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

Efficacy of Immunotherapy in Patients With Bone Metastases From Driver Gene-Negative Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

This study systematically assesses the efficacy of immunotherapy as a first-line treatment for patients with non-small-cell lung cancer (NSCLC) and bone metastases who lack driver gene mutations. This analysis draws on data from randomized controlled trials to support individualized treatment strategies.

Methods

Randomized controlled trials published up to October 1, 2024, were retrieved from PubMed, EMBASE, the Cochrane Library, and the Web of Science. Statistical analyses were conducted using RevMan 5.4 and STATA 17.0, with the results presented in forest plots. Progression-free survival (PFS) and overall survival (OS) were analyzed using hazard ratios (HRs) with corresponding 95% confidence intervals (CIs). This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42024604768).

Results

Meta-analysis demonstrated a significant improvement in OS and PFS for patients with bone metastases receiving immunotherapy (OS: HR: 0.81, 95% CI: 0.71-0.92; PFS: HR: 0.78, 95% CI: 0.62-0.98). Although the survival benefit of immunotherapy was lower in patients with bone metastases than in those without, it was superior to chemotherapy.

Conclusions

Among patients with driver gene-negative NSCLC and bone metastases, immunotherapy significantly improved OS and PFS, thus supporting its role as an effective first-line treatment. Further large-scale trials are recommended to enhance treatment precision and validate these findings.

Clinical Characteristics, Prognostic Factors and Therapeutic Strategies in Gastric Cancer Patients With Bone Metastasis: A Retrospective Analysis

BACKGROUND

Bone metastases are highly refractory and are associated with extremely poor survival. Despite the increasing incidence of bone metastasis in gastric cancer (GC), comprehensive analyses regarding the clinicopathological features, prognosis, and treatment of bone-metastatic GC remain limited.

METHODS

We obtained data from 120 bone-metastatic GC patients from Nanjing Drum Tower Hospital and 36,139 GC patients from the SEER database. Chi-square and Mann-Whitney U-tests evaluated clinicopathological features, while Cox models identified prognostic factors. Kaplan-Meier curves and forest plots assessed the effects of different treatment strategies on overall survival after bone metastasis (OS-BM).

RESULTS

Among 120 bone-metastatic GC patients, 55 (45.83%) were diagnosed with poorly cohesive gastric carcinoma (PCC). The higher incidence of bone metastasis was also observed in SRCC patients from the SEER database (p < 0.0001). PCC patients exhibited distinct pathological features compared to non-PCC patients, including lower PD-L1 (p = 0.042) and E-cadherin expression (p = 0.049). Multivariate analysis identified various negative prognostic factors such as metachronous bone metastasis (p < 0.001, HR = 2.35, 95% CI:1.47-3.74) and CA125 expression (p = 0.036, HR = 1.60, 95% CI:1.03-2.48), whereas immunotherapy was a positive prognostic factor (p < 0.001, HR = 0.44, 95% CI:0.29-0.66). Subgroup analysis also showed improved survival among different populations of bone-metastatic GC patients receiving immunotherapy. Moreover, combinational therapies including immunotherapy and other treatments (anti-angiogenic therapy and/or local radiotherapy) further improved patient OS-BM.

CONCLUSION

Our results suggest bone-metastatic GC patients exhibit distinct clinicopathological features, with a high incidence of bone metastasis in PCC. Immunotherapy-based combination therapies offer improved survival benefits, thus supporting the application of immunotherapy in GC patients at high risk of bone metastasis.

Efficacy of innovative systemic treatments in combination with radiotherapy for bone metastases: a GEMO (the European Study Group of Bone Metastases) state of the art

The management of bone metastases (BoM) requires a multidisciplinary approach to prevent complications, necessitating updated knowledge in light of the rapid advancements in systemic treatments and surgical, interventional radiology or radiation techniques. This review aims to discuss efficacy of new systemic treatments on BoM, the benefits of radiotherapy adjunction, and the optimal methods for combining them. Preliminary evidence suggesting reduced efficacy of immune checkpoint inhibitors (ICI), and several multi-kinase inhibitors regarding BoM may encourage early use of radiotherapy (RT). Systemic treatment efficacy modulation by RT and ablative RT strategies are explored. Concerns for increased side effects for several kinase inhibitors and double ICI in combination with RT imply suspending those systemic treatments during RT. Various timing strategies to combine prostate hormone therapies and RT are developed. Emerging internal vectorized radiotherapy molecules necessitate developing new combination strategies with RT. Further prospective data collection and comparative trials should be encouraged.

Impact of Bone-Modifying Agents on Post-Bone Metastasis Survival Across Cancer Types

BACKGROUND

Bone metastasis is associated with a poor prognosis. Bone-modifying agents (BMA) are commonly used for the prevention or treatment of skeletal-related events (SRE) in patients with bone metastasis; however, whether or not treatment with BMA improves survival remains unclear. In this study, we investigated whether BMA was involved in post-bone metastasis survival.

METHODS

A total of 539 cancer patients were retrospectively analyzed to identify significant independent factors in post-bone metastasis survival.

RESULTS

Among the overall population, patients with the following cancers had a median survival longer than 24 months: thyroid, 97.2 months; breast, 51.5 months; prostate, 47.2 months; and kidney, 38.8 months. In contrast, median post-bone metastasis survival was significantly shorter in gastrointestinal (GI) (6.5 months), head and neck (6.3 months), and urinary tract (3.4 months) cancers. In non-small cell lung cancer (NSCLC), the log-rank test demonstrated that the epidermal growth factor receptor (EGFR) mutation was a significant factor for post-bone metastasis survival: EGFR mutation (-) n = 67, median post-bone metastasis survival 11.5 months (95% CI: 6.0-15.2); EGFR mutation (+) n = 39, median post-bone metastasis survival 28.8 months (95% CI: 18.1-35.7) (p < 0.05). Intriguingly, treatment with BMA was a significant positive prognostic factor: BMA (-) n = 203, median post-bone metastasis survival 7.8 months (95% CI: 5.8-12.5); BMA (+) n = 336, median post-bone metastasis survival 21.9 months (95% CI: 16.1-26.4) (p < 0.001). Moreover, the Cox proportional hazards model showed that this was particularly evident in cancer types with poor prognosis such as GI cancer (hazard ratio [HR]: 0.62, 95% CI: 0.40-0.95; p < 0.05) and NSCLC without the epidermal growth factor receptor (EGFR) mutation (HR: 0.56, 95% CI: 0.34-0.91; p < 0.05).

CONCLUSIONS

Treatment with BMA is recommended not only for the prevention and/or treatment of SRE, but also may have a positive impact on post-bone metastasis survival, particularly in cancers with typically poor post-bone metastasis survival such as GI cancer and NSCLC without the EGFR mutation.

