Surgical management of prostate cancer metastatic to the spine

Stereotactic radiosurgery for patients with spinal metastases from prostate cancer

PURPOSE

Spinal metastases may result in intractable pain, neurological deficit, and vertebral body collapse. There are only a few studies describing outcomes following spine stereotactic radiosurgery (SRS) specifically for prostate cancer metastases.

METHODS

A prospectively collected database of patients with prostate cancer spinal metastases treated at the University of Pittsburgh Medical Center from 2003 to 2023 was analyzed. The primary outcome was local control (LC). Secondary outcomes were overall survival (OS), pain resolution, and adverse radiation effects (AREs).

RESULTS

Thirty-seven patients and 51 lesions were identified. Fifteen lesions (29%) were previously resected and 34 lesions (67%) were previously irradiated. The median tumor volume was 37.0 cc (range: 2.9-263.3). A majority of lesions (71%) were treated in a single fraction (median 20 Gy, range: 14-22.5); multi-fractionated treatment consisted of 21-30 Gy in 2-5 fractions. Median follow-up was 12 months (range: 1-146). The 6-month, 1-year, and 2-year LC rates were 97%, 91%, and 91%, respectively. No tested prognostic factors were associated with LC, including hormone sensitivity. The 6-month, 1-year, and 2-year OS rates were 71%, 56%, and 32%; age > 70 years (p = 0.048) and tumor volume > 30 cc (p = 0.03) were associated with inferior rates of OS. Complete or partial pain response was observed in 58% of patients. There were 8 instances (16%) of AREs, 2 of which were vertebral compression fractures (4%).

CONCLUSION

Radiosurgery as a primary or adjuvant treatment modality for prostate cancer spinal metastases confers durable LC and moderate pain relief with minimal toxicity. Further studies are warranted to optimize management in this patient population.

Impact of surgical treatment on patient reported outcome in patients with spinal metastases from prostate cancer

OBJECTIVE

This study aimed to elucidate postoperative outcomes in patients with spinal metastases of prostate cancer, with a focus on patient-oriented assessments.

METHODS

This was a prospective multicenter registry study involving 35 centers. A total of 413 patients enrolled in the Japanese Association for Spine Surgery and Oncology Multicenter Prospective Study of Surgery for Metastatic Spinal Tumors were evaluated for inclusion. The eligible patients were followed for at least 1 year after surgery. The Frankel Classification, Eastern Cooperative Oncology Group Performance Status, visual analog scale for pain, face scale, Barthel Index, vitality index, indications for oral pain medication, and the EQ-5D-5L questionnaire were used for evaluating functional status, activities of daily living, and patient motivation.

RESULTS

Of the 413 eligible patients, 41 with primary prostate cancer were included in the study. The patient-oriented assessments indicated that the patients experienced postoperative improvements in quality of life and motivation in most items, with the improvements extending for up to 6 months. More than half of the patients with Frankel classifications B or C showed improved neurological function at 1 month after surgery, and most patients presented maintained or improved their classification at 6 months.

CONCLUSION

Surgical intervention for spinal metastases of prostate cancer significantly improved neurological function, quality of life, and motivation of the patients. Consequently, our results support the validity of surgical intervention for improving the neurological function and overall well-being of patients with spinal metastases of prostate cancer.

Does the Presence of Missing Data Affect the Performance of the SORG Machine-learning Algorithm for Patients With Spinal Metastasis? Development of an Internet Application Algorithm

BACKGROUND

The Skeletal Oncology Research Group machine-learning algorithm (SORG-MLA) was developed to predict the survival of patients with spinal metastasis. The algorithm was successfully tested in five international institutions using 1101 patients from different continents. The incorporation of 18 prognostic factors strengthens its predictive ability but limits its clinical utility because some prognostic factors might not be clinically available when a clinician wishes to make a prediction.

QUESTIONS/PURPOSES

We performed this study to (1) evaluate the SORG-MLA's performance with data and (2) develop an internet-based application to impute the missing data.

METHODS

A total of 2768 patients were included in this study. The data of 617 patients who were treated surgically were intentionally erased, and the data of the other 2151 patients who were treated with radiotherapy and medical treatment were used to impute the artificially missing data. Compared with those who were treated nonsurgically, patients undergoing surgery were younger (median 59 years [IQR 51 to 67 years] versus median 62 years [IQR 53 to 71 years]) and had a higher proportion of patients with at least three spinal metastatic levels (77% [474 of 617] versus 72% [1547 of 2151]), more neurologic deficit (normal American Spinal Injury Association [E] 68% [301 of 443] versus 79% [1227 of 1561]), higher BMI (23 kg/m 2 [IQR 20 to 25 kg/m 2 ] versus 22 kg/m 2 [IQR 20 to 25 kg/m 2 ]), higher platelet count (240 × 10 3 /µL [IQR 173 to 327 × 10 3 /µL] versus 227 × 10 3 /µL [IQR 165 to 302 × 10 3 /µL], higher lymphocyte count (15 × 10 3 /µL [IQR 9 to 21× 10 3 /µL] versus 14 × 10 3 /µL [IQR 8 to 21 × 10 3 /µL]), lower serum creatinine level (0.7 mg/dL [IQR 0.6 to 0.9 mg/dL] versus 0.8 mg/dL [IQR 0.6 to 1.0 mg/dL]), less previous systemic therapy (19% [115 of 617] versus 24% [526 of 2151]), fewer Charlson comorbidities other than cancer (28% [170 of 617] versus 36% [770 of 2151]), and longer median survival. The two patient groups did not differ in other regards. These findings aligned with our institutional philosophy of selecting patients for surgical intervention based on their level of favorable prognostic factors such as BMI or lymphocyte counts and lower levels of unfavorable prognostic factors such as white blood cell counts or serum creatinine level, as well as the degree of spinal instability and severity of neurologic deficits. This approach aims to identify patients with better survival outcomes and prioritize their surgical intervention accordingly. Seven factors (serum albumin and alkaline phosphatase levels, international normalized ratio, lymphocyte and neutrophil counts, and the presence of visceral or brain metastases) were considered possible missing items based on five previous validation studies and clinical experience. Artificially missing data were imputed using the missForest imputation technique, which was previously applied and successfully tested to fit the SORG-MLA in validation studies. Discrimination, calibration, overall performance, and decision curve analysis were applied to evaluate the SORG-MLA's performance. The discrimination ability was measured with an area under the receiver operating characteristic curve. It ranges from 0.5 to 1.0, with 0.5 indicating the worst discrimination and 1.0 indicating perfect discrimination. An area under the curve of 0.7 is considered clinically acceptable discrimination. Calibration refers to the agreement between the predicted outcomes and actual outcomes. An ideal calibration model will yield predicted survival rates that are congruent with the observed survival rates. The Brier score measures the squared difference between the actual outcome and predicted probability, which captures calibration and discrimination ability simultaneously. A Brier score of 0 indicates perfect prediction, whereas a Brier score of 1 indicates the poorest prediction. A decision curve analysis was performed for the 6-week, 90-day, and 1-year prediction models to evaluate their net benefit across different threshold probabilities. Using the results from our analysis, we developed an internet-based application that facilitates real-time data imputation for clinical decision-making at the point of care. This tool allows healthcare professionals to efficiently and effectively address missing data, ensuring that patient care remains optimal at all times.

RESULTS

Generally, the SORG-MLA demonstrated good discriminatory ability, with areas under the curve greater than 0.7 in most cases, and good overall performance, with up to 25% improvement in Brier scores in the presence of one to three missing items. The only exceptions were albumin level and lymphocyte count, because the SORG-MLA's performance was reduced when these two items were missing, indicating that the SORG-MLA might be unreliable without these values. The model tended to underestimate the patient survival rate. As the number of missing items increased, the model's discriminatory ability was progressively impaired, and a marked underestimation of patient survival rates was observed. Specifically, when three items were missing, the number of actual survivors was up to 1.3 times greater than the number of expected survivors, while only 10% discrepancy was observed when only one item was missing. When either two or three items were omitted, the decision curves exhibited substantial overlap, indicating a lack of consistent disparities in performance. This finding suggests that the SORG-MLA consistently generates accurate predictions, regardless of the two or three items that are omitted. We developed an internet application ( https://sorg-spine-mets-missing-data-imputation.azurewebsites.net/ ) that allows the use of SORG-MLA with up to three missing items.

CONCLUSION

The SORG-MLA generally performed well in the presence of one to three missing items, except for serum albumin level and lymphocyte count (which are essential for adequate predictions, even using our modified version of the SORG-MLA). We recommend that future studies should develop prediction models that allow for their use when there are missing data, or provide a means to impute those missing data, because some data are not available at the time a clinical decision must be made.

CLINICAL RELEVANCE

The results suggested the algorithm could be helpful when a radiologic evaluation owing to a lengthy waiting period cannot be performed in time, especially in situations when an early operation could be beneficial. It could help orthopaedic surgeons to decide whether to intervene palliatively or extensively, even when the surgical indication is clear.

Risk Factors for Radiotherapy Failure in the Treatment of Spinal Metastases

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To build a predictive model for risk factors for failure of radiation therapy, hypothesizing a higher SINS would correlate with failure.

