Involved-field radiation therapy for recurrent ovarian cancer: Results of a multi-institutional prospective phase II trial

Study protocol for prospective multi-institutional phase III trial of standard of care therapy with or without stereotactic ablative radiation therapy for recurrent ovarian cancer (SABR-ROC)

BACKGROUND

Efforts have been made to investigate the role of salvage radiotherapy (RT) in treating recurrent ovarian cancer (ROC). Stereotactic ablative radiation therapy (SABR) is a state-of-the-art therapy that uses intensity modulation to increase the fractional dose, decrease the number of fractions, and target tumors with high precision.

METHODS

The SABR-ROC trial is a phase 3, multicenter, randomized, prospective study to evaluate whether the addition of SABR to the standard of care significantly improves the 3-year overall survival (OS) of patients with ROC. Patients who have completed the standard treatment for primary epithelial ovarian cancer are eligible. In addition, patients with number of metastases ≤ 10 and maximum diameter of each metastatic site of gross tumor ≤ 5 cm are allowed. Randomization will be stratified by (1) No. of the following clinical factors met, platinum sensitivity, absence of ascites, normal level of CA125, and ECOG performance status of 0-1; 0-3 vs. 4; (2) site of recurrence; with vs. without lymph nodes; and (3) PARP inhibitor; use vs. non-use. The target number of patients to be enrolled in this study is 270. Participants will be randomized in a 1:2 ratio. Participants in Arm 2 will receive SABR for recurrent lesions clearly identified in imaging tests as well as the standard of care (Arm 1) based on treatment guidelines and decisions made in multidisciplinary discussions. The RT fraction number can range from 1 to 10, and the accepted dose range is 16-45 Gy. The RT Quality Assurance (QA) program consists of a three-tiered system: general credentialing, trial-specific credentialing, and individual case reviews.

DISCUSSION

SABR appears to be preferable as it does not interfere with the schedule of systemic treatment by minimizing the elapsed days of RT. The synergistic effect between systemic treatment and SABR is expected to reduce the tumor burden by eradicating gross tumors identified through imaging with SABR and controlling microscopic cancer with systemic treatment. It might also be beneficial for quality-of-life preservation in older adults or heavily treated patients.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov (NCT05444270) on June 29th, 2022.

Radiotherapy in recurrent ovarian cancer: updated results of involved-field radiation therapy

OBJECTIVE

This study aimed to update the possible clinical benefits of radiation therapy in recurrent ovarian cancer.

METHODS

The medical records of 495 patients with recurrent ovarian cancer after initially undergoing maximal cytoreductive surgery and adjuvant platinum-based chemotherapy based on the pathologic stage between January 2010 and December 2020 were analyzed: 309 and 186 patients were treated without and with involved-field radiation therapy, respectively. Involved-field radiation therapy is defined as radiation therapy only to the areas of the body involved by tumor. The prescribed doses were ≥45 Gy (equivalent dose in 2 Gy/fraction). Overall survival was compared between patients treated with and without involved-field radiation therapy. The favorable group was defined as patients who satisfied at least four of the following factors: good performance, no ascites, normal CA-125, platinum-sensitive tumor, and nodal recurrence.

RESULTS

The median age of the patients was 56 years (range 49-63) and median time to recurrence was 11.1 months (range 6.1-15.5). 217 patients (43.8%) were treated at a single site. Radiation therapy, performance status, CA-125, platinum sensitivity, residual disease, and ascites were all significant prognostic factors. The 3-year overall survival of all patients, patients treated without radiation therapy, and patients treated with radiation therapy was 54.0%, 44.8%, and 69.3%, respectively. Radiation therapy was associated with higher overall survival rates in the unfavorable and favorable patient groups. Patient characteristics showed higher rates of normal CA-125, lymph node metastasis only, lower platinum sensitivity, and higher rates of ascites in the radiation therapy group. After propensity score matching, the radiation therapy group showed superior overall survival to the non-radiation therapy group. Normal CA-125, good performance status, and platinum sensitivity were associated with a good prognosis in patients treated with radiation therapy.

CONCLUSION

Our study showed that higher overall survival was observed in patients treated with radiation therapy in recurrent ovarian cancer.

Role of salvage radiotherapy for recurrent ovarian cancer

OBJECTIVE

This study aimed to report clinical outcomes of salvage radiotherapy for recurrent ovarian cancer and identify predictors of clinical outcomes.

