Prediction of anti-angiogenesis escape

The prospects of microphysiological systems in modeling platelet pathophysiology in cancer

The contribution of platelets is well recognized in thrombosis and hemostasis. However, platelets also promote tumor progression and metastasis through their crosstalk with various cells of the tumor microenvironment (TME). For example, several cancer models continue to show that platelet functions are readily altered by cancer cells upon activation leading to the formation of platelet-tumor aggregates, triggering release of soluble factors from platelet granules and altering platelet turnover. Further, activated platelets protect tumor cells from shear forces in circulation and assault of cytotoxic natural killer (NK) cells. Platelet-secreted factors promote proliferation of malignant cells, metastasis, and chemoresistance. Much of our knowledge of platelet biology in cancer has been achieved with animal models, particularly murine. However, this preclinical understanding of the complex pathophysiology is yet to be fully realized and translated to clinical trials in terms of new approaches to treat cancer via controlling the platelet function. In this review, we summarize the current state of knowledge of platelet physiology obtained through existing in vivo and in vitro cancer models, the complex interactions of platelets with cancer cells in TME and the pathways by which platelets may confer chemoresistance. Since the FDA Modernization Act recently passed by the US government has made animal models optional in drug approvals, we critically examine the existing and futuristic value of employing bioengineered microphysiological systems and organ-chips to understand the mechanistic role of platelets in cancer metastasis and exploring novel therapeutic targets for cancer prevention and treatment.

Role of bFGF in Acquired Resistance upon Anti-VEGF Therapy in Cancer

Anti-angiogenic approaches targeting the vascular endothelial growth factor (VEGF) signaling pathway have been a significant research focus during the past decades and are well established in clinical practice. Despite the expectations, their benefit is ephemeral in several diseases, including specific cancers. One of the most prominent side effects of the current, VEGF-based, anti-angiogenic treatments remains the development of resistance, mostly due to the upregulation and compensatory mechanisms of other growth factors, with the basic fibroblast growth factor (bFGF) being at the top of the list. Over the past decade, several anti-angiogenic approaches targeting simultaneously different growth factors and their signaling pathways have been developed and some have reached the clinical practice. In the present review, we summarize the knowledge regarding resistance mechanisms upon anti-angiogenic treatment, mainly focusing on bFGF. We discuss its role in acquired resistance upon prolonged anti-angiogenic treatment in different tumor settings, outline the reported resistance mechanisms leading to bFGF upregulation, and summarize the efforts and outcome of combined anti-angiogenic approaches to date.

Anti-angiogenesis triggers exosomes release from endothelial cells to promote tumor vasculogenesis

Although anti-angiogenic therapies (AATs) have some effects against multiple malignancies, they are limited by subsequent tumor vasculogenesis and progression. To investigate the mechanisms by which tumor vasculogenesis and progression following AATs, we transfected microRNA (miR)-9 into human umbilical vein endothelial cells (HUVECs) to mimic the tumor-associated endothelial cells in hepatocellular carcinoma and simulated the AATs in vitro and in vivo. We found that administration of the angiogenesis inhibitor vandetanib completely abolished miR-9-induced angiogenesis and promoted autophagy in HUVECs, but induced the release of vascular endothelial growth factor (VEGF)-enriched exosomes. These VEGF-enriched exosomes significantly promoted the formation of endothelial vessels and vasculogenic mimicry in hepatocellular carcinoma and its progression in mice. Anti-autophagic therapy is proposed to improve the efficacy of AATs. However, similar effects by AATs were observed with the application of anti-autophagy by 3-methyladenine. Our results revealed that tumor vasculogenesis and progression after AATs and anti-autophagic therapies were due to the cross-talk between endothelial and tumor cells via VEGF-enriched exosomes.

