The role of radiotherapy in epithelial ovarian cancer: a literature overview

Role of DNA methylation and non‑coding RNAs expression in pathogenesis, detection, prognosis, and therapy‑resistant ovarian carcinoma (Review)

Ovarian cancer is the deadliest gynecological cancer globally, with epithelial ovarian cancer (EOC) comprising up to 90% of cases. A molecular characterization linking the histological subtypes with tumor grade in EOC has been suggested. Variations in genetic biomarkers such as BRCA1/2, MSH2, MLH1/6, BRIP1, and RAD51C/D have been studied in EOC. In addition, molecular characteristics, including DNA methylation and RNA transcription, are being explored as potential new biomarkers for the diagnosis and prognosis of this type of neoplasia. The present review focused on the role of DNA methylation and non‑coding RNA expression in the development of ovarian carcinomas and their association with diagnosis, prognosis, and the resistance of cancer cells to radiotherapy and chemotherapy. The present review considered the transition from the DNA structure to the RNA expression in ovarian carcinoma.

Development of machine learning prognostic models for overall survival of epithelial ovarian cancer patients: a SEER-based study

RESEARCH DESIGN AND METHODS

Data were obtained from the SEER database for women diagnosed with EOC between 2004 and 2020. Clinical features, treatment regimens and overall survival (OS) were analyzed. Cox regression was conducted to identify prognostic factors associated with EOC. We employed 5-fold cross-validation to improve the accuracy of the model. Random Survival Forest (RSF), Gradient Boosting Survival Analysis (GBSA) and Support Vector Machine (SVM) were used to develop ML models, then compared with the Cox model. The predictive performance of these models was assessed using AUC, concordance index (C-index), and Brier scores.

RESULTS

A total of 12,949 EOC patients were selected from the SEER database. We identified 14 independent prognostic factors for OS and constructed predictive models. The GBSA model demonstrated superior AUC, C-index, and Brier scores across different time points, outperforming the Cox model. SHAP analysis showed that FIGO stage, grade, and lymph node dissection were the most important features in the GBSA model.

CONCLUSIONS

The GBSA model outperforms traditional methods in survival prediction, offering a valuable tool for clinicians to make informed decisions about patient prognosis.

Is Prophylactic Radiotherapy to the Lymphatic Drainage Area Necessary for Patients With Stage III Ovarian Cancer After Chemotherapy Following Surgery?

BACKGROUND

For patients with stage III epithelial ovarian cancer, there are limited studies on the effects of postoperative adjuvant radiotherapy (RT). Here we assessed the therapeutic efficacy and toxicity of postoperative radiotherapy to the abdominal and pelvic lymphatic drainage area for stage III epithelial ovarian cancer patients, who had all received surgery and chemotherapy (CT).

METHODS

We retrospectively collected patients with stage III epithelial ovarian cancer after cytoreductive surgery (CRS) and full-course adjuvant CT. The chemoradiotherapy (CRT) group patients were treated with intensity modulated radiotherapy (IMRT) to the abdominal and pelvic lymphatic drainage area in our hospital between 2010 and 2020. A propensity score matching analysis was conducted to compare the results between the CRT and CT groups. Kaplan-Meier analysis estimated overall survival (OS), disease-free survival (DFS), and local control (LC) rates. The log-rank test determined the significance of prognostic factors.

RESULTS

A total of 132 patients with median follow-up of 73.9 months (9.1-137.7 months) were included (44 and 88 for the CRT and RT groups, retrospectively). The baseline characteristics of age, histology, level of CA12-5, surgical staging, residual tumour, courses of adjuvant CT, and courses to reduce CA12-5 to normal were all balanced. The median DFS time, 5-year OS, and local recurrence free survival (LRFS) were 100.0 months vs 25.9 months (P = .020), 69.2% vs 49.9% (P = .002), and 85.9% vs 50.5% (P = .020), respectively. The CRT group mainly presented with acute haematological toxicities, with no statistically significant difference compared with grade III intestinal adverse effects (3/44 vs 6/88, P = .480).

CONCLUSION

This report demonstrates that long-term DFS could be achieved in stage III epithelial ovarian cancer patients treated with IMRT preventive radiation to the abdominal and pelvic lymphatic area. Compared with the CT group, DFS and OS were significantly prolonged and adverse effects were acceptable.