METHODS

We retrospectively reviewed data of patients who received salvage radiotherapy for recurrent ovarian cancer between January 2011 and June 2021. Stereotactic body radiotherapy, involved-field radiotherapy with conventional fractionation, and non-involved-field radiotherapy with conventional fractionation were included in this study. Local failure-free survival, progression-free survival, chemotherapy-free survival, and overall survival were assessed. Additionally, potential prognostic factors for survival were analyzed.

RESULTS

A total of 79 patients were included with 114 recurrent lesions. The median follow-up was 18.3 months (range 1.7-83). The 2-year local failure-free survival, progression-free survival, chemotherapy-free survival, and overall survival rates were 80.7%, 10.6%, 21.2%, and 74.7%, respectively. Pre-radiotherapy platinum resistance (hazard ratio (HR) 3.326, p<0.001) and short pre-radiotherapy CA-125 doubling time (HR 3.664, p<0.001) were associated with poor chemotherapy-free survival. The 1-year chemotherapy-free survival rates of patients with both risk factors, a single risk factor, and no risk factor were 0%, 20.4%, and 53.5%, respectively. The difference between risk groups was statistically significant: low risk versus intermediate risk (p<0.001) and intermediate risk versus high risk (p<0.001).

CONCLUSIONS

Salvage radiotherapy for recurrent ovarian cancer resulted in local control with improved chemotherapy-free survival in carefully selected patients. Our results suggest that the consideration of pre-radiotherapy platinum resistance and pre-radiotherapy CA-125 doubling time could help with patient selection.

Management of oligometastatic ovarian cancer recurrence during PARP inhibitor maintenance

OBJECTIVE

The benefit of surgery and maintenance treatment with PARP inhibitors (PARPi) has been clearly demonstrated in ovarian cancer. Also, the efficacy and safety of stereotactic body radiotherapy has been shown in patients with metastatic, persistent, and recurrent disease. The aim of this study is to evaluate the management of oligometastatic progression during PARPi maintenance treatment.

METHODS

This is an observational, retrospective, single-arm study conducted from June 2017 to December 2020 in patients with recurrent ovarian cancer with oligometastatic progression under PARPi maintenance treatment and receiving surgery or stereotactic body radiotherapy for such recurrence. PARPi treatment was continued until further progression of the disease. The primary objective of the study was the median prolongation of the treatment-free interval-p (without platinum) after local treatment.

RESULTS

A total of 186 patients with ovarian cancer were treated with PARPi at recurrence. Of these, 30 (16%) developed oligometastatic progression. The median age was 49.5 years (range 35-73). Olaparib, niraparib and rucaparib were administered to 33%, 60%, and 7% of patients, respectively. The median prolongation of the treatment-free interval-p of patients treated with surgery or stereotactic body radiotherapy was 6 and 10 months, respectively (p=0.53). The median treatment-free interval-p of patients treated with surgery or stereotactic body radiotherapy at the time of oligometastatic progression was 32 and 29 months, respectively (p=0.44). At the time of this publication, 50% of patients are still on treatment with PARPi following progression.

CONCLUSIONS

Patients with recurrent ovarian cancer who have oligometastic progression during PARPi maintenance may continue to benefit from PARPi if combined with local treatment.

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.

Efficacy of Modified Qingre Jiedu Decoction Combined with Three-Dimensional Conformal Radiotherapy in Treating Moderate to Advanced Ovarian Carcinoma and Its Effect on Levels of Serum Carcinoembryonic Antigen and Carbohydrate Antigen 125

Objective

To explore the efficacy of modified Qingre Jiedu decoction combined with three-dimensional conformal radiotherapy (3D-CRT) in treating moderate to advanced ovarian carcinoma (OC) and its effect on patients' serum carcinoembryonic antigen (CEA) and carbohydrate antigen 125 (CA125).

Methods

The clinical data of 84 patients with moderate to advanced OC treated in the gynecology department of Changqing District People's Hospital of Jinan from February 2017 to February 2018 were selected for retrospective analysis, and the patients were divided into the single chemotherapy group (taxol + carboplatin, n = 42) and the combined group (modified Qingre Jiedu decoction+3D-CRT, n = 42) according to the parity of their admission numbers. By measuring their levels of serum CEA and CA125 after treatment, the cellular immune levels of the two groups were compared.

