Overcoming immunosuppression in bone metastases

Nanomaterials for bone metastasis

Bone metastasis, a prevalent occurrence in primary malignant tumors, is often associated with a grim prognosis. The bone microenvironment comprises various coexisting cell types, working together in a coordinated manner. This dynamic microenvironment plays a pivotal role in the initiation and progression of bone metastases. While cancer therapies have made advancements, the available options for addressing bone metastases remain insufficient. The advent of nanotechnology has ushered in a new era for managing and preventing bone metastases because of the physicochemical and adaptable advantages of nanoplatforms. In this review, we make an introduction of the underlying mechanisms and the current clinical therapies of bone metastases, highlighting the advances of intelligent nanosystems that can stimulate vascular regeneration, promote bone regeneration, eliminate tumor cells, minimize bone damage, and expedite bone healing. The innovation surrounding bone-targeting nanoplatforms presents a fresh approach to the theranostics of bone metastases.

Randomized Phase II Study Evaluating the Addition of Pembrolizumab to Radium-223 in Metastatic Castration-resistant Prostate Cancer

The checkpoint immunotherapeutic pembrolizumab induces responses in a small minority of patients with metastatic castration-resistant prostate cancer (mCRPC). Radium-223 (R223) may increase immunogenicity of bone metastases and increase pembrolizumab (P) activity. In a randomized phase II study, we assessed the effect of R223+P compared with R223 on tumor immune infiltration, safety, and clinical outcomes in patients with mCRPC. The primary endpoint was differences in CD4+ and CD8+ T-cell infiltrate in 8-week versus baseline bone metastasis biopsies; secondary endpoints were safety, radiographic progression-free survival (rPFS), and overall survival (OS). Of the 42 treated patients (29 R223+P, 13 R223), 18 R223+P and 8 R223 patients had evaluable paired tumor biopsies. Median fold-change of CD4+ T cells was -0.7 (range: -9.3 to 4.7) with R223+P and 0.1 (-11.1 to 3.7) with R223 (P = 0.66); for CD8+ T cells, median fold-change was -0.6 (-7.4 to 5.3) with R223+P and -1.3 (-3.1 to 4.8) with R223 (P = 0.66). Median rPFS and OS was 6.1 (95% confidence interval: 2.7-11.0) and 16.9 months [12.7-not reached (NR)], respectively, with R223+P and 5.7 (2.6-NR) and 16.0 (9.0-NR), respectively, with R223. Although R223+P was well tolerated with no unexpected toxicity, the combination did not improve efficacy. High-dimensional flow cytometry demonstrated minimal immune modulation with R223, whereas R223+P induced CTLA-4 expression on circulating CD4+ T cells. Clinical responders possessed lower circulating frequencies of Ki67+ T and myeloid cells at baseline and higher circulating frequencies of TIM-3+ T and myeloid cells by week 9. Although R223+P did not induce T-cell infiltration into the tumor microenvironment, exhaustion of induced peripheral T-cell immune responses may dampen the combination's clinical activity.

Site-Specific Response and Resistance Patterns in Patients with Advanced Non-Small-Cell Lung Cancer Treated with First-Line Systemic Therapy

Patients with advanced NSCLC have heterogenous responses to immune checkpoint inhibitors (ICIs) with or without chemotherapy. In NSCLC, the impact of the distribution of metastatic sites and the response to systemic therapy combinations remain poorly understood. In a retrospective cohort study of patients with unresectable stage III/IV NSCLC who received first-line systemic therapy, we sought to assess the association between the site of metastases with patterns of response and progression. Data regarding demographics, tumour characteristics (including site, size, and volume of metastases), treatment, and outcomes were examined at two cancer care centres. The endpoints included organ site-specific response rate, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). Two-hundred and eighty-five patients were included in the analysis. In a multivariate analysis, patients with bone metastases had a reduced ORR, PFS, and OS. Primary resistance was also more likely in patients with bone metastases. Patients with bone or liver metastases had a shorter OS when receiving ICIs with or without chemotherapy, but not with chemotherapy alone, suggesting an immunological basis for therapeutic resistance. A directed assessment of the tumour microenvironment in these locations and a deeper understanding of the drivers of organ-specific resistance to immunotherapy are critical to optimise novel combination therapies and sequencing in these patients.

