Repopulation of tumour cells between cycles of chemotherapy: a neglected factor

Are we making progress in curing advanced cervical cancer-again?

Major improvements in radiotherapy over the past two decades in the definitive treatment of locally advanced cervical cancer have significantly improved loco-regional control and survival, whereas little progress has been made with chemotherapy since the implementation of concomitant cisplatin 25 years ago. However, the randomized study INTERLACE (A phase III multicenter trial of weekly induction chemotherapy followed by standard chemoradiation versus standard chemoradiation alone in patients with locally advanced cervical cancer) of neoadjuvant chemotherapy presented recently, has shown significant improvement in survival with the use of six cycles of weekly carboplatin and paclitaxel. Although INTERLACE is yet to be published, neoadjuvant chemotherapy is already being advocated as the new standard, and studies are being designed with neoadjuvant chemotherapy followed by chemoradiation and brachytherapy as the standard arm. It is noteworthy that INTERLACE was initiated before the improvements in radiotherapy mentioned above were broadly implemented. The survival rate in the standard arm of INTERLACE was therefore inferior to the results obtained with the latest state-of-the-art external beam radiotherapy and image guided adaptive brachytherapy (EMBRACE, Magnetic Resonance Imaging (MRI)-Guided Brachytherapy in Locally Advanced Cervical Cancer). Moreover, patient selection impedes the comparison of INTERLACE with other studies as the patients included in INTERLACE were younger, had better performance status, and had less advanced disease than in other studies. Notably patients with involved para-aortic nodes were excluded. In this review, we discuss neoadjuvant chemotherapy in the frame of the EMBRACE studies and show how the impact of modern radiotherapy and patient selection affects the interpretation of the results of INTERLACE. This has led us to conclude that neoadjuvant chemotherapy is not needed for the majority of patients with cervical cancer treated with definitive modern radiotherapy, and may cause harm. However, it is possible that short course neoadjuvant chemotherapy may benefit a minor subgroup of patients who need to be identified. Comprehensive understanding, including cost utility analyses, are needed to draw conclusions regarding the potential benefit of neoadjuvant chemotherapy in low and middle income countries with limited access to modern radiotherapy.

Radiotherapy for pediatric low-grade glioma

INTRODUCTION

Radiotherapy is a highly effective treatment for pediatric low-grade glioma, serving as the standard for evaluating progression-free and overall survival, as well as vision preservation. Despite its proven efficacy, concerns about treatment complications have led to increased use of chemotherapy and targeted therapy, which are associated with poorer progression-free survival outcomes.

METHODS

This review by Indu Bansal and Thomas E. Merchant examines the indications, timing, and results of radiotherapy for pediatric low-grade glioma. The authors provide a comprehensive analysis of clinical management strategies, addressing the controversies surrounding the use and timing of radiotherapy compared to other therapies.

RESULTS

The review highlights that while radiotherapy is essential for certain patients, particularly those who are not candidates for complete resection due to the tumor's infiltrative nature or location, it is often deferred in favor of systemic therapies. This deferral can lead to significant morbidity, including poor visual outcomes. Reports indicate that systemic therapy negatively impacts progression-free survival in patients who eventually undergo radiotherapy. Newer radiotherapy techniques have been developed to minimize complications, offering potential benefits over traditional methods.

DISCUSSION

The evolving clinical management of pediatric low-grade glioma involves balancing the benefits of radiotherapy with concerns about its side effects. Although systemic therapies are increasingly favored, their associated inferior progression-free survival and potential for significant morbidity underscore the need for careful consideration of radiotherapy, particularly in older children, adolescents, or those with progressive disease post-systemic therapy. The emerging role of targeted therapy presents additional challenges, including uncertainties about long-term side effects and its interaction with radiotherapy. Further research is needed to optimize treatment strategies and improve outcomes for pediatric patients with low-grade glioma.

Antimelanoma Effects of Alchemilla vulgaris: A Comprehensive In Vitro and In Vivo Study

Due to the rich ethnobotanical and growing evidence-based medicine records, the Alchemillae herba, i.e., the upper parts of the Lady's mantle (Alchemilla vulgaris L.), was used for the assessment of antimelanoma activity. The ethanolic extract of A. vulgaris strongly suppressed the viability of B16F1, B16F10, 518A2, and Fem-X cell lines. In contrast to the in vitro study, where the B16F1 cells were more sensitive to the treatment than the more aggressive counterpart B16F10, the results obtained in vivo using the corresponding syngeneic murine model were quite the opposite. The higher sensitivity of B16F10 tumors in vivo may be attributed to a more complex response to the extract compared to one triggered in vitro. In addition, the strong immunosuppressive microenvironment in the B16F1 model is impaired by the treatment, as evidenced by enhanced antigen-presenting potential of dendritic cells, influx and activity of CD4+ T and CD8+ T lymphocytes, decreased presence of T regulatory lymphocytes, and attenuation of anti-inflammatory cytokine production. All these effects are supported by the absence of systemic toxicity. A. vulgaris extract treatment results in a sustained and enhanced ability to reduce melanoma growth, followed by the restoration of innate and adopted antitumor immunity without affecting the overall physiology of the host.

Phase I dose-escalation study of nab-paclitaxel combined with cisplatin and capecitabin as induction chemotherapy followed by concurrent chemoradiotherapy in patients with nasopharyngeal carcinoma

BACKGROUND AND PURPOSE

Nab-paclitaxel is a promising albumin-bound paclitaxel with a therapeutic index superior to that of docetaxel, but the optimal dose of nab-paclitaxel combined with cisplatin and capecitabine as induction chemotherapy followed by concurrent chemoradiotherapy for patients with locally advanced nasopharyngeal carcinoma remains unknown.

MATERIALS AND METHODS

This was an open-label, single-arm study investigating the safety and efficacy of nab-paclitaxel + cisplatin + capecitabin as IC for three cycles, followed by cisplatin CCRT, conducted by using the standard "3 + 3" design in LA-NPC. If more than one-third of the patients in a cohort experienced dose-limiting toxicity (DLT), the dose used in the previous cohort was designated the maximum tolerated dose (MTD). The recommended phase 2 dose (RP2D) was defined as one level below the MTD.

RESULTS

From 29 May 2021 to 17 March 2022, 19 patients with LA-NPC were enrolled, one patient withdrew informed consent. Two DLTs occurred in cohort 4 (grade 4 febrile neutropenia and grade 3 peripheral neuropathy), and an MTD was established as 225 mg/m2. The most frequent grade 3 or 4 adverse events were neutropenia (16.7 %), hypertriglyceridemia (16.7 %), leukopenia (5.6 %) and peripheral neuropathy (5.6 %) during IC.

CONCLUSION

The RP2D is nab-paclitaxel 200 mg/m2 on day 1, combined with cisplatin 75 mg/mg2 on day 1 and capecitabin1000 mg/m2 on days 1-14, twice a day, every 3 weeks, for three cycles as an IC regimen prior to CCRT.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04850235.

Opportunities in Cancer Therapies: Deciphering the Role of Cancer Stem Cells in Tumour Repopulation

Tumour repopulation during treatment is a well acknowledged yet still challenging aspect of cancer management. The latest research results show clear evidence towards the existence of cancer stem cells (CSCs) that are responsible for tumour repopulation, dissemination, and distant metastases in most solid cancers. Cancer stem cell quiescence and the loss of asymmetrical division are two powerful mechanisms behind repopulation. Another important aspect in the context of cancer stem cells is cell plasticity, which was shown to be triggered during fractionated radiotherapy, leading to cell dedifferentiation and thus reactivation of stem-like properties. Repopulation during treatment is not limited to radiotherapy, as there is clinical proof for repopulation mechanisms to be activated through other conventional treatment techniques, such as chemotherapy. The dynamic nature of stem-like cancer cells often elicits resistance to treatment by escaping drug-induced cell death. The aims of this scoping review are (1) to describe the main mechanisms used by cancer stem cells to initiate tumour repopulation during therapy; (2) to present clinical evidence for tumour repopulation during radio- and chemotherapy; (3) to illustrate current trends in the identification of CSCs using specific imaging techniques; and (4) to highlight novel technologies that show potential in the eradication of CSCs.

