Combining novel agents with radiotherapy for gynecologic malignancies: beyond the era of cisplatin

Understanding the molecular mechanism responsible for developing therapeutic radiation-induced radioresistance of rectal cancer and improving the clinical outcomes of radiotherapy - A review

Rectal cancer accounts for the second highest cancer-related mortality, which is predominant in Western civilizations. The treatment for rectal cancers includes surgery, radiotherapy, chemotherapy, and immunotherapy. Radiotherapy, specifically external beam radiation therapy, is the most common way to treat rectal cancer because radiation not only limits cancer progression but also significantly reduces the risk of local recurrence. However, therapeutic radiation-induced radioresistance to rectal cancer cells and toxicity to normal tissues are major drawbacks. Therefore, understanding the mechanistic basis of developing radioresistance during and after radiation therapy would provide crucial insight to improve clinical outcomes of radiation therapy for rectal cancer patients. Studies by various groups have shown that radiotherapy-mediated changes in the tumor microenvironment play a crucial role in developing radioresistance. Therapeutic radiation-induced hypoxia and functional alterations in the stromal cells, specifically tumor-associated macrophage (TAM) and cancer-associated fibroblasts (CAF), play a crucial role in developing radioresistance. In addition, signaling pathways, such as - the PI3K/AKT pathway, Wnt/β-catenin signaling, and the hippo pathway, modulate the radiation responsiveness of cancer cells. Different radiosensitizers, such as small molecules, microRNA, nanomaterials, and natural and chemical sensitizers, are being used to increase the effectiveness of radiotherapy. This review highlights the mechanism responsible for developing radioresistance of rectal cancer following radiotherapy and potential strategies to enhance the effectiveness of radiotherapy for better management of rectal cancer.

Case report: A kidney metastasis from vulvar squamous cell carcinoma

Introduction

Distant metastases of vulvar SCC most commonly involve the lung, liver, bone, skin, and lymph nodes. Metastasis from vulvar SCC to the kidneys is extremely rare, with only one case reported in the literature to date.

Case presentation

We report the case of a 53-year-old postmenopausal female patient was diagnosed with vulvar squamous cell carcinoma in an external hospital and following the diagnosis, she had been performed a vulvectomy for squamous cell carcinoma of the vulva, at that time, the patient had not undergone inguinal lymphadenectomy. In July 2019, she was admitted to our hospital due to upper right quadrant pain. An enhanced whole-body CT scan showed a mixed-density tumor of the right kidney with invasion into the right renal portal vein and multiple enlarged retroperitoneal lymph nodes. Positron emission tomography-computed tomography (PET - CT) scan showed a significantly increased radioactivity uptake in the tumor and enlarged lymph nodes, but PET-CT did not show abnormal enlargement of bilateral inguinal lymph nodes and no abnormal increase in radioactivity uptake. PET-CT examination did not show recurrence in terms of local of vulvar. These results led us to be gravely worried about possible renal carcinoma, so it was agreed upon to perform laparoscopic nephrectomy of the right kidney in the same month. Histology of the resected tumor confirmed it to be poorly differentiated squamous cell carcinoma with invasion consistent with metastatic vulvar carcinoma. Based on clinical history, radiological and histological facts, the patient was diagnosed with kidney metastasis from vulvar squamous cell carcinoma. Recovery from surgery went well and the patient was transferred to the oncology department and underwent a chemotherapy regimen consisting of paclitaxel and nedaplatin for further treatment. After 6 courses of chemotherapy. For a year after treatment, the patient had lived progression-free. Unfortunately, she died of tumor progression in July 2022.

Conclusion

Although renal metastasis from vulvar SCC is rare, renal metastasis should be considered for the patient with a history of vulvar cancer, whenever a mass is identified in the kidney. Timely surgical removal of renal metastasis may prolong the survival time.