METHODS

Patients with spinal metastasis being treated with radiation at a tertiary care academic center between September 2014 and October 2018 were identified. The primary outcome measure was radiation therapy failure as defined by persistent pain, need for re-irradiation, or surgical intervention. Risk factors were primary tumor type, Karnofsky and ECOG scores, time to treatment, biologically effective dose (BED) calculations using α/β ratio = 10, and radiation modality. A logistic regression was used to construct a prediction model for radiation therapy failure.

RESULTS

One hundred and seventy patients were included. Median follow up was 91.5 days. Forty-three patients failed radiation therapy. Of those patients, 10 required repeat radiation and 7 underwent surgery. Thirty-six patients reported no pain relief, including some that required re-irradiation and surgery. Total SINS score for those who failed reduction therapy was <7 for 27 patients (62.8%), between 7-12 for 14 patients (32.6%), and >12 for 2 patients (4.6%). In the final prediction model, BED (OR .451 for BED > 43 compared to BED ≤ 43; P = .174), Karnofksy score (OR .736 for every 10 unit increase in Karnofksy score; P = .008), and gender (OR 2.147 for male compared to female; P = .053) are associated with risk of radiation failure (AUC .695). A statistically significant association between SINS score and radiation therapy failure was not found.

CONCLUSIONS

In the multivariable model, BED ≤ 43, lower Karnofksy score, and male gender are predictive for radiotherapy failure. SINS score was among the candidate risk factors included in multivariable model building procedure, but it was not selected in the final model.

LEVEL OF EVIDENCE

Prognostic level III.

Surgical Management of the Metastatic Spine Disease: A Review of the Literature and Proposed Algorithm

STUDY DESIGN

Narrative Review. The spine remains the most common site for bony metastasis. It is estimated that up to 70% of cancer patients harbor secondary spinal disease. And up to 10% will develop a clinically significant lesion. The last two decades have seen a substantial leap forward in the advancements of the management of spinal metastases. What once was a death sentence is now a manageable, even potentially treatable condition. With marked advancements in the surgical treatment and post-operative radiotherapy, a standardized approach to stratify and manage these patients is both prudent and now feasible.

OBJECTIVES

This article looks to examine the best available evidence in the stratification and surgical management of patients with spinal metastases. So the aim of this review is to offer a standardized approach for surgical management and surgical planning of patients with spinal metastases.

Outcomes of Patients With Spinal Metastases From Prostate Cancer Treated With Conventionally-Fractionated External Beam Radiation Therapy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate the outcomes of conventionally-fractionated external beam radiation therapy (cEBRT) in the treatment of prostate cancer spinal metastases (PCSM).

METHODS

Patients who received palliative cEBRT for PCSM in our institution between 2008 and 2018 were included. Our outcomes were local progression-free survival (LPFS), overall survival (OS), pain response and toxicities graded using CTCAE version 4.03. Univariable and multivariable Cox proportional hazard regressions were performed to identify predictors for LPFS and OS.

RESULTS

A total of 100 patients with 132 sites of PCSM were identified, with a median follow-up of 54 months. Fourteen-percent of patients underwent surgical intervention before receiving cEBRT. Eighteen spinal segments (13.6%) had local progression, with a median time to local progression of 8 months. The median LPFS and OS were 7.8 and 9.0 months, respectively. The complete and partial pain response rates were 57% and 39% respectively. The incidence of grade ≥3 acute toxicities was 11%. Better ECOG performance status (0 to 1), castration-sensitive disease, spinal surgery and use of novel antiandrogen agent were identified as significant predictors for improved OS on multivariable analysis.

CONCLUSIONS

In our prostate cancer cohort, cEBRT is an effective treatment modality for local palliation of spinal metastases. More aggressive treatment approach should be considered for patients with excellent performance status and castration-sensitive disease in light of their expected longer survival. Further studies are warranted to identify the predictors for radiotherapy response in this population.

Efficacy and Safety of Subfascial Epidural Drainage Protocol After Intraoperative Durotomy in Posterior Thoracic and Lumbar Spine Surgery: Reoperation Prevention and Outcomes Among Drained and Undrained Cohorts

BACKGROUND

Persistent cerebrospinal fluid (CSF) egress after durotomy in posterior thoracic or lumbar spine surgery may cause devastating complications. Persistent CSF leaks may require reoperation, which confers additional cost and morbidity.

OBJECTIVE

To evaluate the efficacy of our subfascial epidural drainage protocol in the setting of durotomy to prevent reoperation.

METHODS

A retrospective cohort study of drained and undrained cohorts was completed to identify factors associated with reoperation for persistent CSF leak-related symptoms. The efficacy and safety of this 7-day subfascial epidural drainage protocol was assessed by comparing reoperation incidence, perioperative complications, rehabilitation necessity, and readmissions.

RESULTS

In total, 156 patients underwent subfascial epidural drainage, and 14 were not drained. Subfascial drainage for up to 7 days was associated with a significantly lower incidence of reoperation than no drainage (3.3% vs 14%, respectively; P = .03). Perioperative complication incidence was similar between cohorts (12.8% vs 21.4%, respectively; P = .37), and length of stay was unchanged regardless of drainage (median 7 days). Subfascial drainage conferred a nearly 2-fold relative risk reduction in inpatient rehabilitation requirement (RR 0.55) and 3-fold relative risk reduction in 30-day (RR 0.31) and 90-day readmission (RR 0.36). Factors associated with reoperation among drained patients included drainage longer than 7 days, tobacco use, age younger than 50 years, and longer segment operations. Revision spine surgery was associated with reoperation among undrained patients.

CONCLUSION

When followed after durotomy, our subfascial epidural drainage protocol results in fewer reoperations than in an undrained cohort without prohibitive cost and no added morbidity.

Systemic considerations for the surgical treatment of spinal metastatic disease: a scoping literature review

Systemic assessment is a pillar in the neurological, oncological, mechanical, and systemic (NOMS) decision-making framework for the treatment of patients with spinal metastatic disease. Despite this importance, emerging evidence relating systemic considerations to clinical outcomes following surgery for spinal metastatic disease has not been comprehensively summarised. We aimed to conduct a scoping literature review of this broad topic. We searched MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and CINAHL databases from Jan 1, 2000, to July 31, 2021. 61 articles were included, accounting for a total of 22 335 patients. Preoperative systemic variables negatively associated with postoperative clinical outcomes included demographics (eg, older age [>60 years], Black race, male sex, low or elevated body-mass index, and smoking status), medical comorbidities (eg, cardiac, pulmonary, hepatic, renal, endocrine, vascular, and rheumatological), biochemical abnormalities (eg, hypoalbuminaemia, atypical blood cell counts, and elevated C-reactive protein concentration), low muscle mass, generalised motor weakness (American Spinal Cord Injury Association Impairment Scale grade and Frankel grade) and poor ambulation, reduced performance status, and systemic disease burden. This is the first comprehensive scoping review to broadly summarise emerging evidence relevant to the systemic assessment component of the widely used NOMS framework for spinal metastatic disease decision making. Medical, surgical, and radiation oncologists can consider these findings when prognosticating spinal metastatic disease-related surgical outcomes on the basis of patients' systemic condition. These factors might inform a shared decision-making approach with patients and their families.

A Novel Nomogram for Survival Prediction of Patients with Spinal Metastasis From Prostate Cancer

STUDY DESIGN

A retrospective study of 84 patients with spinal metastasis from prostate cancer (SMPCa) was performed.

OBJECTIVE

The aim of this study was to predict the survival of patients with SMPCa by establishing an effective prognostic nomogram model, associating with the affecting factors and compare its efficacy with the existing scoring models.

SUMMARY OF BACKGROUND DATA

Prostate cancer (PCa) is the second most frequently malignant cancer causing death in men, and the spine is the most common site of bone metastatic burden. The aim of this study was to establish a prognostic nomogram for survival prediction of patients with SMPCa, explore associated factors, and compare the effectiveness of the new nomogram prediction model with the existing scoring systems.

METHODS

Included in this study were 84 SMPCa patients who were admitted in our spinal tumor center between 2006 and 2018. Their clinical data were retrospectively analyzed by univariate and multivariate analyses to identify independent variables that enabled to predict prognosis. A nomogram, named Changzheng Nomogram for Survival Prediction (CNSP), was established on the basis of preoperative independent variables, and then subjected to bootstrap re-samples for internal validation. The predictive accuracy and discriminative ability were measured by concordance index (C-index). Receiver-operating characteristic (ROC) analysis with the corresponding area under the ROC was used to estimate the prediction efficacy of CNSP and compare it with the four existing prognostic models Tomita, Tokuhashi, Bauer, and Crnalic.

RESULTS

A total of seven independent variables including Gleason score (P = 0.001), hormone refractory (P < 0.001), visceral metastasis (P < 0.001), lymphocyte to monocyte ratio (P = 0.009), prostate-specific antigen (P = 0.018), fPSA/tPSA (P = 0.029), Karnofsky Performance Status (P = 0.039) were identified after accurate analysis, and then entered the nomogram with the C-index of 0.87 (95% confidence interval, 0.84-0.90). The calibration curves for probability of 12-, 24-, and 36-month overall survival (OS) showed good consistency between the predictive risk and the actual risk. Compared with the previous prognostic models, the CNSP model was significantly more effective than the four existing prognostic models in predicting OS of the SMPCa patients (p < 0.05).