Exosomal Induction of Tumor Innervation

The naïve view of tumors as isolated islands of rogue cells has given way to a deeper understanding of cancer as being closer to a foreign organ. This "organ" contains immunologic, vascular, and neural connections to its host that provide not only mechanisms for disease progression but also opportunities for therapeutic intervention. The presence of nerves within tumor tissues has long been appreciated. However, a mechanistic understanding of how tumors recruit nerves has been slower to emerge. Tumor release of neurotrophic factors and axonal guidance molecules likely directs axons toward the tumor bed. Newly emerging data support a contribution of tumor-released exosomes in the induction of axonogenesis toward the tumor. Exosomes, small membrane-bound vesicles that carry a complex cargo (DNA, RNA, miRNA, lipids, and proteins), protect their cargo from the low pH of the tumor microenvironment. They also represent an efficient means of local and distal communication between the tumor and potentially innervating nerves. Likely, a combination of neurotrophins, guidance molecules, and exosomes work in concert to promote tumor innervation. As such, defining the critical components driving tumor innervation will identify new targets for intervention. Moreover, with a deepening understanding, tumor innervation may emerge as a new hallmark of cancer.

Molecular-targeted therapies and precision medicine for endometrial cancer

The overall survival rate of patients with early-stage endometrial cancer is relatively high; however, there are few treatment options for patients with advanced or recurrent endometrial cancer, and the prognosis of such patients remains poor. Recent progress in molecular-targeted therapies demonstrated that they have the potential to improve the long-term survival of cancer patients with appropriate biomarkers. However, the median progression-free survival of patients who received single-agent molecular-targeted therapy was <5 months, and the development of molecular-targeted therapies for endometrial cancer patients is urgently needed. This review highlights the previous efforts, including antiangiogenesis therapy, PI3K/AKT/mTOR pathway inhibitor treatment and epidermal growth factor receptor inhibitor treatment and reports on ongoing phase 2 clinical trials, including immune checkpoint inhibitor and PARP inhibitor. We also summarized the genetic background of endometrial cancer according to The Cancer Genome Atlas data and considered the theoretical background for future efforts to prolong the survival of patients with refractory endometrial cancer and for other interesting challenges.

Tumor progression and metastatic dissemination in ovarian cancer after dose-dense or conventional paclitaxel and cisplatin plus bevacizumab

The efficacy of therapeutic regimens incorporating weekly or every-3-weeks paclitaxel (PTX) for ovarian cancer is debated. We investigated the addition of bevacizumab in regimens of chemotherapy with different PTX doses and schedules in preclinical models. Treatments were cisplatin (DDP) with weekly PTX (conventional), or dose-dense-equi (every other day to the conventional cumulative dose), or dose-dense-high (total dose 1.5 times higher), with or without bevacizumab. Treatment efficacy was evaluated analyzing tumor growth in different time-windows in two patient-derived ovarian cancer xenografts with different sensitivity to cisplatin. Tumor progression, metastasis and survival were studied in ovarian cancer models growing orthotopically and disseminating in the mouse peritoneal cavity. Short-term effects on cell cycle, tumor cell proliferation/apoptosis and vasculature were evaluated by flow cytometry and immunohistochemistry. PTX dose-dense (with/without DDP) was superior to the conventional scheme in a dose-dependent manner; the high efficacy was confirmed by the lower ratio of tumor to normal cells. All schemes benefited from bevacizumab, which reduced tumor vessels. However, DDP/PTX dose-dense-high (only chemotherapy) was at least as active as DDP/PTX conventional plus bevacizumab. DDP/PTX dose-dense-high plus bevacizumab was the most effective in delaying tumor progression, though it did not prolong mouse survival and the continuous treatment with bevacizumab was associated with a malignant disease. These findings indicate that the effect of bevacizumab in combination with chemotherapy may depend on the schedule-dose of the treatment and help to explain the unclear benefits after bevacizumab.

Prediction of therapy response in ovarian cancer: Where are we now?