Intra-bone marrow injection with engineered Lactococcus lactis for the treatment of metastatic tumors: Primary report

Bone marrow has the capacity to produce different types of immune cells, such as natural killer cells, macrophages, dendritic cells (DCs) and T cells. Improving the activation of immune cells in the bone marrow can enhance the therapy of bone metastases. Previously, we designed an engineered probiotic Lactococcus lactis, capable of expressing a fusion protein of Fms-like tyrosine kinase 3 ligand and co-stimulator OX40 ligand (FOLactis), and proved that it can induce the activation and differentiation of several immune cells. In this research, we successfully establish mouse models of bone metastasis, lung metastasis and intraperitoneal dissemination, and we are the first to directly inject the probiotics into the bone marrow to inhibit tumor growth. We observe that injecting FOLactis into the bone marrow of mice can better regulate the immune microenvironment of tumor-bearing mice, resulting in a tumor-suppressive effect. Compared to subcutaneous (s.c.) injection, intra-bone marrow (IBM) injection is more effective in increasing mature DCs and CD8+ T cells and prolonging the survival of tumor-bearing mice. Our results confirm that IBM injection of FOLactis reprograms the immune microenvironment of bone marrow and has remarkable effectiveness in various metastatic tumor models.

Clinical variables associated with immune checkpoint inhibitor outcomes in patients with metastatic urothelial carcinoma: a multicentre retrospective cohort study

OBJECTIVES

Immune checkpoint inhibitors (ICIs) are indicated for metastatic urothelial cancer (mUC), but predictive and prognostic factors are lacking. We investigated clinical variables associated with ICI outcomes.

METHODS

We performed a multicentre retrospective cohort study of 135 patients who received ICI for mUC, 2016-2021, at three Canadian centres. Clinical characteristics, body mass index (BMI), metastatic sites, neutrophil-to-lymphocyte ratio (NLR), response and survival were abstracted from chart review.

RESULTS

We identified 135 patients and 62% had received ICI as a second-line or later treatment for mUC. A BMI ≥25 was significantly correlated to a higher overall response rate (ORR) (45.4% vs 16.3%, p value=0.020). Patients with BMI ≥30 experienced longer median overall survival (OS) of 24.8 vs 14.4 for 25≤BMI<30 and 8.5 months for BMI <25 (p value=0.012). The ORR was lower in the presence of bone metastases (16% vs 41%, p value=0.006) and liver metastases (16% vs 39%, p value=0.013). Metastatic lymph nodes were correlated with higher ORR (40% vs 20%, p value=0.032). The median OS for bone metastases was 7.3 versus 18 months (p value <0.001). Patients with liver metastases had a median OS of 8.6 versus 15 months (p value=0.006). No difference for lymph nodes metastases (13.5 vs 12.7 months, p value=0.175) was found. NLR ≥4 had worse OS (8.2 vs 17.7 months, p value=0.0001). In multivariate analysis, BMI ≥30, bone metastases, NLR ≥4, performance status ≥2 and line of ICI ≥2 were independent factors for OS.

CONCLUSIONS

Our data identified BMI and bone metastases as novel clinical biomarkers that were independently associated with ICI outcomes in mUC. External and prospective validation are warranted.

Single-Component Dual-Functional Autoboost Strategy by Dual Photodynamic and Cyclooxygenase-2 Inhibition for Lung Cancer and Spinal Metastasis

Coloading adjuvant drugs or biomacromolecules with photosensitizers into nanoparticles to enhance the efficiency of photodynamic therapy (PDT) is a common strategy. However, it is difficult to load positively charged photosensitizers and negatively charged adjuvants into the same nanomaterial and further regulate drug release simultaneously. Herein, a single-component dual-functional prodrug strategy is reported for tumor treatment specifically activated by tumor microenvironment (TME)-generated HOCl. A representative prodrug (DHU-CBA2) is constructed using indomethacin grafted with methylene blue (MB). DHU-CBA2 exhibited high sensitivity toward HOCl and achieved simultaneous release of dual drugs in vitro and in vivo. DHU-CBA2 shows effective antitumor activity against lung cancer and spinal metastases via PDT and cyclooxygenase-2 (COX-2) inhibition. Mechanistically, PDT induces immunogenic cell death but stimulates the gene encoding COX-2. Downstream prostaglandins E2 and Indoleamine 2,3 dioxygenase 1 (IDO1) mediate immune escape in the TME, which is rescued by the simultaneous release of indomethacin. DHU-CBA2 promotes infiltration and function of CD8+ T cells, thus inducing a robust antitumor immune response. This work provides an autoboost strategy for a single-component dual-functional prodrug activated by TME-specific HOCl, thereby achieving favorable tumor treatment via the synergistic therapy of PDT and a COX-2 inhibitor.

Multiple influence of immune cells in the bone metastatic cancer microenvironment on tumors

Bone is a common organ for solid tumor metastasis. Malignant bone tumor becomes insensitive to systemic therapy after colonization, followed by poor prognosis and high relapse rate. Immune and bone cells in situ constitute a unique immune microenvironment, which plays a crucial role in the context of bone metastasis. This review firstly focuses on lymphatic cells in bone metastatic cancer, including their function in tumor dissemination, invasion, growth and possible cytotoxicity-induced eradication. Subsequently, we examine myeloid cells, namely macrophages, myeloid-derived suppressor cells, dendritic cells, and megakaryocytes, evaluating their interaction with cytotoxic T lymphocytes and contribution to bone metastasis. As important components of skeletal tissue, osteoclasts and osteoblasts derived from bone marrow stromal cells, engaging in 'vicious cycle' accelerate osteolytic bone metastasis. We also explain the concept tumor dormancy and investigate underlying role of immune microenvironment on it. Additionally, a thorough review of emerging treatments for bone metastatic malignancy in clinical research, especially immunotherapy, is presented, indicating current challenges and opportunities in research and development of bone metastasis therapies.