CONCLUSION

The overall performance of the CNSP model was satisfactory and could be used to estimate the survival outcome of individual patients more precisely and thus help clinicians design more specific and individualized therapeutic regimens.Level of Evidence: 4.

Spine metastasis in patients with prostate cancer: Survival prognosis assessment

BACKGROUND

Patients presenting spine metastasis (SpM) from prostate cancer (PC) form a heterogeneous population, through this study, we aimed to clarify and update their prognostic assessment.

METHODS

The patient data used in this study was obtained from a French national multicenter database of patients treated for PC with SpM between 2014 and 2017. A total of 72 patients and 365 SpM cases were diagnosed.

RESULTS

The median overall survival time for all patients following the event of SpM was 28.8 months. First, we identified three significant survival prognostic factors of PC patients with SpM: good Eastern Cooperative Oncology Group/World Health Organization personnel status (Status 0 hazard ratio [HR]: 0.031, 95% confidence interval [CI]: 0.008-0.127; p < .0001) or (Status 1 HR: 0.163, 95% CI: 0.068-0.393; p < .0001) and SpM radiotherapy (HR: 2.923, 95% CI: 1.059-8.069; p < .0001). Secondly, the presence of osteolytic lesions of the spine (vs. osteoblastic) was found to represent an independent prognosis factor for longer survival [HR: 0.424, 95% CI: 0.216-0.830; p = .01]. Other factors including the number of SpM, surgery, extraspinal metastasis, synchrone metastasis, metastasis-free survival, and SpM recurrence were not identified as being prognostically relevant to the survival of patients with PC.

CONCLUSION

Survival and our ability to estimate it in patients presenting PC with SpM have improved significantly. Therefore, we advocate the relevance of updating SpM prognostic scoring algorithms by incorporating data regarding the timeline of PC as well as the presence of osteolytic SpM to conceive treatments that are adapted to each patient.

Clinical outcome of surgical management for symptomatic metastatic spinal cord compression from prostate cancer

BACKGROUND

Metastatic spinal cord compression (MSCC) from prostate cancer (PC) influences not only patients' prognosis but also their quality of life. However, little is known about the clinical outcome of surgery for MSCC from PC. We evaluated both the oncological and functional outcomes of decompression and reconstruction surgery for patients with symptomatic MSCC from PC.

METHODS

We assessed 19 patients who underwent decompression and reconstruction surgery for symptomatic MSCC from PC. Of these 19 patients, 8 had metastatic hormone-naïve PC (mHNPC) and 11 had metastatic castration-resistant PC (mCRPC).

RESULTS

The median age of the patients with mHNPC and mCRPC was 72 and 65 years, respectively. The median prostate-specific antigen level at the time of diagnosis of MSCC in patients with mHNPC and mCRPC was 910 and 67 ng/mL, respectively. Although two of eight patients (25.0%) with mHNPC were ambulatory preoperatively, six patients (75.0%) were ambulatory postoperatively. Among 11 patients with mCRPC, only 3 (27.3%) were ambulatory preoperatively, while 6 (54.5%) were ambulatory postoperatively. The median postoperative overall survival among patients with mHNPC and mCRPC were not reached and 8 months, respectively.

CONCLUSIONS

Decompression and reconstruction surgery for symptomatic MSCC from PC might contribute to a favorable functional outcome among men with mHNPC and mCRPC. However, its role in improving the oncological outcome remains unclear. The treatment strategy should be chosen by shared decision-making among patients, urologists, radiation oncologists, and orthopedic surgeons.

Prognostic factors for overall survival in patients with spinal metastasis secondary to prostate cancer: a systematic review and meta-analysis

Background

To guide the selection of treatments for spinal metastases, the expected survival time is one of the most important determinants. Few scoring systems are fully applicable for spinal metastasis secondary to prostate cancer (PCa). This study aimed to identify the independent factors to predict the overall survival (OS) of patients with spinal metastases from PCa.

Methods

The PubMed, Embase and CENTRAL were retrieved by two reviewers independently, to identify studies analyzed the prognostic effect of different factors in spinal metastasis from PCa. A systematic review and quantitative meta-analysis was conducted with hazard ratio (HR) and 95% confidence interval (95%CI) as the effect size.

Results

A total of 12 retrospective cohort studies (1566 patients) were eligible for qualitative synthesis and 10 for quantitative meta-analyses. The OS was significantly influenced by performance status, visceral metastasis, ambulatory status and time from PCa diagnosis in more than half of the available studies. The meta-analyses demonstrated that OS was significantly influenced by visceral metastasis (HR = 2.24, 95%CI:1.53–3.27, p < 0.001), pre-treatment ambulatory status (HR = 2.64, 95%CI:1.82–3.83, p < 0.001), KPS (HR = 4.45, 95%CI:2.01–9.85, p < 0.001), ECOG (HR = 2.96, 95%CI:2.02–4.35, p < 0.001), extraspinal bone metastasis (HR = 2.04, 95%CI:1.13–3.68, p = 0.018), time developing motor deficit (HR = 1.57, 95%CI:1.30–1.88, p < 0.001) and time from PCa diagnosis (HR = 1.37, 95%CI:1.17–1.59, p < 0.001).

Conclusions

Visceral metastasis, ambulatory status, extraspinal bone metastasis, performance status, time developing motor deficit and time interval from primary tumor diagnosis were significantly associated with the OS for spinal metastasis from PCa. When selecting the treatment modality, clinicians should fully consider the patients’ systematic status based on all potential prognostic factors.

Level of evidence

I Meta-analysis.

Surgical Decompression of High-Grade Spinal Cord Compression from Hormone Refractory Metastatic Prostate Cancer

BACKGROUND

Spine and nonspine skeletal metastases occur in more than 80% of patients with prostate cancer.

OBJECTIVE

To examine the characteristics of the patient population undergoing surgery for the treatment of prostate cancer metastatic to the spine.

METHODS

A retrospective chart review was performed on all patients treated at our institution from June 1993 to August 2014 for surgical management of metastatic spine disease from prostate cancer.

RESULTS

During the study period, 139 patients with 157 surgical lesions underwent surgery for metastatic spine disease. Decompression for high-grade epidural spinal cord compression was required for 126 patients with 143 lesions. Preoperatively, 69% had a motor deficit and 21% were nonambulatory, with 32% due to motor weakness. At surgery, 87% of patients had hormone-refractory prostate cancer (HRPC) and 61% failed prior radiation. Median overall survival for HRPC patients was 6.6 mo (95% confidence interval [CI]: 5.6-8.6) while the median overall survival for hormone-sensitive patients was 16.3 mo (95% CI: 4.0-26.6).

CONCLUSION

The majority of patients undergoing surgery for prostate cancer metastases to the spine were refractory to hormone therapy, indicating that patients with hormone-sensitive prostate cancer are unlikely to develop symptomatic spinal cord compression or spinal instability. A significant number of HRPC patients presented with neurological deficits attributable to spinal cord compression. Vigilant monitoring for the development of signs and symptoms of epidural spinal cord compression and spinal instability in hormone-refractory patients is recommended. Surgical decision making may be affected by the much shorter postoperative survival for HRPC patients as compared to patients with hormone-sensitive cancer.

Cerebrospinal fluid leaks after spine tumor resection: avoidance, recognition and management

Post-operative CSF leaks are a known complication of spine surgery in general, and patients undergoing surgical intervention for spinal tumors may be particularly predisposed due to the presence of intradural tumor and a number of other factors. Post-operative CSF leaks increase morbidity, lengthen hospital stays, prolong immobilization and subject patients to a number of associated complications. Intraoperative identification of unintended durotomies and effective primary repair of dural defects is an important first step in the prevention of post-operative CSF leaks, but in patients who develop post-operative pseudomeningoceles, durocutaneous fistulae or other CSF-leak-related sequelae, early recognition and secondary intervention are paramount to preventing further CSF-leak-related complications and achieving the best patient outcomes possible. In this article, the incidence, risk factors and complications of CSF leaks after spine tumor surgery are reviewed, with an emphasis on avoidance of post-operative CSF leaks, early post-operative identification and effective secondary intervention.

Prognostic effect of factors involved in revised Tokuhashi score system for patients with spinal metastases: a systematic review and Meta-analysis

Background

Cancer patients’ survival time has obviously improved, with the development of systemic treatment techniques. However, the probability of metastases to the vertebrae has also been increased which makes some adverse effects on patients’ quality of life. The prediction of survival plays a key role in choosing therapeutic modality, and Tokuhashi Score was established as one of the most commonly used predictive systems for spinal metastases. Thus, this study was conducted to identify the prognostic effect of factors involved in revised Tokuhashi Score (RTS).

Methods

Two investigators independently retrieved relevant literature on platforms of PubMed, Embase and Cochrane Library. We identified eligible studies through title/abstract and full-text perusing. Data was extracted including general information of studies, participants’ characteristics, therapeutic modality, overall survival and prognostic effect of factors. Hazard ratio (HR) for each factor was synthesized if available through fixed- or random-effect models as appropriate.