Results

Compared with the single chemotherapy group after treatment, the combined group obtained significantly higher total clinical effective rate and 1-year, 2-year, and 3-year survival rates (P < 0.05), significantly higher CD4⁺/CD8⁺ and NK cell level values (P < 0.001), significantly lower serum CA125 and CEA level values (P < 0.001), and significantly lower total incidence rates of toxic and side effects (P < 0.05).

Conclusion

The abovementioned results show that the combined treatment modality has a significant effect on prolonging the survival of patients with moderate to advanced OC and can effectively reduce the levels of tumor markers and improve the body's immunity. Further study will be conducive to establishing a better solution for OC patients.

Dual Knockdown of Musashi RNA-Binding Proteins MSI-1 and MSI-2 Attenuates Putative Cancer Stem Cell Characteristics and Therapy Resistance in Ovarian Cancer Cells

In ovarian cancer, therapy resistance mechanisms complicate cancer cell eradication. Targeting Musashi RNA-binding proteins (MSI) may increase therapeutic efficacy. Database analyses were performed to identify gene expression associations between MSI proteins and key therapy resistance and cancer stem cell (CSC) genes. Then, ovarian cancer cells were subjected to siRNA-based dual knockdown of MSI-1 and MSI-2. CSC and cell cycle gene expression was investigated using quantitative polymerase chain reaction (qPCR), western blots, and flow cytometry. Metabolic activity and chemoresistance were assessed by MTT assay. Clonogenic assays were used to quantify cell survival post-irradiation. Database analyses demonstrated positive associations between MSI proteins and putative CSC markers NOTCH, MYC, and ALDH4A1 and negative associations with NOTCH inhibitor NUMB. MSI-2 expression was negatively associated with the apoptosis regulator p21. MSI-1 and MSI-2 were positively correlated, informing subsequent dual knockdown experiments. After MSI silencing, CSC genes were downregulated, while cell cycle progression was reduced. Metabolic activity was decreased in some cancer cells. Both chemo- and radioresistance were reduced after dual knockdown, suggesting therapeutic potential. Dual knockdown of MSI proteins is a promising venue to impede tumor growth and sensitize ovarian cancer cells to irradiation and chemotherapy.

Ultrasound-stimulated microbubbles enhances radiosensitivity of ovarian cancer

BACKGROUND

Radiation therapy is regarded as an effective treatment for early ovarian cancer (OC). However, due to radiation resistance caused by DNA double-strand breaks (DSBs) and angiogenesis, the efficacy of radiotherapy for advanced OC is limited and controversial.

PURPOSE

To explore whether ultrasound-stimulated microbubbles (USMBs) can enhance the radiosensitivity of OC.

MATERIAL AND METHODS

OC cells (ES-2) were respectively irradiated with 5-Gy and 10-Gy radiation doses with or without exposure to USMB. Methyl thiazolyltetrazolium (MTT) and colony-formation assays were conducted to detect the viability and proliferation of ES-2 cells after USMBs and ionizing radiation (IR) treatment. Immunofluorescence assays were conducted to examine levels of gamma-H2A histone family member X (γ-H2AX), an indicator for DSBs. Flow cytometry analyses were carried out to assess the apoptosis of ES-2 cells. The angiogenic activity of human umbilical vein endothelial cells (HUVECs) was measured by tube formation assays.

RESULTS

USMBs enhanced IR-induced suppressive effect on the viability and proliferation of OC cells. The protein levels of phosphorylated γ-H2AX and CHK1 were significantly upregulated after IR treatment and further enhanced by USMBs. In addition, USMBs enhanced the promotion of IR-mediated OC cell apoptosis. The inhibitory effect of IR on angiogenesis was further enhanced by USMBs, and protein levels of AT1R, VEGFA, and EGFR were downregulated by IR in a dose-dependent way and then enhanced by USMB treatment in HUVECs.

CONCLUSIONS

USMB exposure significantly enhances the radiosensitivity of OC by suppressing cell proliferation, promoting OC cell apoptosis, and inhibiting angiogenesis.