Nanotechnology-integrated ovarian cancer metastasis therapy: Insights from the metastatic mechanisms into administration routes and therapy strategies

Ovarian cancer is a kind of malignant tumour which locates in the pelvic cavity without typical clinical symptoms in the early stages. Most patients are diagnosed in the late stage while about 60 % of them have suffered from the cancer cells spreading in the abdominal cavity. The high recurrence rate and mortality seriously damage the reproductive needs and health of women. Although recent advances in therapeutic regimes and other adjuvant therapies improved the overall survival of ovarian cancer, overcoming metastasis has still been a challenge and is necessary for achieving cure of ovarian cancer. To present potential targets and new strategies for curbing the occurrence of ovarian metastasis and the treatment of ovarian cancer after metastasis, the first section of this paper explained the metastatic mechanisms of ovarian cancer comprehensively. Nanomedicine, not limited to drug delivery, offers opportunities for metastatic ovarian cancer therapy. The second section of this paper emphasized the advantages of various administration routes of nanodrugs in metastatic ovarian cancer therapy. Furthermore, the third section of this paper focused on advances in nanotechnology-integrated strategies for targeting metastatic ovarian cancer based on the metastatic mechanisms of ovarian cancer. Finally, the challenges and prospects of nanotherapeutics for ovarian cancer metastasis therapy were evaluated. In general, the greatest emphasis on using nanotechnology-based strategies provides avenues for improving metastatic ovarian cancer outcomes in the future.

Optimizing induction chemotherapy regimens for radiotherapy in patients with locoregionally advanced nasopharyngeal carcinoma

BACKGROUND AND PURPOSE

The optimal number of cycles of induction chemotherapy (IC) in locoregionally advanced nasopharyngeal carcinoma (LANPC) remains unresolved. This study aimed to quantitatively assess the changes in gross tumor volumes (GTVs) and to select the most optimal number of IC cycles.

METHODS

We analyzed 54 patients who received a three-cycle IC before commencing radiotherapy, with the tumor and nodal responses assessed by a CT scan before IC and after each IC cycle. The gross tumor volumes of the nasopharynx primary lesion (GTV_T), involved retropharyngeal lymph node (GTV_RP), and involved cervical lymph node (GTV_N) were contoured on each scan. The volume change following each IC cycle was evaluated with Wilcoxon signed-rank test. The three-dimensional vector displacements of target centers were also calculated and compared.

RESULTS

The volume reductions of GTVs following IC varied across different patients and showed different trends for the three GTV types. GTV_T and GTV_RP did not display further volume reduction after two IC cycles, whereas GTV_N showed monotonic volume decreases. For GTV_T and GTV_RP following the three IC cycles, the total volume reduction relative to the initial volume before IC was 12.0%, 22.5%, and 20.1% and 26.0%, 44.1%, and 42.2%, respectively. In contrast, for GTV_N, continuing volume reduction was observed with a total reduction of 25.3%, 43.2%, and 54.7% following the three cycles, and the reductions were all significant. Average displacements of the GTVs were <1.5 mm in all directions; their average three-dimensional displacements were 2.6, 4.0, and 1.7 mm, respectively. Acceptable toxicity was observed in most patients.

CONCLUSION

This study supports two cycles of IC before radiotherapy for patients with LANPC if the initial metastatic cervical lymph node volume is not dominating. Otherwise, three cycles of IC is recommended to further reduce the cervical node volume.

Clinical outcomes and toxicities of locally advanced esophageal squamous cell carcinoma patients treated with early thoracic radiation therapy after induction chemotherapy

OBJECTIVE

The purpose of this study was to compare the clinical outcomes and toxicities between induction chemotherapy (IC) + chemo-radiotherapy (CRT) and CRT alone in patients with locally advanced esophageal squamous cell carcinoma (ESCC), to explore the appropriate thoracic radiotherapy (TRT) timing after IC and to identify prognostic factors.

METHODS

450 ESCC patients were included from September 2011 to December 2020, 238 of whom received IC/CRT. Propensity score matching was performed to balance potential confounders between the two groups. Multivariate Cox regression analysis was used to identify the independent prognostic factors.

RESULTS

Patients who received IC/CRT experienced improved overall survival (OS) (38.5 vs. 28.8 months) and progression-free survival (PFS) (41.0 vs. 22.0 months) before matching, with similar results after matching. In the IC/CRT group, early TRT had more favorable survival than late TRT both matching before and after. In subgroup analysis, early TRT combination concurrent chemotherapy had better OS and PFS than late TRT combination concurrent chemotherapy. In addition, early TRT had better survival benefits regardless of the N stage. Notably, the IC/CRT group and early TRT group had manageable toxicities reaction compared with CRT alone group and the late TRT group. The nomogram was developed to predict the OS and PFS based on multivariate analysis results. The C-index was 0.743 and 0.722, respectively.

CONCLUSION

IC/CRT and early TRT could yield satisfactory clinical outcomes and controllable toxicities in locally advanced ESCC. The IC plus early concurrent CRT might be a promising treatment strategy for improving further survival in ESCC.

Cell proliferation, drug distribution and therapeutic effects in relation to the vascular system of solid tumours

In this perspective, the authors summarise some properties of the solid tumour micro-environment that have been explored during the last 55 years. It is well established that the concentrations of nutrients, including oxygen, decrease with increasing distance from tumour blood vessels, and that low extracellular pH is found in nutrient-poor regions. Cell proliferation is dependent on nutrient metabolites and decreases in regions distal from patent blood vessels. Proliferating cells cause migration of neighbouring cells further from blood vessels where they may die, and their breakdown products pass into regions of necrosis. Anticancer drugs reach solid tumours via the vascular system and establish concentration gradients such that drug concentration within tumours may be quite variable. Treatment with chemotherapy such as doxorubicin or docetaxel can kill well-nourished proliferating cells close to blood vessels, thereby interrupting migration toward necrotic regions and lead to re-oxygenation and renewed proliferation of distal cells, as can occur with radiotherapy. This effect leads to the paradox that cancer treatment can rescue cells that were destined to die in the untreated tumour. Renewed and sometimes accelerated repopulation of surviving tumour cells can counter the effects of cell killing from repeated treatments, leading to tumour shrinkage and regrowth without changes in the intrinsic sensitivity of cells to the administered treatment. Strategies to prevent these effects include the combined use of chemotherapy with agents that selectively kill hypoxic tumour cells, including inhibitors of autophagy, since this is a process that may allow recycling of cellular macromolecules from dying cells and improve their survival.

Microbial cancer therapeutics: A promising approach

The success of conventional cancer therapeutics is hindered by associated dreadful side-effects of antibiotic resistance and the dearth of antitumor drugs' selectivity and specificity. Hence, the conceptual evolution of anti-cancerous therapeutic agents that selectively target cancer cells without impacting the healthy cells or tissues, has led to a new wave of scientific interest in microbial-derived bioactive molecules. Such strategic solutions may pave the way to surmount the shortcomings of conventional therapies and raise the potential and hope for the cure of wide range of cancer in a selective manner. This review aims to provide a comprehensive summary of anti-carcinogenic properties and underlying mechanisms of bioactive molecules of microbial origin, and discuss the current challenges and effective therapeutic application of combinatorial strategies to attain minimal systemic side-effects.

MiR-26b-5p in small extracellular vesicles derived from dying tumor cells after irradiation enhances the metastasis promoting microenvironment in esophageal squamous cell carcinoma

Radiation therapy is effective in achieving local control in esophageal squamous cell carcinoma; however, changes in the tumor microenvironment induced by radiation can also promote metastasis. Dying tumor cells play vital roles in promoting the survival of living tumor cells; however, few studies have investigated the effects of dying tumor cells on the tumor microenvironment. Since myeloid-derived suppressor cells (MDSCs) and macrophages constitute the pre-metastatic niche (PMN), we used a 4-nitroquinoline-1-oxide induced in situ tumor model to investigate the effects of irradiation on MDSCs and macrophages in esophageal squamous cell carcinoma (ESCC). When primary tumor sites were irradiated, we observed an increase in MDSCs in the spleen and the deposition of PMN components in lung and liver. Enhanced MDSC accumulation and function were induced by small extracellular vesicles (sEVs) isolated from irradiated tumor-bearing mice. The MDSC induction function of sEVs after irradiation was reaffirmed using sEVs derived from ESCC cell lines. The irradiation-induced upregulation of miR-26b-5p in sEVs enhanced MDSC expansion and activation by targeting phosphatase and tensin homolog. Our results first elucidated a mechanism by which dying tumor cells enhanced the deposition of PMN components and potentiated MDSCs in ESCC after irradiation. sEVs played a vital role in mediating signals between the primary tumor and the microenvironment to form a metastasis-promoting microenvironment after irradiation. Furthermore, miR-26b-5p or PI3K/AKT signaling pathway inhibitors should be evaluated in clinical trials in combination with radiotherapy as a strategy to improve outcomes.

Comparison and quantification of different concurrent chemotherapy regimens with radiotherapy in locally advanced non-small cell lung cancer: Clinical outcomes and theoretical results from an extended LQ and TCP model

PURPOSE

To develop a new radiobiological model and compare the efficacy of four concurrent chemotherapy regimens administered with radiotherapy in locally advanced non-small-cell lung cancer (LANSCLC) by in-field locoregional progression-free survival (LPFS).