Results

A total of 63 eligible studies with 10,411 participants were identified. Overall, cases with thyroid cancer had the highest survival rate, while the ones with non-small cell lung cancer and hepatocellular carcinoma lived for the shorted survival time. Performance status, bone metastasis, number of involved vertebrae, visceral metastasis, primary tumor and neurological status were regarded as significant predictors in 71.4, 40.0, 18.2, 63.4, 73.1 and 44.7% of the involved studies respectively. Thirty-eight articles were included in meta-analysis, and prognostic effects of five factors (apart from primary tumor) were analyzed. Factors were all proved to be significant except comparisons between KPS (Karnofsky Performance Status) 10–40 VS. 50–70 and single VS. multiple spinal metastases.

Conclusion

All factors of RTS were significant on prognosis predicting and should be considered when choosing therapeutic modality for spinal metastases. What’s more, we believe that more accurate prognosis may be obtained after removal of the cut-offs for KPS 10–40 VS. 50–70 and single VS. multiple involved vertebrae.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5139-2) contains supplementary material, which is available to authorized users.

Classification and scoring systems for metastatic spine tumors: a literature review

Introduction

Accurate evaluation of metastasis and life prognosis is essential for selecting a suitable therapeutic strategy for metastatic spine tumors owing to limitations in treatment options. For this purpose, various classification, evaluation, and scoring systems have been developed.

Methods

Classification, evaluation, and scoring systems for metastatic spine tumors reported to date were identified by performing a literature search on PubMed. We reviewed the most cited classifications and scorings before 2009, and all classifications and scorings reported after 2010 from the search results.

Results

Six classifications and 23 scorings were reviewed. The classification/evaluation methods are divided into 1) anatomical classification/evaluation methods, 2) evaluation methods for neurological symptoms/instability, and 3) scoring systems for predicting life expectancy. The first 2 were useful for the planning and evaluation of surgical indications. Scoring systems for life prognosis also permitted rough prediction of the outcomes and were useful for the selection of a suitable treatment. However, variation of the patient background, diversity of adopted prognostic factors, and the absence of scoring systems that could predict the outcome with an accuracy of 90% or higher introduced some limitations.

Conclusion

The identified classification, evaluation, and scoring systems have been generally useful for treatment strategies. However, we emphasize the necessity of multidisciplinary development and revision of classification and evaluation methods to adapt to the prolongation of survival associated with increased diversity and improvement of treatment options.

Hospital-acquired conditions: predictors and implications for outcomes following spine tumor resection

OBJECTIVE

Hospital-acquired conditions (HACs) significantly compromise patient safety, and have been identified by the Centers for Medicare and Medicaid Services as events that will be associated with penalties for surgeons. The mitigation of HACs must be an important consideration during the postoperative management of patients undergoing spine tumor resection. The purpose of this study was to identify the risk factors for HACs and to characterize the relationship between HACs and other postoperative adverse events following spine tumor resection.

METHODS

The 2008–2014 American College of Surgeons’ National Surgical Quality Improvement Program database was used to identify adult patients undergoing the resection of intramedullary, intradural extramedullary, and extradural spine lesions via current procedural terminology and ICD-9 codes. Demographic, comorbidity, and operative variables were evaluated via bivariate statistics before being incorporated into a multivariable logistic regression model to identify the independent risk factors for HACs. Associations between HACs and other postoperative events, including death, readmission, prolonged length of stay, and various complications were determined through multivariable analysis while controlling for other significant variables. The c-statistic was computed to evaluate the predictive capacity of the regression models.

RESULTS

Of the 2170 patients included in the study, 195 (9.0%) developed an HAC. Only 2 perioperative variables, functional dependency and high body mass index, were risk factors for developing HACs (area under the curve = 0.654). Hospital-acquired conditions were independent predictors of all examined outcomes and complications, including death (OR 2.26, 95% CI 1.24–4.11, p = 0.007), prolonged length of stay (OR 2.74, 95% CI 1.98–3.80, p < 0.001), and readmission (OR 9.16, 95% CI 6.27–13.37, p < 0.001). The areas under the curve for these models ranged from 0.750 to 0.917.

CONCLUSIONS

The comorbidities assessed in this study were not strongly predictive of HACs. Other variables, including hospital-associated factors, may play a role in the development of these conditions. The presence of an HAC was found to be an independent risk factor for a variety of adverse events. These findings highlight the need for continued development of evidence-based protocols designed to reduce the incidence and severity of HACs.

Utility of the Surgical Apgar Score for Patients Who Undergo Surgery for Spinal Metastasis

STUDY DESIGN

Retrospective review of patients who underwent surgery for spinal metastasis between 2005 and 2011.

OBJECTIVE

To assess the utility of the surgical Apgar score (SAS) in patients who underwent surgery for spinal metastasis.

SUMMARY OF BACKGROUND DATA

Surgery for spinal metastasis can be associated with relatively high morbidity and mortality. Consequently, identifying patients at risk for major postoperative complications is important. Several studies have validated SAS for predicting 30-day complication risk.

METHODS

SASs were calculated and patients stratified into 5 groups: scores 0-2, 3-4, 5-6, 7-8, 9-10 points. Multivariate logistic regression assessed whether SAS was an independent predictor of major complication 30 days after surgery. Multivariate analysis of covariance assessed whether SAS was independently associated with length of stay.

RESULTS

Ninety-seven patients with a variety of metastatic tumors were analyzed. There was no obvious trend in complication rates, or significant association between SAS and complication rate (P=0.413). Complication rates were 25.0% for SASs 0-2, 33.3% for 3-4, 18.4% for 5-6, 10.0% for 7-8, and 33.3% for 9-10 points. On multivariate analysis, SAS was not independently associated with complications; age above 65 years (odds ratio 4.19; 95% confidence interval, 1.31-52.27; P=0.028) and preoperative Karnofsky Performance Score of 10-40 (odds ratio 9.13; 95% confidence interval, 1.42-58.63; P=0.020) were associated with higher odds of complication. SASs 0-2 were an independent predictor of longer hospital stay (P=0.004).

CONCLUSIONS

Our findings suggest that SAS is not a significant predictor of major perioperative complications after spinal metastasis surgery; preoperative functional status and age are stronger predictors. The need continues for a preoperative scoring system to reliably predict risk for perioperative complications after spinal metastasis surgery.

Systematic Review of the Outcomes of Surgical Treatment of Prostate Metastases to the Spine

STUDY DESIGN

Systematic review.

OBJECTIVE

Surgical decompression and reconstruction of symptomatic spinal metastases has improved the quality of life in cancer patients. However, most data has been collected on cohorts of patients with mixed tumor histopathology. We systematically reviewed the literature for prognostic factors specific to the surgical treatment of prostate metastases to the spine.

METHODS

A systemic review of the literature was conducted to answer the following questions: Question 1. Describe the survival and functional outcomes of surgery or vertebral augmentation for prostate metastases to the spine. Question 2. Determine whether overall tumor burden, Gleason score, preoperative functional markers, and hormonal naivety favor operative intervention. Question 3. Establish whether clinical outcomes vary with the evolution of operative techniques.

RESULTS

A total of 16 studies met the preset inclusion criteria. All included studies were retrospective series with a level of evidence of IV. Included studies consistently showed a large effect of hormone-naivety on overall survival. Additionally, studies consistently demonstrated an improvement in motor function and the ability to maintain/regain ambulation following surgery resulting in moderate strength of recommendation. All other parameters were of insufficient or low strength.

CONCLUSIONS

There is a dearth of literature regarding the surgical treatment of prostate metastases to the spine, which represents an opportunity for future research. Based on existing evidence, it appears that the surgical treatment of prostate metastases to the spine has consistently favorable results. While no consistent preoperative indicators favor nonoperative treatment, hormone-naivety and high Karnofsky performance scores have positive effects on survival and clinical outcomes.

Contemporary spinal oncology treatment paradigms and outcomes for metastatic tumors to the spine: A systematic review of breast, prostate, renal, and lung metastases

Metastatic spinal disease most frequently arises from carcinomas of the breast, lung, prostate, and kidney. Management of spinal metastases (SpM) is controversial in the literature. Recent studies advocate more aggressive surgical resection than older studies which called for radiation therapy alone, challenging previously held beliefs in conservative therapy. A literature search of the PubMed database was performed for spinal oncology outcome studies published in the English language between 2006 and 2016. Data concerning study characteristics, patient demographics, tumor origin and spinal location, treatment paradigm, and median survival were collected. The search retrieved 220 articles, 24 of which were eligible to be included. There were overall 3457 patients. Nine studies of 1723 patients discussed parameters affecting median survival time with comparison of different primary cancers. All studies found that primary cancer significantly predicted survival. Median survival time was highest for primary breast and renal cancers and lowest for prostate and lung cancers, respectively. Multiple spinal metastases, a cervical location of metastasis, and pathologic fracture each had no significant influence on survival. Survival in metastatic spinal tumors is largely driven by primary tumor type, and this should influence palliative management decisions. Surgery has been shown to greatly increase quality of life in patients who can tolerate the procedure, even in those previously treated with radiotherapy. Surgery for SpM can be used as first-line therapy for preservation of function and symptom relief. Future studies of management of SpM are warranted and primary tumor diagnosis should be studied to determine contribution to survival.

