Henri Azaïs

Assessment of the specificity of a new folate-targeted photosensitizer for peritoneal metastasis of epithelial ovarian cancer to enable intraperitoneal photodynamic therapy. A preclinical study

BACKGROUND Ovarian cancers prognosis remains dire after primary therapy. Recurrence rate is disappointingly high as 60% of women with epithelial ovarian cancer considered in remission will develop recurrent disease within 5 years. Special attention to undetected peritoneal metastasis during surgery is necessary as they are the main predictive factors of recurrences. Folate Receptor α (FRα) shows promising prospects in targeting ovarian cancerous cells and intraperitoneal photodynamic therapy (PDT) could be a solution in addition to macroscopic cytoreductive surgery to treat peritoneal micrometastasis. The aim of this preclinical study is to assess the specificity of a folate-targeted photosensitizer for ovarian peritoneal micrometastasis. METHODS We used the NuTu-19 epithelial ovarian cancer cell line to induce peritoneal carcinomatosis in female Fischer 344 rats. Three groups of 6 rats were studied (Control (no photosensitizer)/Non-conjugated photosensitizer (Porph)/Folate-conjugated photosensitizer (Porph-s-FA)). Four hours after the administration of the photosensitizer, animals were sacrificed and intraperitoneal organs tissues were sampled. FRα tissue expression was evaluated by immunohistochemistry. Tissue incorporation of photosensitizers was assessed by confocal microscopy and tissue quantification. RESULTS FRα is overexpressed in tumor, ovary, and liver whereas, peritoneum, colon, small intestine, and kidney do not express it. Cytoplasmic red endocytosis vesicles observed by confocal microscopy are well correlated to FRα tissue expression. Photosensitizer tissue quantification shows a mean tumor-to-normal tissue ratio of 9.6. CONCLUSION We demonstrated that this new generation folate-targeted photosensitizer is specific of epithelial ovarian peritoneal metastasis and may allow the development of efficient and safe intraperitoneal PDT procedure.

Stability of folic acid under several parameters

Folic acid is a small molecule, also known as vitamin B9. It is an essential compound involved in important biochemical processes. It is widely used as a vector for targeted treatment and diagnosis especially in cancer therapeutics. Nevertheless, not many authors address the problem of folic acid degradation. Several researchers reported their observations concerning its denaturation, but they generally only took into account one parameter (pH, temperature, light or O2etc.). In this review, we will focus on five main parameters (assessed individually or in conjunction with one or several others) that have to be taken into account to avoid the degradation of folic acid: light, temperature, concentration, oxygen and pH, which are the most cited in the literature. Scrupulous bibliographic research enabled us to determine two additional degradation factors that are the influence of singlet oxygen and electron beam on folic acid stability, which are not considered as among the prime factors. Although these two factors are not commonly present as compared to the others, singlet oxygen and electron beams intervene in new therapeutic technologies and must be taken in consideration for further applications such photodynamic or X-rays therapies.

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

Understanding biology and progression mechanisms of peritoneal metastases of epithelial ovarian cancer (EOC) is a cornerstone in the knowledge and the comprehensive management of the disease. Despite clinical remission after the association of complete cytoreductive surgery and platinum-based chemotherapy, peritoneal recurrence still occurs in 60% of patients. Eligible studies, published from 1980 to June 2016, were retrieved through ClinicalTrials.gov, MEDLINE, Cochrane databases and bibliography searches. We reviewed all publications that deals with microscopic peritoneal metastases of EOC in French and English. To discuss expected benefits of intraperitoneal (IP) chemotherapy, fluorescence-guided surgery or IP photodynamic therapy, we reviewed most recent and relevant studies. The final reference list was generated on the basis of originality and relevance to the broad scope of this review. Published data concerning early-stage ovarian cancer suggest that occult peritoneal or epiploic metastases are present in 1.2%-15.1% of cases. In the frequent case of advanced-stage disease, residual microscopic lesions are ignored by conventional surgery. We are convinced that microscopic peritoneal metastases are a relevant surgical therapeutic target. This article discusses existing data on microscopic peritoneal metastases, the treatment indications, the diagnostic and therapeutic surgical approaches to be developed and their expected benefits. A local therapeutic strategy to target microscopic lesions is needed in addition to complete macroscopic cytoreductive surgery to decrease the rate of peritoneal recurrence. Intraperitoneal chemotherapy, and targeted photodynamic therapy could play a role in this new paradigm. The roles of these different options must be defined by future researches.

Targeted approaches and innovative illumination solutions:A new era for photodynamic therapy applications in gynecologic oncology?

Different studies have been carried out to investigatethe potential application of photodiagnosisand photodynamic therapy (PDT) in the field of gynecological cancer treatment without finding a place in current standard clinical practice.

[FRα: a target for prophylactic photodynamic therapy of ovarian peritoneal metastasis?].

Partly due to delays in its diagnosis, ovarian cancers prognosis remains dire after primary therapy. Treatment consists in complete cytoreductive surgery and platinum-based chemotherapy. Recurrence rates are disappointingly high, as 60% of women with advanced epithelial ovarian cancer considered in remission will develop recurrent disease within five years. Special attention to undetected peritoneal metastasis and residual tumorous cells during surgery is necessary as they are the main predictors of recurrences. Targeted therapies aim to bring chemotherapy, radiotherapy and selective tumor photosensitizer (PS) agents to the targeted cell and its tumoral microenvironment. Folate receptor α (FRα) shows promising prospects in targeting ovarian cancerous cells. Indeed, with good specificity and frequent overexpression in ovarian cancer, FRα is a recurrent topic in recent publications. The aim of this review is to present FRα and the reasons that make it an ideal targeting ligand for ovarian carcinoma therapy. Prophylactic photodynamic therapy (PPDT) using new generation FRα-coupled agents combined with complete cytoreductive surgery could allow for a significant decrease in recurrence rates. Preclinical trials are being run in order to allow for human clinical applications.

