Hyperprogressive disease: recognizing a novel pattern to improve patient management

Role of medical imaging for immune checkpoint blockade therapy: From response assessment to prognosis prediction

Immune checkpoint blockade (ICB) represents a promising approach in cancer therapy. Owing to the peculiar biologic mechanisms of anticancer activity, checkpoint blockers are accompanied with distinctive response patterns and toxicity profiles. Medical imaging is the cornerstone for response assessment to immunotherapy and plays a critical role in monitoring of immune-related adverse events (irAEs). Imaging-based biomarkers have shown tremendous potential for the prediction of therapeutic efficacies and clinical outcomes in patients treated with checkpoint inhibitors. In this article, the landscape of current response assessment systems for immunotherapy was reviewed with a special focus on the latest advances in the assessment of responses to ICB. Emerging imaging biomarkers were discussed along with the challenges regarding their clinical transformation. In addition, the biological mechanisms and clinical applications of ICB and irAEs were also within the scope of this review.

Non-small-cell lung cancer: what are the benefits and challenges of treating it with immune checkpoint inhibitors?

Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape of advanced non-small-cell lung cancer (NSCLC). It has improved the overall survival in the first- and second-line setting with manageable adverse events. Multiple challenges still impede the success of ICI in the whole population of NSCLC namely the lack of reliable predictive biomarkers, the scarcity of data regarding the optimal treatment duration with ICI and possibility of rechallenge with ICI as well as the efficacy of ICI in special subgroups of patients such as those with oncogenic addicted tumors or patients with brain metastases. In this framework, we review the benefits and challenges of ICI in NSCLC, in monotherapy and in combinations, in the advanced setting.

The Evaluation of Response to Immunotherapy in Metastatic Renal Cell Carcinoma: Open Challenges in the Clinical Practice

Immunotherapy has changed the therapeutic scenario of metastatic renal cell carcinoma (mRCC), however the evaluation of disease response to immune-checkpoint inhibitors is still an open challenge. Response evaluation criteria in solid tumors (RECIST) 1.1 criteria are the cornerstone of response assessment to anti-neoplastic treatments, but the use of anti-programmed death receptor 1 (PD1) and other immunotherapeutic agents has shown atypical patterns of response such as pseudoprogression. Therefore, immune-modified criteria have been developed in order to more accurately categorize the disease response, even though their use in the everyday clinical practice is still limited. In this review we summarize the available evidence on this topic, with particular focus on the application of immune-modified criteria in the setting of mRCC.

New therapeutic targets for cancer: the interplay between immune and metabolic checkpoints and gut microbiota

Transformation and growth of tumor cells are associated with profound alterations in neighbouring cells and their environment, together forming the tumor microenvironment (TME). The TME provides a conducive but complex milieu for the tumors to thrive while incapacitating the immune cells that home there as part of our natural immunosurveillance mechanism. The orchestration of this successful survival strategy by tumor cells is associated with exploitation of numerous metabolic and immune checkpoints, as well as metabolic reprogramming in the tumor cells. Together these form an intricate network of feedback mechanisms that favor the growing tumor. In addition, an ecosystem of microbiota, proximal or distal to tumors, influences the successful survival or elimination of tumor cells mediated by immune cells. Discovery and clinical application of immune checkpoint inhibitors (ICIs) i.e., monoclonal antibodies (mAbs) blocking specific immune checkpoints CTLA-4 and PD-1/PD-L1, have revolutionized therapy of various cancers. However, they are still associated with limited response rates, severe immune-related adverse events, development of resistance, and more serious exacerbation of cancer progression termed hyper-progressive disease. Checkpoint inhibitors only represent a milestone and not the finish-line in the quest for treating and curing cancer. Efforts are underway to investigate and develop inhibitors of other immune as well as metabolic checkpoint molecules. Future therapy for various cancers is projected to target immune and metabolic checkpoints and the microbiota together.

Tumor Growth Rate as a Validated Early Radiological Biomarker Able to Reflect Treatment-Induced Changes in Neuroendocrine Tumors: The GREPONET-2 Study

PURPOSE

Tumor growth rate (TGR) represents the percentage change in tumor volume per month (%/m). Previous results from the GREPONET study showed that TGR measured after 3 months (TGR_3m) of starting systemic treatment (ST) or watch and wait (WW) was an early biomarker predicting progression-free survival (PFS) in neuroendocrine tumors (NET).