Symptomatic spinal metastasis: A systematic literature review of the preoperative prognostic factors for survival, neurological, functional and quality of life in surgically treated patients and methodological recommendations for prognostic studies

Purpose

While several clinical prediction rules (CPRs) of survival exist for patients with symptomatic spinal metastasis (SSM), these have variable prognostic ability and there is no recognized CPR for health related quality of life (HRQoL). We undertook a critical appraisal of the literature to identify key preoperative prognostic factors of clinical outcomes in patients with SSM who were treated surgically. The results of this study could be used to modify existing or develop new CPRs.

Methods

Seven electronic databases were searched (1990–2015), without language restriction, to identify studies that performed multivariate analysis of preoperative predictors of survival, neurological, functional and HRQoL outcomes in surgical patients with SSM. Individual studies were assessed for class of evidence. The strength of the overall body of evidence was evaluated using GRADE for each predictor.

Results

Among 4,818 unique citations, 17 were included; all were in English, rated Class III and focused on survival, revealing a total of 46 predictors. The strength of the overall body of evidence was very low for 39 and low for 7 predictors. Due to considerable heterogeneity in patient samples and prognostic factors investigated as well as several methodological issues, our results had a moderately high risk of bias and were difficult to interpret.

Conclusions

The quality of evidence for predictors of survival was, at best, low. We failed to identify studies that evaluated preoperative prognostic factors for neurological, functional, or HRQoL outcomes in surgical patients with SSM. We formulated methodological recommendations for prognostic studies to promote acquiring high-quality evidence to better estimate predictor effect sizes to improve patient education, surgical decision-making and development of CPRs.

Thirty-day readmission and reoperation after surgery for spinal tumors: a National Surgical Quality Improvement Program analysis

OBJECTIVE

The goal of this study was to use a large national registry to evaluate the 30-day cumulative incidence and predictors of adverse events, readmissions, and reoperations after surgery for primary and secondary spinal tumors.

METHODS

Data from adult patients who underwent surgery for spinal tumors (2011–2014) were extracted from the prospective National Surgical Quality Improvement Program (NSQIP) registry. Multivariable logistic regression was used to evaluate predictors of reoperation, readmission, and major complications (death, neurological, cardiopulmonary, venous thromboembolism [VTE], surgical site infection [SSI], and sepsis). Variables screened included patient age, sex, tumor location, American Society of Anesthesiologists (ASA) physical classification, preoperative functional status, comorbidities, preoperative laboratory values, case urgency, and operative time. Additional variables that were evaluated when analyzing readmission included complications during the surgical hospitalization, hospital length of stay (LOS), and discharge disposition.

RESULTS

Among the 2207 patients evaluated, 51.4% had extradural tumors, 36.4% had intradural extramedullary tumors, and 12.3% had intramedullary tumors. By spinal level, 20.7% were cervical lesions, 47.4% were thoracic lesions, 29.1% were lumbar lesions, and 2.8% were sacral lesions. Readmission occurred in 10.2% of patients at a median of 18 days (interquartile range [IQR] 12–23 days); the most common reasons for readmission were SSIs (23.7%), systemic infections (17.8%), VTE (12.7%), and CNS complications (11.9%). Predictors of readmission were comorbidities (dyspnea, hypertension, and anemia), disseminated cancer, preoperative steroid use, and an extended hospitalization. Reoperation occurred in 5.3% of patients at a median of 13 days (IQR 8–20 days) postoperatively and was associated with preoperative steroid use and ASA Class 4–5 designation. Major complications occurred in 14.4% of patients: the most common complications and their median time to occurrence were VTE (4.5%) at 9 days (IQR 4–19 days) postoperatively, SSIs (3.6%) at 18 days (IQR 14–25 days), and sepsis (2.9%) at 13 days (IQR 7–21 days). Predictors of major complications included dependent functional status, emergency case status, male sex, comorbidities (dyspnea, bleeding disorders, preoperative systemic inflammatory response syndrome, preoperative leukocytosis), and ASA Class 3–5 designation (p < 0.05). The median hospital LOS was 5 days (IQR 3–9 days), the 30-day mortality rate was 3.3%, and the median time to death was 20 days (IQR 12.5–26 days).

CONCLUSIONS

In this NSQIP analysis, 10.2% of patients undergoing surgery for spinal tumors were readmitted within 30 days, 5.3% underwent a reoperation, and 14.4% experienced a major complication. The most common complications were SSIs, systemic infections, and VTE, which often occurred late (after discharge from the surgical hospitalization). Patients were primarily readmitted for new complications that developed following discharge rather than exacerbation of complications from the surgical hospital stay. The strongest predictors of adverse events were comorbidities, preoperative steroid use, and higher ASA classification. These models can be used by surgeons to risk-stratify patients preoperatively and identify those who may benefit from increased surveillance following hospital discharge.

Factors associated with improved survival following surgical treatment for metastatic prostate cancer in the spine: retrospective analysis of 29 patients in a single center

Background

Prostate cancer (PCa) is very common and frequently metastasizes to the spine. However, PCa spinal metastases were rarely reported in the literature. In this study, the outcome of therapies and prognostic factors affecting surgical outcomes for patients with PCa spinal metastases are discussed to select the best candidates for aggressive surgical resection.

Methods

All patients affected by the spinal metastatic PCa surgically treated at our spine tumor center were reviewed. Overall survival was analyzed from the time of spinal surgery. A univariate survival analysis and a multivariate Cox proportional hazard analysis to identify independent prognostic factors were carried out. The survival rate was estimated by the Kaplan-Meier method, and differences were analyzed by the log-rank test. Factors with P values of 0.1 or less were subjected to multivariate analysis for survival rate by multivariate Cox proportional hazard analysis.

Results

A total of 31 consecutive patients were identified. Of these, 29 underwent surgical resection. The median survival time of all patients after their spinal surgery was 44.0 months. Visceral metastases, revised Tokuhashi scores (0–8/9–11/12–15), Tomita scores (7–10/2–6), hormone status, and bisphosphonate treatment were suggested as the potential prognostic factors through univariate analysis. As they were submitted to the multivariate Cox regression model, visceral metastases and Tomita score were found as independent prognostic factors.

Conclusions

Patients without visceral metastases and a Tomita score no more than 6 are favorable prognostic factors for PCa metastases in the mobile spine.

Prognostic Factors Influencing the Outcome of 64 Consecutive Patients Undergoing Surgery for Metastatic Melanoma of the Spine

BACKGROUND

Melanoma metastases to the spine remain a challenge for neurosurgeons.

OBJECTIVE

To identify factors associated with survival in a series of patients who underwent spinal surgery for metastatic melanoma.

METHODS

We retrospectively reviewed all patients (n = 64) who received surgical intervention for melanoma metastases to the spine at the University of Texas MD Anderson Cancer Center between July 1993 and March 2012.

RESULTS

No patients were excluded from the study, and vital status data were available for all patients. Median overall survival was 5.7 months (95% confidence interval, 2.7-28.7). On univariate survival analysis, diagnosis of spinal metastasis after prior diagnosis of systemic metastasis, higher total spinal disease burden (including but not exclusive to the operative site), presence of progressive systemic disease at the moment of spine surgery, and postoperative complications were associated with poorer overall survival, whereas the presence of only bone metastasis at the moment of surgery was associated with improved overall survival. On multivariate survival analysis, both progressive systemic disease at the moment of spine surgery and total spinal disease burden of ≥3 vertebral levels were significantly associated with worse overall survival (hazard ratio, 6.00; 95% confidence interval, 3.19-11.28; P < .001; and hazard ratio, 2.87; 95% confidence interval, 1.62-5.07; P < .001, respectively).

CONCLUSION

On multivariate analysis, involvement of ≥3 vertebral bodies and progressive systemic disease were associated with worse overall survival. Consideration of these factors should influence surgical decision making in this patient population.

Indications and Techniques for Spinal Instrumentation in Thoracic Disk Surgery

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To identify the indications, techniques, and outcomes for instrumented fusion during thoracic discectomy.

SUMMARY OF BACKGROUND DATA

Thoracic discectomy may require extensive bone removal to avoid spinal cord manipulation, but the indications and techniques for instrumented fusion during thoracic discectomy remain poorly delineated.

METHODS

The authors identified 220 consecutive patients who underwent thoracic discectomy between 1992 and 2012. Clinical and radiographic variables were compared between patients who underwent instrumented fusion and patients without instrumentation, and among surgical approaches utilized for discectomy.

RESULTS

Patient age for the entire cohort averaged 49±13.01 years, and mean clinical follow-up was 45 months (range, 1-218 mo). Patients underwent 226 thoracic discectomy procedures, including 48 thoracotomy, 136 thoracoscopy, and 42 posterolateral approaches. Seventy-eight patients required instrumented fusion and, compared with patients without instrumentation, were more likely to present with myelopathy (P<0.0001) and harbor giant (P=0.0012), calcified (P=0.019), or transdural (P=0.0004) herniated disks. Surgery with instrumentation resulted in greater blood loss (P<0.0001), longer hospital stay (P<0.0001), and a higher complication rate (22% vs. 9.9%), yet patients in both cohorts had similar rates of symptom resolution postoperatively. Of the patients who underwent thoracic discectomy without instrumentation, 3 (2.1%) developed delayed deformity or instability and required subsequent surgery for fixation and fusion at an average 6.3 months postoperatively (range, 4-8 mo). Patients who underwent instrumented fusion exhibited no nonunions or delayed deformity.