Overall Survival Among Patients With De Novo Stage IV Metastatic and Distant Metastatic Recurrent Non-Small Cell Lung Cancer

Importance

Despite recent breakthroughs in therapy, advanced lung cancer still poses a therapeutic challenge. The survival profile of patients with metastatic lung cancer remains poorly understood by metastatic disease type (ie, de novo stage IV vs distant recurrence).

Objective

To evaluate the association of metastatic disease type on overall survival (OS) among patients with non-small cell lung cancer (NSCLC) and to identify potential mechanisms underlying any survival difference.

Design, Setting, and Participants

Cohort study of a national US population based at a tertiary referral center in the San Francisco Bay Area using participant data from the National Lung Screening Trial (NLST) who were enrolled between 2002 and 2004 and followed up for up to 7 years as the primary cohort and patient data from Stanford Healthcare (SHC) for diagnoses between 2009 and 2019 and followed up for up to 13 years as the validation cohort. Participants from NLST with de novo metastatic or distant recurrent NSCLC diagnoses were included. Data were analyzed from January 2021 to March 2023.

Exposures

De novo stage IV vs distant recurrent metastatic disease.

Main Outcomes and Measures

OS after diagnosis of metastatic disease.

Results

The NLST and SHC cohort consisted of 660 and 180 participants, respectively (411 men [62.3%] vs 109 men [60.6%], 602 White participants [91.2%] vs 111 White participants [61.7%], and mean [SD] age of 66.8 [5.5] vs 71.4 [7.9] years at metastasis, respectively). Patients with distant recurrence showed significantly better OS than patients with de novo metastasis (adjusted hazard ratio [aHR], 0.72; 95% CI, 0.60-0.87; P < .001) in NLST, which was replicated in SHC (aHR, 0.64; 95% CI, 0.43-0.96; P = .03). In SHC, patients with de novo metastasis more frequently progressed to the bone (63 patients with de novo metastasis [52.5%] vs 19 patients with distant recurrence [31.7%]) or pleura (40 patients with de novo metastasis [33.3%] vs 8 patients with distant recurrence [13.3%]) than patients with distant recurrence and were primarily detected through symptoms (102 patients [85.0%]) as compared with posttreatment surveillance (47 patients [78.3%]) in the latter. The main finding remained consistent after further adjusting for metastasis sites and detection methods.

Conclusions and Relevance

In this cohort study, patients with distant recurrent NSCLC had significantly better OS than those with de novo disease, and the latter group was associated with characteristics that may affect overall survival. This finding can help inform future clinical trial designs to ensure a balance for baseline patient characteristics.

Immunotherapy as a potential treatment approach for currently incurable bone metastasis

Once cancer metastasizes to the bone, the prognosis of cancer patients becomes extremely poor. Unfortunately, the current most successful treatment for bone metastasis can extend their survival by only a few months. Although recent studies have revealed promising impacts of cancer immunotherapies, their treatment efficacy on bone metastatic diseases remains controversial. Therefore, in this review, we discussed (i) preclinical and clinical evidence of the immunotherapeutic strategies for cancer bone metastasis, mainly focusing on cell-based immunotherapy, cytokine-based immunotherapy, and immune checkpoint blockade, and (ii) current shortcomings of immunotherapy for bone metastasis and their potential future directions. Although the evidence on treatment efficacy and safety, as well as long-term effects, is limited, immunotherapies could induce partial or complete remissions in a few cancer patients with bone metastasis. However, there are still hurdles, such as the immunosuppressive nature of the bone marrow microenvironment and poor distribution of cell-based immunotherapies to bone, that need to be overcome to enhance the treatment efficacy of immunotherapies on bone metastasis. While it is apparent that further investigation is needed regarding immunotherapeutic treatment efficacy in patients with bone metastasis, this therapy may prove to be clinically novel in this subset of cancer patients.

Bone serves as a transfer station for secondary dissemination of breast cancer

Metastasis is responsible for the majority of deaths among breast cancer patients. Although parallel polyclonal seeding has been shown to contribute to organ-specific metastasis, in the past decade, horizontal cross-metastatic seeding (metastasis-to-metastasis spreading) has also been demonstrated as a pattern of distant metastasis to multiple sites. Bone, as the most frequent first destination of breast cancer metastasis, has been demonstrated to facilitate the secondary dissemination of breast cancer cells. In this review, we summarize the clinical and experimental evidence that bone is a transfer station for the secondary dissemination of breast cancer. We also discuss the regulatory mechanisms of the bone microenvironment in secondary seeding of breast cancer, focusing on stemness regulation, quiescence-proliferation equilibrium regulation, epigenetic reprogramming and immune escape of cancer cells. Furthermore, we highlight future research perspectives and strategies for preventing secondary dissemination from bone.