EXPERIMENTAL DESIGN

Patients from 7 centers with advanced grade (G) 1/2 NETs from the pancreas (P)/small bowel (SB) initiating ST/WW were eligible. Computed tomography (CT)/MRI performed at prebaseline, baseline, and 3(±1) months of study entry were retrospectively reviewed. Aim-1: explore treatment-induced changes in TGR (ΔTGR_3m-BL; paired T test), and Aim-2: validate TGR_3m (<0.8%/m vs. ≥0.8%/m) as an early biomarker in an independent cohort (Kaplan-Meier/Cox regression).

RESULTS

Of 785 patients screened, 127 were eligible. Mean (SD) TGR₀ and TGR_3m were 5.4%/m (14.9) and -1.4%/m (11.8), respectively. Mean (SD) ΔTGR_3m-BL paired-difference was -6.8%/m (19.3; P < 0.001). Most marked ΔTGR_3m-BL [mean (SD)] were identified with targeted therapies [-11.3%/m (4.7); P = 0.0237] and chemotherapy [-7.9%/m (3.4); P = 0.0261]. Multivariable analysis confirmed the absence of previous treatment (OR = 4.65; 95% CI, 1.31-16.52; P = 0.018) and low TGR_3m (continuous variable; OR 1.09; 95% CI, 1.01-1.19; P = 0.042) to be independent predictors of radiologic objective response. When the multivariable survival analysis for PFS (Cox regression) was adjusted to grade (P = 0.004) and stage (P = 0.017), TGR_3m ≥ 0.8 (vs. <0.8) maintained its significance as a prognostic factor (P < 0.001), whereas TGR₀ and ΔTGR_3m-BL did not. TGR_3m ≥ 0.8%/m was confirmed as an independent prognostic factor for PFS [external validation; Aim-2; multivariable HR 2.21 (95% CI, 1.21-3.70; P = 0.003)].

CONCLUSIONS

TGR has a role as a biomarker for monitoring response to therapy for early identification of treatment-induced changes and for early prediction of PFS and radiologic objective response.

Immune checkpoint inhibitors in esophageal squamous cell carcinoma: progress and opportunities

Esophageal squamous cell carcinoma (ESCC) is one of the common malignant tumors in the world. More than half of patients with ESCC were detected in advanced or metastatic disease at the time of initial diagnosis and lost the opportunities of surgery. Currently, surgical resection, radiotherapy, and chemotherapy are most utilized in clinical practice, however, they are associated with limited survival benefits. Recognition of the limitation of traditional antitumor strategies prompt the development of new means to treat human cancer. In recent years, studies on immune checkpoint inhibitors (eg PD-1/PD-L1 inhibitors, CTLA-4 inhibitors, etc.) in ESCC have shown promising results. In addition, the combination of immune checkpoint inhibitor and traditional antitumor strategies for ESCC has caused extensive interest, and the results are encouraging. Previous analysis indicated that tumor cell PD-L1 expression, tumor mutation load (TMB), microsatellite instability-high status (MSI-H), and other biomarkers have relatively correlated with the efficacy of immunotherapy. This review explores the recent studies investigating checkpoint inhibitors in ESCC.

Immune Checkpoint Inhibitor Use Near the End of Life Is Associated With Poor Performance Status, Lower Hospice Enrollment, and Dying in the Hospital

Background:

Immune checkpoint inhibitors have changed the landscape of cancer care by increasing progression-free and overall survival in some patients with cancer. We evaluated use and variables contributing to immune checkpoint inhibitor treatment near the end of life.

Methods:

We studied 157 patients who received immune checkpoint inhibitors and died between January 2015 and December 2018. All patients had a palliative care consult any time between starting an immune checkpoint inhibitor and death. Univariate and multivariate models were used to examine variables related to immune checkpoint inhibitor use near the end of life.