MATERIALS AND METHODS

151 LANSCLC patients were reviewed and divided into 5 groups according to their concurrent chemotherapy regimens, including 24 patients treated with radiotherapy alone, 30 treated with concurrent 4-week etoposide-cisplatin (EP), 26 with 3-week pemetrexed-cisplatin (AP), 37 with weekly paclitaxel-cisplatin (TP) and 34 with weekly docetaxel-cisplatin (DP). In-field LPFS and toxicities were compared among groups. A novel tumor control probability (TCP) model, LQRGC, incorporating four "R"s of radiobiology, Gompertzian tumor growth and chemotherapeutic effect, was related to in-field LPFS. Chemo-induced biologically effective doses (BEDs) in LQRGC/TCP model were used to quantify the concurrent chemotherapeutic efficacy.

RESULTS

The median follow-up time was 54.5 months. The weekly DP and 4-week EP groups had favorable median in-field LPFS (EP:46.2 months, AP:30.3 months, TP:12.2 months, DP: not reached, radiotherapy alone: 12.2 months, p = 0.001). The 4-week EP group had a higher incidence of ≥grade 3 leukopenia (EP:76.7%, AP:15.4%, TP:24.3%, DP:14.7%, radiotherapy alone: 12.5%, p < 0.001) than the other four. The LQRGC/TCP model fitted well with the in-field LPFS with the average absolute and relative fitting errors of 6.36% and 12.12%. The chemo-induced BEDs of EP, AP, TP and DP were 5.17, 0.63, 1.89 and 2.52 Gy, respectively.

CONCLUSION

The LQRGC/TCP model achieved promising fitting accuracy for in-field LPFS. As quantified by the model, the 4-week EP and weekly DP showed higher chemo-induced BEDs when concurrently administered with radiotherapy in LANSCLC.

Debris-stimulated tumor growth: a Pandora's box?

Current cancer therapies aim at eradicating cancer cells from the body. However, killing cells generates cell “debris” which can promote tumor progression. Thus, therapy can be a double-edged sword. Specifically, injury and debris generated by cancer therapies, including chemotherapy, radiation, and surgery, may offset their benefit by promoting the secretion of pro-tumorigenic factors (e.g., eicosanoid-driven cytokines) that stimulate regrowth and metastasis of surviving cells. The debris produced by cytotoxic cancer therapy can also contribute to a tumor microenvironment that promotes tumor progression and recurrence. Although not well understood, several molecular mechanisms have been implicated in debris-stimulated tumor growth that we review here, such as the involvement of extracellular vesicles, exosomal miR-194-5p, Bax, Bak, Smac, HMGB1, cytokines, and caspase-3. We discuss the cases of pancreatic and other cancer types where debris promotes postoperative tumor recurrence and metastasis, thus offering a new opportunity to prevent cancer progression intrinsically linked to treatment by stimulating resolution of tumor-promoting debris.

Optimal Combinations of Chemotherapy and Radiotherapy in Low-Grade Gliomas: A Mathematical Approach

Low-grade gliomas (LGGs) are brain tumors characterized by their slow growth and infiltrative nature. Treatment options for these tumors are surgery, radiation therapy and chemotherapy. The optimal use of radiation therapy and chemotherapy is still under study. In this paper, we construct a mathematical model of LGG response to combinations of chemotherapy, specifically to the alkylating agent temozolomide and radiation therapy. Patient-specific parameters were obtained from longitudinal imaging data of the response of real LGG patients. Computer simulations showed that concurrent cycles of radiation therapy and temozolomide could provide the best therapeutic efficacy in-silico for the patients included in the study. The patient cohort was extended computationally to a set of 3000 virtual patients. This virtual cohort was subject to an in-silico trial in which matching the doses of radiotherapy to those of temozolomide in the first five days of each cycle improved overall survival over concomitant radio-chemotherapy according to RTOG 0424. Thus, the proposed treatment schedule could be investigated in a clinical setting to improve combination treatments in LGGs with substantial survival benefits.

Delay to surgery after neoadjuvant chemotherapy in head and neck squamous cell carcinoma affects oncologic outcomes

BACKGROUND

Neoadjuvant chemotherapy (NAC) is used in head and neck squamous cell carcinoma (HNSCC) for downstaging advanced disease and decreasing distant metastasis (DM). To the authors' knowledge, no study has specifically examined the impact of a delayed time to surgery (TTS) after NAC on oncologic outcomes. They thus aimed to identify a cutoff for TTS after NAC and its effect on survival indices.

METHODS

This was a retrospective review of all patients with HNSCC receiving NAC followed by surgery with curative intent between March 2016 and March 2019 at the MD Anderson Cancer Center. Receiver operating characteristic analysis was used to identify a cutoff for TTS, and this cutoff was used to analyze the overall survival (OS), locoregional recurrence rate, DM-free rate, and disease-free survival (DFS). A multivariate Cox regression analysis was performed.

RESULTS

One hundred one patients were analyzed with a median follow-up of 24.7 months. The 3-year OS and locoregional recurrence rates did not differ with a TTS ≥ 34 days. However, the 3-year DM-free rate was significantly worse (56% vs 90%; P = .001) in the group with a TTS ≥ 34 days, and the 3-year DFS was significantly lower (26% vs 64%; P = .006). In a multivariate analysis, a TTS ≥ 34 days (hazard ratio [HR], 4.92; 95% confidence interval [CI], 1.84-13.13) and extracapsular extension (HR, 3.01; 95% CI, 1.13-8.00) were significant independent predictors of a poorer DM-free rate. Weight loss > 10% (HR, 5.53; 95% CI, 1.02-30.24) was the only independent predictor for a TTS ≥ 34 days.

CONCLUSIONS

Emphasis should be placed on early definitive locoregional treatment after NAC, particularly in patients who do not respond to NAC. There is a need to validate these findings and establish new benchmarks for the interval between NAC and surgery.

Early prediction of pathologic response to neoadjuvant treatment of breast cancer: use of a cell-loss metric based on serum thymidine kinase 1 and tumour volume

Background

After neoadjuvant chemotherapy of breast cancer pathologic complete response (pCR) indicates a favorable prognosis. Among non-selected patients, pCR is, however, achieved in only 10–30%. Early evaluation of tumour response to treatment would facilitate individualized therapy, with ineffective chemotherapy interrupted or changed. The methodology for this purpose is still limited. Tumour imaging and analysis of macromolecules, released from disrupted tumour cells, are principal alternatives.

Objective

To investigate whether a metric of cell-loss, defined as the ratio between serum concentration of thymidine kinase1 (sTK1, ng x ml^− 1) and tumour volume, can be used for early prediction of pathologic response.

Methods

One hunred four women with localized breast cancer received neoadjuvant epirubicin/docetaxel in 6 cycles, supplemented with bevacizumab in cycles 3–6. The cell-loss metric was established at baseline (n = 104), 48 h after cycle 2 (n = 104) and prior to cycle 2 (n = 57). The performance of the metric was evaluated by association with pathologic tumour response at surgery 4 months later.

Results

Treatment caused a rise in sTK1, a reduction in tumour volume and a marked increase in the cell-loss metric. Patients were subdivided into quartiles according to the baseline cell-loss metric. For these groups, baseline means were 0.0016, 0.0042, 0.0062, 0.0178 units. After subtraction of baselines, means for the quartiles 48 h after treatment 2 were 0.002, 0.011, 0.030 and 0.357 units. pCR was achieved in 24/104, their distribution in the quartiles (11, 11, 23 and 46%) differed significantly (p = 0.01). In 80 patients with remaining tumour, tumour size was inversely related to the metric (p = 0.002). In 57 patients studied before treatment 2, positive and negative predictive values of the metric were 77.8 and 83.3%, compared to 40.5 and 88.7% 48 h after treatment 2.

Conclusion

A cell-loss metric, based on serum levels of TK1, released from disrupted tumour cells, and tumour volume, reveal tumour response early during neoadjuvant treatment. The metric reflect tumour properties that differ greatly between patients and determine the sensitivity to cytotoxic treatment. The findings point to the significance of cell loss for tumour growth rate. The metric should be considered in personalized oncology and in the evaluation of new therapeutic modalities.

Trial registration

PROMIX (Clinical Trials.govNCT000957125).

Early prediction of pathologic response to neoadjuvant treatment of breast cancer: use of a cell-loss metric based on serum thymidine kinase 1 and tumour volume

BACKGROUND

After neoadjuvant chemotherapy of breast cancer pathologic complete response (pCR) indicates a favorable prognosis. Among non-selected patients, pCR is, however, achieved in only 10-30%. Early evaluation of tumour response to treatment would facilitate individualized therapy, with ineffective chemotherapy interrupted or changed. The methodology for this purpose is still limited. Tumour imaging and analysis of macromolecules, released from disrupted tumour cells, are principal alternatives.

OBJECTIVE

To investigate whether a metric of cell-loss, defined as the ratio between serum concentration of thymidine kinase1 (sTK1, ng x ml^- 1) and tumour volume, can be used for early prediction of pathologic response.