Prostate cancer induced bone pain: pathobiology, current treatments and pain responses from recent clinical trials

PURPOSE

Metastatic spread of prostate cancer to the skeleton may result in debilitating bone pain. In this review, we address mechanisms underpinning the pathobiology of metastatic prostate cancer induced bone pain (PCIBP) that include sensitization and sprouting of primary afferent sensory nerve fibres in bone. We also review current treatments and pain responses evoked by various treatment modalities in clinical trials in this patient population.

METHODS

We reviewed the literature using PubMed to identify research on the pathobiology of PCIBP. Additionally, we reviewed clinical trials of various treatment modalities in patients with PCIBP with pain response outcomes published in the past 7 years.

RESULTS

Recent clinical trials show that radionuclides, given either alone or in combination with chemotherapy, evoked favourable pain responses in many patients and a single fraction of local external beam radiation therapy was as effective as multiple fractions. However, treatment with chemotherapy, small molecule inhibitors and/or immunotherapy agents, produced variable pain responses but pain response was the primary endpoint in only one of these trials. Additionally, there were no published trials of potentially novel analgesic agents in patients with PCIBP.

CONCLUSION

There is a knowledge gap for clinical trials of chemotherapy, small molecule inhibitors and/or immunotherapy in patients with PCIBP where pain response is the primary endpoint. Also, there are no novel analgesic agents on the horizon for the relief of PCIBP and this is an area of large unmet medical need that warrants concerted research attention.

Tumor Microenvironment, Clinical Features, and Advances in Therapy for Bone Metastasis in Gastric Cancer

Gastric cancer (GC) is one of the most malignant neoplasms worldwide, accounting for about 770,000 deaths in 2020. The incidence of gastric cancer bone metastasis (GC-BM) is low, about 0.9–13.4%, and GC patients develop GC-BM because of a suitable bone microenvironment. Osteoblasts, osteoclasts, and tumor cells interact with each other, secreting cytokines such as PTHrP, RANK-L, IL-6, and other growth factors that disrupt the normal bone balance and promote tumor growth. The functions and numbers of immune cells in the bone microenvironment are continuously inhibited, resulting in bone balance disorder due to the cytokines released from destroyed bone and growing tumor cells. Patients with GC-BM are generally younger than 65 years old and they often present with a later stage of the disease, as well as more aggressive tumors. They usually have shorter overall survival (OS) because of the occurrence of skeletal-related events (SREs) and undetected bone destruction due to the untimely bone inspection. Current treatments of GC-BM focus mainly on gastric cancer and SRE-related treatment. This article reviews the clinical features, possible molecular pathogeneses, and the most commonly used diagnostic methods and treatments of bone metastasis in gastric cancer.

Mechanisms, Diagnosis and Treatment of Bone Metastases

Bone and bone marrow are among the most frequent metastatic sites of cancer. The occurrence of bone metastasis is frequently associated with a dismal disease outcome. The prevention and therapy of bone metastases is a priority in the treatment of cancer patients. However, current therapeutic options for patients with bone metastatic disease are limited in efficacy and associated with increased morbidity. Therefore, most current therapies are mainly palliative in nature. A better understanding of the underlying molecular pathways of the bone metastatic process is warranted to develop novel, well-tolerated and more successful treatments for a significant improvement of patients' quality of life and disease outcome. In this review, we provide comparative mechanistic insights into the bone metastatic process of various solid tumors, including pediatric cancers. We also highlight current and innovative approaches to biologically targeted therapy and immunotherapy. In particular, we discuss the role of the bone marrow microenvironment in the attraction, homing, dormancy and outgrowth of metastatic tumor cells and the ensuing therapeutic implications. Multiple signaling pathways have been described to contribute to metastatic spread to the bone of specific cancer entities, with most knowledge derived from the study of breast and prostate cancer. However, it is likely that similar mechanisms are involved in different types of cancer, including multiple myeloma, primary bone sarcomas and neuroblastoma. The metastatic rate-limiting interaction of tumor cells with the various cellular and noncellular components of the bone-marrow niche provides attractive therapeutic targets, which are already partially exploited by novel promising immunotherapies.