CONCLUSIONS

Thoracic discectomy without fixation is a reasonable clinical option in carefully selected patients, but instrumented fusion is safe and effective in other patients. Indications for fixation and fusion are thus proposed.

Surgical management and clinical outcomes of multiple-level symptomatic herniated thoracic discs

Object

Symptomatic herniated thoracic discs (HTDs) are rare, and patients infrequently require treatment of 2 or more disc levels. The authors assess the surgical management and outcomes of patients with multiple-level symptomatic HTDs.

Methods

A retrospective review of a prospectively maintained database was performed of 220 consecutive patients treated surgically for symptomatic HTDs. Clinical and surgical results were compared between patients with single-level disease and patients with multiple-level disease and also among the different approaches used for surgical decompression.

Results

Between 1992 and 2012, 56 patients (mean age 48 years; 26 male, 30 female) underwent 62 procedures for 130 HTDs. Forty-six patients (82%) had myelopathy, and 36 (64%) had thoracic radiculopathy; 24 patients had both conditions in varying degree. Symptom duration averaged 28 months. The surgical approach was dictated by disc size, consistency, and location. Twenty-three thoracotomy, 26 thoracoscopy, and 13 posterolateral procedures were performed. Five patients required a combination of approaches. Patients underwent 2-level (n = 44), 3-level (n = 7), 4-level (n = 4), or 5-level (n = 1) discectomies. Instrumented fusion was performed in 36 patients (64%). Thirteen patients harbored 19 additional discs, which were deemed asymptomatic/nonoperative.

The mean hospital stay was 6.5 days. Complete disc resection was verified with postoperative imaging in every patient. The procedural complication rate was 23%, and the nature of complications differed based on approach. No patients had surgery-related spinal cord injury or new myelopathy.

At a mean follow-up of 48 months, myelopathy and radiculopathy had resolved or improved at a rate of 85% and 92%, respectively. Using a general linear model, preoperative symptom duration (p = 0.037) and perioperative hospital length of stay (p = 0.004) emerged as negative predictors of myelopathy improvement. Most patients (96%) were satisfied with the surgical results.

Compared with 164 patients who underwent single-level HTD decompression, patients requiring surgery for multiple-level HTDs were more often myelopathic (p = 0.012). Surgery for multiple-level HTDs was more likely to require a thoracotomy approach (p = 0.00055) and instrumented fusion (p < 0.0001) and resulted in greater blood loss (p = 0.0036) and higher complication rates (p = 0.0069). The rates of resolution for myelopathy (p = 0.24) and radiculopathy (p = 1.0), however, were similar between the 2 patient groups.

Conclusions

The management of multiple-level symptomatic HTDs is complex, requiring individualized clinical decision making. The surgical approaches must be selected to minimize manipulation of the compressed thoracic spinal cord, and a patient may require a combination of approaches. Excellent surgical results can be achieved in this unique and challenging patient population.

A rat model of metastatic spinal cord compression using human prostate adenocarcinoma: histopathological and functional analysis

BACKGROUND CONTEXT

Cancer is a major global public health problem responsible for one in every four deaths in the United States. Prostate cancer alone accounts for 29% of all cancers in men and is the sixth leading cause of death in men. It is estimated that up to 30% of patients with cancer will develop metastatic disease, the spine being one of the most frequently affected sites in patients with prostate cancer.

PURPOSE

To study this condition in a preclinical setting, we have created a novel animal model of human metastatic prostate cancer to the spine and have characterized it histologically, functionally, and via bioluminescence imaging.

STUDY DESIGN

Translational science investigation of animal model of human prostate cancer in the spine.

METHODS

Luciferase-positive human prostate tumor cells PC3 (PC3-Luc) were injected in the flank of athymic male rats. PC3-Luc tumor samples were then implanted into the L5 vertebral body of male athymic rats (5 weeks old). Thirty-two rats were randomized into three surgical groups: experimental, control, and sham. Tumor growth was assessed qualitatively and noninvasively via bioluminescence emission, upon luciferin injection. To determine the functional impact of tumor growth in the spine, rats were evaluated for gait abnormalities during gait locomotion using video-assisted gait analysis. Rats were euthanized 22 days after tumor implantation, and spines were subjected to histopathological analyses.

RESULTS

Twenty days after tumor implantation, the tumor-implanted rats showed distinct signs of gait disturbances: dragging tail, right- or left-hind limb uncoordination, and absence of toe clearance during forward limb movement. At 20 days, all rats experienced tumor growth, evidenced by bioluminescent signal. Locomotion parameters negatively affected in tumor-implanted rats included stride length, velocity, and duration. At necropsy, all spines showed evidence of tumor growth, and the histological analysis found spinal cord compression and peritumoral osteoblastic reaction characteristic of bony prostate tumors. None of the rats in the sham or control groups demonstrated any evidence of bioluminescence signal or signs of gait disturbances.

CONCLUSIONS

In this project, we have developed a novel animal model of metastatic spine cancer using human prostate cancer cells. Tumor growth, evaluated via bioluminescence and corroborated by histopathological analyses, affected hind limb locomotion in ways that mimic motor deficits present in humans afflicted with metastatic spine disease. Our model represents a reliable method to evaluate the experimental therapeutic approaches of human tumors of the spine in animals. Gait locomotion and bioluminescence analyses can be used as surrogate noninvasive methods to evaluate tumor growth in this model.

Current paradigms for metastatic spinal disease: an evidence-based review

INTRODUCTION

Management of metastatic spine disease is quite complex. Advances in research have allowed surgeons and physicians to better provide chemotherapeutic agents that have proven more efficacious. Additionally, the advancement of surgical techniques and radiosurgical implementation has altered drastically the treatment paradigm for metastatic spinal disease. Nevertheless, the physician-patient relationship, including extensive discussion with the neurosurgeon, medicine team, oncologists, radiation oncologists, and psychologists, are all critical in the evaluation process and in delivering the best possible care to our patients. The future remains bright for continued improvement in the surgical and nonsurgical management of our patients with metastatic spine disease.

METHODS

We include an evidence-based review of decision making strategies when attempting to determine most efficacious treatment options. Surgical treatments discussed include conventional debulking versus en bloc resection, conventional RT, and radiosurgical techniques, and minimally invasive approaches toward treating metastatic spinal disease.

CONCLUSIONS

Surgical oncology is a diverse field in medicine and has undergone a significant paradigm shift over the past few decades. This shift in both medical and surgical management of patients with primarily metastatic tumors has largely been due to the more complete understanding of tumor biology as well as due to advances in surgical approaches and instrumentation. Furthermore, radiation oncology has seen significant advances with stereotactic radiosurgery and intensity-modulated radiation therapy contributing to a decline in surgical treatment of metastatic spinal disease. We analyze the entire spectrum of treating patients with metastatic spinal disease, from methods of diagnosis to the variety of treatment options available in the published literature.

Hormonal therapy with external radiation therapy for metastatic spinal cord compression from newly diagnosed prostate cancer

BACKGROUND

Although hormonal therapy is effective for treatment of prostate cancer, its effect in the treatment of metastatic spinal cord compression (MSCC) has not been established. The objective of this study was to clarify the efficacy of conservative treatment of MSCC-induced paralysis resulting from prostate cancer for patients without a previous treatment history.

METHODS

We reviewed data from 38 patients with MSCC-induced paralysis from newly diagnosed prostate cancer who presented to our service between 1984 and 2010. Conservative treatment consisted of hormonal therapy with external radiation therapy (ERT). Patient demographic data, treatment details, involved spine MRI images, complications, and the course of neurologic recovery were investigated.

RESULTS

Twenty-five patients were treated conservatively. Mean follow-up period was 36.8 months. Sixteen patients (two with Frankel B, 14 with Frankel C) were unable to walk at initial presentation. After initiating conservative treatment, 75% (12 of 16) of these patients regained the ability to walk within 1 month, 88% (14 in 16) did so within 3 months, and all non-ambulatory patients did so within 6 months. No one had morbid complications. Four patients who did not regain the ability to walk at 1 month were found to have progressed to paraplegia rapidly, and tended to have severe compression as visualized on MRI, with a delay in the start of treatment in comparison with those who did so within 1 month (21.0 vs. 7.8 days).

CONCLUSIONS

Hormonal therapy associated with ERT is an important option for treatment of MSCC resulting from newly diagnosed prostate cancer.

Factors Associated With Improved Outcomes Following Decompressive Surgery for Prostate Cancer Metastatic to the Spine

BACKGROUND:

Metastatic spinal cord compression from prostate cancer is a debilitating disease causing neurological deficits, mechanical instability, and intractable pain. Surgical management may improve quality of life.

OBJECTIVE:

To define postoperative outcomes and explore associations with prolonged survival for patients with metastatic prostate cancer.

METHODS:

Retrospective chart reviews were performed of all patients undergoing spinal surgery for metastatic cancer from June 1, 2002 to August 31, 2011. Patient demographics, surgical details, adjuvant therapies, outcomes, complications, and postoperative survival were reviewed.

