Faculty Bibliography

Stereotactic radiosurgery (SRS) has become an increasingly popular treatment modality for spinal tumors due to its noninvasive and targeted approach. Whether SRS has the promise of relieving pretreatment symptoms and providing local tumor control for patients with intradural spine tumors is still debated. This review explores the current literature on SRS treatment for both metastatic and benign intradural tumors, with a focus on differential use for intramedullary and intradural extramedullary neoplasms. Although mortality rates from underlying malignant disease remain high, SRS may benefit patients with spinal metastatic lesions. Benign tumors have shown a promising response to SRS therapy with low rates of complications. Larger studies are necessary to determine the indications and outcome profile of SRS for intradural spinal neoplasms.

STUDY DESIGN:Systematic review. OBJECTIVES:We conducted a systematic review of the literature to answer the following questions regarding the use of steroid therapy in metastatic spinal cord compression (MSCC): 1. In cases of MSCC, what is the effect of steroid administration before definitive radiotherapy or surgery on ambulatory status, bowel and bladder function and survival? 2. What steroid dosing regimens are associated with the best outcomes concerning neurological symptoms and complication prevention in cases of MSCC? SUMMARY OF BACKGROUND DATA:Currently, there is significant variation in the initial bolus dose, daily maintenance dose and duration of treatment when steroids are used as a bridge to definitive therapy for MSCC. METHODS:A literature search following PRISMA guidelines was conducted in June 2016, using Medline via Ovid SP, Medline via PubMed, Embase, Biosis Previews and the Cochrane Library. Search terms used in each database varied slightly to optimize results. All generic steroid formulations were included along with spinal cord compression or myelopathy combined with metastatic or malignant tumors. Papers discussing acute traumatic causes of spinal cord compression were excluded, as were papers discussing cord compression from nonmetastatic tumors or epidural lipomatosis. Subjects were limited to adult humans undergoing definitive treatment with radiotherapy or surgery. RESULTS:Of the 309 papers retrieved, 66 full text studies were reviewed and 6 papers were found to address the stated questions. CONCLUSIONS:There is a paucity of high quality literature evaluating the use of steroids in MSCC. On the basis of the evidence available an initial 10 mg intravenous bolus of dexamethasone followed by 16 mg PO QD has been associated with fewer complications compared with 100 mg bolus and 96 mg QD. Weaning of steroids should occur rapidly after definitive treatment. Risk of gastric bleeding or perforation can be managed with the routine use of proton-pump inhibitors. LEVEL OF EVIDENCE:Level IIIa.

OBJECTIVE Chordoma is a rare malignant tumor for which en bloc resection with wide margins is advocated as primary treatment. Unfortunately, due to anatomical constraints, en bloc resection to achieve wide or marginal margins is not feasible for many patients as the resulting morbidity would be prohibitive. The objective of this study was to evaluate the efficacy of intralesional curettage and separation surgery followed by spinal stereotactic body radiation therapy (SBRT) in patients with chordomas in the mobile spine. METHODS The authors performed a retrospective chart review of all patients with chordoma in the mobile spine treated from 2004 to 2016. Patients were identified from a prospectively collected database. Initially 22 patients were identified with mobile spine chordomas. With inclusion criteria of cytoreductive separation surgery followed closely by SBRT and a minimum of 6 months of follow-up imaging, 12 patients were included. Clinical and pathological characteristics of each patient were collected and data were analyzed. Patients were divided into two cohorts-those undergoing intralesional resection followed by SBRT as initial chordoma treatment at Memorial Sloan Kettering Cancer Center (MSKCC) (Cohort 1) and those undergoing salvage treatment following recurrence (Cohort 2). Treatment toxicities were classified according to the Common Terminology Criteria for Adverse Events version 4.03. Overall survival was analyzed using Kaplan-Meier analysis. RESULTS The 12 patients had a median post-SBRT follow-up time of 26 months. Cohort 1 had 5 patients with median post-SBRT follow-up time of 65.9 months and local control rate of 80% at last follow-up. Only one patient had disease progression, at 48.2 months following surgery and SBRT. Cohort 2 had 7 patients who had been treated at other institutions prior to undergoing both surgery and SBRT (salvage therapy) at MSKCC. The local control rate was 57.1% and the median follow-up duration was 10.7 months. One patient required repeat irradiation. Major surgery- and radiation-related complications occurred in 18% and 27% of patients, respectively. Epidural spinal cord compression scores were collected for each patient pre- and postoperatively. CONCLUSIONS The combination of surgery and SBRT provides excellent local control following intralesional curettage and separation surgery for chordomas in the mobile spine. Patients who underwent intralesional curettage and spinal SBRT as initial treatment had better disease control than those undergoing salvage therapy. High-dose radiotherapy may offer several biological benefits for tumor control.

Metastatic epidural spinal cord compression (MESCC) is an oncologic emergency requiring prompt treatment to maximize neurologic function, ambulatory function and local control. Traditionally, options for MESCC included external beam radiation therapy with or without surgery. Surgery has usually been reserved for the patient with optimal performance status, single level MESCC or mechanical instability. Advances in external beam radiation therapy such as the development of stereotactic body radiation therapy have allowed for the delivery of high-dose radiation, allowing for both long-term pain and local control. Surgical advances, such as separation surgery, minimal access spine surgery and percutaneous instrumentation, have decreased surgical morbidity. This review summarizes the latest advances and evidence in MESCC to enable modern management.

STUDY DESIGN/METHODS: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.