STING suppresses bone cancer pain via immune and neuronal modulation

Patients with advanced stage cancers frequently suffer from severe pain as a result of bone metastasis and bone destruction, for which there is no efficacious treatment. Here, using multiple mouse models of bone cancer, we report that agonists of the immune regulator STING (stimulator of interferon genes) confer remarkable protection against cancer pain, bone destruction, and local tumor burden. Repeated systemic administration of STING agonists robustly attenuates bone cancer-induced pain and improves locomotor function. Interestingly, STING agonists produce acute pain relief through direct neuronal modulation. Additionally, STING agonists protect against local bone destruction and reduce local tumor burden through modulation of osteoclast and immune cell function in the tumor microenvironment, providing long-term cancer pain relief. Finally, these in vivo effects are dependent on host-intrinsic STING and IFN-I signaling. Overall, STING activation provides unique advantages in controlling bone cancer pain through distinct and synergistic actions on nociceptors, immune cells, and osteoclasts.

Osteoimmuno-Oncology: Therapeutic Opportunities for Targeting Immune Cells in Bone Metastasis

Immunotherapies provide a potential treatment option for currently incurable bone metastases. Bone marrow is an important secondary lymphoid organ with a unique immune contexture. Even at non-disease state immune cells and bone cells interact with each other, bone cells supporting the development of immune cells and immune cells regulating bone turnover. In cancer, tumor cells interfere with this homeostatic process starting from formation of pre-metastatic niche and later supporting growth of bone metastases. In this review, we introduce a novel concept osteoimmuno-oncology (OIO), which refers to interactions between bone, immune and tumor cells in bone metastatic microenvironment. We also discuss therapeutic opportunities of targeting immune cells in bone metastases, and associated efficacy and safety concerns.

Bone Metastases, Skeletal-Related Events, and Survival in Patients With Metastatic Non-Small Cell Lung Cancer Treated With Immune Checkpoint Inhibitors

BACKGROUND

Bone metastases and skeletal-related events (SREs) are a frequent cause of morbidity in patients with metastatic non-small cell lung cancer (mNSCLC). Data are limited on bone metastases and SREs in patients with mNSCLC treated using immune checkpoint inhibitors (ICIs), and on the efficacy of bone-modifying agents (BMAs) in this setting. Here we report the incidence, impact on survival, risk factors for bone metastases and SREs, and impact of BMAs in patients with mNSCLC treated with ICIs in a multi-institutional cohort.

PATIENTS AND METHODS

We conducted a retrospective study of patients with mNSCLC treated with ICIs at 2 tertiary care centers from 2014 through 2017. Overall survival (OS) was compared between patients with and without baseline bone metastases using a log-rank test. A Cox regression model was used to evaluate the association between OS and the presence of bone metastases at ICI initiation, controlling for other confounding factors.

RESULTS

We identified a cohort of 330 patients who had received ICIs for metastatic disease. Median patient age was 63 years, most patients were treated in the second line or beyond (n=259; 78%), and nivolumab was the most common ICI (n=211; 64%). Median OS was 10 months (95% CI, 8.4-12.0). In our cohort, 124 patients (38%) had baseline bone metastases, and 43 (13%) developed SREs during or after ICI treatment. Patients with bone metastases had a higher hazard of death after controlling for performance status, histology, line of therapy, and disease burden (hazard ratio, 1.57; 95% CI, 1.19-2.08; P=.001). Use of BMAs was not associated with OS or a decreased risk of SREs.

CONCLUSIONS

Presence of bone metastases at baseline was associated with a worse prognosis for patients with mNSCLC treated with ICI after controlling for multiple clinical characteristics. Use of BMAs was not associated with reduced SREs or a difference in survival.

Systemic effect of radiotherapy before or after nivolumab in lung cancer: an observational, retrospective, multicenter study

BACKGROUND

The combination of radiotherapy (RT) and programmed death 1 inhibitors seems to increase antitumor immune responses.

OBJECTIVE

To assess the outcome and the role of the best combination sequence, i.e. immunotherapy given before, during, and/or after RT, in patients with non-small cell lung cancer (NSCLC).

METHODS

We conducted an observational, retrospective analysis of 95 consecutive patients with advanced NSCLC who received any radiotherapy treatment and nivolumab, as clinically indicated. Median overall survival (OS) and the 95% confidence interval (CI) were estimated with the Kaplan-Meier method. Cox model was used to obtain hazard ratio (HR) and associated 95% CI with statistical inference by log-rank statistic.

RESULTS

Median OS was 11.9 months (95% CI, 6.6-17.2). Patients who received radiotherapy during an immune checkpoint inhibitor treatment started more than 60 days before showed a better outcome than patients who started immunotherapy over 60 days after RT ending (HR, 2.90 [1.37-6.12], p = 0.005; median OS, 22.4 months vs 8.6 months, p = 0.005). Median progression-free survival was 6.3 months (95% CI, 4.6-8.0).

CONCLUSIONS

This study shows that combining irradiation with nivolumab for the treatment of advanced NSCLC leads to improved OS. The optimal time window for the combination of RT and immunotherapy seems to play a critical role for therapeutic antitumor response derived by abscopal effect.