METHODS

One hunred four women with localized breast cancer received neoadjuvant epirubicin/docetaxel in 6 cycles, supplemented with bevacizumab in cycles 3-6. The cell-loss metric was established at baseline (n = 104), 48 h after cycle 2 (n = 104) and prior to cycle 2 (n = 57). The performance of the metric was evaluated by association with pathologic tumour response at surgery 4 months later.

RESULTS

Treatment caused a rise in sTK1, a reduction in tumour volume and a marked increase in the cell-loss metric. Patients were subdivided into quartiles according to the baseline cell-loss metric. For these groups, baseline means were 0.0016, 0.0042, 0.0062, 0.0178 units. After subtraction of baselines, means for the quartiles 48 h after treatment 2 were 0.002, 0.011, 0.030 and 0.357 units. pCR was achieved in 24/104, their distribution in the quartiles (11, 11, 23 and 46%) differed significantly (p = 0.01). In 80 patients with remaining tumour, tumour size was inversely related to the metric (p = 0.002). In 57 patients studied before treatment 2, positive and negative predictive values of the metric were 77.8 and 83.3%, compared to 40.5 and 88.7% 48 h after treatment 2.

CONCLUSION

A cell-loss metric, based on serum levels of TK1, released from disrupted tumour cells, and tumour volume, reveal tumour response early during neoadjuvant treatment. The metric reflect tumour properties that differ greatly between patients and determine the sensitivity to cytotoxic treatment. The findings point to the significance of cell loss for tumour growth rate. The metric should be considered in personalized oncology and in the evaluation of new therapeutic modalities.

TRIAL REGISTRATION

PROMIX (Clinical Trials.govNCT000957125).

Nanofibrous Polydioxanone Depots for Prolonged Intraperitoneal Paclitaxel Delivery

BACKGROUND

Prolonged chemodrug delivery to the tumor site is a prerequisite to maintaining its localised therapeutic concentrations for effective treatment of malignant solid tumors.

OBJECTIVE

The current study aims to develop implantable polymeric depots through conventional electrospinning for sustained drug delivery, specifically to the peritoneum.

METHODS

Non-woven electrospun mats were fabricated by simple electrospinning of Polydioxanone solution loaded with the chemodrug, Paclitaxel. The implants were subjected to the analysis of morphology, mechanical properties, degradation and drug release in phosphate buffer and patient-derived peritoneal drain fluid samples. In vivo studies were conducted by surgical knotting of these implants to the peritoneal wall of healthy mice.

RESULTS

Non-woven electrospun mats with a thickness of 0.65±0.07 mm, weighing ~ 20 mg were fabricated by electrospinning 15 w/v% polymer loaded with 10 w/w% drug. These implants possessing good mechanical integrity showed a drug entrapment efficiency of 87.82±2.54 %. In vitro drug release studies in phosphate buffer showed a sustained profile for ~4 weeks with a burst of 10 % of total drug content, whereas this amounted to >60% in patient samples. Mice implanted with these depots remained healthy during the study period. The biphasic drug release profile obtained in vivo showed a slow trend, with peritoneal lavage and tissues retaining good drug concentrations for a sustained period.

CONCLUSION

The results indicate that non-woven electrospun mats developed from biodegradable Polydioxanone polymer can serve as ideal candidates for easily implantable drug depots to address the challenges of peritoneal metastasis in ovarian cancer.

A Meta-Analysis of the Efficacy and Toxicity of Twice-Daily vs. Once-Daily Concurrent Chemoradiotherapy for Limited-Stage Small Cell Lung Cancer Based on Randomized Controlled Trials

Background: Currently, the accepted standard management of limited-stage small cell lung cancer (SCLC) is concurrent chemoradiotherapy (CCRT), but the frequency of radiotherapy is controversial. Therefore, this meta-analysis, which compared the efficacy and toxicity between twice-daily (BID) and once-daily (OD) CCRT, was performed to help clinicians make better decisions. Methods: Relevant randomized controlled trials (RCTs) were collected by searching the PubMed, Ovid MEDLINE, Embase, ScienceDirect, Web of Science, the Cochrane Library, Scopus and Google Scholar databases to assess antitumor effects (overall survival, OS; progression-free survival, PFS; overall response rate, ORR) and toxicity (adverse effects, AEs). Results: We screened 1499 articles and included 5 RCTs including 1421 patients. We found that BID CCRT improved OS (hazard ratio, HR = 0.88, 95% confidence interval, CI 0.78-0.99, p = 0.03), the 1-year OS rate (OSR-1y, risk ratio, RR = 1.07, 95%CI 1.01-1.13, p = 0.03), and OSR-4y (RR = 1.22, 95%CI 1.03-1.43, p = 0.02), with better trends in OSR-2y, OSR-3y, and OSR-5y, compared to OD CCRT. In addition, BID CCRT had a higher complete response (CR, RR = 1.31, 95%CI 1.01-1.70, p = 0.04) than OD CCRT. PFS (HR = 0.92, 95%CI 0.79-1.07, p = 0.29), annual PFS rate, ORR (RR = 0.99, 95%CI 0.93-1.05, p = 0.72), and AEs for all grades (RR = 1.00, 95%CI 0.98-1.01, p = 0.57), and grades 3-5 (RR = 1.02, 95%CI 0.95-1.09, p = 0.60) were similar between the two arms. Conclusions: BID CCRT appears to be better than OD CCRT for limited-stage SCLC, with better antitumor effects (OS, OSR, and CR) and similar AEs. However, the high levels of AEs in both arms should be taken as a sign of caution. More large sample and high-quality RCTs need to be conducted to confirm our conclusions.

Gallic Acid Triggers Iron-Dependent Cell Death with Apoptotic, Ferroptotic, and Necroptotic Features

Gallic acid (GA) is a natural anti-cancer compound that can be found in many food sources, including edible mushrooms, fruits, and vegetables. Studies generally attribute the anti-cancer activity of GA to the induction of apoptosis. Here, we reported that GA activated iron-dependent cell death mechanisms with apoptotic, ferroptotic, and necroptotic features. Our time-lapse live-cell microscopy study demonstrated that GA could induce coexistence of multiple types of cell death pathways, including apoptosis characterized by mitochondrial cytochrome c release and caspase-3 activation, ferroptosis characterized by lipid peroxidation, and necroptosis characterized by the loss of plasma membrane integrity. This GA-induced cell death could be completely suppressed by exposure to an iron chelator deferoxamine, indicating that it is an iron-dependent cell death process. Importantly, MLKL (mixed lineage kinase domain-like protein) inhibitor necrosulfonamide exerted a synergistic effect by increasing the sensitivity of cancer cells to GA. Taken together, our results provide new mechanistic insights, and also suggest new strategies to enhance the efficacy of this natural anti-cancer compound by identifying the agents that can promote or suppress the GA-induced cell death process.

Enhanced anti-tumor efficacy and safety with metronomic intraperitoneal chemotherapy for metastatic ovarian cancer using biodegradable nanotextile implants

The objective of this study was to evaluate intraperitoneal (IP) metronomic chemotherapy using sustained release paclitaxel (PTX) delivery from electrospun biodegradable polymeric yarns woven into suturable nanotextiles. Following confirmation of in vitro PTX efficacy in ID8-VEGF epithelial ovarian cancer cells, in vivo studies were performed upon surgical peritoneal implantation of nanotextile implants in orthotopic, syngeneic ID8-VEGF tumor-bearing C57BL/6 mice. In comparison to the clinical PTX-solution, there was a significant enhancement of anti-tumor efficacy and safety with PTX-nanotextiles. After 35-days, the peritoneum of tumor-bearing mice with PTX-nanotextiles was completely devoid of tumor nodules and ascitic fluid. Additionally, VEGF levels measured in peritoneal lavage fluid were 300-fold lower compared to PTX-solution and 600-fold lower as compared to untreated tumor-bearing animals. PTX-solution treated group also developed severe metastatic lesions and progressive ascitic fluid buildup. More importantly, no signs of systemic/ organ toxicity were observed in PTX-nanotextile implanted mice, unlike the systemic toxic effects induced by PTX-solution. Collectively, our results show the therapeutic and safety advantages offered by combining clinically translatable metronomic low-dose chemotherapy and IP pharmacokinetics using biodegradable nanotextile implants in addressing the challenges of late-stage ovarian cancer.

