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

PARP inhibitor resistance in breast and gynecological cancer: Resistance mechanisms and combination therapy strategies

Breast cancer and gynecological tumors seriously endanger women’s physical and mental health, fertility, and quality of life. Due to standardized surgical treatment, chemotherapy, and radiotherapy, the prognosis and overall survival of cancer patients have improved compared to earlier, but the management of advanced disease still faces great challenges. Recently, poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis) have been clinically approved for breast and gynecological cancer patients, significantly improving their quality of life, especially of patients with BRCA1/2 mutations. However, drug resistance faced by PARPi therapy has hindered its clinical promotion. Therefore, developing new drug strategies to resensitize cancers affecting women to PARPi therapy is the direction of our future research. Currently, the effects of PARPi in combination with other drugs to overcome drug resistance are being studied. In this article, we review the mechanisms of PARPi resistance and summarize the current combination of clinical trials that can improve its resistance, with a view to identify the best clinical treatment to save the lives of patients.

The role of proton therapy in gynecological radiation oncology

Proton beam therapy is an external beam radiotherapy modality that offers potentially similar efficacy and reduced toxicity compared with photon radiotherapy due to little to no exit dose of radiation beyond the intended target. Improvements in radiotherapy from two-dimensional, to three-dimensional, to intensity-modulated radiation therapy have offered comparable to improved efficacy of radiation therapy with progressive reductions in toxicity. Proton beam therapy may offer further improvements, with multiple dosimetric studies demonstrating potential reductions in exposure of normal tissue to radiation, particularly bowel and bone marrow. Proton beam therapy offers avenues for dose escalation or re-irradiation, which were previously not feasible with photon radiotherapy. Although early clinical data generally demonstrate safety, feasibility, and efficacy in a few series, prospective clinical trials are limited and needed to better define who might benefit from proton therapy. In this review, we discuss the history, dosimetry, available clinical data, and technical needs to deliver high-quality proton therapy.

Gamma Knife Radiosurgery-Based Combination Treatment Strategies Improve Survival in Patients With Central Nervous System Metastases From Epithelial Ovarian Cancer: A Retrospective Analysis of Two Academic Institutions in Korea and Taiwan

Central nervous system (CNS) metastases from epithelial ovarian cancer (EOC) are rare. We investigated the clinico-pathological prognostic factors of patients with CNS metastases from EOC and compared the outcomes of various treatment modalities. We retrospectively reviewed the records of patients with CNS metastases from EOC between 2000 and 2020. Information on the clinical and pathological characteristics, treatment, and outcomes of these patients was retrieved from Samsung Medical Center and National Taiwan University Hospital. A total of 94 patients with CNS metastases were identified among 6,300 cases of EOC, resulting in an incidence of 1.49%. Serous histological type [hazard ratio (HR): 0.49 (95% confidence interval [CI] 0.25-0.95), p=0.03], progressive disease [HR: 2.29 (95% CI 1.16-4.54), p=0.01], CNS involvement in first disease relapse [HR: 0.36 (95% CI 0.18-0.70), p=0.002], and gamma knife radiosurgery (GKS)-based combination treatment for EOC patients with CNS lesions [HR: 0.59 (95% CI 0.44-0.79), p<0.001] significantly impacted survival after diagnosis of CNS metastases. In a subgroup analysis, superior survival was observed in patients with CNS involvement not in first tumor recurrence who underwent GKS-based combination therapeutic regimens. The survival benefit of GKS-based treatment was not significant in patients with CNS involvement in first disease relapse, but a trend for longer survival was still observed. In conclusion, GKS-based combination treatment can be considered for the treatment of EOC patients with CNS metastases. The patients with CNS involvement not in first disease relapse could significantly benefit from GKS-based combination strategies.