Spinal metastasis: narrative reviews of the current evidence and treatment modalities

Trends in the surgical treatment for metastatic spinal tumor in Japanese administrative data between 2012 and 2020

BACKGROUND

Both cancer diagnosis/treatment modality and surgical technique for the spine have been developed recently. Nationwide trends in the surgical treatment for metastatic spinal tumors have not been reported in the last decades. This study aimed to examine recent trends in the surgical treatment for spinal metastasis and in-hospital patient outcomes using nationwide administrative hospital discharge data.

METHODS

The Diagnosis Procedure Combination database from 2012 to 2020 was used to extract data from patients who underwent surgical procedures for spinal metastasis with the number of non-metastatic spinal surgery at the institutions that have performed metastatic spine surgeries at least one case in the same year. Trends in the surgical treatment for spinal metastasis, patients' demographics, and in-hospital mortality/outcomes were investigated.

RESULTS

This study analyzed 10,321 eligible patients with spinal metastasis. The surgical treatment for spinal metastasis increased 1.68 times from 2012 to 2020, especially in fusion surgery, whereas the proportion of metastatic spinal surgery retained with a slight increase in the 2%s. Distributions of the primary site did not change, whereas age was getting older. In-hospital mortality and length of stay decreased over time (9.9-6.8%, p < 0.001; 37-30 days, p < 0.001). Postoperative complication and unfavorable ambulatory retained stable and slightly decreased, respectively.

CONCLUSION

During the last decade, surgical treatment for spinal metastasis, especially fusion surgery, has increased in Japan. In-hospital mortality and length of stay decreased. Recent advances in cancer treatment and surgical techniques might influence this trend.

Metastasis Models: Thermodynamics and Complexity

The thermodynamic formalism of nonequilibrium systems together with the theory of complex systems and systems biology offer an appropriate theoretical framework to explain the complexity observed at the macroscopic level in physiological phenomena. In turn, they allow the establishment of an appropriate conceptual and operational framework to address the study of phenomena such as the emergence and evolution of cancer.This chapter is organized as follows: In Subheading 1, an integrated vision of these disciplines is offered for the characterization of the emergence and evolution of cancer, seen as a nonlinear dynamic system, temporally and spatially self-organized out of thermodynamic equilibrium. The development of the various mathematical models and different techniques and approaches used in the characterization of cancer metastasis is presented in Subheading 2. Subheading 3 is devoted to the time course of cancer metastasis, with particular emphasis on the epithelial-mesenchymal transition (EMT henceforth) as well as chronotherapeutic treatments. In Subheading 4, models of the spatial evolution of cancer metastasis are presented. Finally, in Subheading 5, some conclusions and remarks are presented.

[Translated article] Vertebral metastases. En bloc treatment

En bloc resection of vertebral metastases has been the subject of study in medical literature due to its impact on patients' quality of life and effectiveness in local disease control. This bibliographic analysis examines the findings and perspectives of published studies concerning en bloc resection of oligometastases in the spine. The technique, which involves the complete removal of the tumour along with a portion of the surrounding bone, has been shown to improve local tumour control, reduce recurrence, and potentially prolong patient survival compared to conventional decompression and stabilisation techniques. However, en bloc resection also presents risks and complications, such as surgical morbidity and extended recovery time. Appropriate patient selection, preoperative planning, and a multidisciplinary approach are essential to optimise outcomes. As new techniques and advances in adjuvant treatment develop, en bloc resection of oligometastases in the spine remains an area of interest in oncological research.