RESULTS:

Twenty-seven patients with prostate cancer underwent surgery at a median age of 65 years (range, 46-82 years). After surgery, 93% of patients had preserved or improved neurological status, 56% of nonambulatory patients recovered ambulation, 43% of incontinent patients recovered continence, and 23% experienced complications. Postoperative Frankel grades were significantly improved by at least 1 letter grade at 1 month (P = .03). The median analgesic and steroid usage was significantly lower up to 3 months and 6 months postoperatively, respectively (P = .007, .005). Median survival following surgery was 10.2 months, and patients with castration-resistant prostate cancer had a shorter median survival than those with hormone-naïve disease (9.8 vs 40 months). Better preoperative performance status was an independent predictor of survival (P = .02). Younger age (P = .005) and instrumentation greater than 7 spinal levels (P = .03) were associated with complications.

CONCLUSION:

Spinal surgery for prostate metastases improves neurological function and decreases analgesic requirements. Our findings support surgical intervention for carefully selected patients, and knowledge of preoperative hormone sensitivity and performance status may help with risk stratification.

Four-rod stabilization of severely destabilized lumbar spine caused by metastatic tumor

We report a case of a 67-year-old female with severely destabilized lumbar spine caused by metastatic malignant tumor. The primary lesion was a thyroid follicular adenocarcinoma. Complete destruction of the L3, L4, and L5 vertebrae had resulted in severe instability, which left the patient with severe back pain and bed-ridden. Since the vertebrae were so severely damaged at 3 levels, 4 rods were used to stabilize the spine. Following stabilization, the pain was alleviated and the patient's quality of life improved. We introduce here the 4-rod technique to stabilize the spine over 3 vertebral levels following severe destruction by metastatic tumor.

Early diagnosis and treatment is crucial for neurological recovery after surgery for metastatic spinal cord compression in prostate cancer

BACKGROUND

Spinal cord compression is an oncological and surgical emergency. Delays in referral and diagnosis may influence functional outcome. It is therefore important to identify patients who will regain or maintain the ability to walk after surgery. The aim of the present study was to examine current practice for referral and diagnosis of prostate cancer patients with spinal cord compression and to identify prognostic factors for neurological outcome after surgery.

PATIENTS AND METHODS

The study includes 68 consecutive patients with prostate cancer who underwent surgery due to neurological compromise. Intervals from onset of neurological symptoms to referral, diagnosis, and treatment were analyzed in relation to functional outcome. The prognostic significance of preoperative clinical parameters on gait function one month after surgery was evaluated.

RESULTS

Patients who were referred from local hospitals had longer delay to surgery than those who directly presented to the cancer center (p = 0.004). The rate of diagnosis with MRI increased through the week and peaked on Friday, with few patients being diagnosed during weekends. The ability to walk before surgery, hormone-naive prostate cancer, and/or shorter time from loss of ambulation were associated with more favorable neurological outcome. In patients with hormone-refractory disease who were unable to walk before surgery regaining ambulation was associated with: duration of paresis < 48 hours (p = 0.005), good preoperative performance status (p = 0.04), preoperative PSA serum level < 200 ng/ml (p = 0.03), and surgery with posterior decompression and stabilization (p = 0.03).

CONCLUSION

Early diagnosis and rapid treatment of spinal cord compression in prostate cancer patients is crucial for neurological recovery. Raising awareness of the condition among patients at risk and among physicians is of outmost importance as well as improving local and regional guidelines for treatment.

Independent predictors of complication following surgery for spinal metastasis

PURPOSE

Surgery for spinal metastasis is often associated with significant morbidity. Despite a number of preoperative scoring systems/scales and identified variables that have been reported to predict complication risk, clinical studies that directly evaluate this issue using multivariate analysis are scarce. The goal of our study was to assess independent predictors of complication after surgery for spinal metastasis.

METHODS

We queried electronic medical records to identify a consecutive population of adult patients who underwent surgery for spinal metastasis for the period June 2005 through June 2011. Utilizing multivariate logistic regression, we assessed independent predictors of perioperative and postoperative adverse events.

RESULTS

A total of 106 patients were included in the final analysis. Overall complication rate was 21.7 %. Independent predictors for higher rates of complication were age greater than 40 years [40-65 years had odds ratio (OR) 1.91, 95 % confidence interval (CI) 1.02-16.78 and >65 years had OR 5.17, 95 % CI 1.54-29.81] and metastatic lesions involving three or more contiguous levels of the spine (OR 2.76, 95 % CI 1.09-9.61).

CONCLUSIONS

Patients older than 40 years or patients who have metastatic lesions involving three or more contiguous vertebral levels appear to be at higher risk for complication. Patients older than 65 years have the greatest likelihood of complication.

Predicting survival for surgery of metastatic spinal cord compression in prostate cancer: a new score

STUDY DESIGN

We retrospectively analyzed prognostic factors for survival in patients with prostate cancer operated for metastatic spinal cord compression.

OBJECTIVE

The aim was to obtain a clinical score for prediction of survival after surgery.

SUMMARY OF BACKGROUND DATA

Survival prognosis is important when deciding about treatment of patients with metastatic spinal cord compression. The criteria for identifying patients with prostate cancer who may benefit from surgical treatment are unclear.

METHODS

The study comprised 68 consecutive patients with prostate cancer operated for metastatic spinal cord compression at Umeå University Hospital, Sweden. The indication for surgery was neurological deficit; 53 patients had hormone-refractory prostate cancer and 15 patients had previously untreated, hormone-naïve prostate cancer. In 42 patients, posterior decompression was performed and 26 patients were operated with posterior decompression and stabilization.

RESULTS

A new score for prediction of survival was developed on the basis of the results of survival analyses. The score includes hormone status of prostate cancer, Karnofsky performance status, evidence of visceral metastasis, and preoperative serum prostate-specific antigen (PSA). The total scores ranged from 0 to 6. Three prognostic groups were formulated: group A (n = 32) with scores 0-1; group B (n = 23) with scores 2-4, and group C (n = 12) with scores 5-6. The median overall survival was 3 (0.3-20) months in group A, 16 (1.8-59) months in group B, and more than half (7 of 12) of patients were still alive in group C.

CONCLUSION

We present a new prognostic score for predicting survival of patients with prostate cancer after surgery for metastatic spinal cord compression. The score is easy to apply in clinical practice and may be used as additional support when making decision about treatment.

Independent predictors of survival and the impact of repeat surgery in patients undergoing surgical treatment of spinal metastasis

Object

Surgery for spinal metastasis is considered palliative, and postoperative survival is often less than a year. Recurrence of metastatic lesions is quite common, and it remains unclear whether repeat surgery is effective. In this study, the authors assessed independent predictors for survival at 6 months, 1 year, and 2 years after surgery, and examined whether repeat surgery for recurrence of spinal metastasis influenced survival rates.

Methods

Retrospective review of the electronic medical records was performed to identify a consecutive population of adult patients who underwent surgery for spinal metastasis during the period 2005–2011. Utilizing a Cox proportional hazard regression model, the authors assessed independent predictors and risk factors for survival at 6 months, 1 year, and 2 years after surgery. In addition, the impact of repeat surgery on survival was specifically assessed via multivariable analysis.

Results

A total of 99 patients were included in the final analysis. The overall mean postoperative duration of survival was 9.6 months. In addition to previously identified predictors of survival (preoperative ambulation, Karnofsky Performance Status [KPS], radiotherapy, primary cancer type, presence of extraspinal metastasis, and number of spinal segments with metastasis), pain on presentation and body mass index (BMI) of 25–30 were both independently associated with survival. Patients with recurrence who underwent repeat surgery had longer mean survival times than patients with recurrence who did not undergo repeat surgery (19.6 months vs 12.8 months, respectively). Repeat surgery was also independently associated with higher survival rates on multivariate analysis. Follow-up KPS was significantly higher in patients who underwent repeat surgery as well.

Conclusions

In addition to confirming previously identified predictors of survival following surgery for spinal metastasis, the authors identified BMI and pain on presentation as independent predictors of survival. They also found that repeat surgery may be a viable option in patients with metastatic recurrence and may offer prolonged survival, likely due to improved functionality, mitigating complications associated with immobility.

Spinal cord compression

OPINION STATEMENT

Malignant epidural spinal cord compression (MESCC) remains a common neuro-oncologic emergency with high associated morbidity. Despite widespread availability of MRI, the diagnosis frequently goes unmade until myelopathy supervenes, which is unfortunate because the strongest predictor of neurologic outcome with treatment is the neurologic status when treatment is initiated. Once the diagnosis of MESCC is suspected, patients with neurologic deficits should be started on high-dose corticosteroids (eg, dexamethasone, 10-100 mg intravenously, followed by 16 to 100 mg/d in divided doses). Definitive therapy of MESCC almost always includes radiation therapy and in some cases surgical intervention; factors considered include the patient's performance status and extent of visceral and skeletal disease, spinal stability, the tumor's underlying radiosensitivity, and the degree of spinal cord compression. Patients with spinal instability or radioresistant tumors are likely to have a much better neurologic outcome with tumor resection and spinal stabilization prior to radiation; the same may also pertain to patients with moderately radiosensitive tumors who have good life expectancy in terms of their systemic tumor. Conventional radiation has historically been beneficial after surgery and in patients who are not surgical candidates. Recent studies suggest a role for stereotactic body radiation therapy in patients with spinal metastasis from radioresistant tumors and in patients who have received prior standard radiotherapy, so long as the spinal cord has been decompressed.

