggests that microscopic lesions, which are not eradicated by surgery may be present and may participate in the mechanisms leading to peritoneal recurrence. This paper discusses current available data on microscopic peritoneal metastases, their diagnosis and their treatment. We reviewed all publications dealing with microscopic peritoneal metastases of EOC between 1980 and 2017. The most recent and most relevant publications dealing with the treatment modalities of these metastases were selected. Peritoneal and epiploic microscopic localizations would occur in 1.2 to 15.1% of cases at early-stage and are not treated during conventional surgery. They could represent a potential therapeutic target. Local treatments (intraperitoneal chemotherapy, photodynamic therapy, fluorescence-guided surgery) seem to be necessary in addition to surgery and chemotherapy and may help reduce the risk of peritoneal recurrence. The place of these treatments in the management of EOC remains to be defined by subsequent researches.

Image-guided surgery in gynecologic oncology

Image-guided surgery is a relevant way to reduce surgical morbidity and maximize cytoreductive surgery approach especially in ovarian cancer. Sentinel lymph node detection is a promising approach to avoid radical lymph node dissection and is slightly becoming standard in daily practice in endometrial and cervical cancer surgery even if it needs to be evaluated more precisely. Regarding carcinomatosis of ovarian origin, detection and treatment of microscopic disease could be appropriate to avoid local recurrences. Photodiagnosis and photodynamic therapy are innovative techniques that allow to precise limits of excision (fluorescence-guided surgery) and to treat microscopic disease. Further developments of those strategies are necessary to become standard diagnosis tools and treatment options.

Treatment of peritoneal carcinomatosis with photodynamic therapy: Systematic review of current evidence

BACKGROUND

Peritoneal carcinomatosis results when tumour cells implant and grow within the peritoneal cavity. Treatment and prognosis vary based on the primary cancer. Although therapy with intention-to-cure is offered to selective patients using cytoreductive surgery with chemotherapy, the prognosis remains poor for most of the patients. Photodynamic therapy (PDT) is a cancer-therapeutic modality where a photosensitiser is administered to patients and exerts a cytotoxic effect on cancer cells when excited by light of a specific wavelength. It has potential application in the treatment of peritoneal carcinomatosis.

METHODS

We systematically reviewed the evidence of using PDT to treat peritoneal carcinomatosis in both animals and humans (Medline/EMBASE searched in June 2017).

RESULTS

Three human and 25 animal studies were included. Phase I and II human trials using first-generation photosensitisers showed that applying PDT after surgical debulking in patients with peritoneal carcinomatosis is feasible with some clinical benefits. The low tumour-selectivity of the photosensitisers led to significant toxicities mainly capillary leak syndrome and bowel perforation. In animal studies, PDT improved survival by 15-300%, compared to control groups. PDT led to higher tumour necrosis values (categorical values 0-4 [4=highest]: PDT 3.4±1.0 vs. control 0.4±0.6, p<0.05) and reduced tumour size (residual tumour size is 10% of untreated controls, p<0.001).

CONCLUSION

PDT has potential in treating peritoneal carcinomatosis, but is limited by its narrow therapeutic window and possible serious side effects. Recent improvement in tumour-selectivity and light delivery systems is promising, but further development is needed before PDT can be routinely applied for peritoneal carcinomatosis.

[Intraperitoneal photodynamic therapy for peritoneal metastasis of epithelial ovarian cancer. Limits and future prospects]

High peritoneal recurrence rate in advanced epithelial ovarian cancer after complete macroscopic cytoreductive surgery and platinum-based chemotherapy, raises the issue of peritoneal microscopic disease management and requires the development of additional locoregional treatment strategies. Photodynamic therapy is an effective treatment already applied in other medical and surgical indications. After administration of a photosensitizer which accumulates in cancer cells, illumination with a light of adequate wavelength may induce photochemical reaction between photosensitizer and tissue oxygen which lead to reactive oxygen species production and cytotoxic phenomenon. Photodynamic therapy's ability to treat superficial lesions disseminated on large area makes it an excellent candidate to insure destruction of microscopic peritoneal metastases in addition to macroscopic cytoreductive surgery in order to decrease peritoneal recurrence rate. Development of intraperitoneal photodynamic therapy has been limited by its poor tolerance related to the lack of specificity of photosensitizers and the location of the metastases in proximity to adjacent intraperitoneal organs. Our aim is to review clinical data concerning intraperitoneal photodynamic therapy and epithelial ovarian cancer to identify the limits of this strategy and to provide solutions which may be applied to solve these barriers and enable safe and effective treatment. Targeted photosensitizers and innovative illumination solutions are mandatory to continue research in this field and to consider the feasibility of clinical trials.