Vertebral metastases. En bloc treatment

En bloc resection of vertebral metastases has been the subject of study in medical literature due to its impact on patients' quality of life and effectiveness in local disease control. This bibliographic analysis examines the findings and perspectives of published studies concerning en bloc resection of oligometastases in the spine. The technique, which involves the complete removal of the tumour along with a portion of the surrounding bone, has been shown to improve local tumour control, reduce recurrence, and potentially prolong patient survival compared to conventional decompression and stabilization techniques. However, en bloc resection also presents risks and complications, such as surgical morbidity and extended recovery time. Appropriate patient selection, preoperative planning, and a multidisciplinary approach are essential to optimize outcomes. As new techniques and advances in adjuvant treatment develop, en bloc resection of oligometastases in the spine remains an area of interest in oncological research.

Age, sex, primary tumor type and site are associated with mortality after pathological fractures: an observational study of 1453 patients from the Swedish Fracture Register

BACKGROUND

Pathological fractures are challenging in orthopedic surgery and oncology, with implications for the patient's quality of life, mobility and mortality. The efficacy of oncological treatment on life expectancy for cancer patients has improved, but the metastatic pattern for bone metastases and survival is diverse for different tumor types. This study aimed to evaluate survival in relation to age, sex, primary tumor and site of the pathological fractures.

METHODS

All pathological fractures due to cancer between 1 September 2014 and 31 December 2021 were included in this observational study from the Swedish Fracture Register (SFR). Data on age, sex, tumor type, fracture site and mortality were collected.

RESULTS

A total of 1453 patients with pathological fractures were included (48% women, median age 73, range 18-100 years). Unknown primary tumors were the most common primary site (n = 308). The lower extremities were the most common site of pathological fractures. Lung cancer had the shortest median survival of 78 days (range 54-102), and multiple myeloma had the longest median survival of 432 days (range 232-629). The site at the lower extremity had the shortest (187 days, range 162-212), and the spine had the longest survival (386 days, range 211-561). Age, sex, primary type and site of the pathological fractures were all associated with mortality.

INTERPRETATION

Age, sex, primary tumor type and site of pathological fractures were associated with survival. Survival time is short and correlated with primary tumor type, with lung cancer as the strongest negative predictor of survival.

Risk factors for pulmonary cement embolism after percutaneous vertebroplasty and radiofrequency ablation for spinal metastases

Objective

Pulmonary cement embolism is a rare but underestimated complication of vertebroplasty due to the relative lack of study and examination. This study aims to investigate the incidence of pulmonary cement embolism in patients with spinal metastasis who undergo PVP with RFA and to analyze the relative risk factors.

Methods

A total of 47 patients were retrospectively included and classified into pulmonary cement embolism (PCE) group and non-pulmonary cement embolism (NPCE) group by comparing pre- and postoperative pulmonary CT scan images. The demographic and clinical information of the patients was obtained. Demographic data in the two groups were compared using the chi-square test for qualitative data and the unpaired t test for quantitative data. Multiple logistic regression analysis was used to identify risk factors related to pulmonary cement embolism.

Results

Pulmonary cement embolism was detected in 11 patients (23.4%), and all patients were asymptomatic and followed up regularly. Risk analysis showed that multiple segments (≥3, p=0.022), thoracic vertebrae (p=0.0008), and unipedicular puncture approach (p=0.0059) were risk factors for pulmonary cement embolism. There was a high incidence of pulmonary cement embolism if bone cement leaked into the para vertebral venous plexus in the thoracic vertebra (p<0.0001). Vein leakage of cement was related to the integrity of the vertebral cortex.

Conclusion

The number of involved vertebrae, lesion location, and puncture approach are independent risk factors for pulmonary cement embolism. There was a high incidence of pulmonary cement embolism if bone cement leaked into the para vertebral venous plexus in the thoracic vertebra. Surgeons should consider these factors when formulating therapeutic strategies.