Phase I Trial of Stereotactic MRI-Guided Online Adaptive Radiation Therapy (SMART) for the Treatment of Oligometastatic Ovarian Cancer

PURPOSE

Stereotactic body radiation therapy is increasingly used to treat a variety of oligometastatic histologies, but few data exist for ovarian cancer. Ablative stereotactic body radiation therapy dosing is challenging in sites like the abdomen, pelvis, and central thorax due to proximity and motion of organs at risk. A novel radiation delivery method, stereotactic magnetic-resonance-guided online-adaptive radiation therapy (SMART), may improve the therapeutic index of stereotactic body radiation therapy through enhanced soft-tissue visualization, real-time nonionizing imaging, and ability to adapt to the anatomy-of-the-day, with the goal of producing systemic-therapy-free intervals. This phase I trial assessed feasibility, safety, and dosimetric advantage of SMART to treat ovarian oligometastases.

METHODS AND MATERIALS

Ten patients with recurrent oligometastatic ovarian cancer underwent SMART for oligometastasis ablation. Initial plans prescribed 35 Gy/5 fractions with goal 95% planning target volume coverage by 95% of prescription, with dose escalation permitted, subject to strict organ-at-risk dose constraints. Daily adaptive planning was used to protect organs-at-risk and/or increase target dose. Feasibility (successful delivery of >80% of fractions in the first on-table attempt) and safety of this approach was evaluated, in addition to efficacy, survival metrics, quality-of-life, prospective timing and dosimetric outcomes.

RESULTS

Ten women with seventeen ovarian oligometastases were treated with SMART, and 100% of treatment fractions were successfully delivered. Online adaptive plans were selected at time of treatment for 58% of fractions, due to initial plan violation of organs-at-risk constraints (84% of adapted fractions) or observed opportunity for planning target volume dose escalation (16% of adapted fractions), with a median on-table time of 64 minutes. A single Grade ≥3 acute (within 6 months of SMART) treatment-related toxicity (duodenal ulcer) was observed. Local control at 3 months was 94%; median progression-free survival was 10.9 months. Median Kaplan-Meier estimated systemic-therapy-free survival after radiation completion was 11.5 months, with concomitant quality-of-life improvements.

CONCLUSIONS

SMART is feasible and safe for high-dose radiation therapy ablation of ovarian oligometastases of the abdomen, pelvis, and central thorax with minimal toxicity, high rates of local control, and prolonged systemic-therapy-free survival translating into improved quality-of-life.

Radiation therapy for vaginal and perirectal lesions in recurrent ovarian cancer

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Radiation to isolated vaginal and perirectal ovarian cancer recurrences provides effective in-field control.

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Complete response of targeted lesions after radiation was 88%.

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Radiation increased the chemotherapy-free interval without associated grade 3/4 toxicities.

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Platinum sensitivity prior to radiation may be associated with improved overall survival.

The role for localized radiation to treat ovarian cancer (OC) patients with locally recurrent vaginal/perirectal lesions remains unclear, though we hypothesize these patients may be salvaged locally and gain long-term survival benefit. We describe our institutional outcomes using intensity modulated radiation therapy (IMRT) +/- high-dose rate (HDR) brachytherapy to treat this population. Our primary objectives were to evaluate complete response rates of targeted lesions after radiation and calculate our 5-year in-field control (IFC) rate. Secondary objectives were to assess radiation-related toxicities, chemotherapy free-interval (CFI), as well as post-radiation progression-free (PFS) and overall survival (OS). PFS and OS were defined from radiation start to either progression or death/last follow-up, respectively. This was a heavily pre-treated cohort of 17 recurrent OC patients with a median follow-up of 28.4 months (range 4.5–166.4) after radiation completion. 52.9% had high-grade serous histology and 4 (23.5%) had isolated vaginal/perirectal disease. Four (23.5%) patients had in-field failures at 3.7, 11.2, 24.5, and 27.5 months after start of radiation, all treated with definitive dosing of radiation therapy. Patients who were platinum-sensitive prior to radiation had similar median PFS (6.5 vs. 13.4 months, log-rank p = 0.75), but longer OS (71.1 vs 18.8 months, log-rank p = 0.05) than their platinum-resistant counterparts. Excluding patients with low-grade histology or who were treated with palliative radiation, median CFI was 14.2 months (range 4.7 – 33.0). Radiation was well tolerated with 2 (12.0%) experiencing grade 3/4 gastrointestinal/genitourinary toxicities. In conclusion, radiation to treat locally recurrent vaginal/perirectal lesions in heavily pre-treated OC patients is safe and may effectively provide IFC.