Results:

Among 157 patients studied, 42 (27%) received a dose of immune checkpoint inhibitor in the last 30 days of life. Those who received treatment in the last 30 days of life had lower hospice enrollment (19 [45%] vs 78 [69%], P = .007) and higher rates of dying in the hospital (23 [56%] vs 33 [29%], P = .002). The percentage of patients with Eastern Cooperative Oncology Group (ECOG) ≥3 at the time of last immune checkpoint inhibitor dose was higher in the group that received immune checkpoint inhibitor treatment in the last 30 days of life (11 [26%] vs 9 [8%], P = .003). Lack of traditional chemotherapy after immune checkpoint inhibitor, ECOG ≥3, and lack of hospice enrollment were independently associated with receiving immune checkpoint inhibitor in the last 30 days of life.

Conclusion:

Immune checkpoint inhibitor use in the last 30 days of life is common and associated with poor performance status, lower hospice enrollment, and dying in the hospital.

Biomarkers of hyperprogression and pseudoprogression with immune checkpoint inhibitor therapy

Hyperprogression and pseudoprogression are two atypical responses to immune checkpoint inhibitor therapy that affect therapeutic decisions and prognosis. Identification of predictive biomarkers for atypical responses either before or during treatment remains a huge unmet need in cancer immunotherapy. Many studies have looked at potential biomarkers, including clinical factors and laboratory findings (e.g., peripheral blood counts, circulating tumor DNA, cytokine levels). The results of these studies have been inconsistent, possibly due to small sample sizes, different tumor types and heterogeneity of the definition of these atypical responses.

Paradox-driven adventures in the development of cancer immunology and immunotherapy

After more than one hundred years of documented trials, immunotherapy has become a standard of care in the treatment of human cancer. Much of the knowledge that led to recent breakthroughs seems quite logical from today's point of view. However, what we now cite as facts were originally considered paradoxes, meaning something contrary to expectations or perceived opinion at the time. In order to make gains in the field of immunotherapy, one had to be willing to confront ideas and concepts that seemed to contradict one another, and reconcile how each could be true. This is what led to new knowledge and advances. Here, we highlight some of these paradoxes and the milestone discoveries that followed, each one critical for our understanding of immune checkpoint pathways. By outlining some of the steps that we took and the challenges that we overcame, we hope to inspire and encourage future generations of researchers to confront the paradoxes that still permeate the field.

Comparing and contrasting predictive biomarkers for immunotherapy and targeted therapy of NSCLC

The era of personalized medicine for advanced-stage non-small-cell lung cancer (NSCLC) began when biomarker-based evidence of molecular pathway and/or oncogene addiction of the tumour became mandatory for the allocation of specific targeted therapies. More recently, the immunotherapy revolution, specifically, the development of immune-checkpoint inhibitors (ICIs), has dramatically altered the NSCLC treatment landscape. Herein, we compare and contrast the clinical development of immunotherapy and oncogene-directed therapy for NSCLC, focusing on the role of predictive biomarkers. Immunotherapy biomarkers are fundamentally different from oncogene biomarkers in that they are continuous rather than categorical (binary), spatially and temporally variable and reliant on multiple complex interactions rather than a single, dominant determinant. The performance of predictive biomarkers for ICIs might be improved by combining different markers to reduce the assumptive risks associated with each one. Novel combinations with chemotherapy and ICIs complicate biomarker discovery but do not decrease the value of the markers identified. Perfectly predictive biomarkers of benefit from immunotherapy are unlikely to be identified, although exclusionary biomarkers of minimal benefit or an unacceptable risk of toxicity might be feasible. The clinical adoption and applicability of such biomarkers might vary depending on line of treatment, the available therapeutic alternatives and health economic considerations.

Targeting Treg cells in cancer immunotherapy

Foxp3-expressing regulatory T (Treg) cells, which are indispensable for preventing autoimmunity, also suppress effective tumor immunity. Treg cells abundantly infiltrate into tumor tissues, which is often associated with poor prognosis in cancer patients. Removal of Treg cells enhances anti-tumor immune responses but may also elicit autoimmunity. A key issue in devising Treg-targeting cancer immunotherapy is, therefore, how to specifically deplete Treg cells infiltrating into tumor tissues without affecting tumor-reactive effector T cells, while suppressing autoimmunity. This can be achieved by differentially controlling Treg and effector T cells by various ways. In this review, we discuss how tumor-infiltrating Foxp3⁺ Treg cells hamper effective anti-tumor immune responses especially in tumor tissues and how they can be specifically targeted for augmenting tumor immunity but not autoimmunity.