Long-Term Survival and Prognostic Factors in Locoregionally Advanced Nasopharyngeal Carcinoma Patients Treated with TPF Induction Chemotherapy followed by Cisplatin-Combined Concurrent Chemoradiotherapy

Purpose: The objective of this study was to report long-term results of docetaxel, cisplatin, and 5-fluorouracil (TPF) induction chemotherapy followed by concurrent chemoradiotherapy (CCRT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) and identify prognostic factors for this group of patients. Materials and Methods: From December 2010 to January 2015, 109 patients with locoregionally advanced (III-IVB) NPC were included. Patients were scheduled to complete TPF induction chemotherapy followed by cisplatin based CCRT. Failure-free survival (FFS), overall survival (OS), locoregional failure-free survival (LRFFS) and distant failure-free survival (DFFS) served as clinical outcomes. Kaplan-Meier method, Cox proportional hazards model and receiver operating characteristic (ROC) curves were used for analyzing. Results: With a median follow-up of 60.2 months (range, 7.9-91.6 months), 3-year FFS, OS, LRFFS, and DFFS were 76.8%, 85.1%, 88.3%, and 84.1%, respectively. The highest incidence rate of recurrence and metastasis were in the first year after treatment. Multivariate analyses showed that age, total time of radiation therapy (RTT), and total time of therapy (TTT) were independent prognostic factors for FFS and OS. Body mass index (BMI), RTT and TTT were significant variables predicting DFFS. TTT was the only independent prognostic factor for LRFFS. Conclusion: This study indicated that TPF regimen produced encouraging results in Asian patients with locoregionally advanced nasopharyngeal carcinoma. Toxicity was tolerable and reversible. However, overall treatment time is an important factor that we should take into consideration when make plans of induction chemotherapy related treatment.

Therapeutic bacteria to combat cancer; current advances, challenges, and opportunities

Successful treatment of cancer remains a challenge, due to the unique pathophysiology of solid tumors, and the predictable emergence of resistance. Traditional methods for cancer therapy including radiotherapy, chemotherapy, and immunotherapy all have their own limitations. A novel approach is bacteriotherapy, either used alone, or in combination with conventional methods, has shown a positive effect on regression of tumors and inhibition of metastasis. Bacteria-assisted tumor-targeted therapy used as therapeutic/gene/drug delivery vehicles has great promise in the treatment of tumors. The use of bacteria only, or in combination with conventional methods was found to be effective in some experimental models of cancer (tumor regression and increased survival rate). In this article, we reviewed the major advantages, challenges, and prospective directions for combinations of bacteria with conventional methods for tumor therapy.

Mifepristone inhibits non-small cell lung carcinoma cellular escape from DNA damaging cisplatin

Background

Lung cancer is the leading cause of cancer deaths in the world. The major histopathological subtype of lung cancer is non-small cell lung cancer (NSCLC). Platinum-based therapy is the standard of care for patients with advanced stage NSCLC. However, even with treatment, most patients will die of this disease within 5 years and most of these deaths are due to recurrence. One strategy to inhibit recurrence is to use cytostatic compounds following courses of lethal chemotherapy. We have shown in various cancer cell types that mifepristone (MF), an anti-progestin/anti-glucocorticoid, is a powerful cytostatic anti-cancer agent. Thus, in this work we tested the hypothesis that MF should be efficacious in inducing cytostasis and preventing repopulation of NSCLC following cisplatin (CDDP) therapy.

Methods

We established an in vitro approach wherein human NSCLC cells with different genetic backgrounds and sensitivities to CDDP (A549 and H23) were exposed to rounds of lethal concentrations of CDDP for 1 h followed or not by MF monotherapy. Every 2 days, cell number, cell viability, and colony-forming ability of viable cells were studied.

Results

CDDP killed the majority of cells, yet there were remnant cells escaping CDDP lethality and repopulating the culture, as evidenced by the improved clonogenic survival of viable cells. In contrast, when cells exposed to CDDP where further treated with MF following CDDP removal, their number and clonogenic capacity were reduced drastically.

Conclusion

This study reports that there is repopulation of NSCLC cells following a lethal concentration of CDDP monotherapy, that NSCLC cells are sensitive to the growth inhibition properties of MF, and that MF abrogates the repopulation of NSCLC cells following CDDP therapy. Our study supports further evaluating MF as an adjuvant therapy for NSCLC.

Anastasis: recovery from the brink of cell death

Anastasis is a natural cell recovery phenomenon that rescues cells from the brink of death. Programmed cell death such as apoptosis has been traditionally assumed to be an intrinsically irreversible cascade that commits cells to a rapid and massive demolition. Interestingly, recent studies have demonstrated recovery of dying cells even at the late stages generally considered immutable. Here, we examine the evidence for anastasis in cultured cells and in animals, review findings illuminating the potential mechanisms of action, discuss the challenges of studying anastasis and explore new strategies to uncover the function and regulation of anastasis, the identification of which has wide-ranging physiological, pathological and therapeutic implications.

Effects of thoracic radiotherapy timing and duration on progression-free survival in limited-stage small cell lung cancer

Concurrent chemoradiotherapy (CRT) has been recommended and applied widely as the standard treatment for limited‐stage small cell lung cancer (LS‐SCLC). However, controversies remain regarding the optimal timing and treatment duration of thoracic radiotherapy (TRT), and their effects on patient survival. To evaluate prognostic values of TRT timing and duration on progression‐free survival (PFS) in LS‐SCLC and their dependence on TRT fractionation and clinicopathological characteristics, we retrospectively analyzed 197 LS‐SCLC patients receiving CRT from 2000 to 2016 at Sun Yat‐sen University Cancer Center. Based on the optimal cut‐off values of TRT timing and duration generated by Cutoff Finder, patients were divided into early TRT/late TRT group and short TRT/long TRT group respectively. Univariate and multivariate Cox analysis were performed to assess correlations of TRT timing, duration, fractionation, and clinicopathological characteristics with PFS. Univariate analysis revealed that early‐initiated TRT (P = 2.54 × 10⁻⁴) and short TRT (P = .001) significantly correlated with longer PFS. Their PFS benefits persisted in patients receiving hyperfractionated TRT and etoposide‐cisplatin (EP) chemotherapy, but were less prominent in those receiving once‐daily TRT and non‐EP chemotherapy. Multivariate analysis further identified early initiated TRT (P = .004) and short TRT (P = .017) as independent prognostic factors for longer PFS in LS‐SCLC. Our study confirmed that early‐initiated TRT and short TRT had positive prognostic roles in LS‐SCLC, especially in patients receiving hyperfractionated TRT and etoposide‐cisplatin chemotherapy. TRT fractionation was not an independent prognostic factor in LS‐SCLC.

HMGB1 released by irradiated tumor cells promotes living tumor cell proliferation via paracrine effect

Tumor repopulation during therapy is an important cause of treatment failure. Strategies to overcome repopulation are arising in parallel with advances in the comprehension of underlying biological mechanisms. Here, we reveal a new mechanism by which high mobility group box 1 (HMGB1) released by dying cells during radiotherapy or chemotherapy could stimulate living tumor cell proliferationInhibition or genetic ablation of HMGB1 suppressed tumor cell proliferation. This effect was due to binding of HMGB1with the member receptor for advanced glycation end-products (RAGE), which activated downstream ERK and p38 signaling pathway and promoted cell proliferation. Furthermore, higher HMGB1 expression in tumor tissue correlated with poor overall survival and higher HMGB1 concentration was detected in serum of patients who accepted radiotherapy. Collectively, the results from this study suggested that interaction between dead cells and surviving cells might influence the fate of tumor. HMGB1 could be a novel tumor promoter with therapeutic and prognostic relevance in cancers.

Detecting Anastasis In Vivo by CaspaseTracker Biosensor

Anastasis (Greek for "rising to life") is a recently discovered cell recovery phenomenon whereby dying cells can reverse late-stage cell death processes that are generally assumed to be intrinsically irreversible. Promoting anastasis could in principle rescue or preserve injured cells that are difficult to replace such as cardiomyocytes or neurons, thereby facilitating tissue recovery. Conversely, suppressing anastasis in cancer cells, undergoing apoptosis after anti-cancer therapies, may ensure cancer cell death and reduce the chances of recurrence. However, these studies have been hampered by the lack of tools for tracking the fate of cells that undergo anastasis in live animals. The challenge is to identify the cells that have reversed the cell death process despite their morphologically normal appearance after recovery. To overcome this difficulty, we have developed Drosophila and mammalian CaspaseTracker biosensor systems that can identify and permanently track the anastatic cells in vitro or in vivo. Here, we present in vivo protocols for the generation and use of the CaspaseTracker dual biosensor system to detect and track anastasis in Drosophila melanogaster after transient exposure to cell death stimuli. While conventional biosensors and protocols can label cells actively undergoing apoptotic cell death, the CaspaseTracker biosensor can permanently label cells that have recovered after caspase activation - a hallmark of late-stage apoptosis, and simultaneously identify active apoptotic processes. This biosensor can also track the recovery of the cells that attempted other forms of cell death that directly or indirectly involved caspase activity. Therefore, this protocol enables us to continuously track the fate of these cells and their progeny, facilitating future studies of the biological functions, molecular mechanisms, physiological and pathological consequences, and therapeutic implications of anastasis. We also discuss the appropriate controls to distinguish cells that undergo anastasis from those that display non-apoptotic caspase activity in vivo.