Therapy resistance is a major challenge in the management of ovarian cancer (OC). Advances in detection and new technology validation have led to the emergence of biomarkers that can predict responses to available therapies. It is important to identify predictive biomarkers to select resistant and sensitive patients in order to reduce important toxicities, to reduce costs and to increase survival. The discovery of predictive and prognostic biomarkers for monitoring therapy is a developing field and provides promising perspectives in the era of personalized medicine. This review article will discuss the biology of OC with a focus on targetable pathways; current therapies; mechanisms of resistance; predictive biomarkers for chemotherapy, antiangiogenic and DNA-targeted therapies, and optimal cytoreductive surgery; and the emergence of liquid biopsy using recent studies from the Medline database and ClinicalTrials.gov.

Major clinical research advances in gynecologic cancer in 2016: 10-year special edition

In 2016, 13 topics were selected as major research advances in gynecologic oncology. For ovarian cancer, study results supporting previous ones regarding surgical preventive strategies were reported. There were several targeted agents that showed comparable responses in phase III trials, including niraparib, cediranib, and nintedanib. On the contrary to our expectations, dose-dense weekly chemotherapy regimen failed to prove superior survival outcomes compared with conventional triweekly regimen. Single-agent non-platinum treatment to prolong platinum-free-interval in patients with recurrent, partially platinum-sensitive ovarian cancer did not improve and even worsened overall survival (OS). For cervical cancer, we reviewed robust evidences of larger-scaled population-based study and cost-effectiveness of nonavalent vaccine for expanding human papillomavirus (HPV) vaccine coverage. Standard of care treatment of locally advanced cervical cancer (LACC) was briefly reviewed. For uterine corpus cancer, new findings about appropriate surgical wait time from diagnosis to surgery were reported. Advantages of minimally invasive surgery over conventional laparotomy were reconfirmed. There were 5 new gene regions that increase the risk of developing endometrial cancer. Regarding radiation therapy, Post-Operative Radiation Therapy in Endometrial Cancer (PORTEC)-3 quality of life (QOL) data were released and higher local control rate of image-guided adaptive brachytherapy was reported in LACC. In addition, 4 general oncology topics followed: chemotherapy at the end-of-life, immunotherapy with reengineering T-cells, actualization of precision medicine, and artificial intelligence (AI) to make personalized cancer therapy real. For breast cancer, adaptively randomized trials, extending aromatase inhibitor therapy, and ribociclib and palbociclib were introduced.

Impact of bevacizumab containing first line chemotherapy on recurrent disease in epithelial ovarian cancer: A case-control study

OBJECTIVE

To evaluate the timing and pattern of relapse, and duration of response to second line chemotherapy in advanced ovarian cancer (AOC) patients treated with first line carboplatin-paclitaxel chemotherapy with or without bevacizumab.

PATIENTS AND METHODS

This is a case-control study including 222 AOC patients. Seventy-four women treated with first line carboplatin-paclitaxel-bevacizumab chemotherapy (Cases) were matched based on laparoscopic predictive index value, and residual tumor at first surgery with 148 AOC patients treated with carboplatin-paclitaxel. Distribution of pattern of relapse, and response to second line chemotherapy was compared between the two groups. Time to Progression (TTP) for second line chemotherapy was also analyzed for study purpose.

RESULTS

Median platinum-free interval (PFI) was 16months (range 2-65) in Cases, compared with 9months (1-83) in Controls (p-value=0.001). Twenty patients (51.3%) among Cases showed recurrence in multiple anatomic sites, compared with 31 (31.9%) in the Control group (p-value=0.035). Peritoneal recurrence occurred as diffuse in 30 Cases (96.8%), and 60 Controls (82.2%; p-value=0.046). Secondary cytoreductive surgery (SCS) was successfully completed in 53.5% of Controls compared to 10.0% of Cases (p-value=0.016). In women with fully platinum-sensitive relapse, response rate to second line chemotherapy was 85.2% in Controls, compared to 38.4% in Cases (p-value=0.002). Finally, Cases showed a shorter TTP, compared to Controls (5months vs 8months; p-value=0.041).

CONCLUSIONS

Incorporation of bevacizumab into upfront regimens prolongs PFI in AOC patients, but is associated with wider presentation of relapse, lower rate of complete SCS, and shorter TTP to second line chemotherapy in women with platinum-sensitive disease.