Predictive value of Tokuhashi scoring systems in spinal metastases, focusing on various primary tumor groups: evaluation of 448 patients in the Aarhus spinal metastases database

STUDY DESIGN

We conducted a prospective cohort study of 448 patients with spinal metastases from a variety of cancer groups.

OBJECTIVE

To determine the specific predictive value of the Tokuhashi scoring system (T12) and its revised version (T15) in spinal metastases of various primary tumors.

SUMMARY OF BACKGROUND DATA

The life expectancy of patients with spinal metastases is one of the most important factors in selecting the treatment modality. Tokuhashi et al formulated a prognostic scoring system with a total sum of 12 points for preoperative prediction of life expectancy in 1990 and revised it in 2005 to a total sum of 15 points. There is a lack of knowledge about the specific predictive value of those scoring systems in patients with spinal metastases from a variety of cancer groups.

METHODS

We included 448 patients with vertebral metastases who underwent surgical treatment during November 1992 to November 2009 in Aarhus University Hospital NBG. Data were retrieved from Aarhus Metastases Database. Scores based on T12 and T15 were calculated prospectively for each patient. We divided all the patients into different groups dictated by the site of their primary tumor. Predictive value and accuracy rate of the 2 scoring systems were compared in each cancer group.

RESULTS

Both the T12 and T15 scoring systems showed statistically significant predictive value when the 448 patients were analyzed in total (T12, P < 0.0001; T15, P < 0.0001). The accuracy rate was significantly higher in T15 (P < 0.0001) than in T12. The further analyses by primary cancer groups showed that the predictive value of T12 and T15 was primarily determined by the prostate (P = 0.0003) and breast group (P = 0.0385). Only T12 displayed predictive value in the colon group (P = 0.0011). Neither of the scoring systems showed significant predictive value in the lung (P > 0.05), renal (P > 0.05), or miscellaneous primary tumor groups (P > 0.05). The accuracy rate of prognosis in T15 was significantly improved in the prostate (P = 0.0032) and breast group (P < 0.0001).

CONCLUSION

Both T12 and T15 showed significant predictive value in patients with spinal metastases. T15 has a statistically higher accuracy rate than T12. Among the various cancer groups, the 2 scoring systems are especially reliable in prostate and breast metastases groups. T15 is recommended as superior to T12 because of its higher accuracy rate.

Outcome after surgery for metastatic spinal cord compression in 54 patients with prostate cancer

BACKGROUND AND PURPOSE

The criteria for selecting patients who may benefit from surgery of spinal cord compression in metastatic prostate cancer are poorly defined. We therefore studied patients operated for metastatic spinal cord compression in order to evaluate outcome of surgery and to find predictors of survival.

PATIENTS AND METHODS

We reviewed the records of 54 consecutive patients with metastatic prostate cancer who were operated for spinal cord compression at Umeå University Hospital. The indication for surgery was neurological deficit due to spinal cord compression. 41 patients had hormone-refractory cancer and 13 patients had previously untreated, hormone-naïve prostate cancer. 29 patients were operated with posterior decompression only, and in 25 patients posterior decompression and stabilization was performed.

RESULTS

Preoperatively, 6/54 of patients were able to walk. 1 month after surgery, 33 patients were walking, 15 were non-ambulatory, and 6 had died. Mortality rate was 11% at 1 month, 41% at 6 months, and 59% at 1 year. In the hormone-naïve group, 8/13 patients were still alive with a median postoperative follow-up of 26 months. In the hormone-refractory group, median survival was 5 months. Patients with hormone-refractory disease and Karnofsky performance status (KPS) of ≤ 60% had median survival of 2.5 months, whereas those with KPS of 70% and KPS of ≥ 80% had a median survival of 7 months and 18 months, respectively (p < 0.001). Visceral metastases were present in 12/41 patients with hormone-refractory tumor at the time of spinal surgery, and their median survival was 4 months-as compared to 10 months in patients without visceral metastases (p = 0.003). Complications within 30 days of surgery occurred in 19/54 patients.

INTERPRETATION

Our results indicate that patients with hormone-naive disease, and those with hormone-refractory disease with good performance status and lacking visceral metastases, may be helped by surgery for metastatic spinal cord compression.

Surgical management of unknown primary tumors metastatic to the spine

OBJECT

Patients presenting with spinal metastases from unknown primary tumors (UPTs) are rare. The authors reviewed their surgical experience to evaluate outcomes and identify predictors of survival in these patients.

METHODS

This study is a retrospective analysis of patients undergoing surgery for metastatic spine disease from UPTs between June 1993 and February 2007 at The University of Texas M. D. Anderson Cancer Center.

RESULTS

Fifty-one patients undergoing 52 surgical procedures were identified. The median age at spine surgery was 60 years. The median survival from time of diagnosis was 15.8 months (95% CI 8.1-23.6) and it was 8.1 months (95% CI 1.6-14.7) from time of spine surgery. Postoperative neurological function (Frankel score) was the same or improved in 94% of patients. At presentation, 77% had extraspinal disease, which was associated with poorer survival (6.4 vs 18.1 months; p = 0.041). Multiple sites (vs a single site) of spine disease did not impact survival (12.7 vs 8.7 months; p = 0.50). Patients with noncervical spinal disease survived longer than those with cervical disease (11.8 vs 6.4 months, respectively; p = 0.029). Complete versus incomplete resection at index surgery had no impact on survival duration (p > 0.5) or local recurrence (p = 1.0). Identification of a primary cancer was achieved in 31% of patients.

CONCLUSIONS

This is the first reported surgical series of patients with an unknown source of spinal metastases. The authors found that multiple sites of spinal disease did not influence survival; however, the presence of extraspinal disease had a negative impact. The extent of resection had no effect on survival duration or local recurrence. With an overall median survival of 8.1 months following surgery, aggressive evaluation and treatment of patients with metastatic disease of the spine from an unknown primary source is warranted.

Predictors of survival in patients with prostate cancer and spinal metastasis

Object

Prostate cancer is the second most common malignancy to cause death in men, with metastases to the spine being the most common site of metastatic burden. A retrospective observational study was performed to determine survival of patients in whom spinal metastasis from prostate cancer had been diagnosed.

Methods

The patient population was obtained from the Prostate Clinical Research Information System (CRIS) at the Dana-Farber Cancer Institute. Patients were observed over a period of 19 years, between June 1990 and April 2009. Clinical covariates were studied in their relationship to overall survival, the primary outcome, by using the Kaplan-Meier method and Cox regression.

Results

Of a total of 9010 patients in the Prostate CRIS database, 333 were identified as having developed spinal metastases. The median overall survival after diagnosis of spinal metastasis was 24 months (95% CI 21–28 months). The estimated 1-year overall survival was 73% (95% CI 67%–77%). In 85% of patients, at least 1 additional site of metastasis was documented. Among 28 patients who had no additional sites of metastases, the median survival was 55.9 months, whereas an increasing burden of disease was associated with shorter survival (p = 0.0001). The association was observed regardless of whether the metastatic burden was characterized as the presence of additional (nonspinal) bone metastasis, the presence of additional nonbone metastasis, or as the number of concomitant metastatic sites (all p = 0.0001). In multivariate analysis, a higher prostate-specific antigen level at the diagnosis of spinal metastasis, a longer duration between the diagnosis of prostate cancer and spinal metastasis, and the presence of additional metastasis at the time of diagnosis of spinal metastasis (all p = 0.0001) were independently associated with a shorter overall survival.

Conclusions

The results of this study are important for oncologists, neurosurgeons, and primary care physicians who have patients with prostate cancer that metastasizes to the spine, because these results can be used to form a prognosis and guide the physician in making appropriate decisions regarding the patient's treatment. Future work should include building a predictive model that accurately determines survival in patients with metastatic disease, because this would guide the physician in devising the most appropriate treatment plan for each patient.

Emerging therapeutic targets in breast cancer bone metastasis

In the past decade, our understanding of the molecular mechanisms that underlie breast cancer pathology and progression has dramatically improved. Using this knowledge, we have identified additional targets and developed novel therapeutic interventions in breast cancer. Together, these translational research efforts are helping to usher us into an age of personalized cancer therapy. Metastasis to bone is a common and devastating consequence of breast cancer. Bisphosphonates, which represent the current gold standard in bone metastasis therapies, are being improved with newer and more efficacious generations of these compounds being developed. Breast cancer growth in the bone requires activation of various signaling pathways in both cancer cells and stromal cells, including those that are stimulated by TGF-β and RANKL, and mediated through the Src tyrosine kinase. Bone cells and cancer cells alike express promising targets for therapeutic intervention, including Cathepsin K, CXCR4 and GPNMB. In this article we discuss the molecular mechanisms behind these pro-metastatic molecules and review the most recent findings in the clinical development of their associated targeted therapies.