Survival Analysis of Radiation Therapy in Ovarian Cancer: A SEER Database Analysis

RESULTS

A total of 20031 ovarian cancer patients were included, with 291 (1.45%) patients who received radiotherapy. The median overall survival (OS) in patients who received radiotherapy was shorter than which in patients without radiotherapy (23 vs. 75 months, P < 0.001). The Elderly, nonepithelial pathology, advanced American Joint Committee on Cancer (AJCC) stage, elevated level of CA125, and receiving radiotherapy were risk predictors to survival in both multivariable analyses before and after PSM. Among 11872 patients with III/IV stage, the radiotherapy group also showed a significantly worse prognosis (median OS: 19 vs. 44 months in patients without radiotherapy, P < 0.001). Consistent results were observed in stratification analyses on pathology and stage among patients with III/IV stage.

CONCLUSIONS

For patients with ovarian cancer, radiotherapy was associated with a poor prognosis regardless of pathology or stage. Considering this is a retrospective study, future studies concerning radiotherapy combination with other new agents in ovarian cancer are needed.

Palliative Radiation Therapy for Metastatic, Persistent, or Recurrent Epithelial Ovarian Cancer: Efficacy in the Era of Modern Technology and Targeted Agents

PURPOSE

Metastatic, persistent, or recurrent epithelial ovarian cancer (MPR-EOC) remains a significant threat to patient mortality despite advances in novel targeted agents. Radiation therapy (RT) is often used as a palliative option. We report outcomes of a large series of MPR-EOC patients treated with modern palliative RT (PRT) in an era of novel systemic therapies.

METHODS AND MATERIALS

A retrospective review was conducted of women treated with PRT for MPR-EOC between 2007 and 2019 at an academic institution. Clinical response rates were recorded at <1 month, 1 to 3 months, and >3 months. Radiographic responses were categorized by RECIST 1.1 criteria. Overall response rate (ORR) was the sum of complete and partial response. Linear regression analyses of baseline characteristics were conducted for statistical testing.

RESULTS

Eighty-six patients with PMR-OC received 120 courses of palliative RT. Median follow-up was 8.6 months. Median age was 61 (range, 22-82). Thirty-six percent of women received central nervous system (CNS)-directed RT. In addition, 43% received targeted therapies before RT. Clinical ORR within 1 month and at last follow-up for non-CNS lesions was 79% and 61% (69% and 88% for CNS lesions, respectively). High-grade serous lesions were more likely to have clinical response (P = .04). Biologically effective doses (BED) >39 Gy were associated with improved clinical response in CNS lesions (P = .049). Bony sites were associated with worse clinical (P = .004) response in non-CNS lesions compared with soft tissue or nodal sites. Acute or late grade 3+ toxicities with bevacizumab were low (8.7%/4.3%).

CONCLUSIONS

PRT offers excellent rates of response for symptomatic patients with MPR-EOC within 1 month of treatment, with durable responses beyond 3 months. High-grade serous lesions were associated with improved response in all patients. Higher BED and soft tissue or nodal sites were associated with improved response in CNS and non-CNS patients, respectively. Acute or late toxicities with bevacizumab and PRT were low. Prospective investigation is warranted to determine the optimal PRT regimen.

Improved prognosis for recurrent epithelial ovarian cancer by early diagnosis and 125I seeds implantation during suboptimal secondary cytoreductive surgery: a case report and literature review

Background

Epithelial ovarian cancer (EOC) has the worst prognosis in all of gynecologic malignant tumors because of its high recurrence and eventually chemo-resistance. Early diagnosis of recurrence is crucial to avoid diffuse dissemination. Failure of traditional treatment in recurrent epithelial ovarian cancer remains a challenge for clinicians. On the other hand, ¹²⁵I brachytherapy has been accepted as a useful and hopeful treatment for multiple advanced cancers in recent years. However, its success in advanced epithelial ovarian cancer is limited. Here we report a case of recurrent ovarian cancer who had been early diagnosis of isolated recurrence and successfully treated with ¹²⁵I seeds implantation during suboptimal cytoreductive surgery.