CAR-T cell immunotherapy for ovarian cancer: hushing the silent killer

As the most lethal gynecologic oncological indication, carcinoma of the ovary has been ranked as the 5th cause of cancer-related mortality in women, with a high percentage of the patients being diagnosed at late stages of the disease and a five-year survival of ~ 30%. Ovarian cancer patients conventionally undergo surgery for tumor removal followed by platinum- or taxane-based chemotherapy; however, a high percentage of patients experience tumor relapse. Cancer immunotherapy has been regarded as a silver lining in the treatment of patients with various immunological or oncological indications; however, mirvetuximab soravtansine (a folate receptor α-specific mAb) and bevacizumab (a VEGF-A-specific mAb) are the only immunotherapeutics approved for the treatment of ovarian cancer patients. Chimeric antigen receptor T-cell (CAR-T) therapy has achieved tremendous clinical success in the treatment of patients with certain B-cell lymphomas and leukemias, as well as multiple myeloma. In the context of solid tumors, CAR-T therapies face serious obstacles that limit their therapeutic benefit. Such hindrances include the immunosuppressive nature of solid tumors, impaired tumor infiltration, lack of qualified tumor-associated antigens, and compromised stimulation and persistence of CAR-Ts following administration. Over the past years, researchers have made arduous attempts to apply CAR-T therapy to ovarian cancer. In this review, we outline the principles of CAR-T therapy and then highlight its limitations in the context of solid tumors. Ultimately, we focus on preclinical and clinical findings achieved in CAR-T-mediated targeting of different ovarian cancer-associated target antigens.

The utility of 1.5 tesla MR-guided adaptive stereotactic body radiotherapy for recurrent ovarian tumor – Case reports and review of the literature

Introduction

Although epithelioid ovarian cancer (EOC) is a radiosensitive tumor and radiotherapy (RT) played a significant role in adjuvant treatment management in the past, the role of RT has evolved with the advent of platinum-based chemotherapy regimens. Nonetheless, modern RT techniques may be useful in certain patients particularly those with recurrent disease.

Presentation of case

After surgery and chemotherapy, two patients, aged 57 and 70, presented with recurrent lesions in the parailiac region. The recurrent lesions were treated with high field 1.5-Tesla MR-Linac treatment in 5 fractions at a dose of 30 Gy. The patients tolerated the treatment well and were disease free after 12 and 20 months of magnetic resonance guided radiotherapy (MRgRT), respectively.

Discussion

MRgRT is a novel and rapidly evolving technology that allows for the highly precise treatment of even mobile targets through direct visualization of the tumor. The majority of patients with EOC frequently present with abdominal-pelvic recurrences. It has been demonstrated that EOC requires high radiation doses for curative treatment. MR-Linac enables monitoring of organ motion during treatment, which is necessary for delivering higher doses to target volumes while sparing surrounding organs.

Conclusion

To reduce radiation doses to nearby normal tissues, MRgRT allows for the delivery of hypofractionated RT with tight safety margins. Regardless of initial resistance or gradual development of intolerance to standard chemotherapy regimens, the role of RT in patients with persistent or recurrent EOC should be reconsidered.

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Abdominal-pelvic region or other distant recurrence is common in ovarian cancer patients.

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The role of radiotherapy is debatable in ovarian cancer patients due to toxicity.

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Magnetic resonance guided RT allows direct target visualization during treatment delivery.

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We present two cases of recurrent ovarian cancer treated with adaptive MRgRT using 1.5 T-MR linac.

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MRgRT may be an alternative treatment option in patients with persistent or recurrent ovarian cancer.

Prediction for 2-year mortality of metastatic ovarian cancer patients based on surveillance, epidemiology, and end results database

Aim

To establish prediction models for 2-year overall survival of ovarian cancer patients with metastasis.

Methods

In total, 4,929 participants from Surveillance, Epidemiology, and End Results (SEER) database were randomly divided into the training set (n = 3,451) and the testing set (n = 1,478). Univariate and multivariable regression were conducted in the training set to identify predictors for 2-year overall survival of metastatic ovarian cancer patients. The C-index was calculated for assessing the performance of the models. The nomogram for the model was plotted. The prediction value of the model was validated in the testing set. Subgroup analysis were performed concerning surgery and chemotherapy status of patients and the metastatic site of ovarian cancer in the testing set. The calibration curves were plotted and the decision curve analysis (DCA) were conducted.