Systematic Review-Based Treatment Algorithm for the Multidisciplinary Treatment of Lung Cancer Bone Metastases

Background: The prognosis for patients with lung cancer bone metastases has improved with the use of novel systemic agents. These patients might need surgery or radiotherapy to alleviate symptoms or maintain function. However, there is currently no disease specific algorithm to guide multidisciplinary decisions. Methods: The inclusion criteria encompassed studies with ≥10 patients offering multivariate analysis data on survival that were published after 2000 until September 2023. Clinical factors were categorized based on their characteristics and the pooled hazard ratios (HRs) for each category were calculated. A treatment algorithm was proposed based on clinical importance and the pooled HRs. Results: Fifteen studies involving 3759 patients with lung cancer bone metastases were included. The median survival ranged between 1.8-28.3 months (median: 12.4). Among the studies involving patients with EGFR+ or treated with TKIs, the median survival ranged between 19.5-28.3 months. The most reported significant factor was ECOG performance (nine studies) followed by chemotherapy use (six studies). In the pooled analyses, the pooled HR [95% confidence interval (CI)] of the EGFR status category was 2.109 (1.345-3.305); the ECOG performance category was 2.007 (1.536-2.622); the visceral metastases category was 2.060 (1.370-3.098); the bone metastases characteristics category (e.g., multiplicity, weight-bearing bone metastases) was 1.910 (1.443-2.527); the body weight category was 1.805 (1.334-2.442); the anti-absorbants category was 1.784 (1.448-2.196); the systemic treatment category was 1.695 (1.407-2.041); the skeletal-related event category was 1.616 (1.063-2.458); the smoking status category was 1.530 (1.306-1.793); the gender category was 1.482 (1.270-1.729); and the histology category was 1.450 (1.186-1.772). Conclusions: Oncological prognoses are influenced by various interrelated factors. Our treatment algorithm supports multidisciplinary strategies for managing NSCLC bone metastases, considering the complex factors influencing prognosis.

Immunotherapy in the Battle Against Bone Metastases: Mechanisms and Emerging Treatments

Bone metastases are a prevalent complication in advanced cancers, particularly in breast, prostate, and lung cancers, and are associated with severe skeletal-related events (SREs), including fractures, spinal cord compression, and debilitating pain. Conventional bone-targeted treatments like bisphosphonates and RANKL inhibitors (denosumab) reduce osteoclast-mediated bone resorption but do not directly impact tumor progression within the bone. This review focuses on examining the growing potential of immunotherapy in targeting the unique challenges posed by bone metastases. Even though immune checkpoint inhibitors (ICIs) have significantly changed cancer treatment, their impact on bone metastases appears limited because of the bone microenvironment's immunosuppressive traits, which include high levels of transforming growth factor-beta (TGFβ) and the immune-suppressing cells, such as regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). This review underscores the investigation of combined therapeutic approaches that might ease these difficulties, such as the synergy of immune checkpoint inhibitors with agents aimed at bones (denosumab, bisphosphonates), chemotherapy, and radiotherapy, as well as the combination of immune checkpoint inhibitors with different immunotherapeutic methods, including CAR T-cell therapy. This review provides a comprehensive analysis of preclinical studies and clinical trials that show the synergistic potential of these combination approaches, which aim to both enhance immune responses and mitigate bone destruction. By offering an in-depth exploration of how these strategies can be tailored to the bone microenvironment, this review underscores the need for personalized treatment approaches. The findings emphasize the urgent need for further research into overcoming immune evasion in bone metastases, with the goal of improving patient survival and quality of life.

Impact of bone metastasis on prognosis in non-small cell lung cancer patients treated with immune checkpoint inhibitors: a systematic review and meta-analysis

Background

Lung cancer is a leading cause of cancer-related deaths globally, with non-small cell lung cancer (NSCLC) accounting for approximately 85% of cases. While immune checkpoint inhibitors (ICIs) have transformed treatment for advanced NSCLC, the role of bone metastasis in modulating ICI efficacy remains unclear. Bone metastasis, occurring in 30-40% of advanced NSCLC cases, is associated with worse outcomes. However, how this affects the therapeutic benefit of ICIs has not been fully elucidated, highlighting a critical knowledge gap in optimizing treatment for this patient population.

Methods

A comprehensive literature search across multiple databases, including PubMed, Embase, and Cochrane, identified 13 studies with a total of 3,681 patients, of whom 37.6% had bone metastasis. Overall survival (OS) and progression-free survival (PFS) were compared between NSCLC patients with and without bone metastasis. Data were analyzed using a random-effects model to account for study heterogeneity.

Results

The meta-analysis demonstrated that bone metastasis significantly worsened overall survival (OS) and progression-free survival (PFS) in NSCLC patients treated with ICIs. Specifically, bone metastasis was associated with a 45% increased risk of death (HR: 1.45, 95% CI: 1.30-1.62, p < 0.001) and a 40% increased risk of disease progression (HR: 1.40, 95% CI: 1.25-1.58, p < 0.001). No statistically significant impact on PFS was observed. (HR: 1.28, 95% CI: 0.77-2.10, p = 0.34). High heterogeneity was observed in some subgroup analyses (I² = 72%), indicating variability in the results.

Conclusion

Bone metastasis is a significant negative prognostic factor for NSCLC patients treated with ICIs, associated with a higher risk of mortality and disease progression. These results underscore the importance of tailored treatment approaches for NSCLC patients with bone metastasis and call for further research to optimize therapy outcomes in this group.

Immunotherapy in the Fight Against Bone Metastases: A Review of Recent Developments and Challenges

OPINION STATEMENT

Bone metastasis, a frequent and detrimental complication of advanced cancers, often triggers bone deterioration events that severely compromise patient quality of life and prognosis. The past few years have witnessed the emergence and continuous advancements in immunotherapy, ushering in innovative therapeutic prospects for bone metastasis. These advancements include not only the use of immune checkpoint inhibitors (ICIs), both as standalone and combined treatments, but also the investigation of novel targets within immune cells residing in bone metastases. These breakthroughs have instilled fresh optimism for effectively managing patients with bone metastasis. This article endeavors to present an exhaustive review of the recent progress made across a spectrum of immunotherapeutic strategies and targeted therapies specifically designed for individuals battling bone metastasis from malignant tumors. By doing so, it seeks to offer insights that can inform clinical practices and guide further medical research in this domain.

Prognostic significance of bone metastasis and clinical value of bone radiotherapy in metastatic non-small cell lung cancer receiving PD-1/PD-L1 inhibitors: results from a multicenter, prospective, observational study

Background

Bone metastasis (BoM) is a prevalent occurrence in patients with non-small cell lung cancer (NSCLC), significantly impacting prognosis and diminishing both survival rates and patients' quality of life. More and more studies have demonstrated that immunotherapy can improve the prognosis of NSCLC patients with bone metastases. Previous investigations pertaining to BoM in NSCLC have generally suffered from small sample sizes, absence of propensity score matching (PSM) to equate baseline characteristics, and an omission of the examination of patterns of treatment failure. This study aims to evaluate the prognostic significance of BoM and potential clinical value of bone radiation in metastatic NSCLC patients receiving immunotherapy.