Case presentation

A 59-year-old woman presented with recurrent epithelial ovarian cancer who have had a history of ovarian cancer stage IIIB and an R0 resection had been achieved nearly 2 years before presented in our hospital. She underwent suboptimal secondary cytoreductive surgery after four cycles of chemotherapy with little effectiveness and severe chemotherapy-related side effects. Approximately 70% of the cancer-bulk was resected during surgery. For residual lesion which fixed around the right ureter and right external iliac vessel, ¹²⁵I seeds implantation was performed. Postoperatively, the patient was treated with two cycles of combination chemotherapy with paclitaxel and carboplatin. The patient was free of disease at 26 months’ follow-up period.

Conclusion

In recurrent EOC patients with unresectable isolated lesion, salvage 125I seeds implantation are feasible and may contribute to survival.

Clear cell carcinoma of the ovary: a clinical and molecular perspective

Clear cell carcinoma of the ovary has distinct biology and clinical behavior. There are significant geographical and racial differences in the incidence of clear cell carcinoma compared with other epithelial ovarian tumors. Patients with clear cell carcinoma are younger, tend to present at an early stage, and their tumors are commonly associated with endometriosis, which is widely accepted as a direct precursor of clear cell carcinoma and has been identified pathologically in approximately 50% of clear cell carcinoma cases. The most frequent and important specific gene alterations in clear cell carcinoma are mutations of AT-rich interaction domain 1A (ARID1A) (~50% of cases) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (~50% cases). More broadly, subgroups of clear cell carcinoma have been identified based on C-APOBEC (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like) and C-AGE (age-related) mutational signatures. Gene expression profiling shows upregulation of hepatocyte nuclear factor 1-beta (HNF1β) and oxidative stress-related genes, and has identified epithelial-like and mesenchymal-like tumor subgroups. Although the benefit of platinum-based chemotherapy is not clearly defined it remains the mainstay of first-line therapy. Patients with early-stage disease have a favorable clinical outcome but the prognosis of patients with advanced-stage or recurrent disease is poor. Alternative treatment strategies are required to improve patient outcome and the development of targeted therapies based on molecular characteristics is a promising approach. Improved specificity of the histological definition of this tumor type is helping these efforts but, due to the rarity of clear cell carcinoma, international collaboration will be essential to design appropriately powered, large-scale clinical trials.

Stereotactic Ablative Radiotherapy for Recurrent or Metastatic Gynecological Cancer: Extending Lives?

OPINION STATEMENT

Recent phase II clinical trials suggest that stereotactic ablative radiation therapy (SABR) can potentially improve survival for patients with oligometastatic cancer. However, these studies have mostly enrolled primaries other than gynecologic malignancies. While level I evidence is limited, recent publications exploring the use of SABR for oligometastatic gynecologic cancers have indicated a potential role for this treatment in para-aortic lymph node recurrences, and in visceral and brain metastases. The use of SABR for recurrences in the pelvis presents a number of challenges as these patients have often received previous radiation treatment. In these settings, care must be taken to avoid trespassing normal tissue tolerance with SABR leading to toxicity, especially as the potential benefit of SABR in this setting is not based on high-level evidence. Although SABR is feasible and in general safe for oligometastatic gynecologic malignancies, insufficient data are available to indicate whether it is associated with improved survival. Clinical judgment that incorporates patient and tumor factors is needed to determine if SABR is appropriate for selecting patients. Future directions include combining SABR with novel systemic therapies, determining optimal sequencing of treatments, and generating more robust randomized data pertaining to the use of SABR for oligometastatic gynecologic cancers.

Rethinking the Role of Radiation Therapy in the Management of Epithelial Ovarian Cancer

Radiation has been relegated to a palliative role in the management of epithelial ovarian cancer (EOC). Contemporary radiation techniques, including intensity modulated radiation therapy (IMRT), stereotactic body radiation therapy (SBRT), and image-guided radiation therapy, enable conformal treatment that controls local disease with minimal morbidity. Recent studies from multiple institutions support the role of radiation in the ablative treatment of oligometastatic disease and control of locally recurrent and metastatic disease. Effective local treatment with radiation complements the role of systemic therapy in the management of EOC; reduces symptoms and disease burden, and may contribute to a prolonged drug free interval.