Hyperprogressive disease during PD-1/PD-L1 blockade in patients with non-small-cell lung cancer

BACKGROUND

Immune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade.

PATIENTS AND METHODS

We enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8+ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD.

RESULTS

A total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868-7.440] and overall survival (HR, 5.079; 95% CI, 3.136-8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8+ T lymphocytes, a lower frequency of effector/memory subsets (CCR7-CD45RA- T cells among the total CD8+ T cells) and a higher frequency of severely exhausted populations (TIGIT+ T cells among PD-1+CD8+ T cells) were associated with HPD and inferior survival rate.

CONCLUSION

HPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.

Germinal immunogenetics as a predictive factor for immunotherapy

Clinical response to checkpoint inhibitors-based (CPIs) therapies can vary among tumor types and between patients. This led to a significant amount of pre-clinical and clinical research into biomarker identification. Biomarkers have been found to cover both the tumor itself and the tumor microenvironment. Entering host-related parameters into the equation should provide a valuable strategy for identifying not only factors predictive of treatment efficacy but also of treatment-related toxicity. It is clear that germline variants can offer efficient and easily-assessable indicators (blood DNA) to enlarge the spectrum of predictive markers for CPI-based treatment. A major issue concerns the real functional significance of the reported single-nucleotide polymorphisms (SNPs) linked to CPI-treatment outcome. Powered calculations should lead to an optimal trade-off between sample size and allele frequency. New molecular technologies and new analytical methods should provide opportunities to bridge the knowledge gap between SNP-CPI treatment associations and the functional impact of these SNPs.

Adaptive Responses to Monotherapy in Head and Neck Cancer: Interventions for Rationale-Based Therapeutic Combinations

Most Phase II and III clinical trials in head and neck cancer (HNC) combine two or more treatment modalities, which are based, in part, on knowledge of the molecular mechanisms of innate and acquired resistance to monotherapy. In this review, we describe the range of tumor-cell autonomously derived (intrinsic) and tumor-microenvironment-derived (extrinsic) acquired-resistance mechanisms to various FDA-approved monotherapies for HNC. Specifically, we describe how tumor cells and the tumor microenvironment (TME) respond to radiation, chemotherapy, targeted therapy (cetuximab), and immunotherapies [programmed cell death 1 (PD-1) inhibitors] and adapt to the selective pressure of these monotherapies. Due to the diversity of adaptive responses to monotherapy, monitoring the response to treatment in patients is critical to understand the path that leads to resistance and to guide the optimal therapeutic drug combinations in the clinical setting. We envisage that applying such a rationale-based therapeutic strategy will improve treatment efficacy in HNC patients.

Hyperprogressive disease during nivolumab or irinotecan treatment in patients with advanced gastric cancer

Background

Nivolumab showed a survival benefit for advanced gastric cancer (AGC). However, an acceleration of tumour growth during immunotherapy, (hyperprogressive disease, HPD) has been reported in various cancers. This study reviewed the HPD in patients with AGC treated with nivolumab or irinotecan.

Methods

The subjects of this retrospective study were patients with AGC with measurable lesions, and their tumour growth rates (TGR) during nivolumab or irinotecan were compared with those during prior therapy. HPD was defined as an increase in TGR more than twofold.

Results

34 and 66 patients received nivolumab and irinotecan in third or later line between June 2009 and September 2018 at our hospital; 22 patients receiving nivolumab had prior treatment with irinotecan, and one patient received irinotecan after nivolumab. Nivolumab and irinotecan showed no differences in disease control rates (38.2% and 34.8%) and in progression-free survival (PFS) (HR 1.1, 95% CI 0.7 to 1.6, p=0.802). The incidence of HPD was slightly higher after nivolumab (29.4%) than after irinotecan (13.5%) (p=0.0656), showing no differences in background between the patients with and without HPD. Compared between HPD and PD other than HPD after nivolumab, the HRs for PFS and overall survival (OS) were 1.1 (95% CI 0.5 to 2.7; p=0.756), and 2.1 (95% CI 0.7 to 5.8; p=0.168), but such clear difference in OS was not observed after irinotecan.