Methods

Metastatic NSCLC patients receiving programmed cell death protein 1/programmed cell death-ligand 1 (PD-1/PD-L1) inhibitors from three academic centers were enrolled in a prospective, observational trial (https://clinicaltrials.gov/study/NCT04766515) and those with measurable disease and adequate follow-up were retrospectively reviewed. Propensity score matched (PSM) patients with and without BoM were included in this study. Treatment efficacy, pattern of failure and clinical value of bone radiotherapy were extensively evaluated.

Results

A total of 544 out of 1,451 immunotherapy-treated NSCLC patients were included after PSM, including 272 with BoM and 272 without. Patients with baseline BoM had a median progression-free survival (PFS) of 7.8 months [95% confidence interval (CI): 7.0-8.7], lower than those without it (9.5 months; 95% CI: 8.9-10.0) (P<0.001). Patients with baseline BoM had a median overall survival (OS) of 14.5 months (95% CI: 12.6-16.4), lower than those without 27.6 months (95% CI: 25.1-30.1) (P<0.001). Patients with BoM also had lower objective response rate than those without it (11.1% vs. 15.8%, P<0.001). Initial disease progression in the bone was more common in those with BoM (56.5%) compared to those without it (31.7%) (P<0.001). Meanwhile, among patients with BoM, no significant difference of PFS was found between those receiving bone radiation or not, possibly due to a dominant use of palliative radiotherapy.

Conclusions

Baseline BoM correlated with worse prognosis and palliative bone radiation did not improve PFS in metastatic NSCLC patients receiving PD-1/PD-L1 inhibitors.

Response rate specific to bone metastasis of various cancers for immune checkpoint inhibitors: a systematic review

PURPOSE

Immune checkpoint inhibitors (ICIs) have improved the prognosis of patients with cancer, such as melanoma, renal cell carcinoma, head and neck cancer, non-small cell lung cancer (NSCLC), and urothelial carcinoma. The extension of life expectancy has led to an increased incidence of bone metastases (BM) among patients with cancer. BM result in skeletal-related events, including severe pain, pathological fractures, and nerve palsy. Surgery is typically required for the treatment of BM in patients with an impending fracture; however, it may be avoided in those who respond to ICIs. We systematically reviewed studies analyzing BM responses to treatment with ICIs.

METHODS

This study was conducted in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 statement and registered in the UMIN Clinical Trials Registry (ID: UMIN000053707). Studies reporting response rates based on the Response Evaluation Criteria in Solid Tumors (RECIST) or the MD Anderson Cancer Center (MDA) criteria specific for BM in patients treated with ICIs were included; reports of fewer than five cases and review articles were excluded. Studies involving humans, published in English and Japanese, were searched. The PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched. Ultimately, nine studies were analyzed. The Risk of Bias Assessment tool for Non-randomized Studies was used to assess the quality of studies.

RESULTS

Based on the MDA criteria, complete response (CR) or partial response (PR) was observed in 44-78% and 62% patients treated with ICIs plus denosumab for NSCLC and melanoma, respectively. According to the RECIST, CR or PR was recorded in 5% and 7-28% of patients treated with ICIs for renal cell carcinoma and urothelial carcinoma, respectively.

CONCLUSION

Although response rates to ICIs for BM are poor, patients treated with ICI plus denosumab for bone metastases with impending fractures from NSCLC and melanoma are likely to avoid surgery to prevent fractures.

Thyroid autoantibodies at baseline predict longer survival in non-small cell lung cancer patients treated with anti-programmed cell death-1 blockade: a prospective study

The presence of anti-thyroid antibodies (ATAs) is a biomarker for the development of thyroid dysfunction induced by anti-programmed cell death-1 antibodies (PD-1-Abs). While patients with thyroid dysfunction reportedly showed better overall survival (OS), it remains unknown if ATAs at baseline can predict OS. Therefore, in this study, we examined the association of ATAs at baseline with OS in non-small cell lung cancer (NSCLC) patients with different levels of programmed cell death-1 ligand 1 (PD-L1) positivity associated with PD-1-Ab treatment efficacy. A total of 81 NSCLC patients treated with PD-1-Abs were evaluated for ATAs at baseline and prospectively for OS. Among the 81 patients, 49 and 32 patients had ≥50% (group A) and <50% (group B) PD-L1 positivity, respectively. Median OS did not differ significantly between patients with (n = 13) and without (n = 36) ATAs at baseline in group A. In contrast, median OS was significantly longer in patients with (n = 10) versus without (n = 22) ATAs at baseline in group B (not reached vs 378 days, respectively; 95% CI, 182 to 574 days, p = 0.049). These findings suggest that the presence of ATAs at baseline is a biomarker to predict better treatment efficacy of PD-1-Abs in NSCLC patients with low PD-L1 positivity, while the difference in OS in those with high PD-L1 positivity may be masked by increased tumor expression of PD-L1.

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.

Development of a predictive model to predict postoperative bone metastasis in pathological I-II non-small cell lung cancer

Background

Bone is a common metastatic site in postoperative metastasis, but related risk factors for early-stage non-small cell lung cancer (NSCLC) remain insufficiently investigated. Thus, the study aimed to identify risk factors for postoperative bone metastasis in early-stage NSCLC and construct a nomogram to identify high-risk individuals.

Methods

Between January 2015 and January 2021, we included patients with resected stage I-II NSCLC at the Department of Thoracic Surgery, West China Hospital. Univariable and multivariable Cox regression analyses were used to identify related risk factors. Additionally, we developed a visual nomogram to forecast the likelihood of bone metastasis. Evaluation of the model involved metrics such as the area under the curve (AUC), C-index, and calibration curves. To ensure reliability, internal validation was performed through bootstrap resampling.

Results

Our analyses included 2,106 eligible patients, with 54 (2.56%) developing bone metastasis. Multivariable Cox analyses showed that tumor nodules with solid component, higher pT stage, higher pN stage, and histologic subtypes especially solid/micropapillary predominant types were considered as independent risk factors of bone metastasis. In the training set, the developed model demonstrated AUCs of 0.807, 0.769, and 0.761 for 1-, 3-, and 5-year follow-ups, respectively. The C-index, derived from 1,000 bootstrap resampling, showed values of 0.820, 0.793, and 0.777 for 1-, 3-, and 5-year follow-ups. The calibration curve showed that the model was well calibrated.

Conclusions

The predictive model is proven to be valuable in estimating the probability of bone metastasis in early-stage NSCLC following surgery. Leveraging four easy-to-acquire clinical parameters, this model effectively identifies high-risk patients and enables individualized surveillance strategies for better patient care.

Recent trends in bone metastasis treatments: A historical comparison using the new Katagiri score system

BACKGROUND

Bone metastasis has various negative impacts. Activities of daily living (ADL) and quality of life (QOL) can be significantly decreased, survival may be impacted, and medical expenses may increase. It is estimated that at least 5% cancer patients might be suffering from bone metastases. In 2016, we published the Comprehensive Guidelines for the Diagnosis and Treatment of Bone Metastasis. Since then, the therapeutic outcomes for patients have gradually improved. As life expectancy is a major determinant of surgical intervention, the strategy should be modified if the prolongation of survival is to be achieved.