BACKGROUND:Hepatocellular carcinoma (HCC) frequently metastasizes to the spine. The impact of medical and/or surgical intervention on overall survival has been examined in a limited number of clinical studies, and herein we systematically review these data. METHODS:We performed a literature review using PubMed, Embase, CINAHL, and Web of Science to identify articles that reported survival, clinical outcomes, and/or prognostic factors associated with patients diagnosed with spinal metastases. The methodologic quality of each review was assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses tool. RESULTS:There were 26 articles (152 patients) that met the inclusion criteria and were treated with either surgery, radiotherapy, chemotherapy, and/or observation. There were 3 retrospective cohort studies, 17 case reports, 5 case series, and 1 longitudinal observational study. Of the patients with known overall survival after diagnosis of spinal metastasis, survival at 3 months, 6 months, 1 year, 2 years, and 5 years was 95.2%, 83.0%, 28.6%, 2.0%, and 1.4%, respectively. The median survival after diagnosis of the metastasis was 0.7 months in the patients who received no treatment, 7 months in the patients treated with surgical intervention alone, 6 months for patients who received chemotherapy and/or radiation, and 13.5 months in the patients treated with a combination of surgery and medical management. All other clinical or prognostic parameters were of low or insufficient strength. CONCLUSIONS:Patients diagnosed with HCC spinal metastasis have a 10.6-month overall survival. Further analysis of patients in prospective controlled trials will be essential to the development of treatment algorithms for these patients in the future.

STUDY TYPE/METHODS:A review of the literature. OBJECTIVE:The aim of this study was to discuss the evolution of molecular signatures and the history and development of targeted therapeutics in metastatic tumor types affecting the spinal column. SUMMARY OF BACKGROUND DATA/BACKGROUND:Molecular characterization of metastatic spine tumors is expected to usher in a revolution in diagnostic and treatment paradigms. Molecular characterization will provide critical information that can be used for initial diagnosis, prognosticating the ideal treatment strategy, assessment of treatment efficacy, surveillance and monitoring recurrence, and predicting complications, clinical outcome, and overall survival in patients diagnosed with metastatic cancers to the spinal column. METHODS:A review of the literature was performed focusing on illustrative examples of the role that molecular-based therapeutics have played in clinical outcomes for patients diagnosed with metastatic tumor types affecting the spinal column. RESULTS:The impact of molecular therapeutics including receptor tyrosine kinases and immune checkpoint inhibitors and the ability of molecular signatures to provide prognostic information are discussed in metastatic breast cancer, lung cancer, prostate cancer, melanoma, and renal cell cancer affecting the spinal column. CONCLUSION/CONCLUSIONS:For the providers who will ultimately counsel patients diagnosed with metastases to the spinal column, molecular advancements will radically alter the management/surgical paradigms utilized. Ultimately, the translation of these molecular advancements into routine clinical care will greatly improve the quality and quantity of life for patients diagnosed with spinal malignancies and provide better overall outcomes and counseling for treating physicians. LEVEL OF EVIDENCE/METHODS:N/A.

Study Design Literature review. Objective Functional secretory tumors metastatic to the spine can secrete hormones, growth factors, peptides, and/or molecules into the systemic circulation that cause distinct syndromes, clinically symptomatic effects, and/or additional morbidity and mortality. En bloc resection has a limited role in metastatic spine disease due to the current paradigm that systemic burden usually determines morbidity and mortality. Our objective is to review the literature for studies focused on en bloc resection of functionally active spinal metastasis as the primary indication. Methods A review of the PubMed literature was performed to identify studies focused on functional secreting metastatic tumors to the spinal column. We identified five cases of patients undergoing en bloc resection of spinal metastases from functional secreting tumors. Results The primary histologies of these spinal metastases were pheochromocytoma, carcinoid tumor, choriocarcinoma, and a fibroblast growth factor 23-secreting phosphaturic mesenchymal tumor. Although studies of en bloc resection for these rare tumor subtypes are confined to case reports, this surgical treatment option resulted in metabolic cures and decreased clinical symptoms postoperatively for patients diagnosed with solitary functional secretory spinal metastasis. Conclusion Although the ability to formulate comprehensive conclusions is limited, case reports demonstrate that en bloc resection may be considered as a potential surgical option for the treatment of patients diagnosed with solitary functional secretory spinal metastatic tumors. Future prospective investigations into clinical outcomes should be conducted comparing intralesional resection and en bloc resection for patients diagnosed with solitary functional secretory spinal metastasis.

STUDY DESIGN/METHODS:Review of the literature. OBJECTIVE:Surgery and cement augmentation procedures are effective palliative treatment of symptomatic spinal metastases. Our objective is to systematically review the literature to describe the survival, prognostic factors, and clinical outcomes of surgery and cement augmentation procedures for breast cancer metastases to the spine. METHODS:We performed a literature review using PubMed to identify articles that reported outcomes and/or prognostic factors of the breast cancer patient population with spinal metastases treated with any surgical technique since 1990. RESULTS:The median postoperative survival for metastatic breast cancer was 21.7 months (8.2 to 36 months), the mean rate of any pain improvement was 92.9% (76 to 100%), the mean rate of neurologic improvement was 63.8% (53 to 100%), the mean rate of neurologic decline was 4.1% (0 to 8%), and the local tumor control rate was 92.6% (89 to 100%). Kyphoplasty studies reported a high rate of pain control in selected patients. Negative prognostic variables included hormonal (estrogen and progesterone) and human epidermal growth factor receptor 2 (HER2) receptor refractory tumor status, high degree of axillary lymph node involvement, and short disease-free interval (DFI). All other clinical or prognostic parameters were of low or insufficient strength. CONCLUSION/CONCLUSIONS:With respect to clinical outcomes, surgery consistently yielded neurologic improvements in patients presenting with a deficit with a minimal risk of worsening; however, negative prognostic factors associated with shorter survival following surgery include estrogen receptor/progesterone receptor negativity, HER2 negativity, and a short DFI.