Results

At the end of follow-up, 2,587 patients were survived and 2,342 patients were dead within 2 years. The 2-year survival rate was 52.5%. The prediction models were constructed based on predictors including age, radiation, surgery and chemotherapy, CA125, and bone, liver, and lung metastasis. The prediction model for 2-year overall survival of ovarian cancer patients with metastasis showed good predictive ability with the C-index of the model of 0.719 (95% CI: 0.706–0.731) in the training set and 0.718 (95% CI: 0.698–0.737) in the testing set. In terms of patients with bone metastasis, the C-index was 0.740 (95% CI: 0.652–0.828) for predicting the 2-year overall survival of ovarian cancer patients. The C-index was 0.836 (95% CI: 0.694–0.979) in patients with brain metastasis, 0.755 (95% CI: 0.721–0.788) in patients with liver metastasis and 0.725 (95% CI: 0.686–0.764) in those with lung metastasis for predicting the 2-year overall survival of ovarian cancer patients.

Conclusion

The models showed good predictive performance for 2-year overall survival of metastatic ovarian cancer patients.

Clinical application of radiotherapy in patients with oligometastatic ovarian cancer: a sharp tool to prolong the interval of systemic treatment

BACKGROUND

With the advances of radiation technology, treatment of oligometastatic disease, with limited metastatic burden, have more chances to achieve long-term local control. Here we aim to evaluate the efficacy and safety of radiotherapy (RT) in oligometastatic ovarian cancer patients.

METHODS

A retrospective analysis collecting 142 patients (189 lesions) with oligometastatic ovarian cancer were included in the study. All pateints received radiotherapy and the curative effect and response rate were evaluated by diagnostic imaging after 1-3 months of radiotherapy with RECIST. Endpoints were the rate of complete response (CR), chemotherapy-free interval (CFI), local control (LC) rate and overall survival (OS) rate. Toxicity was evaluated by the Radiation Therapy Oncology Group (RTOG). Logistic and Cox regression were used for the uni- and multivariate analysis of factors influencing survival outcomes.

RESULTS

From 2013.1.1 to 2020.12.30, a total of 142 ovarian cancer patients (189 oligometastasis lesions) were included in the analysis. Prescribed doses to an average GTV of 3.10 cm were 1.8-8 Gy/fraction, median BED (28-115, a/b = 10 Gy), 5-28 fractions. For 179 evaluable lesions, the cases of CR, partial response (PR), stable disease (SD) and progressive disease (PD) after radiotherapy were 22,39,38 and 80 respectively. The disease control rate (DCR): CR + PR + SD was 55.31%, and the objective response rate (ORR): CR + PR was 34.08%. No patient developed grade 3 or higher side effect. The median CFI was 14 months (1-99 months), and the LC rate was 69.7%, 54.3% and 40.9% in 1 year, 2 years and 5 years respectively. GTV < 3 cm before treatment, platinum sensitivity, time from the last treatment ≥ 6 months, single lesion and BED(a/b = 10 Gy) ≥ 60 are the factors of good LC (p < 0.05). The total OS of 1 year, 2 years and 5 years were 67.1%, 52.6% and 30.3%, respectively. Single lesion (HR 0.598, 95%CI 0.405-0.884), DCR (HR 0.640, 95% CI 0.448-0.918) and ORR(HR 0.466, 95% CI 0.308-0.707) were the significant factors influencing 5-year OS.

CONCLUSION

For patients with oligometastatic ovarian cancer, radiotherapy has high LC, long chemotherapy-free interval, and survival benefits. Subgroup analysis shows that patients with single lesion and good local treatment results have higher overall survival rate, suggesting that active treatment is also beneficial for oligometastatic ovarian cancer patients.