AIM

To monitor how bone metastasis treatment has changed before and after launch of our guidelines for bone metastasis.

METHODS

For advanced cancer patients with bone metastasis who visited the Department of Clinical Oncology at Akita University hospital between 2012 and 2023, parameters including the site and number of bone metastases, laboratory data, and survival time, were extracted from electronic medical records and the Katagiri score was calculated. The association with survival was determined for each factor.

RESULTS

Data from 136 patients were obtained. The 1-year survival rate for the poor prognosis group with a higher Katagiri score was 20.0% in this study, which was 6% and an apparent improvement from 2014 when the scoring system was developed. Other factors significantly affecting survival included five or more bone metastases than less (P = 0.0080), and treatment with chemotherapy (P < 0.001), bone modifying agents (P = 0.0175) and immune checkpoint inhibitors (P = 0.0128). In recent years, advances in various treatment methods have extended the survival period for patients with advanced cancer. It is necessary not only to simply extend survival time, but also to maintain ADL and improve QOL.

CONCLUSION

Various therapeutic interventions including surgical approach for bone metastasis, which is a disorder of locomotor organs, are increasingly required. Guidelines and scoring system for prognosis need to be revised promptly.

CT-based radiomics and clinical characteristics for predicting bone metastasis in lung adenocarcinoma patients

Background

The occurrence of bone metastasis (BM) will seriously shorten the survival time of lung adenocarcinoma patients and aggravate the suffering of patients. Computed tomography (CT)-based clinical radiomics nomogram may help clinicians stratify the risk of BM in lung adenocarcinoma patients, thereby enabling personalized individualized clinical decision making.

Methods

A total of 501 patients with lung adenocarcinoma from March 2017 to March 2019 were enrolled in the study. Based on plain chest CT images, 1130 radiomics features were extracted from each lesion. One-way analysis of variance (ANOVA) and least absolute shrinkage selection operator (LASSO) algorithm were used for radiomics features selection. Univariate and multivariate analyses were used to screen for clinical characteristics and identify independent predictors of BM. Three models (radiomics model, clinical model and combined model) were constructed to predict BM in lung adenocarcinoma patients. Receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to evaluate the performance of the three models. The DeLong test was used to compare the performance of the models.

Results

Finally, the clinical model for predicting BM in lung adenocarcinoma patients was constructed based on 5 independent predictors: cytokeratin 19-fragments (CYFRA21-1), stage, Ki-67, edge, and lobulation. The radiomics model was constructed based on 5 radiomics features. The combined model incorporating clinical independent predictors and radiomics was constructed. In the validation cohort, the area under the curve (AUC) of the clinical model, radiomics model and combined model was 0.824, 0.842 and 0.866, respectively. Delong test showed that in the training cohort, the AUC values of the radiomics model and the combined model were statistically different (P=0.03), and the AUC values of the other models were not statistically different. DCA showed that the nomogram had a highest net clinical benefit.

Conclusions

The CT-based clinical radiomics nomogram can be used as a non-invasive and quantitative method to help clinicians stratify the risk of BM in patients with lung adenocarcinoma, thereby enabling personalized clinical decision making.

Machine learning based on SPECT/CT to differentiate bone metastasis and benign bone lesions in lung malignancy patients

BACKGROUND

Bone metastasis is a common event in lung cancer progression. Early diagnosis of lung malignant tumor with bone metastasis is crucial for selecting effective treatment strategies. However, 14.3% of patients are still difficult to diagnose after SPECT/CT examination.

PURPOSE

Machine learning analysis of [99mTc]-methylene diphosphate (99mTc-MDP) SPECT/CT scans to distinguish bone metastases from benign bone lesions in patients with lung cancer.

METHODS

One hundred forty-one patients (69 with bone metastases and 72 with benign bone lesions) were randomly assigned to the training group or testing group in a 7:3 ratio. Lesions were manually delineated using ITK-SNAP, and 944 radiomics features were extracted from SPECT and CT images. The least absolute shrinkage and selection operator (LASSO) regression was used to select the radiomics features in the training set, and the single/bimodal radiomics models were established based on support vector machine (SVM). To further optimize the model, the best bimodal radiomics features were combined with clinical features to establish an integrated Radiomics-clinical model. The diagnostic performance of models was evaluated using receiver operating characteristic (ROC) curve and confusion matrix, and performance differences between models were evaluated using the Delong test.

RESULTS

The optimal radiomics model comprised of structural modality (CT) and metabolic modality (SPECT), with an area under curve (AUC) of 0.919 and 0.907 for the training and testing set, respectively. The integrated model, which combined SPECT, CT, and two clinical features, exhibited satisfactory differentiation in the training and testing set, with AUC of 0.939 and 0.925, respectively.

CONCLUSIONS

The machine learning can effectively differentiate between bone metastases and benign bone lesions. The Radiomics-clinical integrated model demonstrated the best performance.

The association between serum albumin and alkaline phosphatase in cancer patients

The role of serum albumin (ALB) has been extensively studied in patients with cancer; however, research on its effect on bone metastasis in these patients remains limited. This study aimed to investigate the relationship between serum ALB and alkaline phosphatase (ALP) levels in patients with tumors. Using data from the National Health and Nutrition Examination Survey 2011 to 2018, we assessed the correlation between serum ALB and ALP levels using a weighted multivariate linear regression model, whereas a weighted generalized additive model and smooth curve fitting were used to address potential nonlinearities. A total of 1876 patients with cancer were included in our study. In the subgroup analysis stratified by sex, race/ethnicity, and liver disease, the negative correlation of ALB with ALP remained for most groups, except in blacks (β = -1.755, 95%CI: [-3.848, 0.338], P = .103) and patients with gout (β = -0.676, 95%CI: [-2.061, 0.709], P = .340). In black people and patients with gout, the relationship between ALB and ALP showed an inverted U-shaped curve, with an inflection point at approximately 42 g/dL. Our study showed an inverse correlation between ALB and ALP levels in most patients with tumors, but not in black patients and those with gout. The measurement of ALB levels can serve as a screening tool for bone metastases while guiding therapeutic intervention strategies.

Construction of a predictive model for bone metastasis from first primary lung adenocarcinoma within 3 cm based on machine learning algorithm: a retrospective study

Background

Adenocarcinoma, the most prevalent histological subtype of non-small cell lung cancer, is associated with a significantly higher likelihood of bone metastasis compared to other subtypes. The presence of bone metastasis has a profound adverse impact on patient prognosis. However, to date, there is a lack of accurate bone metastasis prediction models. As a result, this study aims to employ machine learning algorithms for predicting the risk of bone metastasis in patients.