Survival and Functional Outcomes after Surgical Treatment for Spinal Metastasis in Patients with a Short Life Expectancy

This study aimed to analyze the survival and functional outcome after surgery in spinal metastasis patients with a short life expectancy and to compare the baseline characteristics based on 3-month survival. A total of 492 surgical treatment cases with a preoperative revised Tokuhashi score ≤ 8were reviewed. Median survival was calculated and Kaplan−Meier analysis was used to analyze the survival rates at 6 months, 1 year, and 2 years postoperatively. The surgical period was divided into three time frames to examine the time trends. For the functional outcome, Eastern Cooperative Oncology Group Performance Status (ECOG-PS) was analyzed. This study categorized subjects based on 3-month survival and compared the baseline characteristics. The median overall survival was 10.6 months. The 2013−2020 period showed a significantly better median survival than the other two periods (p < 0.001). Lung and kidney cancers showed a significant survival improvement in 2013−2020 (p < 0.001). Patients with ECOG-PS ≤ 2 increased from 37.4% preoperatively to 63.7% postoperatively (p < 0.001). There were significantly more cases of preoperative favorable performance status, slow and moderate growth cancers, and chemotherapy after surgery in the survival ≥3 months group. Depending on the type of primary cancer, surgery can be considered even in spinal metastasis patients with a short life expectancy, particularly those with a good performance status.

A novel nomogram to stratify quality of life among advanced cancer patients with spinal metastatic disease after examining demographics, dietary habits, therapeutic interventions, and mental health status

Background

It would be very helpful to stratify patients and direct patient selection if risk factors for quality of life were identified in a particular population. Nonetheless, it is still challenging to forecast the health-related quality of life among individuals with spinal metastases. The goal of this study was to stratify patient’s populations for whom the assessment of quality of life should be encouraged by developing and validating a nomogram to predict the quality of life among advanced cancer patients with spine metastases.

Methods

This study prospectively analyzed 208 advanced cancer patients with spine metastases, and collected their general characteristics, food preferences, addictions, comorbidities, therapeutic strategies, and mental health status. The functional assessment of cancer therapy-general (FACT-G) and hospital anxiety and depression scale (HADS) were used to assess quality of life and mental health, respectively. The complete cohort of patients was randomly divided into two groups: a training set and a validation set. Patients from the training set were conducted to train and develop a nomogram, while patients in the validation set were performed to internally validate the nomogram. The nomogram contained significant variables discovered using the least absolute shrinkage and selection operator (LASSO) approach in conjunction with 10-fold cross-validation. The nomogram’s predictive ability was assessed utilizing discrimination, calibration, and clinical usefulness. Internal validation was also completed using the bootstrap method after applying 500 iterations of procedures. A web calculator was also developed to promote clinical practice.

Results

Advance cancer patients with spinal metastases had an extremely low quality of life, as indicated by the average FACT-G score of just 60.32 ± 20.41. According to the LASSO and 10-fold cross-validation, Eastern Cooperative Oncology Group (ECOG) score, having an uncompleted life goal, preference for eating vegetables, chemotherapy, anxiety status, and depression status were selected as nomogram predictors. In the training set, the area under the receiver operating characteristic curve (AUROC) was 0.90 (95% CI: 0.84–0.96), while in the validation set, it was 0.85 (95% CI: 0.78–0.93). They were 0.50 (95% CI: 0.41–0.58) and 0.44 (95% CI: 0.33–0.56), respectively, for the discrimination slopes. The nomogram had favorable capacity to calibrate and was clinically useful, according to the calibration curve and decision curve analysis. When compared to patients in the low-risk group, patients in the high-risk group were above four times more likely to experience a poor quality of life (82.18% vs. 21.50%, P < 0.001). In comparison to patients in the low-risk group, patients in the high-risk group also exhibited significant higher levels of anxiety and depression. The webpage for the web calculator was https://starshiny.shinyapps.io/DynNomapp-lys/.

Conclusions

This study suggests a nomogram that can be applied as a practical clinical tool to forecast and categorize the quality of life among patients with spine metastases. Additionally, patients with poor quality of life experience more severe anxiety and depression. Effective interventions should be carried out as soon as possible, especially for patients in the high-risk group, to improve their quality of life and mental health condition.