Anti-Tumor and Anti-Invasive Effects of ONC201 on Ovarian Cancer Cells and a Transgenic Mouse Model of Serous Ovarian Cancer

ONC201 is a promising first-in-class small molecule that has been reported to have anti-neoplastic activity in various types of cancer through activation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as well as activation of mitochondrial caseinolytic protease P (ClpP). The present study was to explore the anti-tumor potential effect of ONC201 in ovarian cancer cell lines and in a transgenic mouse model of high grade serous ovarian cancer under obese (high fat diet) and lean (low fat diet) conditions. ONC201 significantly suppressed cell proliferation, induced arrest in G1 phase, and increased cellular stress and apoptosis, accompanied by dual inhibition of the AKT/mTOR/S6 and MAPK pathways in OC cells. ONC201 also resulted in inhibition of adhesion and invasion via epithelial–mesenchymal transition and reduction of VEGF expression. Pre-treatment with the anti-oxidant, N-acetylcysteine (NAC), reversed the ONC201-induced oxidative stress response, and prevented ONC201-reduced VEGF and cell invasion by regulating epithelial–mesenchymal transition protein expression. Knockdown of ClpP in ovarian cancer cells reduced ONC201 mediated the anti-tumor activity and cellular stress. Diet-induced obesity accelerated ovarian tumor growth in the KpB mouse model. ONC201 significantly suppressed tumor growth, and decreased serum VEGF production in obese and lean mice, leading to a decrease in tumoral expression of Ki-67, VEGF and phosphorylation of p42/44 and S6 and an increase in ClpP and DRD5, as assessed by immunohistochemistry. These results suggest that ONC201 may be a promising therapeutic agent to be explored in future clinical trials in high-grade serous ovarian cancer.

Beta-glucans is a potential inhibitor of ovarian cancer: based on molecular and biological aspects

Ovarian cancer is a lethal type of cancer which is initiated in the ovaries and affects 1 out of every 75 women. Due to the high number of deaths (almost 152,000) related to this cancer, it seems that novel effiecient therapeutic methods are required in this field. Beta-glucans are a type of glucose linear polymers which have proven to have a lot of advantageous activities. Recently, investigations have declared that these polysaccharides have the potential to be used as anti-cancer drugs. These agents are able to affect several mechanisms such as inflammation and apoptosis and that is how cancers are prone to be affected by them. In this review, we attempt to investigate the role of beta-glucans on ovarian cancer. We hope that this paper might give novel insights in the field of ovarian cancer treatment.

Asparagus officinalis Exhibits Anti-Tumorigenic and Anti-Metastatic Effects in Ovarian Cancer

Ovarian cancer is one of the leading causes of female cancer death. Emerging evidence suggests that many dietary natural products have anti-tumorigenic activity, including that of asparagus officinalis. The current study aimed to assess the anti-tumorigenic and anti-metastatic effects of asparagus officinalis on serous ovarian cancer cell lines and a transgenic mouse model of high grade serous ovarian cancer. Asparagus officinalis decreased cellular viability, caused cell cycle G1 phase arrest and induced apoptosis in the OVCAR5 and SKOV3 cells. Induction of apoptosis and inhibition of cell proliferation was rescued by the pan-caspase inhibitor, Z-VAD-FMK, implying that its cytotoxic effects were mainly dependent on caspase pathways. Asparagus officinalis increased levels of ROS and decreased mitochondrial membrane potential with corresponding increases in PERK, Bip, Calnexin PDI and ATF4 in both cell lines. Treatment with asparagus officinalis also reduced ability of adhesion and invasion through epithelial-mesenchymal transition and reduction of VEGF expression. The combination of Asparagus officinalis with paclitaxel had synergistic anti-proliferative activity. Furthermore, Asparagus officinalis significantly inhibited tumor growth and reduced serum VEGF in a genetically engineered mouse model of ovarian cancer under obese and lean conditions, accompanied with a decrease in the expression of Ki67, VEGF and phosphorylated S6, and in an increase in phosphorylation of AMPK in the ovarian tumor tissues. Overall, our data provide a pre-clinical rationale for asparagus officinalis in the prevention and treatment of ovarian cancer as a novel natural product.

Comparison of the Effect of Alpha and Hydrocortisone Ointments on Prevention of Acute Skin Complications Due to Radiotherapy in Breast Cancer Patients

Background

Radiotherapy in breast cancer patients is associated with acute and delayed side effects. This study aimed to compare the effect of alpha and hydrocortisone 1% (H1%) ointments on prevention of acute skin complications due to radiotherapy in breast cancer patients.