Method

We collected a dataset comprising 19,454 cases of solitary, primary lung adenocarcinoma with pulmonary nodules measuring less than 3 cm. These cases were diagnosed between 2010 and 2015 and were sourced from the Surveillance, Epidemiology, and End Results (SEER) database. Utilizing clinical feature indicators, we developed predictive models using seven machine learning algorithms, namely extreme gradient boosting (XGBoost), logistic regression (LR), light gradient boosting machine (LightGBM), Adaptive Boosting (AdaBoost), Gaussian Naive Bayes (GNB), multilayer perceptron (MLP) and support vector machine (SVM).

Results

The results demonstrated that XGBoost exhibited superior performance among the four algorithms (training set: AUC: 0.913; test set: AUC: 0.853). Furthermore, for convenient application, we created an online scoring system accessible at the following URL: https://www.xsmartanalysis.com/model/predict/?mid=731symbol=7Fr16wX56AR9Mk233917, which is based on the highest performing model.

Conclusion

XGBoost proves to be an effective algorithm for predicting the occurrence of bone metastasis in patients with solitary, primary lung adenocarcinoma featuring pulmonary nodules below 3 cm in size. Moreover, its robust clinical applicability enhances its potential utility.

Impact of bone metastasis on the prognosis of non-small cell lung cancer patients treated with immune checkpoint inhibitors: a systematic review and meta-analysis

BACKGROUND

This review was implemented to examine the impact of bone metastasis on the prognosis of non-small cell lung cancer patients (NSCLC) treated with immune checkpoint inhibitors (ICIs).

METHODS

A literature search was conducted in the PubMed, CENTRAL, Web of Science, and Embase databases up to 4th September 2022. Multivariable adjusted data were pooled in a random-effects model.

RESULTS

13 studies were included. On a combined analysis of 10 studies, it was noted that bony metastasis was associated with poor overall survival (OS) in NSCLC patients treated with ICIs (HR: 1.55 95% CI 1.24, 1.94 I2 = 69% p = 0.001). Meta-analysis of seven studies showed that bony metastasis was not associated with poor progression-free survival (PFS) in NSCLC patients treated with ICIs (HR: 1.31 95% CI 0.85, 2.01 I2 = 85% p = 0.22). Meta-regression analysis using the moderator's age, male gender, smoking history, squamous histology, and ICI as 1st line therapy for the outcome OS was not statistically significant.

CONCLUSION

The presence of bone metastasis is a predictor of poor OS in NSCLC treated with ICIs. However, PFS does not seem to be influenced by the presence of bone metastasis. Clinicians should prioritize the management of NSCLC patients with bone metastasis and explore the use of combination therapies to achieve optimal results. Further studies taking into account different combination therapies for such patients would strengthen the evidence.

Nanoparticles for the Treatment of Bone Metastasis in Breast Cancer: Recent Advances and Challenges

Although the frequency of bone metastases from breast cancer has increased, effective treatment is lacking, prompting the development of nanomedicine, which involves the use of nanotechnology for disease diagnosis and treatment. Nanocarrier drug delivery systems offer several advantages over traditional drug delivery methods, such as higher reliability and biological activity, improved penetration and retention, and precise targeting and delivery. Various nanoparticles that can selectively target tumor cells without causing harm to healthy cells or organs have been synthesized. Recent advances in nanotechnology have enabled the diagnosis and prevention of metastatic diseases as well as the ability to deliver complex molecular "cargo" particles to metastatic regions. Nanoparticles can modulate systemic biodistribution and enable the targeted accumulation of therapeutic agents. Several delivery strategies are used to treat bone metastases, including untargeted delivery, bone-targeted delivery, and cancer cell-targeted delivery. Combining targeted agents with nanoparticles enhances the selective delivery of payloads to breast cancer bone metastatic lesions, providing multiple delivery advantages for treatment. In this review, we describe recent advances in nanoparticle development for treating breast cancer bone metastases.

Chinese expert consensus on the diagnosis and treatment of bone metastasis in lung cancer (2022 edition)

Lung cancer is the leading cause of cancer-related deaths worldwide. Bone is a common metastatic site of lung cancer, about 50% of bone metastatic patients will experience skeletal related events (SREs). SREs not only seriously impact the quality of life of patients, but also shorten their survival time. The treatment of bone metastasis requires multi-disciplinary therapy (MDT) and development of individualized treatment plan. In order to standardize the diagnosis and treatment of bone metastasis in lung cancer, the expert group of the MDT Committee of the Chinese Medical Doctor Association has developed the expert consensus on the diagnosis and treatment of lung cancer bone metastasis.

Premetastatic Niche Mimicking Bone-On-A-Chip: A Microfluidic Platform to Study Bone Metastasis in Cancer Patients

Primary cancer modulates the bone microenvironment to sow the seeds of dormancy and metastasis in tumor cells, leading to multiple organ metastasis and death. In this study, 3D printing and bone-on-a-chip (BOC) are combined to develop a BOC platform that mimics the pre-metastatic niches (PMNs) and facilitates elucidation of the interactions between bone-resident cells and metastatic tumor cells under the influence of primary cancer. Photocrosslinkable gelatin methacrylate (GelMA) is used as a 3D culturing hydrogel to encapsulate cells, and circulate tumor culture medium (CM) adjacent to the hydrogel to verify the critical role of mesenchymal stem cells (MSCs) and osteoclasts (RAW264.7s). Three niches: the dormancy niche, the perivascular niche, and the "vicious cycle" niche, are devised to recapitulate bone metastasis in one chip with high cell viability and excellent nutrient exchange. With respect to tumor dormancy and reactivation, the invadopodia formation of A549 lung cancer cells in communication with MSCs and RAW264.7 via the cortactin pathway is researched. As a proof of concept, the functionality and practicality of the platform are demonstrated by analyzing the invadopodia formation and the influence of various cells, and the establishment of the dynamic niches paves the way to understanding PMN formation and related drug discovery.

Comparative bioinformatic analysis of KRAS, STK11 and KEAP1 (co-)mutations in non-small cell lung cancer with a special focus on KRAS G12C

OBJECTIVES

Mutations in STK11 (STK11MUT) and KEAP1 (KEAP1MUT) occur frequently in non-small cell lung cancer (NSCLC) and are often co-mutated with KRAS. Several studies linked the co-occurrence of KRASMUT + STK11MUT, as well as KRASMUT + KEAP1MUT to reduced response to immune checkpoint inhibitors (ICI) and even a negative impact on survival. Data focusing STK11 + KEAP1 co-mutations or the triple mutation (KRAS + STK11 + KEAP1) are scarce. The recent availability of KRAS-G12C inhibitors increases the clinical relevance of those co-mutations in KRAS-mutated NSCLC.

MATERIALS AND METHODS

We present a comprehensive bioinformatic analysis encompassing six datasets retrieved from cBioPortal.

RESULTS

Independent of the treatment, triple mutations and STK11MUT + KEAP1MUT were significantly associated with a reduced overall survival (OS). Across treatments, OS of patients with a KRAS G12C triple mutation was significantly reduced compared to patients with KRAS G12C-only. Under ICI-therapy, there was no significant difference in OS between patients harboring the KRAS G12C-only and patients with the KRAS G12C triple mutation, but a significant difference between patients harboring KRAS non-G12C and KRAS non-G12C triple mutations. Triple mutated primary tumors showed a significantly increased frequency of distant metastases to bone and adrenal glands compared to KRAS-only mutated tumors. Additionally, our drug response analysis in cancer cell lines harboring the triple mutations revealed the WNT pathway inhibitor XAV-939 as a potential future drug candidate for this mutational situation.