BMN673 Is a PARP Inhibitor with Unique Radiosensitizing Properties: Mechanisms and Potential in Radiation Therapy

BMN673 is a relatively new PARP inhibitor (PARPi) that exhibits superior efficacy in vitro compared to olaparib and other clinically relevant PARPi. BMN673, similar to most clinical PARPi, inhibits the catalytic activities of PARP-1 and PARP-2 and shows impressive anticancer potential as monotherapy in several pre-clinical and clinical studies. Tumor resistance to PARPi poses a significant challenge in the clinic. Thus, combining PARPi with other treatment modalities, such as radiotherapy (RT), is being actively pursued to overcome such resistance. However, the modest to intermediate radiosensitization exerted by olaparib, rucaparib, and veliparib, limits the rationale and the scope of such combinations. The recently reported strong radiosensitizing potential of BMN673 forecasts a paradigm shift on this front. Evidence accumulates that BMN673 may radiosensitize via unique mechanisms causing profound shifts in the balance among DNA double-strand break (DSB) repair pathways. According to one of the emerging models, BMN673 strongly inhibits classical non-homologous end-joining (c-NHEJ) and increases reciprocally and profoundly DSB end-resection, enhancing error-prone DSB processing that robustly potentiates cell killing. In this review, we outline and summarize the work that helped to formulate this model of BMN673 action on DSB repair, analyze the causes of radiosensitization and discuss its potential as a radiosensitizer in the clinic. Finally, we highlight strategies for combining BMN673 with other inhibitors of DNA damage response for further improvements.

Drug repurposing as a potential source of innovative therapies in cervical cancer

OBJECTIVE

Drug repurposing is an alternative development pathway that utilizes the properties of drugs approved for other diseases and builds on available safety and pharmacological data to develop the drug as a potential treatment for other diseases. A literature-based approach was performed to identify drug repurposing opportunities in cervical cancer to inform future research and trials.

METHODS

We queried PubMed for each drug included in two databases (ReDO_DB and CDcervix_DB, which include 300+ non-cancer drugs and 200+ cancer drugs not used in cervical cancer, respectively) and manually assessed all abstracts for relevance and activity in cervix cancer, and type of evidence. Subsequently, we also performed a search of clinical trial databases where we generated a list of registered trials in cervical cancer with all drugs from our databases.

RESULTS

Of the 534 drugs from both databases, 174 (33%) had at least one relevant abstract or registered trial in cervical cancer. 94 (18%) drugs had at least human data available, and 52 (10%) drugs were evaluated in registered trials. To prioritize drugs to consider for future trials, all 174 drugs were further assessed for strength of scientific rationale, feasibility for integration in cervical cancer standard of care, evidence of radiosensitization, and potential mechanism of action. Out of the 174 drugs, 38 (22%) potential drug candidates were selected.

CONCLUSION

This study resulted in a list of candidate drugs for potential evaluation in cervical cancer. Many drugs might warrant additional (pre)clinical investigation, which could be done in a coordinated manner using platform trials.

Long-term survival following definitive radiation therapy for recurrence or oligometastases in gynecological malignancies: A landmark analysis

OBJECTIVE

Radiation therapy (RT) may improve outcomes for patients with oligometastatic cancer. We sought to determine if there are long-term survivors treated with definitive RT for recurrent or oligometastatic gynecological cancer (ROMGC), and to evaluate the clinical and disease characteristics of these patients.

METHODS

We performed a landmark analysis in 48 patients with ROMGC who survived for ≥5 years following definitive RT of their metastasis. Patient characteristics were extracted from the medical record. DFS was modeled using the Kaplan-Meier method.