Reciprocal interactions between osteoclasts and nociceptive sensory neurons in bone cancer pain

Many common cancers such as breast, prostate, and lung cancer metastasize to bones at advanced stages, producing severe pain and functional impairment. At present, the current pharmacotherapies available for bone cancer pain are insufficient to provide safe and efficacious pain relief. In this narrative review, we discuss the mechanisms used by cancer cells within the bone tumor microenvironment (TME) to drive bone cancer pain. In particular, we highlight the reciprocal interactions between tumor cells, bone-resorbing osteoclasts, and pain-sensing sensory neurons (nociceptors), which drive bone cancer pain. We discuss how tumor cells present within the bone TME accelerate osteoclast differentiation (osteoclastogenesis) and alter osteoclast activity and function. Furthermore, we highlight how this perturbed state of osteoclast overactivation contributes to bone cancer pain through (1) direct mechanisms, through their production of pronociceptive factors that act directly on sensory afferents; and (2) by indirect mechanisms, wherein osteoclasts drive bone resorption that weakens tumor-bearing bones and predisposes them to skeletal-related events, thereby driving bone cancer pain and functional impairment. Finally, we discuss some potential therapeutic agents, such as denosumab, bisphosphonates, and nivolumab, and discuss their respective effects on bone cancer pain, osteoclast overactivation, and tumor growth within the bone TME.

Survival in patients with carcinomas presenting with bone metastasis at diagnosis: a SEER population-based cohort study

INTRODUCTION

Carcinoma metastasis to bone is a common reason for consultation to orthopedic surgeons. The presence of bone metastases (BM) is usually associated with poor prognosis which is worsened in the presence of synchronous metastases. The purpose of this study was to: (1) identify the most common carcinomas presenting with BM at diagnosis, to (2) analyze their survival, and (3) compare this against the survival of patients with additional synchronous metastasis based on a large population analysis.

MATERIALS AND METHODS

Patients diagnosed with carcinoma between January 2010 and December 2015 were identified from the Surveillance, Epidemiology and End Results (SEER) database. The most common carcinomas presenting with BM at diagnosis were identified. Survival based on the presence of BM and synchronous metastases (lung, brain, liver, lymph nodes) was evaluated with Kaplan-Meier analysis. Five-year survival (%) stratified by carcinoma type was calculated. Hazard ratio (HR) for mortality comparing isolated BM to other synchronous metastases was performed.

RESULTS

A total of 4.85% of patients (98,606/2,035,204) with carcinoma presented with BM at diagnosis, most commonly from a lung primary. Five-year survival with isolated BM was lowest in patients with pancreatic carcinoma (5.8%, 95% CI 3.0-9.9%), and highest in patients with breast carcinoma (41.1%, 95% CI 38.6-43.5%). Synchronous metastases increased significantly the risk of mortality within the majority of carcinomas.

CONCLUSION

BM at diagnosis has a poor prognosis which is worsened if synchronous metastases are present; a fact to consider when planning orthopedic interventions.

LEVEL OF EVIDENCE

Level III, prognostic study.

Pan-Cancer Analyses Reveal Prognostic Value of Osteomimicry Across 20 Solid Cancer Types

Background

Osteomimicry of cancer cells had been widely reported in prostate cancer and breast cancer. However, the prognostic value of osteomimicry in various cancer types remained unclear. We hypothesized that osteomimicry would result in remodeling of the tumor microenvironment and was eligible to predict patient prognosis.

Methods

A comprehensive transcriptomic analysis of the osteomimicry, which was characterized by mRNA expression of SPARC, SPP1, and BGLAP, across 20 solid tumors (7564 patients) using RNA-seq data from The Cancer Genome Atlas (TCGA) was conducted. Samples of each cancer type were classified into subgroups (high vs. low) based on median value of osteomimetic markers, the associations of these markers with clinical outcomes, immune cell infiltration and immune checkpoints expression were explored.

Results

Each osteomimetic marker harbored prognostic value in the pan-cancer analyses [SPARC: hazard ratio (HR) = 1.10, p = 0.028; SPP1: HR = 1.25, p < 0.001; BGLAP: HR = 1.13, p = 0.005]. Patients with high expression of all the three genes also had significantly unfavorable survival (HR = 1.61, p < 0.0001) compared with those of low expression. Correlation analyses demonstrated that osteomimicry was closely related to tumor purity, dendritic cells (DC) infiltration and expression of immune checkpoints.

Conclusion

Osteomimicry had prognostic value in various cancer types and the underlying mechanism might correlate to the trapping and dysfunction of DCs in the tumor microenvironment, revealing the potential of osteomimicry as a target of immunotherapy.

Adverse impact of bone metastases on clinical outcomes of patients with advanced non-small cell lung cancer treated with immune checkpoint inhibitors

Background

Bone metastasis (BoM) is common in patients with advanced non‐small cell lung cancer (NSCLC) and considered as one of the negative prognostic factors. However, the impact of BoM on clinical outcomes of patients with advanced NSCLC treated with immune checkpoint inhibitors (ICIs) remains unclear.