Assessment of the antitumor potential of Bithionol in vivo using a xenograft model of ovarian cancer

In terms of the concept of 'drug repurposing', we focused on pharmaceutical-grade Bithionol (BT) as a therapeutic agent against ovarian cancer. Our recent in-vitro study provides preclinical data suggesting a potential therapeutic role for BT against recurrent ovarian cancer. BT was shown to cause cell death by caspases-mediated apoptosis. The present preliminary study further explores the antitumor potential of pharmaceutical-grade BT in an in-vivo xenograft model of human ovarian cancer. Nude Foxn1 mice bearing SKOV-3 human ovarian tumor xenografts were treated with titrated doses of BT and the therapeutic efficacy of pharmaceutical BT was determined using bioluminescence imaging. BT-induced changes in cell proliferation and apoptosis were evaluated by Ki-67 immunochemical staining and TUNEL assay. The effect of BT on autotaxin levels in serum, ascitic fluid, and tumor tissue was assessed by colorimetric and western blot techniques. BT treatment did not show antitumor potential or enhanced survival time at any of the doses tested. No apparent signs of toxicity were observed with any of the doses tested. Immunohistological analysis of tumor sections did not indicate a significant decrease in cellular proliferation (Ki-67 assay). An increase in apoptosis (by TUNEL assay) was observed in all BT-treated mice compared with vehicle-treated mice. Although BT did not show significant antitumor activity in the present study, the ability of BT to induce apoptosis still makes it a promising therapeutic agent. Further confirmatory and optimization studies are essential to enhance the therapeutic effects of BT.

Blockade of the LRP16-PKR-NF-κB signaling axis sensitizes colorectal carcinoma cells to DNA-damaging cytotoxic therapy

Acquired therapeutic resistance by tumors is a substantial impediment to reducing the morbidity and mortality that are attributable to human malignancies. The mechanisms responsible for the dramatic shift between chemosensitivity and chemoresistance in colorectal carcinoma have not been defined. Here, we report that LRP16 selectively interacts and activates double-stranded RNA-dependent kinase (PKR), and also acts as scaffolds to assist the formation of a ternary complex of PKR and IKKβ, prolonging the polymers of ADP-ribose (PAR)-dependent nuclear factor kappa B (NF-κB) transactivation caused by DNA-damaging agents and confers acquired chemoresistance. We also identified a small molecule, MRS2578, which strikingly abrogated the binding of LRP16 to PKR and IKKβ, converting LRP16 into a death molecule and forestalling colon tumorigenesis. Inclusion of MRS2578 with etoposide, versus each drug alone, exhibited synergistic antitumor cytotoxicity in xenografts. Our combinatorial approach introduces a strategy to enhance the efficacy of genotoxicity therapies for the treatment of tumors.

Acridine Orange/exosomes increase the delivery and the effectiveness of Acridine Orange in human melanoma cells: A new prototype for theranostics of tumors

Specifically targeted drug delivery systems with low immunogenicity and toxicity are deemed to increase efficacy of cancer chemotherapy. Acridine Orange (AO) is an acidophilic dye with a strong tumoricidal action following excitation with a light source at 466 nm. However, to date the clinical use of AO is limited by the potential side effects elicited by systemic administration. The endogenous nanocarrier exosomes have been recently introduced as a natural delivery system for therapeutic molecules. In this article, we show the outcome of the administration to human melanoma cells of AO charged Exosomes (Exo-AO), in both monolayer and spheroid models. The results showed an extended drug delivery time of Exo-AO to melanoma cells as compared to the free AO, improving the cytotoxicity of AO. This study shows that Exo-AO have a great potential for a real exploitation as a new theranostic approach against tumors based on AO delivered through the exosomes.

Up-regulation of autophagy is a mechanism of resistance to chemotherapy and can be inhibited by pantoprazole to increase drug sensitivity

BACKGROUND

Autophagy is a survival mechanism that allows recycling of cellular breakdown products, particularly in stressed cells. Here we evaluate the hypotheses that up-regulation of autophagy is a common mechanism of resistance to chemotherapy, and that drug resistance can be reversed by inhibiting autophagy with a proton pump inhibitor.

METHODS

We exposed human PC3, LNCaP and MCF7 cells to seven clinically-used chemotherapy drugs ± pantoprazole, examined the up-regulation of autophagy and the effect on cellular proliferation by Western Blots, MTS assay and colony-forming assay. The distribution of drug effects and of autophagy was quantified in LNCaP tumor sections in relation to blood vessels and hypoxia by immunohistochemistry using γH2AX, cleaved caspase-3 and p62.

RESULTS

All anticancer drugs led to up-regulation of autophagy in cultured tumor cells. Pantoprazole inhibited the induction of autophagy in a time- and dose-dependent manner, and sensitized cancer cells to the seven anti-cancer drugs. Treatment of LNCaP xenografts with paclitaxel induced both DNA damage and autophagy; autophagy was inhibited and markers of toxicity were increased by pantoprazole.

CONCLUSIONS

Induction of autophagy is a general mechanism associated with resistance to anticancer drugs and that its inhibition is a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes.

Hematological parameters during concurrent chemoradiotherapy as potential prognosticators in patients with stage IIB cervical cancer

We hypothesized that hemoglobin levels, absolute neutrophil count, and absolute lymphocyte count were associated with radiotherapy response and cancer progression and that they might reflect tumor repopulation during concurrent chemoradiotherapy. This study aimed to investigate these hematological parameters as prognosticators of cervical cancer. We analyzed 105 stage IIB cervical cancer patients treated with concurrent chemoradiotherapy, using log-rank tests and multivariate analyses. Hazard ratios were calculated weekly to evaluate changes in hemoglobin, absolute neutrophil count, and absolute lymphocyte count that were associated with disease-specific survival. Patients were categorized into the high hematological risk (patients with low hemoglobin plus high absolute neutrophil count and/or low absolute lymphocyte count) and the low hematological risk (others) groups according to the median cutoff values. During the second week of concurrent chemoradiotherapy, hematological factors were significantly associated with survival. In multivariate analysis, hematological risk was independently associated with disease-specific survival and progression-free survival. The 5-year disease-specific survival and progression-free survival rates in the high hematological risk group were significantly lower compared with those in the low hematological risk group (81.6% vs 92.6%, p = 0.0297; 73.7% vs 89.3%, p = 0.0163, respectively). During the second week of concurrent chemoradiotherapy, the hematological parameters could predict treatment outcome in stage IIB cervical cancer.

Role of vascular normalization in benefit from metronomic chemotherapy

Metronomic dosing of chemotherapy-defined as frequent administration at lower doses-has been shown to be more efficacious than maximum tolerated dose treatment in preclinical studies, and is currently being tested in the clinic. Although multiple mechanisms of benefit from metronomic chemotherapy have been proposed, how these mechanisms are related to one another and which one is dominant for a given tumor-drug combination is not known. To this end, we have developed a mathematical model that incorporates various proposed mechanisms, and report here that improved function of tumor vessels is a key determinant of benefit from metronomic chemotherapy. In our analysis, we used multiple dosage schedules and incorporated interactions among cancer cells, stem-like cancer cells, immune cells, and the tumor vasculature. We found that metronomic chemotherapy induces functional normalization of tumor blood vessels, resulting in improved tumor perfusion. Improved perfusion alleviates hypoxia, which reprograms the immunosuppressive tumor microenvironment toward immunostimulation and improves drug delivery and therapeutic outcomes. Indeed, in our model, improved vessel function enhanced the delivery of oxygen and drugs, increased the number of effector immune cells, and decreased the number of regulatory T cells, which in turn killed a larger number of cancer cells, including cancer stem-like cells. Vessel function was further improved owing to decompression of intratumoral vessels as a result of increased killing of cancer cells, setting up a positive feedback loop. Our model enables evaluation of the relative importance of these mechanisms, and suggests guidelines for the optimal use of metronomic therapy.

Molecular signature of anastasis for reversal of apoptosis

Anastasis (Greek for "rising to life") is a cell recovery phenomenon that rescues dying cells from the brink of cell death. We recently discovered anastasis to occur after the execution-stage of apoptosis in vitro and in vivo. Promoting anastasis could in principle preserve injured cells that are difficult to replace, such as cardiomyocytes and neurons. Conversely, arresting anastasis in dying cancer cells after cancer therapies could improve treatment efficacy. To develop new therapies that promote or inhibit anastasis, it is essential to identify the key regulators and mediators of anastasis - the therapeutic targets. Therefore, we performed time-course microarray analysis to explore the molecular mechanisms of anastasis during reversal of ethanol-induced apoptosis in mouse primary liver cells. We found striking changes in transcription of genes involved in multiple pathways, including early activation of pro-cell survival, anti-oxidation, cell cycle arrest, histone modification, DNA-damage and stress-inducible responses, and at delayed times, angiogenesis and cell migration. Validation with RT-PCR confirmed similar changes in the human liver cancer cell line, HepG2, during anastasis. Here, we present the time-course whole-genome gene expression dataset revealing gene expression profiles during the reversal of apoptosis. This dataset provides important insights into the physiological, pathological, and therapeutic implications of anastasis.