RESULTS

This cohort included 20 patients (42%) with ovarian cancer, 16 (33%) with endometrial cancer, 11 (23%) with cervical cancer, and one (2%) with vaginal cancer. The sites of ROMGC were the pelvic (46%), para-aortic (44%), supraclavicular (7%), mediastinal (4%), axillary (4%) lymph nodes and the lung (5.5%). Median total RT dose and fractionation were 62.1 Gy and 2.1 Gy/fraction; one patient was treated with SBRT. 32 patients (67%) received chemoradiation; these patients had higher rates of median DFS than those treated with RT alone (93 vs. 34 months, P = 0.05). At median follow-up of 11.7 years, 11 (23%) patients had progression of disease. 20 (42%) patients had died, 9 (19%) died from non-gynecologic cancer and 8 (17%) from gynecologic cancer (three were unknown). 25 (52%) patients were alive and disease-free (10 initially had endometrial cancer [63% of these patients], eight had cervical cancer [73%], six had ovarian cancer [30%], one had vaginal cancer [100%]).

CONCLUSIONS

Long-term survival is possible for patients treated with definitive RT for ROMG, however randomized data are needed to identify which patients derive the most benefit.

miR-200a/b/-429 downregulation is a candidate biomarker of tumor radioresistance and independent of hypoxia in locally advanced cervical cancer

Many patients with locally advanced cervical cancer experience recurrence within the radiation field after chemoradiotherapy. Biomarkers of tumor radioresistance are required to identify patients in need of intensified treatment. Here, the biomarker potential of miR-200 family members was investigated in this disease. Also, involvement of tumor hypoxia in the radioresistance mechanism was determined, using a previously defined 6-gene hypoxia classifier. miR-200 expression was measured in pre-treatment tumor biopsies of an explorative cohort (n=90) and validation cohort 1 (n=110) by RNA sequencing. Publicly available miR-200 data of 79 patients were included for validation of prognostic significance. A score based on expression of the miR-200a/b/-429 (miR-200a, miR-200b and miR-429) cluster showed prognostic significance in all cohorts. The score was significant in multivariate analysis of central pelvic recurrence. No association with distant recurrence or hypoxia status was found. Potential miRNA target genes were identified from gene expression profiles and showed enrichment of genes in extracellular matrix organization and cell adhesion. miR-200a/b/-429 overexpression had a pronounced radiosensitizing effect in tumor xenografts, whereas the effect was minor in vitro. In conclusion, miR-200a/b/-429 downregulation is a candidate biomarker of central pelvic recurrence and seems to predict cell-adhesion-mediated tumor radioresistance independent of clinical markers and hypoxia.

Advances in the treatment of platinum resistant epithelial ovarian cancer: an update on standard and experimental therapies

Introduction: Platinum-resistant ovarian cancer (PROC) is broadly defined as disease recurrence within 6 months of completing platinum-based chemotherapy, either in the primary or recurrent setting. Although there is significant heterogeneity, PROC is generally associated with poor outcomes and low response rates to standard chemotherapy. There have been novel developments in therapeutics for PROC based on biomarkers and a more nuanced understanding of DNA repair and immunologic pathways.Areas covered: This review provides a summary of standard of care and experimental therapies for patients with PROC. Recent advances in our understanding of the DNA damage response and immunobiology of ovarian cancer have paved the way for single agent and combinatorial strategies involving PARP inhibitors, cell cycle checkpoint inhibitors, and immune checkpoint inhibitors to overcome PARP resistance, capitalize on high replication stress, and promote effective anti-tumor immunity, respectively. Furthermore, novel agents including antibody drug conjugates, bispecific antibodies, and recombinant fusion proteins show promise as experimental treatment options.Expert opinion: Standard and experimental treatment options available to patients with PROC have expanded. Testing for BRCA status, tumor mutational burden, and mismatch repair deficiency is recommended to guide therapy. Clinical trial participation is strongly encouraged with a focus on biomarker-driven trials targeting specific patient populations. Novel approaches such as ADCs, bispecific antibodies, targeting the GAS6/AXL and Notch pathways, and oncolytic virotherapy show considerable promise as emerging therapies.

Immune correlates of therapy outcomes in women with cervical cancer treated with chemoradiotherapy: A systematic review

Background

Immune markers have been correlated with prognosis in a variety of solid tumors, including cervical cancer.