Fischer 344 Rat: A Preclinical Model for Epithelial Ovarian Cancer Folate-Targeted Therapy.

Objective Ovarian cancer prognosis remains dire after primary therapy. Recurrence rates are disappointingly high as 60% of women with advanced epithelial ovarian cancer considered in remission will develop recurrent disease within 5 years. Special attention to undetected peritoneal metastasis and residual tumorous cells during surgery is necessary as they are the main predictive factors of recurrences. Folate receptor &agr; (FR&agr;) shows promising prospects in targeting ovarian cancerous cells. Our aim was to determine if the Fischer model described by Rose et al could be used to evaluate folate-targeted therapies in preclinical studies. Methods NuTu-19 epithelial ovarian cancer cell line was used to induce peritoneal carcinomatosis in female Fischer 344 rats. FR&agr; expression by NuTu-19 cells was assessed in vitro by immunofluorescence using “Cytospin®” protocol. In vitro folate-targeted compound uptake by NuTu-19 cells was evaluated by incubation of FR&agr;-positive ovarian cancer cell lines (NuTu-19/SKOV-3/OVCAR-3/IGROV-1) with or without (control) a folate-targeted photosensitizer. Intracellular incorporation was assessed by confocal microscopy. Determination of in vivo FR&agr; tissue expression by several organs of the peritoneal cavity was studied by immunohistochemistry. Results NuTu-19 cells express FR&agr; which allows intracellular incorporation of folate-targeted compound by endocytosis. FR&agr; is expressed in tumor tissue, ovary, and liver. Peritoneum, colon, small intestine, and kidney do not express the receptor. Conclusions Female Fischer 344 rat is an inexpensive reproducible and efficient preclinical model to study ovarian peritoneal carcinomatosis folate-targeted therapies.

Operative and diagnostic hysteroscopy: A novel learning model combining new animal models and virtual reality simulation

CONTEXT Hysteroscopy is one of the most common gynaecological procedure. Training for diagnostic and operative hysteroscopy can be achieved through numerous previously described models like animal models or virtual reality simulation. We present our novel combined model associating virtual reality and bovine uteruses and bladders. STUDY DESIGN End year residents in obstetrics and gynaecology attended a full day workshop. The workshop was divided in theoretical courses from senior surgeons and hands-on training in operative hysteroscopy and virtual reality Essure® procedures using the EssureSim™ and Pelvicsim™ simulators with multiple scenarios. Theoretical and operative knowledge was evaluated before and after the workshop and General Points Averages (GPAs) were calculated and compared using a Students T test. RESULTS GPAs were significantly higher after the workshop was completed. The biggest difference was observed in operative knowledge (0,28 GPA before workshop versus 0,55 after workshop, p<0,05). All of the 25 residents having completed the workshop applauded the realism an efficiency of this type of training. The force feedback allowed by the cattle uteruses gives the residents the possibility to manage thickness of resection as in real time surgery. Furthermore, the two-horned bovine uteruses allowed to reproduce septa resection in conditions close to human surgery CONCLUSION: Teaching operative and diagnostic hysteroscopy is essential. Managing this training through a full day workshop using a combined animal model and virtual reality simulation is an efficient model not described before.

Photosensibilisateur spécifique pour la thérapie photodynamique ciblée des métastases péritonéales des cancers ovariens

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.

Chemotherapy Drug Extravasation in Totally Implantable Venous Access Port Systems: How Effective is Early Surgical Lavage?:

Purpose Totally implantable venous access port systems (TIVAPS) are a widely used and an essential tool in the efficient delivery of chemotherapy. Chemotherapy drug extravasation (CDE) can have dire consequences and will delay treatment. The purpose of this study is to both clarify the management of CDE and show the effectiveness of early surgical lavage (ESL). Methods Patients who had presented to the Cancer Center of Lille (France) with TIVAPS inserted between January 2004 and April 2013 and CDE had their medical records reviewed retrospectively. Results Thirty patients and 33 events were analyzed. Implicated agents were vesicants (51.5%), irritants (45.5%) and non-vesicants (3%). Huber needle malpositionning was involved in 27 cases. Surgery was performed in 97% of cases, 87.5% of which were for ESL with 53.1% of the latter requiring TIVAPS extraction. Six patients required a second intervention due to adverse outcomes (severe cases). Vesicants were found to be implicated in four out of six severe cases and oxaliplatin in two others. Extravasated volume was above 50 ml in 80% of cases. Only one patient required a skin graft. Conclusions CDEs should be managed in specialized centers. ESL allows for limited tissue contact of the chemotherapy drug whilst using a simple, widely accessible technique. The two main factors that correlate with adverse outcome seem to be the nature of the implicated agent (vesicants) and the extravasated volume (above 50 ml) leading to worse outcomes. Oxaliplatin should be considered as a vesicant.

Laser interstitial thermotherapy application for breast surgery: Current situation and new trends

While breast specialists debate on therapeutic de-escalation in breast cancer, the treatment of benign lesions is also discussed in relation to new percutaneous ablation techniques. The purpose of these innovations is to minimize potential morbidity. Laser Interstitial ThermoTherapy (LITT) is an option for the ablation of targeted nodules. This review evaluated the scientific publications investigating the LITT approach in malignant and benign breast disease. Three preclinical studies and eight clinical studies (2 studies including fibroadenomas and 6 studies including breast cancers) were reviewed. Although the feasibility and safety of LITT have been confirmed in a phase I trial, heterogeneous inclusion criteria and methods seem to be the main reason for LITT not being yet an extensively used treatment option. In conclusion, further development is necessary before this technique can be used in daily practice.