Methods

This clinical trial was conducted on 86 patients with breast cancer in the radiotherapy center of Imam Reza Hospital of Kermanshah, Iran. Using the records, the patients were selected and randomly divided into alpha and H1% groups after obtaining informed consent. The severity of dermatitis, complications, and patient complaints during treatment were evaluated weekly for up to 6 weeks by RTOG criteria. Data were analyzed using SPSS-16 software.

Results

At the end of the third, fourth, fifth, and sixth weeks, 10 (11.7%), 25 (29.1%), 53 (61.6%), and 28 (32.6%) patients had skin complications, respectively. In weeks 5 and 6 in the H1 group, the incidence of complications was higher (P = 0.001). The frequency of pain and burning complaints at the end of the third, fourth, fifth, and sixth weeks was 15 (17.4%), 37 (43.0%), 52 (60.5%), and 1(1.2%), respectively. Pain and burning intensity in the fourth and fifth weeks in the H1 group was lower than alpha (P = 0010). Complaints of skin itching at the end of the third, fourth, and fifth weeks were 16 (18.6%), 25 (29.1%), and 28 (32.6), respectively. This complication was lower in the H1% group during these weeks (P < 0.05).

Conclusion

Alpha ointment is more effective than H1% in relieving pain and burning, preventing complications except itching. It seems using an alpha ointment or combining it with H1% is an appropriate strategy to reduce the rate of injuries and skin complications of radiotherapy.

Activation of COL11A1 by PRRX1 promotes tumor progression and radioresistance in ovarian cancer

PURPOSE

Although radiotherapy is a common treatment option for all kinds of cancer patients, including ovarian cancer, a major obstacle limiting its application in the development of resistance. Therefore, it is urgently needed to clarify the mechanism of radiosensitivity modulation.

MATERIALS AND METHODS

We obtained open datasets and analyzed the expression of collagen type XI alpha 1 (COL11A1) in ovarian cancer patients with different stages. Meanwhile, the correlation of COL11A1 and survival outcomes is determined by Kaplan-Meier analysis. The role of COL11A1 in cell proliferation was observed in an in vitro knockdown system. SKOV3 radioresistant cells were established to determine the role of COL11A1 on radioresistant in ovarian cancer.

RESULTS AND DISCUSSION

COL11A1 were highly enriched in late-stage ovarian cancer tumor tissues and negatively correlated with survival outcomes in ovarian cancer. The functional analysis found that COL11A1 promoted ovarian cancer cell proliferation in vitro. Importantly, COL11A1 decreased radiosensitivity in ovarian cancer by AKT activation. Paired related homeobox 1 (PRRX1) acted as an upstream transcription factor to regulate COL11A1 expression in ovarian cancer. Increased COL11A1 expression is related to low survival outcomes and radiosensitivity in ovarian cancer.

CONCLUSIONS

Targeting COL11A1 is a promising strategy for improving radiotherapy efficiency.

The effect of surgery plus intensity-modulated radiotherapy on treatment in laryngeal cancer: A clinical retrospective study

PURPOSE

As a common head and neck tumor, laryngeal cancer has attracted heightened attention for its treatment and prognosis. Surgery and radiotherapy were mainly therapeutic approaches in laryngeal cancer, and intensity-modulated radiotherapy (IMRT) was a precision treatment way in radiotherapy. However, the therapeutic effect of surgery plus IMRT in laryngeal cancer was rarely reported. This study aims to determine the effect of IMRT on the treatment of patients with laryngeal cancer.

METHODS

A total of 125 patients with laryngeal cancer were collected and retrospectively analyzed based on their clinical data and follow-up results. These patients had a clear treatment plan for surgery and intensity-modulated radiotherapy.

RESULTS

Smoking, lymph node metastasis, TNM staging and therapeutic approaches could affect the survival of patients with laryngeal cancer. It was shown that the laryngeal function retention rate in the simple IMRT group was significantly higher than the simple surgery group and surgery plus IMRT group. The 5-year survival rate of surgery plus IMRT, simple surgery and simple IMRT were 82.86%, 53.85% and 43.33%, respectively. The locoregional recurrences rate of surgery plus IMRT, simple surgery and simple IMRT were 14.29%, 34.62% and 43.33%.