Objective

To review the literature on hematologic and immune markers and their association with recurrence and survival among patients with cervical cancer treated with chemoradiation.

Evidence review

This systematic review was conducted in accordance with PRISMA guidelines via searches of Ovid MEDLINE, Ovid Embase, and the Cochrane Library using keywords regarding cervical cancer, immune markers, and HIV. Studies involving patients treated with cisplatin‐based chemoradiotherapy were selected and reviewed by at least two independent reviewers, with disagreements resolved by a third reviewer.

Findings

A total of 737 studies were identified, of which 314 assessed immune biomarkers in immunocompetent patients (30 included in the final analysis) and 327 studies in immunosuppressed patients (5 included in the final analysis). The strongest prognostic indicators were lymphopenia and elevated neutrophil‐to‐lymphocyte ratio. Other potential markers included HPV‐specific lymphocyte response, cytokine profile, expression of immune‐blocking antigens on cell surfaces, and tumor‐associated lymphocyte, macrophage, and neutrophil infiltration. Studies of immunosuppressed patients described more severe cytopenic changes overall and concluded that viral suppression led to improved outcomes.

Conclusions

The immunologic interplay at work in cervical cancer development, progression, and treatment is complex. Strong evidence was found in favor of lymphopenia and elevated neutrophil‐to‐lymphocyte ratio being prognostic for worse outcomes with other markers showing potential associations as well. Although the interpretation of immune status with regard to treatment approach remains unclear, future studies should aim to tailor treatment that minimizes possible detrimental immune effects.

Immune markers have been correlated with prognosis in a variety of solid tumors, including cervical cancer. In this systematic review of immune markers for cervical cancer patients being treated with chemoradiation, we surveyed the literature for immunologic and hematologic prognostic markers and found the strongest negative prognostic indicators were lymphopenia and elevated neutrophil‐to‐lymphocyte ratio.

BRD4 inhibition sensitizes cervical cancer to radiotherapy by attenuating DNA repair

Cisplatin-based chemoradiotherapy is the recommended treatment for local advanced cervical cancer, but radioresistance remains one of the most important and unresolved clinical problems. Investigations have revealed aberrant epigenetic modifications as one of the chief culprits for the development of radioresistance. Here, we attempt to identify a radiosensitizer from an epigenetic drug synergy screen and explore the underlying mechanism. We integrated epigenetic inhibitors and radiotherapy in cervical cancer cell lines to identify potential radiosensitizers. We further verified the sensitization effect of the drug and the function of its target gene both in vitro and in vivo. Finally, we validated the clinical significance of its target gene in clinical cervical cancer specimens. We identified JQ1, a BRD4 inhibitor, as a potent radiosensitizer. Functional assays demonstrated that repressing BRD4 activity led to significant radiosensitization and potentiation of DNA damage in cervical cancer cell lines. By using RNA-seq to determine JQ1-mediated changes in transcription, we identified RAD51AP1 as a major BRD4 target gene involved in radiosensitivity. A dual-luciferase reporter assay and ChIP-qPCR showed that BRD4 binds to the promoter region of RAD51AP1 and promotes its transcription, whereas this activity was attenuated by BRD4 inhibition. The in vivo experiments also suggested a synergy between BRD4 inhibition and radiotherapy. High BRD4 expression was found to be related to a worse prognosis and radiation resistance. BRD4 inhibition sensitizes cervical cancer to radiotherapy by inhibiting RAD51AP1 transcription. The combination of JQ1 with radiotherapy merits further evaluation as a therapeutic strategy for improving local control in cervical cancer.