Methods

A total of 103 patients treated with ICI monotherapy and 101 patients treated with ICIs combined with chemotherapy or antiangiogenesis therapy were retrospectively analyzed. The differences in progression‐free survival (PFS), overall survival (OS) and objective response rate (ORR) between BoM+ and BoM− were investigated.

Results

Of those 101 patients who received combination therapy, no significant difference between BoM− and BoM+ in terms of both median PFS and median OS (median PFS, 10.1 vs. 12.1 months, P = 0.6; median OS, NR vs. 24.6 months, P = 0.713) was determined. In contrast, of the 103 patients who received ICI monotherapy, BoM+ patients had an inferior PFS (4.2 vs. 6.7 months, P = 0.0484) and OS (12.5 vs. 23.9 months, P = 0.0036) compared with BoM− patients. The univariate and multivariate analysis in the ICI monotherapy group also identified BoM as an independent factor attenuating the efficacy of ICI monotherapy. Of all BoM+ patients who received ICI monotherapy, neither palliative radiotherapy nor bisphosphonate drugs improved OS (palliative radiotherapy: 12.5 vs. 16.7 months, P = 0.487; bisphosphonate drugs: 12.5 vs. 9.7 months, P = 0.568).

Conclusions

BoM attenuated the efficacy of ICI monotherapy in patients with advanced NSCLC. Of BoM+ patients who received ICI monotherapy, neither palliative radiotherapy nor bisphosphonate drugs improved OS. Other therapeutic strategies are needed for patients with BoM.

Nanoformulation of CCL21 greatly increases its effectiveness as an immunotherapy for neuroblastoma

Neuroblastoma is the most commonly diagnosed extracranial solid tumor in children. The patients with aggressive metastatic disease or refractory/relapsed neuroblastoma currently face a dismally low chance of survival. Thus, there is a great need for more effective therapies for this illness. In previous studies, we, as well as others, showed that the immune cell chemoattractant C-C motif chemokine ligand 21 (CCL21) is effective as an intratumoral therapy able to slow the growth of cancers. In this current study, we developed and tested an injectable, slow-release, uniform, and optimally loaded alginate nanoformulation of CCL21 as a means to provide prolonged intratumoral treatment. The alginate-nanoformulated CCL21, when injected intratumorally into mice bearing neuroblastoma lesions, significantly prolonged survival and decreased the tumor growth rate compared to CCL21 alone, empty nanoparticles, or buffer. Notably, we also observed complete tumor clearance and subsequent full protection against tumor rechallenge in 33% of nanoformulated CCL21-treated mice. Greater intratumoral presence of nanoformulated CCL21, compared to free CCL21, at days 1 and 2 after treatment ended was confirmed through fluorescent labeling and tracking. Nanoformulated CCL21-treated tumors exhibited a general pattern of prolonged increases in anti-tumor cytokines and relatively lower levels of pro-tumor cytokines in comparison to tumors treated with CCL21 alone or buffer only. Thus, this novel nanoformulation of CCL21 is an effective treatment for neuroblastoma, and may have potential for the delivery of CCL21 to other types of solid tumors in the future and as a slow-release delivery modality for other immunotherapies.

Prostate cancer cell-intrinsic interferon signaling regulates dormancy and metastatic outgrowth in bone

The latency associated with bone metastasis emergence in castrate-resistant prostate cancer is attributed to dormancy, a state in which cancer cells persist prior to overt lesion formation. Using single-cell transcriptomics and ex vivo profiling, we have uncovered the critical role of tumor-intrinsic immune signaling in the retention of cancer cell dormancy. We demonstrate that loss of tumor-intrinsic type I IFN occurs in proliferating prostate cancer cells in bone. This loss suppresses tumor immunogenicity and therapeutic response and promotes bone cell activation to drive cancer progression. Restoration of tumor-intrinsic IFN signaling by HDAC inhibition increased tumor cell visibility, promoted long-term antitumor immunity, and blocked cancer growth in bone. Key findings were validated in patients, including loss of tumor-intrinsic IFN signaling and immunogenicity in bone metastases compared to primary tumors. Data herein provide a rationale as to why current immunotherapeutics fail in bone-metastatic prostate cancer, and provide a new therapeutic strategy to overcome the inefficacy of immune-based therapies in solid cancers.

Unexpected Response to Nivolumab in a "Fast Progressor" Head and Neck Cancer Patient

Prior to the advent of immune checkpoint inhibitors targeting PD-1/PD-L1 axis no drug demonstrated to improve survival or quality of life in the second-line treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M-HNSCC). Nivolumab appear to have a clear clinical benefit for R/M-HNSCC, based on improved survival, good toxicity profile, reduction in symptoms and improvement in overall quality of life. This benefit seems to be greater for PD-L1 positive patients and independent of previous treatment, even being observed among heavily pre-treated patients. However, even in responding tumors acquired resistance to nivolumab usually occurred, limiting the drug's activity. We report a case of unexpected prolonged stable disease in second-line treatment with nivolumab after a rapid progression disease under first-line chemotherapy in biomarker-positive R/M-HNSCC.