Involved-field radiation therapy for selected cases of recurrent ovarian cancer

OBJECTIVES

In our institutional experience, involved-field radiation therapy (IFRT) yields favorable outcomes in patients with recurrent epithelial ovarian cancer (EOC). This retrospective study aimed to investigate the clinical benefits of IFRT in this patient population.

METHODS

Among patients treated with IFRT for recurrent EOC between 2010 and 2017, 61 patients with 90 treatments were included. IFRT encompassed all treatable lesions identified via imaging studies with 10-15-mm margins. Prescribed doses were ≥45 Gy (equivalent dose in 2 Gy/fraction).

RESULTS

Patients were followed up for a median of 19.0 (Interquartile range, 8.6-34.9) months after IFRT. The 2-year in-field control, progression-free survival, and overall survival (OS) rates were 42.7%, 24.2%, and 78.9%, respectively. Fifty-three IFRT sessions (58.9%) were followed by systemic chemotherapy, and the median chemotherapy-free interval (CFI) was 10.5 (95% confidence interval=7.3-13.7) months. A higher carbohydrate antigen-125 (CA-125) level correlated with a worse 2-year OS (69.2% vs. 91.0%; p=0.001) and shorter median CFI (4.7 vs. 11.9 months; p<0.001). Twenty-eight (31.1%) of 90 treatments yielded a long-term CFI >12 months. For patients with a normal CA-125 level and/or platinum-sensitive tumor, IFRT prolonged CFI regardless of pre-existing carcinomatosis, gross tumor volume, and number of treatment sites.

CONCLUSION

Our early experience demonstrates the safety and feasibility of IFRT as an effective salvage therapy and enables a "chemotherapy holiday" in selected recurrent EOC settings. The CA-125 value before IFRT (within normal range) and/or platinum sensitivity could be used as selection criteria for IFRT.

[Radiotherapy for ovarian carcinoma management: Literature review]

Ovarian cancer is the fifth most common cancer in women in France with 4714 new cases in 2017. More than 70% of patients whose disease is initially locally advanced will present locoregional or distant recurrence. Therapeutic options in this situation are not consensual. They are based on chemotherapy possibly associated with an iterative cytoreductive surgery when it is bearable by the patient. The place of radiotherapy in the management of the disease is hidden in the vast majority of national or international standards. We conducted a general review of the literature to clarify the role of irradiation in the global management of ovarian cancers, particularly in recurrence.

Proton beam therapy for recurrent ovarian carcinoma: A case report

The efficacy and feasibility of proton beam therapy (PBT) for recurrent ovarian carcinoma had not been determined. Here we presented a case of recurrent ovarian carcinoma that was successfully treated with PBT. A 48-year-old woman who was diagnosed as left ovarian clear cell carcinoma underwent surgery without removal of two tumors. After achieving complete remission with postoperative chemotherapy, a recurrent tumor was found in the sigmoid colon, for which a colostomy was performed. Because second-line chemotherapy was not effective, PBT was selected; there were no complications, except for a transient low-grade fever. After 1 year of PBT, the tumor completely disappeared and the patient had been disease-free for over 8 years. PBT may be an effective and less invasive treatment modality for recurrent ovarian carcinoma.

Recent advances in gynecologic radiation oncology

PURPOSE OF REVIEW

Radiation has long been a primary treatment modality in locally advanced gynecologic carcinomas and a tool for palliation of metastatic disease. Here we review advances in imaging and radiation technologies and the corresponding clinical evolution of the role for radiation oncology in the treatment of gynecologic malignancies.

RECENT FINDINGS

Advances in MRI are impacting diagnosis, radiation target delineation, planning, treatment delivery, and response assessment. The combination of MRI and PET-computed tomography (PET-CT) has the potential to significantly change treatment recommendations as compared with a single imaging modality. Advances in radiation delivery including intensity modulated radiation therapy (IMRT) and stereotactic ablative radiotherapy (SABR) have expanded the role for radiation in the definitive treatment of high risk and oligometastatic ovarian cancer. Finally, global disparities in oncology resources has led to the development of resource stratified treatment guidelines for gynecologic malignancies. The use of ultrasound for brachytherapy planning may help improve access to this critical treatment modality.

SUMMARY

As imaging and radiation technologies advance, the indications for radiation in the treatment of gynecologic malignancies continues to evolve. Here we review the changing landscape of radiation oncology in the multidisciplinary management of gynecologic cancers.