Is There a Place for Immune Checkpoint Inhibitors in Vulvar Neoplasms? A State of the Art Review

Vulvar cancer (VC) is a rare neoplasm, usually arising in postmenopausal women, although human papilloma virus (HPV)-associated VC usually develop in younger women. Incidences of VCs are rising in many countries. Surgery is the cornerstone of early-stage VC management, whereas therapies for advanced VC are multimodal and not standardized, combining chemotherapy and radiotherapy to avoid exenterative surgery. Randomized controlled trials (RCTs) are scarce due to the rarity of the disease and prognosis has not improved. Hence, new therapies are needed to improve the outcomes of these patients. In recent years, improved knowledge regarding the crosstalk between neoplastic and tumor cells has allowed researchers to develop a novel therapeutic approach exploiting these molecular interactions. Both the innate and adaptive immune systems play a key role in anti-tumor immunesurveillance. Immune checkpoint inhibitors (ICIs) have demonstrated efficacy in multiple tumor types, improving survival rates and disease outcomes. In some gynecologic cancers (e.g., cervical cancer), many studies are showing promising results and a growing interest is emerging about the potential use of ICIs in VC. The aim of this manuscript is to summarize the latest developments in the field of VC immunoncology, to present the role of state-of-the-art ICIs in VC management and to discuss new potential immunotherapeutic approaches.

Stereotactic body radiation therapy for oligometastatic gynecologic malignancies: A systematic review

OBJECTIVE

To assess the efficacy and safety of stereotactic body radiation therapy (SBRT) for oligometastatic gynecologic malignancies.

METHOD

A comprehensive search of the PubMed, Medline, and EMBASE databases was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. "Oligometastatic" was defined as a limited number of uncontrolled/untreated metastatic lesions (typically ≤ 5), including regional nodal metastases. Primary outcomes were response rate (complete response or partial response), local control of oligometastatic lesions, and toxicity.

RESULTS

Of 716 screened records, 17 studies (13 full length articles, 4 conference abstracts) were selected and analyzed as 16 unique studies. A total of 667 patients were treated with ~1071 metastatic lesions identified. Primary sites included ovarian (57.6%), cervical (27.1%), uterine (11.1%), vaginal (0.4%), vulvar (0.3%), and other/unspecified (3.4%). Most patients (65.4%) presented with a single metastatic lesion. Metastatic lesion sites included the abdomen (44.2%), pelvis (18.8%), thorax (15.5%), neck (4.6%), central nervous system (4.3%), bone (1.6%), and other/unspecified (11%). Of the lesions, 64% were nodal. Response rate (among 8 studies) ranged from 49% to 97%, with 7/8 studies reporting > 75% response rate. Local control ranged from 71% to 100%, with 14/16 studies reporting ≥ 80% local control. No grade ≥ 3 toxicities were observed in 9/16 (56%) studies. Median progression-free survival (PFS) (among 10 studies) ranged from 3.3 months to 21.7 months. Disease progression most commonly occurred outside of the SBRT radiation field (79% to 100% of failures).

CONCLUSIONS

SBRT for oligometastatic gynecologic malignancies is associated with favorable response and local control rates but a high rate of out-of-field progression and heterogeneous PFS. Additional study into rational combinations of SBRT and systemic therapy appears warranted to further improve patient outcomes.

New small-molecule compound Hu-17 inhibits estrogen biosynthesis by aromatase in human ovarian granulosa cancer cells

Estrogen-dependent cancers (breast, endometrial, and ovarian) are among the leading causes of morbidity and mortality in women worldwide. Aromatase is the main enzyme that catalyzes the biosynthesis of estrogen, which drives proliferation, and antiestrogens can inhibit the growth of these estrogen-dependent cancers. Hu-17, an aromatase inhibitor, is a novel small-molecule compound that suppresses viability of and promotes apoptosis in ovarian cancer cells. Therefore, this study aimed to predict targets of Hu-17 and assess its intracellular signaling in ovarian cancer cells. Using the Similarity Ensemble Approach software to predict the potential mechanism of Hu-17 and combining phospho-proteome arrays with western blot analysis, we observed that Hu-17 could inhibit the ERK pathway, resulting in reduced estrogen synthesis in KGN cells, a cell line derived from a patient with invasive ovarian granulosa cell carcinoma. Hu-17 reduced the expression of CYP19A1 mRNA, responsible for producing aromatase, by suppressing the phosphorylation of cAMP response element binding-1. Hu-17 also accelerated aromatase protein degradation but had no effect on aromatase activity. Therefore, Hu-17 could serve as a potential treatment for estrogen-dependent cancers albeit further investigation is warranted.