CONCLUSION

The triple mutation status may serve as a negative prognostic and predictive factor across treatments compared to KRASMUT-only. KRAS G12C generally seems to be a negative predictive marker for ICI-therapy.

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.

Abscopal Effect on Bone Metastases from Solid Tumors: A Systematic Review and Retrospective Analysis of Challenge within a Challenge

BACKGROUND

Abscopal effect (AE) describes the ability of radiotherapy (RT) to induce immune-mediated responses in nonirradiated distant metastasis. Bone represents the third most frequent site of metastasis and an immunologically favorable environment for the proliferation of cancer cells. We revised the literature, searching documented cases of AE involving bone metastases (BMs) and evaluated the incidence of AE involving BMs in patients requiring palliative RT on BMs or non-BMs treated at our department.

METHODS

Articles published in the PubMed/MEDLINE database were selected using the following search criteria: ((abscopal effect)) AND ((metastases)). Patients with BMs, who underwent performed bone scintigraphy before and at least 2-3 months after RT, were selected and screened between January 2015 and July 2022. AE was defined as an objective response according to the scan bone index for at least one nonirradiated metastasis at a distance > 10 cm from the irradiated lesion. The primary endpoint was the rate of AE on BMs.

RESULTS

Ten cases experiencing AE of BMs were identified from the literature and eight among our patients.

CONCLUSIONS

The analysis performed here suggests the use of hypofractionated radiotherapy as the only triggering factor for AE of BMs through the activation of the immune response.

Nivolumab or Atezolizumab in the Second-Line Treatment of Advanced Non-Small Cell Lung Cancer? A Prognostic Index Based on Data from Daily Practice

BACKGROUND

The efficacy of nivolumab and atezolizumab in advanced pre-treated NSCLC was documented in prospective trials. We aim to confirm the benefits and indicate predictive factors for immunotherapy in daily practice.

METHODS

This study was a retrospective analysis. The median PFS and OS were estimated using the Kaplan-Meier method. The log-rank test was used for comparisons. Multivariate analyses were performed using the Cox regression method.

RESULTS

A total of 260 patients (ECOG 0-1) with advanced NSCLC (CS III-IV) were eligible to receive nivolumab or atezolizumab as second-line treatment. Median PFS and OS were three months (95% confidence interval [CI] 2.57-3.42) and 10 months (95% CI 8.03-11.96), respectively, for the overall population. The median OS for the atezolizumab arm was eight months (95% CI 5.89-10.1), while for the nivolumab group, it was 14 months (95% CI 10.02-17.97) (p = 0.018). The sum of all measurable changes >100.5 mm (p = 0.007; HR = 1.003, 95% CI 1.001-1.005), PLT > 281.5 G/l (p < 0.001; HR = 1.003, 95% CI 1.001-1.003) and bone metastases (p < 0.004; HR = 1.58, 95% CI 1.04-2.38) were independent negative prognostic factors for OS in multivariate analysis. Based on preliminary analyses, a prognostic index was constructed to obtain three prognostic groups. Median OS in the subgroups was 16 months (95% CI 13.3-18.7), seven months (95% CI 4.83-9.17) and four months (95% CI 2.88-5.13), respectively (p < 0.001).

CONCLUSIONS

Nivolumab and atezolizumab provided clinical benefit in real life. Clinical and laboratory factors may help to identify subgroups likely to benefit. The use of prognostic indices may be valuable in clinical practice.

Construction and validation of a novel web-based nomogram for patients with lung cancer with bone metastasis: A real-world analysis based on the SEER database

Purpose

Patients with lung cancer with bone metastasis (LCBM) often have a very poor prognosis. The purpose of this study is to characterize the prevalence and associated factors and to develop a prognostic nomogram to predict the overall survival (OS) and cancer-specific survival (CSS) for patients with LCBM using multicenter population-based data.

Methods

Patients with LCBM at the time of diagnosis were identified using the Surveillance, Epidemiology, and End Results (SEER) Program database of the National Cancer Institute (NCI) from 2010 to 2015. Multivariable and univariate logistic regression analyses were performed to identify factors associated with all-cause mortality and lung cancer (LC)-specific mortality. The performance of the nomograms was evaluated with the calibration curves, area under the curve (AUC), and decision curve analysis (DCA). Kaplan-Meier analysis and log-rank tests were used to estimate the survival times of patients with LCBM.

Results

We finally identified 26,367 patients with LCBM who were selected for survival analysis. Multivariate analysis demonstrated age, sex, T stage, N stage, grade, histology, radiation therapy, chemotherapy, primary site, primary surgery, liver metastasis, and brain metastasis as independent predictors for LCBM. The AUC values of the nomogram for the OS prediction were 0.755, 0.746, and 0.775 in the training cohort; 0.757, 0.763, and 0.765 in the internal validation cohort; and 0.769, 0.781, and 0.867 in the external validation cohort. For CSS, the values were 0.753, 0.753, and 0.757 in the training cohort; 0.753, 0.753, and 0.757 in the internal validation cohort; and 0.767, 0.774, and 0.872 in the external validation cohort.

Conclusions

Our study constructs a new prognostic model and clearly presents the clinicopathological features and survival analysis of patients with LCBM. The result indicated that the nomograms had favorable discrimination, good consistency, and clinical benefits in patients. In addition, our constructed nomogram prediction models may assist physicians in evaluating individualized prognosis and deciding on treatment for patients.

Combination of Bone-Modifying Agents with Immunotarget Therapy for Hepatocellular Carcinoma with Bone Metastases

Due to limited investigations about efficacy of tyrosine kinase inhibitors (TKIs) plus immune-checkpoint inhibitors (ICIs) versus TKIs alone, and effects of durations of bone modifying agents (BMAs) on the survival of patients with hepatocellular carcinoma (HCC) and bone metastases (BoM), we aim to compare the efficacy of TKIs both alone and in combination with ICIs, as well as comparing long-term and no or perioperative use of BMAs for patients with HCC and BoM. Patients with pathologically confirmed HCC and BoM were included in the study. They were stratified into the TKIs group and the TKIs + ICIs group, and the perioperative and the long-term use of BMAs group. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR) were calculated to assess the response to these regimes. The cumulative risk of initial skeletal-related events (SREs) was used to evaluate treatment efficacy for bone lesions. A total of 21 (33.9%) patients received TKIs (Sorafenib or Lenvatinib) alone and 41 (66.1%) received TKIs + ICIs. The combination group showed higher ORR than monotherapy group (1/21, 4.7% vs. 9/41, 22.0%; p = 0.1432); Additionally, the TKIs + ICIs group offered improved OS (18 months vs. 31 months; p = 0.015) and PFS (10 months vs. 23 months; p = 0.014), while this survival benefits were more profound in virus-infected patients than those non-infected. Prolonged OS (33 months vs. 16 months; p = 0.0048) and PFS (33 months vs. 11 months; p = 0.0027) were observed in patients with long-term use of BMAs compared with no or perioperative use of BMAs. The TKIs + ICIs combination and long-term adjuvant of BMAs may offer a survival advantage for HCC patients with BoM without severe adverse events, which requires further validations.