Molecular signature of anastasis for reversal of apoptosis

Anastasis (Greek for "rising to life") is a cell recovery phenomenon that rescues dying cells from the brink of cell death. We recently discovered anastasis to occur after the execution-stage of apoptosis in vitro and in vivo. Promoting anastasis could in principle preserve injured cells that are difficult to replace, such as cardiomyocytes and neurons. Conversely, arresting anastasis in dying cancer cells after cancer therapies could improve treatment efficacy. To develop new therapies that promote or inhibit anastasis, it is essential to identify the key regulators and mediators of anastasis – the therapeutic targets. Therefore, we performed time-course microarray analysis to explore the molecular mechanisms of anastasis during reversal of ethanol-induced apoptosis in mouse primary liver cells. We found striking changes in transcription of genes involved in multiple pathways, including early activation of pro-cell survival, anti-oxidation, cell cycle arrest, histone modification, DNA-damage and stress-inducible responses, and at delayed times, angiogenesis and cell migration. Validation with RT-PCR confirmed similar changes in the human liver cancer cell line, HepG2, during anastasis. Here, we present the time-course whole-genome gene expression dataset revealing gene expression profiles during the reversal of apoptosis. This dataset provides important insights into the physiological, pathological, and therapeutic implications of anastasis.

Molecular Mimics of Classic P-Glycoprotein Inhibitors as Multidrug Resistance Suppressors and Their Synergistic Effect on Paclitaxel

P-glycoprotein (Pgp) is a membrane bound efflux pump spread in a variety of tumor cells and considered as a main component of multidrug resistance (MDR) to chemotherapies. In this work, three groups of compounds (imidazolone, oxazolone and vinyl dipeptide derivatives) were synthesized aiming to develop a molecular framework that effectively suppresses MDR. When tested for their influence on Pgp activity, four compounds coded Cur1-01, Cur1-12V, Curox-1 and Curox-3 significantly decreased remaining ATP concentration indicating Pgp substrate site blocking. On the other hand, Cur-3 and Cur-10 significantly increased remaining ATP concentration, which is indicative of Pgp ATPase inhibition. The cytotoxicity of synthesized compounds was examined against Pgp expressing/highly resistant colorectal cancer cell lines (LS-174T). Compounds Cur-1 and Cur-3 showed considerable cytotoxicity with IC50 values of 7.6 and 8.9 μM, respectively. Equitoxic combination (at IC50 concentrations) of PTX and Cur-3 greatly diminished resistant cell clone from 45.7% to 2.5%, albeit with some drop in potency from IC50 of 7.9 nM to IC50 of 23.8 nM. On the other hand, combination of PTX and the non-cytotoxic Cur1-12V (10 μM) significantly decreased the IC50 of PTX to 3.8 nM as well as the resistant fraction to 16.2%. The combination test was confirmed using the same protocol but on another resistant CRC cell line (HCT-116) as we obtained similar results. Both Cur-3 and Cur1-12V (10 μM) significantly increased the cellular entrapment of Pgp probe (doxorubicin) elevating its intracellular concentration from 1.9 pmole/cell to 3.0 and 2.9 pmole/cell, respectively.

Emergent properties of a computational model of tumour growth

While there have been enormous advances in our understanding of the genetic drivers and molecular pathways involved in cancer in recent decades, there also remain key areas of dispute with respect to fundamental theories of cancer. The accumulation of vast new datasets from genomics and other fields, in addition to detailed descriptions of molecular pathways, cloud the issues and lead to ever greater complexity. One strategy in dealing with such complexity is to develop models to replicate salient features of the system and therefore to generate hypotheses which reflect on the real system. A simple tumour growth model is outlined which displays emergent behaviours that correspond to a number of clinically relevant phenomena including tumour growth, intra-tumour heterogeneity, growth arrest and accelerated repopulation following cytotoxic insult. Analysis of model data suggests that the processes of cell competition and apoptosis are key drivers of these emergent behaviours. Questions are raised as to the role of cell competition and cell death in physical cancer growth and the relevance that these have to cancer research in general is discussed.

Intercalated chemotherapy and erlotinib for non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutations

Among attempts to delay development of resistance to tyrosine kinase inhibitors (TKIs) in patients with advanced non-small cell lung cancer (NSCLC) with activating mutations of epidermal growth factor receptor (EGFR), intercalated therapy has not been properly evaluated. In a phase II trial, 38 patients with EGFR mutated NSCLC in advanced stage were treated with 4 to 6 3-weekly cycles of intercalated schedule with gemcitabine (1250 mg/m2, days 1 and 4), cisplatin (75 mg/m2, day 2) and erlotinib (150 mg, days 5 - 15), followed by continuous erlotinib as maintenance. In addition to standard radiologic evaluation according to RECIST, PET/CT was done prior to treatment and at 6 months, using PERCIST as a method for assessment of response. The primary endpoint was progression-free survival (PFS). In general, tolerance to treatment was good, even among 8 patients with performance status 2-3 and 13 patients with brain metastases; grade 4 toxicity included 2 cases of neutropenia and 4 thrombo-embolic events. Complete response (CR) or partial response (PR) were seen in 15 (39.5%) and 17 (44.7%) cases, respectively. All cases of CR were confirmed also by PET/CT. Median PFS was 23.4 months and median overall survival (OS) was 38.3  months. After a median follow-up of 35 months, 8 patients are still in CR and on maintenance erlotinib. In conclusion, intercalated treatment for treatment-naive patients with EGFR activating mutations leads to excellent response rate and prolonged PFS and survival. Comparison of the intercalated schedule to monotherapy with TKIs in a randomized trial is warranted.

Mechanisms of Drug Resistance Related to the Microenvironment of Solid Tumors and Possible Strategies to Inhibit Them

Drug resistance can occur at the individual cellular level or as a result of properties of the tumor microenvironment. The convoluted vasculature within tumors results in robustly proliferating well-nourished cells located proximal to functional blood vessels and regions of slowly proliferating (often hypoxic) cells located distal to functional blood vessels. Irregular blood flow and large distances between functional blood vessels in solid tumors lead to poor drug distribution within them such that cells distal from functional blood vessels are exposed to ineffective concentrations of drug, resulting in therapeutic resistance. Strategies to improve or complement the distribution of anticancer drugs within tumors hold promise for increasing antitumor effects without corresponding increases in normal tissue toxicity. In particular, use of hypoxia-targeted agents and modulation of autophagy have shown promising results in enhancing the distribution of drug activity within solid tumors and hence antitumor efficacy. In this review, we describe causes of resistance to chemotherapy that relate to the microenvironment of solid tumors and the potential to improve antitumor effects by countering such mechanisms of resistance.

Molecular Pathways: Targeting Cancer Stem Cells Awakened by Chemotherapy to Abrogate Tumor Repopulation

Cytotoxic chemotherapy remains the first-line therapy for many advanced solid tumors; hence, understanding the underlying mechanisms to overcome chemoresistance remains a top research priority. In the clinic, chemotherapy is administered in multiple cycles that are spaced out to allow the recovery or repopulation of normal tissues and tissue stem cells between treatment cycles. However, residual surviving cancer cells and cancer stem cells can also repopulate tumors during the gap periods between chemotherapy cycles. Tumor repopulation is a phenomenon that has not been well studied; it is often overlooked due to current customized experimental study strategies. Recent findings reveal an alarming role for dying cells targeted by chemotherapy in releasing mitogens to stimulate active repopulation of quiescent cancer stem cells. Therefore, new therapeutic options to abrogate tumor repopulation will provide new avenues to improve chemotherapeutic response and clinical outcome.

Risk factors and patterns of early recurrence after curative hepatectomy for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) often recurs after curative hepatectomy; and early recurrence after hepatectomy (ERAH) is associated with poor prognosis. This study aimed to clarify risk factors and disease patterns for ERAH.

METHODS

We retrospectively analyzed clinicopathological factors of 232 patients who underwent initial curative hepatectomies for HCC between April 2000 and March 2013, and examined associated risk factors and early recurrence patterns by liver function status (as indicated by indocyanine green retention rate at 15 min [ICGR15]).

RESULTS

Patients who experienced recurrence within 6 months after hepatectomy (i.e., ERAH) had significantly shorter survival than those with longer disease-free intervals (P < 0.001). In multivariate analysis, microvascular invasion (mVI; P = 0.034) and ICGR15 ≥ 16% (P = 0.010) were independent risk factors for ERAH. In the ICGR1<16% subgroup, positive L3-AFP (P = 0.04), tumor size ≥ 5 cm (P = 0.011), surgical margin = 0 (P = 0.0103), mVI (P = 0.034), and extrahepatic recurrence were significant predictors of ERAH; in the ICGR15 ≥ 16%, subgroup, multiple tumors (P = 0.046) were identified as a risk factor for ERAH; however, this group did not experience much extrahepatic recurrence.