Conclusions

HPD was observed more frequently after nivolumab compared with irinotecan, which was associated with a poor prognosis after nivolumab but not so clearly after irinotecan.

PD-1+ regulatory T cells amplified by PD-1 blockade promote hyperprogression of cancer

PD-1 blockade is a cancer immunotherapy effective in various types of cancer. In a fraction of treated patients, however, it causes rapid cancer progression called hyperprogressive disease (HPD). With our observation of HPD in ∼10% of anti-PD-1 monoclonal antibody (mAb)-treated advanced gastric cancer (GC) patients, we explored how anti-PD-1 mAb caused HPD in these patients and how HPD could be treated and prevented. In the majority of GC patients, tumor-infiltrating FoxP3^highCD45RA^-CD4⁺ T cells [effector Treg (eTreg) cells], which were abundant and highly suppressive in tumors, expressed PD-1 at equivalent levels as tumor-infiltrating CD4⁺ or CD8⁺ effector/memory T cells and at much higher levels than circulating eTreg cells. Comparison of GC tissue samples before and after anti-PD-1 mAb therapy revealed that the treatment markedly increased tumor-infiltrating proliferative (Ki67⁺) eTreg cells in HPD patients, contrasting with their reduction in non-HPD patients. Functionally, circulating and tumor-infiltrating PD-1⁺ eTreg cells were highly activated, showing higher expression of CTLA-4 than PD-1^- eTreg cells. PD-1 blockade significantly enhanced in vitro Treg cell suppressive activity. Similarly, in mice, genetic ablation or antibody-mediated blockade of PD-1 in Treg cells increased their proliferation and suppression of antitumor immune responses. Taken together, PD-1 blockade may facilitate the proliferation of highly suppressive PD-1⁺ eTreg cells in HPDs, resulting in inhibition of antitumor immunity. The presence of actively proliferating PD-1⁺ eTreg cells in tumors is therefore a reliable marker for HPD. Depletion of eTreg cells in tumor tissues would be effective in treating and preventing HPD in PD-1 blockade cancer immunotherapy.

Comparison of Immune Checkpoint Inhibitors between Older and Younger Patients with Advanced or Metastatic Lung Cancer: A Systematic Review and Meta-Analysis

OBJECTIVES

Despite the fact that it is widely acknowledged that immune checkpoint inhibitors (ICIs) rely on the presence of immune response to take their antitumor effect, little is known whether there is an influence exerted on the efficacy of ICIs based on patients' age. We performed a systematic review and meta-analysis to explore the efficacy of ICIs between younger and older patients.

MATERIALS AND METHODS

We searched online database and major conference proceedings for randomized controlled trials (RCTs) published of ICIs and included RCTs that conducted subgroup comparisons of age with available combination of hazard ratios (HRs) and 95% confidence interval (95%CI). Subsequently, we figured out the pooled HR and 95%CI in younger and older patients with a random-effects model and evaluated the within-study heterogeneity by using subgroup, sensitivity, and meta-regression analysis.

RESULTS AND CONCLUSION

A total of 12 eligible RCTs included in our study, which reported OS according to patients' age. The overall estimated random-effects for HR was 0.75 with 95% CI of 0.65-0.87 in younger arm versus 0.81 with 95% CI of 0.72-0.92 in older arm. ICIs can improve OS for patients with advanced or metastatic lung cancer when compared to controls, especially for those patients with NSCLC, anti-PD-1/PD-L1 inhibitors, non-squamous, Pembrolizumab or Atezolizumab used as well as subsequent-line setting, and the magnitude of benefit in OS had comparable efficacy in both younger and older arms using a cut-off of 65 yr. Conversely, we also drew a statically significant conclusion that older patients failed to acquire benefit from ICIs when subdivided with a further cut-off of 75 yr.