Advanced non-small cell lung cancer treated with palliative systemic therapy complicated by calvarial metastasis: a case report

Background

Bony metastases are often seen in advanced cancers and lead to deterioration in patient quality of life with common complications of pain, bone fractures, and hypercalcemia. While most sites of metastasis to bone are observed in the axial skeleton from patients with a primary lung, breast or prostate cancer, metastases to the calvarium from lung cancer are less common, and thus less likely to be identified and managed.

Case Description

A 69-year-old Caucasian female with advanced non-small cell lung cancer (NSCLC) presented with worsening symptoms of widespread body pain, fatigue, and weight loss. Physical examination was remarkable for a palpable protrusion on the patient's head. Imaging revealed a parieto-occipital calvarial lesion, a likely metastasis from her lung cancer. A previously performed CT-guided lung biopsy was evaluated for actionable tumor markers to allow for more specific and efficacious line of treatments; the patient's tumor had lacked any notable gene mutations. The treatment plan included radiotherapy, combined immunotherapy and chemotherapy consisting of pembrolizumab, pemetrexed, and carboplatin. Despite the treatment, the patient's skull lesion had continued to grow, and her overall condition deteriorated to the point where she required hospice.

Conclusions

Given the unique location of calvarial metastases, early detection appears to correlate with improving patient outcomes and quality of life. A multimodal approach with a high index of suspicion is essential for diagnosing and managing rare presentations of metastatic disease.

Value of CT Radiomics and Clinical Features in Predicting Bone Metastases in Patients with NSCLC

Objective

To explore the CT radiomic features and clinical imaging features of the primary tumor in patients with nonsmall cell lung cancer (NSCLC) before treatment and their predictive value for the occurrence of bone metastases.

Methods

From June 2017 to June 2021, 195 patients with NSCLC who were pathologically diagnosed without any treatment in the Cancer Hospital Affiliated to Hainan Medical College were retrospectively analyzed, and they were divided into a bone metastasis group and a nonbone metastasis group. The relationship between clinical imaging features and bone metastasis in patients was analyzed by the t-test, rank sum test, and χ 2 test. At the same time, ITK software was used to extract the radiomic characteristics of the primary tumor of the patients, and the patients were randomly divided into a training group and a validation group in a ratio of 7 : 3. The training model was validated in the validation group, and the performance of the model for predicting bone metastases in NSCLC patients was verified by the ROC curve, and a multivariate logistic regression prediction model was established based on the omics parameters extracted from the best prediction model combined with clinical image features.

Results

Seven features were screened from the primary tumor by LASSO to establish a model for predicting metastasis. The area under the curve was 0.82 and 0.73 in the training and validation sets. The best omics signature and univariate analysis suggested clinical imaging factors (P < 0.05) associated with bone metastases were included in multivariate binary logistic analysis to obtain clinical characteristics of the primary tumor such as gender (OR = 0.141, 95% CI: 0.022-0.919, P = 0.04), increased Cyfra21-1 (OR = 0.12, 95% CI: 0.018-0.782, P = 0.027), Fe content in blood (OR = 0.774, 95% CI: 0.626-0.958, P = 0.018), CT signs such as lesion homogeneity (OR = 0.052, 95% CI: 0.006-0.419, P = 0.006), pleural indentation sign (OR = 0.007, 95% CI: 0.001-0.696, P = 0.034), and omics characteristics glszm_Small Area High Gray Level Emphasis (OR = 0.016, 95% CI: 0.001-0.286, P = 0.005) were independent risk factors for bone metastasis in patients.

Conclusion

The prediction model established based on radiomics and clinical imaging features has high predictive performance for the occurrence of bone metastasis in NSCLC patients.

Bone Microenvironment-Suppressed T Cells Increase Osteoclast Formation and Osteolytic Bone Metastases in Mice

Immunotherapies use components of the immune system, such as T cells, to fight cancer cells, and are changing cancer treatment, causing durable responses in some patients. Bone metastases are a debilitating complication in advanced breast and prostate cancer patients. Approved treatments fail to cure bone metastases or increase patient survival and it remains unclear whether immunotherapy could benefit patients. The bone microenvironment combines various immunosuppressive factors, and combined with T cell products could increase bone resorption fueling the vicious cycle of bone metastases. Using syngeneic mouse models, our study revealed that bone metastases from 4T1 breast cancer contain tumor-infiltrating lymphocyte (TILs) and their development is increased in normal mice compared to immunodeficient and T-cell depleted mice. This effect seemed caused by the TILs specifically in bone, because T-cell depletion increased 4T1 orthotopic tumors and did not affect bone metastases from RM-1 prostate cancer cells, which lack TILs. T cells increased osteoclast formation ex vivo and in vivo contributing to bone metastasis vicious cycle. This pro-osteoclastic effect is specific to unactivated T cells, because activated T cells, secreting interferon γ (IFNγ) and interleukin 4 (IL-4), actually suppressed osteoclastogenesis, which could benefit patients. However, non-activated T cells from bone metastases could not be activated in ex vivo cultures. 4T1 bone metastases were associated with an increase of functional polymorphonuclear and monocytic myeloid-derived suppressor cells (MDSCs), potent T-cell suppressors. Although effective in other models, sildenafil and zoledronic acid did not affect MDSCs in bone metastases. Seeking other therapeutic targets, we found that monocytic MDSCs are more potent suppressors than polymorphonuclear MDSCs, expressing programmed cell death receptor-1 ligand (PD-L1)+ in bone, which could trigger T-cell suppression because 70% express its receptor, programmed cell death receptor-1 (PD-1). Collectively, our findings identified a new mechanism by which suppressed T cells increase osteoclastogenesis and bone metastases. Our results also provide a rationale for using immunotherapy because T-cell activation would increase their anti-cancer and their anti-osteoclastic properties. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Overall Survival Improvement in Patients with Epidermal Growth Factor Receptor-Mutated Non-Small Cell Lung Cancer and Bone Metastasis Treated with Denosumab