Change in practice in gynecologic oncology during the COVID-19 pandemic: a social media survey

OBJECTIVE

COVID-19 has affected gynecologic cancer management. The goal of this survey was to evaluate changes that occurred in gynecologic oncology practice during the COVID-19 pandemic.

METHODS

A anonymous survey consisting of 33 questions (https://sites.google.com/view/gyncacovidfmartinelli) regarding interaction between gynecologic cancers and COVID-19 was distributed online via social media from April 9 to April 30, 2020. Basic descriptive statistics were applied. Analytics of survey-diffusion and generated-interest (visualizations, engagement rates, response rate) were analyzed.

RESULTS

The survey received 20 836 visualizations, generating an average engagement rates by reach of 4.7%. The response rate was 30%. A total of 86% of respondents completed the survey, for a total of 187 physicians surveyed across 49 countries. The majority (143/187; 76%) were gynecologic oncologists, and most were ≤50 years old (146/187; 78%). A total of 49.7% (93/187) were facing the early phase of the COVID-19 pandemic, while 26.7% (50/187) and 23.5% (44/187) were in the peak and plateau phases, respectively. For 97.3% (182/187) of respondents COVID-19 affected or changed their respective clinical practice. Between 16% (27/165) (before surgery) and 25% (26/102) (before medical treatment) did not perform any tests to rule out COVID-19 infection among patients. The majority of respondents did not alter indications of treatment if patients were COVID-19-negative, while treatments were generally postponed in COVID-19-positive patients. Treatments were considered priority for: early stage high-risk uterine cancers (85/187; 45%), newly diagnosed epithelial ovarian cancer (76/187; 41%), and locally advanced cervical cancer (76/187; 41%). Treatment of early stage low-grade endometrioid endometrial cancer was deferred according to 49% (91/187) of respondents, with hormonal treatment as the option of therapy (31%; 56/178). A total of 77% (136/177) of respondents reported no changes in (surgical) treatment for early stage cervical cancer in COVID-19-negative patients, while treatment was postponed by 54% (96/177) of respondent, if the patient tested COVID-19-positive. Neoadjuvant chemotherapy for advanced ovarian cancers was considered by over one-third of respondents as well as hypofractionation of radiation treatment for locally advanced cervical cancers.

CONCLUSION

COVID-19 affected the treatment of gynecologic cancers patients, both in terms of prioritization and identification of strategies to reduce hospital access and length of stay. Social media is a reliable tool to perform fast-tracking, worldwide surveys.

Determinants of Sensitivity to Radiotherapy in Endometrial Cancer

Radiotherapy is one of the cornerstone treatments for endometrial cancer and has successfully diminished the risk of local recurrences after surgery. However, a considerable percentage of patients suffers tumor relapse due to radioresistance mechanisms. Knowledge about the molecular determinants that confer radioresistance or radiosensitivity in endometrial cancer is still partial, as opposed to other cancers. In this review, we have highlighted different central cellular signaling pathways and processes that are known to modulate response to radiotherapy in endometrial cancer such as PI3K/AKT, MAPK and NF-κB pathways, growth factor receptor signaling, DNA damage repair mechanisms and the immune system. Moreover, we have listed different clinical trials employing targeted therapies against some of the aforementioned signaling pathways and members with radiotherapy. Finally, we have identified the latest advances in radiotherapy that have started being utilized in endometrial cancer, which include modern radiotherapy and radiogenomics. New molecular and genetic studies in association with the analysis of radiation responses in endometrial cancer will assist clinicians in taking suitable decisions for each individual patient and pave the path for personalized radiotherapy.