Novel clinical and radiomic predictors of rapid disease progression phenotypes among lung cancer patients treated with immunotherapy: An early report

OBJECTIVES

Immune-checkpoint blockades have exhibited durable responses and improved long-term survival in a subset of advanced non-small cell lung cancer (NSCLC) patients. However, highly predictive markers of positive and negative responses to immunotherapy are a significant unmet clinical need. The objective of this study was to identify clinical and computational image-based predictors of rapid disease progression phenotypes in NSCLC patients treated with immune-checkpoint blockades.

MATERIALS AND METHODS

Using time-to-progression (TTP) and/or tumor growth rates, rapid disease progression phenotypes were developed including hyperprogressive disease. The pre-treatment baseline predictors that were used to identify these phenotypes included patient demographics, clinical data, driver mutations, hematology data, and computational image-based features (radiomics) that were extracted from pre-treatment computed tomography scans. Synthetic Minority Oversampling Technique (SMOTE) was used to subsample minority groups to eliminate classification bias. Patient-level probabilities were calculated from the final clinical-radiomic models to subgroup patients by progression-free survival (PFS).

RESULTS

Among 228 NSCLC patients treated with single agent or double agent immunotherapy, we identified parsimonious clinical-radiomic models with modest to high ability to predict rapid disease progression phenotypes with area under the receiver-operator characteristics ranging from 0.804 to 0.865. Patients who had TTP < 2 months or hyperprogressive disease were classified with 73.41% and 82.28% accuracy after SMOTE subsampling, respectively. When the patient subgroups based on patient-level probabilities were analyzed for survival outcomes, patients with higher probability scores had significantly worse PFS.

CONCLUSIONS

The models found in this study have potential important translational implications to identify highly vulnerable NSCLC patients treated with immunotherapy that experience rapid disease progression and poor survival outcomes.

An update on the currently available and future chemotherapy for treating bone metastases in breast cancer patients

INTRODUCTION

Bone metastases in breast cancer patients are a common clinical problem. Many factors influence the treatment decision, including tumor characteristics, previous treatment and tumor burden in the treatment of metastatic breast cancer.

AREAS COVERED

This present review summarizes the new treatment strategies and the chemotherapeutic agents currently available in the management of metastatic breast cancer with bone metastases.

EXPERT OPINION

Patients with bone metastases more often have hormone receptor-positive tumours. Although new treatment agents for metastatic breast cancer have been investigated, endocrine therapy is still considered as the treatment of choice for patients with bone metastases although chemotherapy still has an important place. In recent years, new chemotherapeutic agents such as etirinotecan and nab-paclitaxel have been established though there are few studies that have looked at particular types of metastases. In the last decade, therapies for bone metastasis resistant to endocrine therapy have predominantly focused on radiotherapy, surgical resection, chemotherapy, bone-targeting radiopharmaceuticals and targeted therapeutics. New targeted agents include: Src inhibitors, cathepsin K inhibitors, CXCR4 inhibitors, TGF-B blockade and integrin antagonists while drug delivery systems for chemotherapy have also been developed. These new treatment options could be future treatment options for bone metastatic disease if early promising results are confirmed by clinical trials.

Multifaceted Roles for Macrophages in Prostate Cancer Skeletal Metastasis

Bone-metastatic prostate cancer is common in men with recurrent castrate-resistant disease. To date, therapeutic focus has largely revolved around androgen deprivation therapy (ADT) and chemotherapy. While second-generation ADTs and combination ADT/chemotherapy approaches have been successful in extending overall survival, the disease remains incurable. It is clear that molecular and cellular components of the cancer-bone microenvironment contribute to the disease progression and potentially to the emergence of therapy resistance. In bone, metastatic prostate cancer cells manipulate bone-forming osteoblasts and bone-resorbing osteoclasts to produce growth and survival factors. While osteoclast-targeted therapies such as bisphosphonates have improved quality of life, emerging data have defined important roles for additional cells of the bone microenvironment, including macrophages and T cells. Disappointingly, early clinical trials with checkpoint blockade inhibitors geared at promoting cytotoxic T cell response have not proved as promising for prostate cancer compared to other solid malignancies. Macrophages, including bone-resident osteomacs, are a major component of the bone marrow and play key roles in coordinating normal bone remodeling and injury repair. The role for anti-inflammatory macrophages in the progression of primary prostate cancer is well established yet relatively little is known about macrophages in the context of bone-metastatic prostate cancer. The focus of the current review is to summarize our knowledge of macrophage contribution to normal bone remodeling and prostate-to-bone metastasis, while also considering the impact of standard of care and targeted therapies on macrophage behavior in the tumor-bone microenvironment.