The impact of an initial skeletal-related event (SRE) and denosumab adjuvant treatment on the survival outcome of epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) patients with bone metastasis remains unclear. This retrospective study included 400 metastatic EGFR-mutated NSCLC patients. Among 190 bone metastasis patients, 61 had initial SREs and 73 received denosumab. We analyzed patient characteristics, SRE-free survival (SRE-FS), and overall survival (OS). In metastatic EGFR-mutated NSCLC, bone metastasis was associated with a poorer OS (21.7 vs. 33.0 months; p < 0.001). Bone metastasis patients with initial SREs at diagnosis had an even shorter OS, compared with those without initial SRE (15.4 vs. 23.6 months; p = 0.026). Denosumab reduced SRE incidence (hazard ratio (HR) 0.57 (95% confidence interval (CI) 0.34−0.94; p = 0.027) and was associated with improved OS (26.6 vs. 20.1 months; p = 0.015). A multivariate analysis demonstrated that denosumab treatment was correlated with a lower incidence of SRE (HR 0.61 (95% CI 0.37−0.98); p = 0.042) and better OS (HR 0.60 (95% CI 0.41−0.88); p = 0.008). In subgroup analyses, denosumab prolonged SRE-FS (HR 0.36 (95% CI 0.19−0.79); p = 0.009) in patients without initial SREs and was related to a better OS (25.3 vs. 12.9 months; p = 0.016) in patients with initial or pre-existing SREs. Osteonecrosis of the jaw was diagnosed in two patients (2.74%) receiving denosumab. Our study confirmed the association between initial SREs and a worse outcome and provided novel evidence of the survival benefit of denosumab for EGFR-mutated NSCLC patients with bone metastasis.

Bone-specific response according to MDA criteria predicts immunotherapy efficacy among advanced non-small cell lung cancer (NSCLC) patients

PURPOSE

The presence of bone metastasis at baseline has been associated with dismal prognosis under immunotherapy in advanced non-small cell lung cancer (NSCLC). Response Evaluation Criteria in Solid Tumors (RECIST) criteria may be limited for bone-specific response evaluation. Whether their assessment through MD Anderson (MDA) criteria predict immunotherapy efficacy is unknown.

MATERIALS AND METHODS

We conducted a single-center retrospective study to assess the use of MDA criteria in evaluating bone metastasis in NSCLC treated with immunotherapy. Radiological imaging were reviewed to classify bone lesions as osteolytic, osteoblastic, or mixed. Bone response to treatment data was classified according to MDA criteria.

RESULTS

222 patients received single-agent immunotherapy. The presence of bone metastasis increased the risk of death both in the univariate (HR: 1.46, 95% CI, 1.05-2.03, p = 0.024) and in the multivariate model (HR: 1.61, 95% CI, 1.10-2.36, p = 0.015). According to MDA criteria, 57.3% of patients had progressive disease as best response, 29.5% stable disease, 11.4% partial response and 1.6% complete response. Bone-specific objective response was associated with a significantly increased median overall survival (11.3 vs. 3.1 months, p = 0.027) and longer median progression-free survival (6 vs. 2.1 months, p = 0.056). The median time to bone failure (TBF) was 2.4 months (IQR, 1.67-3.0). In 25.7% of cases, TBF was shorter than progression-free survival according to RECIST 1.1 criteria. TBF was positively correlated with overall survival (HR = 0.73, p = 0.00019).

CONCLUSIONS

MDA criteria represent a reliable tool in assessing bone-specific response, offering a more accurate evaluation with the aim to earlier predict survival outcomes or treatment failure compared to RECIST criteria for advanced NSCLC patients receiving immunotherapy.

Bone Metastasis and Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer (NSCLC): Microenvironment and Possible Clinical Implications

Patients with non-small cell lung cancer (NSCLC) develop bone metastasis (BoM) in more than 50% of cases during the course of the disease. This metastatic site can lead to the development of skeletal related events (SREs), such as severe pain, pathological fractures, spinal compression, and hypercalcemia, which reduce the patient’s quality of life. Recently, the treatment of advanced NSCLC has radically changed due to the advent of immunotherapy. Immune checkpoint inhibitors (ICI) alone or in combination with chemotherapy have become the main therapeutic strategy for advanced or metastatic NSCLC without driver gene mutations. Since survival has increased, it has become even more important to treat bone metastasis to prevent SRE. We know that the presence of bone metastasis is a negative prognostic factor. The lower efficacy of immunotherapy treatments in BoM+ patients could be induced by the presence of a particular immunosuppressive tumor and bone microenvironment. This article reviews the most important pre-clinical and clinical scientific evidence on the reasons for this lower sensitivity to immunotherapy and the need to combine bone target therapies (BTT) with immunotherapy to improve patient outcome.

The Therapeutic Effect and Clinical Outcome of Immune Checkpoint Inhibitors on Bone Metastasis in Advanced Non-Small-Cell Lung Cancer

Introduction

In advanced non-small-cell lung cancer (NSCLC), immune checkpoint inhibitors (ICIs) have been reported a better treatment outcome on primary lesions, however, the therapeutic effect on bone metastases has not been clarified. This study investigates the therapeutic effect of ICIs on bone metastases in advanced NSCLC.

Methods

The data of patients with advanced NSCLC, treated with ICIs from 2016 to 2019 at our hospital, were analyzed. The therapeutic effects of ICIs on primary lung and metastatic bone lesions, concomitant use of bone modifying agents (BMA), treatment outcomes, and frequency of immune-related adverse events (irAEs) and skeletal-related events (SREs) were investigated.

Results

A total of 29 patients were included (19 men and 10 women; mean age, 64.2 years). Among the ICIs, pembrolizumab was the most used (55.2%), and concomitant use of BMA was prevalent in 21 patients (zoledronic acid=1, denosumab=20). The therapeutic effect was partial response (PR) in 10.3% (n=3) on primary lung lesions by RECIST 1.1, complete response (CR) in 6.9% (n=2) and PR in 17.2% (n=5) on bone metastatic lesions by MDA criteria. ICIs suppressed the progression of bone metastasis in 21 cases (72.4%). All patients in CR and PR were treated with pembrolizumab and denosumab. SREs and irAEs were developed in 3.4% (n=1) and 20.7% (n=6), respectively. The median survival time after treatment with ICIs was 11.0 months. Concomitant therapy with ICIs and denosumab significantly prolonged the overall survival compared to ICI-only therapy (16.0 months vs. 2.5 months, p<0.01).

Conclusions

This study showed that treatment with ICIs may successfully suppress the progression of bone metastasis in advanced NSCLC. Pembrolizumab with denosumab had the highest therapeutic effect on both primary lung lesions and bone metastases. Systemic treatment with this combination and conservative treatment of bone metastasis could be one of the options in the treatment of advanced NSCLC.

Immune Checkpoint Inhibitor Therapy for Bone Metastases: Specific Microenvironment and Current Situation

The treatment of bone metastases is a thorny issue. Immunotherapy may be one of the few hopes for patients with unresectable bone metastases. Immune checkpoint inhibitors are the most commonly used immunotherapy drugs currently. In this review, the characteristics and interaction of bone metastases and their immune microenvironment were systematically discussed, and the relevant research progress of the immunological mechanism of tumor bone metastasis was reviewed. On this basis, we expounded the clinical application of immune checkpoint inhibitors for bone metastasis of common tumors, including non-small-cell lung cancer, renal cell carcinoma, prostate cancer, melanoma, and breast cancer. Then, the deficiencies and limitations in current researches were summarized. In-depth basic research on bone metastases and optimization of clinical treatment is needed.