Immune Checkpoint Ligand Reverse Signaling: Looking Back to Go Forward in Cancer Therapy

The so-called immune checkpoints are pathways that regulate the timing and intensity of the immune response to avoid an excessive reaction and to protect the host from autoimmunity. Immune checkpoint inhibitors (ICIs) are designed to target the negative regulatory pathways of T cells, and they have been shown to restore anti-tumor immune functions and achieve considerable clinical results. Indeed, several clinical trials have reported durable clinical response in different tumor types, such as melanoma, renal cell carcinoma (RCC) and non-small cell lung cancer (NSCLC). Nonetheless, after the initial enthusiasm, it is now evident that the majority of patients do not benefit from ICIs, due to innate or acquired tumor resistance. It is therefore mandatory to find ways to identify those patients who will respond and to find ways to induce response in those who at present do not benefit from ICIs. In this regard, the expression of programmed death ligand 1 (PD-L1) on neoplastic cells was the first, and most obvious, biomarker exploited to predict the activity of anti-programmed death 1 (PD-1) and/or anti-PD-L1 antibodies. As expected, a correlation was confirmed between the levels of PD-L1 and the efficacy of anti-PD-1 therapy in melanoma, NSCLC and RCC. However, further results from clinical trials showed that some patients display a clinical response regardless of tumor cell PD-L1 expression levels, while others do not benefit from ICI treatment despite the expression of PD-L1 on neoplastic elements. These findings strongly support the notion that other factors may be relevant for the efficacy of ICI-based treatment regimens. Furthermore, although the current dogma indicates that the PD-1/PD-L1 axis exerts its regulatory effects via the signal transduced in PD-1-expressing T cells, recent evidence suggests that a reverse signaling may also exist downstream of PD-L1 in both tumor and immune cells. The reverse signaling of PD-L1, but also of other immune checkpoints, might contribute to the pro-tumoral/immune suppressive environment associated with tumor development and progression. Clarifying this aspect could facilitate the prediction of patients’ clinical outcomes, which are so far unpredictable and result in response, resistance or even hyper-progressive disease in some cases.

YWHAZ amplification/overexpression defines aggressive bladder cancer and contributes to chemo-/radio-resistance by suppressing caspase-mediated apoptosis

The objective of this study was to characterize the oncogenic actions of a recently identified cancer‐associated gene YWHAZ (also named as 14‐3‐3 ζ/δ) in urothelial carcinomas of the urinary bladder (UCUB). A genome‐wide study revealed YWHAZ to be involved in the amplicon at 8q22.3, and its genetic amplification was detected predominantly in muscle‐invasive bladder cancer (MIBC). Immunohistochemical staining confirmed the association of YWHAZ overexpression with higher tumor stages, lymph node/vascular invasion, and mitotic activity. Univariate and multivariate analyses further indicated the prognostic potential of YWHAZ for more aggressive cancer types. Both gene set enrichment analysis and STRING network studies suggested involvement of YWHAZ in regulating caspase‐mediated apoptosis. Ectopic expression of YWHAZ in bladder cells with low endogenous YWHAZ levels boosted cell resistance to doxorubicin and cisplatin, as well as to ionizing radiation. Conversely, YWHAZ‐knockdown using specific shRNA in cells with high endogenous YWHAZ levels diminished survival activity, suppressing cell growth and increasing cell death. Our findings confirm the essential role played by YWHAZ in sustaining cell proliferation during chemo/radiotherapy. Treatments based on anti‐YWHAZ strategies may thus be beneficial for UCUB patients overexpressing YWHAZ. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

PD-1+ regulatory T cells amplified by PD-1 blockade promote hyperprogression of cancer

PD-1 blockade is a cancer immunotherapy effective in various types of cancer. However, we observed rapid cancer progression, called hyperprogressive disease (HPD), in ∼10% of advanced gastric cancer patients treated with anti–PD-1 monoclonal antibody. Tumors of HPD patients possessed highly proliferating FoxP3⁺ Treg cells after treatment, contrasting with their reduction in non-HPD tumors. In vitro PD-1 blockade augmented proliferation and suppressive activity of human Treg cells. Likewise, murine Treg cells that were deficient in PD-1 signaling were more proliferative and immunosuppressive. Thus, HPD may occur when PD-1 blockade activates and expands tumor-infiltrating PD-1⁺ Treg cells to overwhelm tumor-reactive PD-1⁺ effector T cells. Depletion of the former may therefore help treat and prevent HPD.