CONCLUSION

Surgery plus IMRT was a feasible and efficacious treatment technique for patients with laryngeal cancer, which effectively prolong the survival time of patients.

Radiation treatment for adult rare cancers: Oldest and newest indication

AIM

Aim of this analysis is to review the role of RT in the management of several rare tumors for adult patients.

METHODS

Collection data regarding RT and rare tumors was made by Pubmed.

RESULTS

For mucosal melanomas, RT is prescribed, being associated with lower local recurrence rate. For trachea tumors, RT was used as adjuvant or salvage treatment for unresectable disease. For pNET, RT can be a suitable option for post-surgical or unresectable/borderline. For bronchopulmonary neuroendocrine tumors the role of adjuvant treatments is uncertain. For hepatobiliary and ovarian malignancy, stereotactic body RT (SBRT) is a promising approach. For soft tissue sarcoma, perioperative treatments are indicated, and a growing role of SBRT in oligometastatic disease is recognized. For endocrine tumors, adjuvant RT has demonstrated benefits through reducing recurrence risk.

CONCLUSION

The radiotherapy is a frequent indication in adult rare cancers; thus the role of Radiation Oncologist must not be neglected.

Abdominal FLASH irradiation reduces radiation-induced gastrointestinal toxicity for the treatment of ovarian cancer in mice

Radiation therapy is the most effective cytotoxic therapy for localized tumors. However, normal tissue toxicity limits the radiation dose and the curative potential of radiation therapy when treating larger target volumes. In particular, the highly radiosensitive intestine limits the use of radiation for patients with intra-abdominal tumors. In metastatic ovarian cancer, total abdominal irradiation (TAI) was used as an effective postsurgical adjuvant therapy in the management of abdominal metastases. However, TAI fell out of favor due to high toxicity of the intestine. Here we utilized an innovative preclinical irradiation platform to compare the safety and efficacy of TAI ultra-high dose rate FLASH irradiation to conventional dose rate (CONV) irradiation in mice. We demonstrate that single high dose TAI-FLASH produced less mortality from gastrointestinal syndrome, spared gut function and epithelial integrity, and spared cell death in crypt base columnar cells compared to TAI-CONV irradiation. Importantly, TAI-FLASH and TAI-CONV irradiation had similar efficacy in reducing tumor burden while improving intestinal function in a preclinical model of ovarian cancer metastasis. These findings suggest that FLASH irradiation may be an effective strategy to enhance the therapeutic index of abdominal radiotherapy, with potential application to metastatic ovarian cancer.

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.

Novel Therapeutic Strategies for Ovarian Cancer Stem Cells

Ovarian cancer (OC) is one of the most lethal gynecologic malignancies. Due to the lack of specific symptoms and screening methods, this disease is usually diagnosed only at an advanced and metastatic stage. The gold-standard treatment for OC patients consists of debulking surgery followed by taxane combined with platinum-based chemotherapy. Most patients show complete clinical remission after first-line therapy, but the majority of them ultimately relapse, developing radio- and chemoresistant tumors. It is now proposed that the cause of recurrence and reduced therapy efficacy is the presence of small populations of cancer stem cells (CSCs). These cells are usually resistant against conventional cancer therapies and for this reason, effective targeted therapies for the complete eradication of CSCs are urgently needed. In this review article, we highlight the mechanisms of CSC therapy resistance, epithelial-to-mesenchymal transition, stemness, and novel therapeutic strategies for ovarian CSCs.

Immune Checkpoint Inhibitors in Epithelial Ovarian Cancer: An Overview on Efficacy and Future Perspectives

Epithelial ovarian cancer (EOC) is the leading cause of death among gynecological cancers. Despite improvements in medical treatments, the prognosis for EOC remains poor, and there is an urgent need for new therapeutic strategies. Immune checkpoint inhibitors (CPIs) have dramatically improved survival of several cancers and are under evaluation in OC. Unfortunately, CPIs have shown globally unsatisfactory results. The aim of this manuscript is to critically review the results from early-phase trials with CPIs in terms of safety and activity, discuss the possible reasons for disappointing results and the new therapeutic approaches to improve patient outcomes.