CONCLUSIONS

ERAH was associated with mVI and ICGR15 ≥ 16%. Recurrence patterns and risk factors vary by liver function status, which should be considered in forming management strategies for early recurrence of HCC after curative hepatectomy.

Concurrent chemo-radiation with or without induction gemcitabine, Carboplatin, and Paclitaxel: a randomized, phase 2/3 trial in locally advanced nasopharyngeal carcinoma

PURPOSE

To compare survival, tumor control, toxicities, and quality of life of patients with locally advanced nasopharyngeal carcinoma (NPC) treated with induction chemotherapy and concurrent chemo-radiation (CCRT), against CCRT alone.

PATIENTS AND METHODS

Patients were stratified by N stage and randomized to induction GCP (3 cycles of gemcitabine 1000 mg/m(2), carboplatin area under the concentration-time-curve 2.5, and paclitaxel 70 mg/m(2) given days 1 and 8 every 21 days) followed by CCRT (radiation therapy 69.96 Gy with weekly cisplatin 40 mg/m(2)), or CCRT alone. The accrual of 172 was planned to detect a 15% difference in 5-year overall survival (OS) with a 5% significance level and 80% power.

RESULTS

Between September 2004 and August 2012, 180 patients were accrued, and 172 (GCP 86, control 86) were analyzed by intention to treat. There was no significant difference in OS (3-year OS 94.3% [GCP] vs 92.3% [control]; hazard ratio 1.05; 1-sided P=.494]), disease-free survival (hazard ratio 0.77, 95% confidence interval 0.44-1.35, P=.362), and distant metastases-free survival (hazard ratio 0.80, 95% confidence interval 0.38-1.67, P=.547) between the 2 arms. Treatment compliance in the induction phase was good, but the relative dose intensity for concurrent cisplatin was significantly lower in the GCP arm. Overall, the GCP arm had higher rates of grades 3 and 4 leukopenia (52% vs 37%) and neutropenia (24% vs 12%), but grade 3 and 4 acute radiation toxicities were not statistically different between the 2 arms. The global quality of life scores were comparable in both arms.

CONCLUSION

Induction chemotherapy with GCP before concurrent chemo-irradiation did not improve survival in locally advanced NPC.

Chemotherapy Rescues Hypoxic Tumor Cells and Induces Their Reoxygenation and Repopulation-An Effect That Is Inhibited by the Hypoxia-Activated Prodrug TH-302

PURPOSE

Chemotherapy targets rapidly proliferating tumor cells, but spares slowly proliferating hypoxic cells. We hypothesized that nutrition of hypoxic cells would improve in intervals between chemotherapy, and that hypoxic cells destined to die without treatment would survive and proliferate.

EXPERIMENTAL DESIGN

We therefore evaluated repopulation and reoxygenation following chemotherapy, and the effects of the hypoxia-activated prodrug TH-302 on these processes. Tumor-bearing mice were treated with doxorubicin or docetaxel ± TH-302. Pimonidazole (given concurrent with chemotherapy) and EF5 (given 24 to 120 hours later) identified hypoxic cells. Proliferation (Ki67) and oxygen status (EF5 uptake) of formerly hypoxic (pimo positive) cells were quantified by immunohistochemistry.

RESULTS

Chronically hypoxic cells had limited proliferation in control tumors. After chemotherapy, we observed reoxygenation and increased proliferation of previously hypoxic cells; these processes were inhibited by TH-302.

CONCLUSIONS

Chemotherapy leads to paradoxical sparing of hypoxic cells destined to die in solid tumors in absence of treatment, and their reoxygenation and proliferation: TH-302 inhibits these processes.

Intercalated chemotherapy and erlotinib for advanced NSCLC: high proportion of complete remissions and prolonged progression-free survival among patients with EGFR activating mutations

Background

Pharmaco-dynamic separation of cytotoxic and targeted drugs might avoid their mutual antagonistic effect in the treatment of advanced non-small cell lung cancer (NSCLC).

Patients and methods.

Eligible patients were treatment-naive with stage IIIB or IV NSCLC. In addition, inclusion was limited to never-smokers or light smokers or, after 2010, to patients with activating epidermal growth-factor receptor (EGFR) mutations. Treatment started with 3-weekly cycles of gemcitabine and cisplatin on days 1, 2 and 4 and erlotinib on days 5 to 15. After 4 to 6 cycles, patients continued with erlotinib maintenance.

Results

Fifty-three patients were recruited into the trial: 24 prior to 2010 (of whom 9 were later found to be positive for EGFR mutations), and 29 EGFR mutation-positive patients recruited later. Unfavourable prognostic factors included stage IV disease (51 patients - 96%), performance status 2–3 (11 patients - 21%) and brain metastases (15 patients -28%). Grade 4 toxicity included 2 cases of neutropenia and 4 thrombo-embolic events. The 15 EGFR negative patients had 33% objective response rate, median progression-free survival (PFS) 6.0 months and median survival 7.6 months. Among 38 EGFR positive patients, complete response (CR) or partial response (PR) were seen in 16 (42.1%) and 17 (44.7%) cases, respectively. PET-CT scanning was performed in 30 patients and confirmed CR and PR in 16 (53.3%) and 9 (30.0%) cases, respectively. Median PFS for EGFR mutated patients was 21.2 months and median survival was 32.5 months.

Conclusions

While patients with EGFR negative tumors do not benefit from addition of erlotinib, the intercalated schedule appears most promising for those with EGFR activating mutations.

Dual-layer surface coating of PLGA-based nanoparticles provides slow-release drug delivery to achieve metronomic therapy in a paclitaxel-resistant murine ovarian cancer model

Development of drug resistance is a central challenge to the treatment of ovarian cancer. Metronomic chemotherapy decreases the extent of drug-free periods, thereby hindering development of drug resistance. Intraperitoneal chemotherapy allows for treatment of tumors confined within the peritoneum, but achieving sustained tumor-localized chemotherapy remains difficult. We hypothesized that modulating the surface properties of poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles could enhance their drug retention ability and extend their release profile, thereby enabling metronomic, localized chemotherapy in vivo. Paclitaxel was encapsulated in particles coated with a layer of polydopamine and a subsequent layer of poly(ethylene glycol) (PEG). These particles achieved a 3.8-fold higher loading content compared to that of nanoparticles formulated from linear PLGA-PEG copolymers. In vitro release kinetic studies and in vivo drug distribution profiles demonstrate sustained release of paclitaxel. Although free drug conferred no survival advantage, low-dose intraperitoneal administration of paclitaxel-laden surface-coated nanoparticles to drug-resistant ovarian tumor-bearing mice resulted in significant survival benefits in the absence of any apparent systemic toxicity.

High dose lansoprazole combined with metronomic chemotherapy: a phase I/II study in companion animals with spontaneously occurring tumors

BACKGROUND

The treatment of human cancer has been seriously hampered for decades by resistance to chemotherapeutic drugs. A very efficient mechanism of tumor resistance to drugs is the proton pumps-mediated acidification of tumor microenvironment. Metronomic chemotherapy has shown efficacy in adjuvant fashion as well as in the treatment of pets with advanced disease. Moreover, we have shown in veterinary clinical settings that pre-treatment with proton-pumps inhibitors (PPI) increases tumor responsiveness to chemotherapeutics. In this study pet with spontaneously occurring cancer have been recruited to be treated by a combination of metronomic chemotherapy and high dose PPIs and their responses have been matched to those of a historical control of ten patients treated with metronomic chemotherapy alone.

METHODS

Single arm, non randomized phase II open study, with historical control group, evaluating safety and efficacy of the combination of metronomic chemotherapy and alkalization. Twenty-four companion animals (22 dogs and 2 cats) were treated adding to their metronomic chemotherapy protocol the pump inhibitor lansoprazole at high dose, and a water alkalizer. Their responses have been evaluated by clinical and instrumental evaluation and matched to those of the control group.

RESULTS

The protocol was overall well tolerated, with only two dogs experiencing side effects due to gastric hypochlorhydria consisting with vomiting and or diarrhea. In terms of overall response, in the alkalized cohort, 18 out of 24 had partial or complete responses (75%), two patients had a stable disease and the remaining patients experienced no response or progressive disease. On the other hand, only one patient in the control group experienced a complete response (10%) and three other experienced short lived responses. Median time to terminal event was 34 weeks for the experimental group versus 2 weeks in the controls (p= 0.042).

CONCLUSIONS

Patient alkalization has shown to be well tolerated and to increase tumor response to metronomic chemotherapy as well the quality of life in pets with advanced cancer. Further studies are warranted to assess the efficacy of this strategy in patients with advanced cancers in companion animals as well as in humans.