PD-1 blockade is a cancer immunotherapy effective in various types of cancer. In a fraction of treated patients, however, it causes rapid cancer progression called hyperprogressive disease (HPD). With our observation of HPD in ∼10% of anti–PD-1 monoclonal antibody (mAb)-treated advanced gastric cancer (GC) patients, we explored how anti–PD-1 mAb caused HPD in these patients and how HPD could be treated and prevented. In the majority of GC patients, tumor-infiltrating FoxP3^highCD45RA⁻CD4⁺ T cells [effector Treg (eTreg) cells], which were abundant and highly suppressive in tumors, expressed PD-1 at equivalent levels as tumor-infiltrating CD4⁺ or CD8⁺ effector/memory T cells and at much higher levels than circulating eTreg cells. Comparison of GC tissue samples before and after anti–PD-1 mAb therapy revealed that the treatment markedly increased tumor-infiltrating proliferative (Ki67⁺) eTreg cells in HPD patients, contrasting with their reduction in non-HPD patients. Functionally, circulating and tumor-infiltrating PD-1⁺ eTreg cells were highly activated, showing higher expression of CTLA-4 than PD-1⁻ eTreg cells. PD-1 blockade significantly enhanced in vitro Treg cell suppressive activity. Similarly, in mice, genetic ablation or antibody-mediated blockade of PD-1 in Treg cells increased their proliferation and suppression of antitumor immune responses. Taken together, PD-1 blockade may facilitate the proliferation of highly suppressive PD-1⁺ eTreg cells in HPDs, resulting in inhibition of antitumor immunity. The presence of actively proliferating PD-1⁺ eTreg cells in tumors is therefore a reliable marker for HPD. Depletion of eTreg cells in tumor tissues would be effective in treating and preventing HPD in PD-1 blockade cancer immunotherapy.

mTOR Signalling in Head and Neck Cancer: Heads Up

The mammalian target of rapamycin (mTOR) signalling pathway is a central regulator of metabolism in all cells. It senses intracellular and extracellular signals and nutrient levels, and coordinates the metabolic requirements for cell growth, survival, and proliferation. Genetic alterations that deregulate mTOR signalling lead to metabolic reprogramming, resulting in the development of several cancers including those of the head and neck. Gain-of-function mutations in EGFR, PIK3CA, and HRAS, or loss-of-function in p53 and PTEN are often associated with mTOR hyperactivation, whereas mutations identified from The Cancer Genome Atlas (TCGA) dataset that potentially lead to aberrant mTOR signalling are found in the EIF4G1, PLD1, RAC1, and SZT2 genes. In this review, we discuss how these mutant genes could affect mTOR signalling and highlight their impact on metabolic processes, as well as suggest potential targets for therapeutic intervention, primarily in head and neck cancer.

Durvalumab for the management of urothelial carcinoma: a short review on the emerging data and therapeutic potential

Urothelial carcinoma (UC) is the second most frequent urogenital malignancy with high incidence in the United States and Europe. Despite poor prognosis, new treatments have emerged with great efficacy and safety such as immune checkpoint inhibitors. Durvalumab, an anti Programmed Death Ligand 1, has been given breakthrough in UC in 2017 in patients who have disease progression during or following platinum-containing chemotherapy or who have disease progression <12 months after neoadjuvant or adjuvant treatment with platinum-containing chemotherapy. Food and Drug Administration approval was given on the results of the Phase I/II study of MEDI 4736. In this article, we will review available data on durvalumab in the treatment of locally advanced and metastatic UC and discuss therapeutic potential.