[Specific folic-acid targeted photosensitizer. The first step toward intraperitoneal photodynamic therapy for epithelial ovarian cancer]

OBJECTIVE

Epithelial ovarian cancer (EOC) management remains association of debulking surgery in combination with platinum-based chemotherapy. Sixty percent of women with EOC considered in remission will develop recurrent disease. An option to improve the completion of cytoreductive surgery may be the use of photodynamic therapy to induce necrosis of peritoneal metastases. A limit of this technique was the toxicity induced by the lack of specificity of old-generation photosensitizer (PS) for tumor tissue if the light could not be specifically applied. To solve this problem, a solution is the design of selective PS. Folate receptor is a promising target for EOC targeted therapy. We present preclinical results concerning properties of a folic-acid targeted photosensitizer.

METHOD

Preclinical studies have been performed in vitro on murine and human cell lines of EOC and in vivo with a preclinical model of peritoneal carcinomatosis (Fisher F344 rat/NuTu-19 cell line). They aimed to precise the ability of PS to target specifically tumor tissue, to emit specific fluorescence, and to obtain cell death.

RESULTS

Tissue quantification of the PS showed specific incorporation of the folate-targeted PS within tumor tissue. Specificity for ovarian cancer metastases is better than previously reported with others photosensitizers (tumor-to-normal tissue ratio 9.6). We could detect specific fluorescence in vitro and in vivo on peritoneal metastases. Folic-acid targeted PDT allows to obtain human EOC cells death.

CONCLUSION

Specific PS may allow the development of efficient and safe intraperitoneal PDT procedure, which could play a role in the prevention of EOC peritoneal recurrences.

The Role of Routine Peritoneal and Omental Biopsies at Risk-Reducing Salpingo-Oophorectomy

STUDY OBJECTIVE

To assess the potential role of peritoneal and omental biopsies in women undergoing risk-reducing salpingo-oopherectomy (RRSO) for prophylactic management of hereditary breast/ovarian cancer (HBOC) syndromes.

DESIGN

A retrospective observational cohort (Canadian Task Force classification II.1).

SETTING

An academic gynecology practice.

PATIENTS

All women who underwent RRSO for a high-risk BRCA1/2 mutation or deletion at a single institution between January 2003 and June 2016.

INTERVENTIONS

After obtaining institutional review board approval, patient demographics, types of surgical intervention, histopathology reports, and outcomes were abstracted. Bilateral fallopian tubes were histologically evaluated using the "sectioning and extensively examining of the fimbriated end" protocol. Descriptive statistics were used to summarize findings.

MEASUREMENTS AND MAIN RESULTS

Seventy women underwent RRSO within the study window; 60% (n = 42) carried a high-risk mutation in BRCA1, 37.1% (n = 26) carried a high-risk mutation in BRCA2, and 2.9% (n = 2) had a high-risk BRCA deletion identified by BRAC analysis rearrangement testing (BART). Serous tubal intraepithelial carcinomas were identified in the distal fallopian tube of 3 subjects. In addition to RRSO, subjects underwent pelvic washings (n = 58, 82.9%), omental biopsy (n = 44, 62.9%), peritoneal biopsies of the bilateral paracolic gutters (n = 51, 72.9%), anterior and posterior cul-de-sac (n = 53, 75.7%), and rectosigmoid mesentery (n = 11, 15.7%). Rare atypical cells favoring reactive cells were identified in pelvic washings of 1 subject (1.7%) with histologically normal fallopian tubes. No evidence of atypical mesothelial proliferations or carcinoma was identified in any omental or peritoneal biopsies. The mean duration of follow-up was 32.5 ± 24.7 months. At the last contact, 3 women (4.3%) had died of metastatic breast cancer, whereas another 3 (4.3%) had been diagnosed with a recurrence of their breast cancer. All other subjects were alive and well (n = 64, 91.4%).

CONCLUSION

The routine use of peritoneal and omental biopsies for women undergoing RRSO does not appear to improve detection of occult malignancy.