Choosing wisely first line immunotherapy in non-small cell lung cancer (NSCLC): what to add and what to leave out

Immunotherapy has dramatically changed the therapeutic scenario in treatment naïve advanced non-small cell lung cancer (NSCLC). While single agent pembrolizumab has become the standard therapy in patients with PD-L1 expression on tumor cells ≥ 50%, the combination of pembrolizumab or atezolizumab and platinum-based chemotherapy has emerged as an effective first line treatment regardless of PD-L1 expression both in squamous and non-squamous NSCLC without oncogenic drivers. Furthermore, double immune checkpoint inhibition has shown promising results in treatment naïve patients with high tumor mutational burden (TMB). Of note, the presence of both negative PD-L1 expression and low TMB may identify a subgroup of patients who has little benefit from immunotherapy combinations and for whom the best treatment option may still be platinum-based chemotherapy. To date, first-line single agent immune checkpoint blockade has demonstrated limited activity in EGFR mutated NSCLC and the combination of immunotherapy and targeted agents has raised safety concerns in both EGFR and ALK positive NSCLC patients. Finally, in EGFR mutated or ALK rearranged NSCLC, atezolizumab in combination with platinum-based chemotherapy and bevacizumab is emerging as a potential treatment option upon progression to first line tyrosine kinase inhibitors.

Nivolumab-refractory patients with advanced non-small-cell lung cancer

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have revolutionised cancer care especially in lung cancer. New response patterns have been described under ICIs such as pseudo-progression or hyper-progressive disease (HPD). The definition of HPD is yet to be consensual. The aim of this study was to suggest a clinical definition of nivolumab-refractory patients and find factors associated with this entity.

METHODS

We performed a multi centric retrospective study including all patients who received nivolumab for the treatment of advanced non-small cell lung cancer (NSCLC) during the French authorisation for temporary use in 2015.

RESULTS

303 patients were included in the cohort and 292 had details on the number of nivolumab injections received. 57 patients (20%) were nivolumab-refractory. These patients had worse PS at nivolumab initiation (p < 0.0001), shorter duration of treatment before nivolumab (p = 0.028) and had dramatically shorter nivolumab overall survival (p < 0.0001) than patients who did not present with refractory disease.

CONCLUSION

Nivolumab-refractory disease can affect up to 20% of patients treated with nivolumab for advanced NSCLC with dramatically shortened survival rates. Further studies are needed to understand the precise mechanisms leading to refractory disease as well as its management.

Circulating mir-320a promotes immunosuppressive macrophages M2 phenotype associated with lung cancer risk

miRNAs play a central role in the complex signaling network of cancer cells with the tumor microenvironment. Little is known on the origin of circulating miRNAs and their relationship with the tumor microenvironment in lung cancer. Here, we focused on the cellular source and relative contribution of different cell types to circulating miRNAs composing our risk classifier of lung cancer using in vitro/in vivo models and clinical samples. A cell‐type specific expression pattern and topography of several miRNAs such as mir‐145 in fibroblasts, mir‐126 in endothelial cells, mir‐133a in skeletal muscle cells was observed in normal and lung cancer tissues. Granulocytes and platelets are the major contributors of miRNAs release in blood. miRNAs modulation observed in plasma of lung cancer subjects was consistent with de‐regulation of the same miRNAs observed during immunosuppressive conversion of immune cells. In particular, activated neutrophils showed a miRNA profile mirroring that observed in plasma of lung cancer subjects. Interestingly mir‐320a secreted by neutrophils of high‐risk heavy‐smokers promoted an M2‐like protumorigenic phenotype through downregulation of STAT4 when shuttled into macrophages. These findings suggest a multifactorial and nonepithelial cell‐autonomous origin of circulating miRNAs associated with risk of lung cancer and that circulating miRNAs may act in paracrine signaling with causative role in lung carcinogenesis and immunosuppression.

What's new?

microRNAs play a central role in the complex signaling network of cancer cells with the tumor microenvironment. However, little is known on the origin of circulating miRNAs and their mechanisms of action. This study found a multifactorial and non‐epithelial cell‐autonomous origin of circulating miRNAs associated with lung cancer risk. The findings also suggest a link between an immunosuppressive and pro‐tumorigenic microenvironment and modulation of circulating miRNAs associated with lung cancer risk. The authors propose a novel mechanism whereby miRNA released by neutrophils induce macrophage polarization to support lung cancer growth, highlighting the potential for reprogramming macrophages toward an anti‐tumor polarization.